// Copyright (c) HashiCorp, Inc. // SPDX-License-Identifier: BUSL-1.1 package structs import ( "encoding/json" "fmt" "math" "net/http" "regexp" "sort" "strconv" "strings" "time" "github.com/hashicorp/go-bexpr" "github.com/hashicorp/go-multierror" "github.com/mitchellh/copystructure" "github.com/mitchellh/hashstructure" "github.com/hashicorp/consul/acl" "github.com/hashicorp/consul/agent/cache" "github.com/hashicorp/consul/lib" "github.com/hashicorp/consul/lib/maps" ) const ( // Names of Envoy's LB policies LBPolicyMaglev = "maglev" LBPolicyRingHash = "ring_hash" LBPolicyRandom = "random" LBPolicyLeastRequest = "least_request" LBPolicyRoundRobin = "round_robin" // Names of Envoy's LB policies HashPolicyCookie = "cookie" HashPolicyHeader = "header" HashPolicyQueryParam = "query_parameter" ) var ( validLBPolicies = map[string]bool{ "": true, LBPolicyRandom: true, LBPolicyRoundRobin: true, LBPolicyLeastRequest: true, LBPolicyRingHash: true, LBPolicyMaglev: true, } validHashPolicies = map[string]bool{ HashPolicyHeader: true, HashPolicyCookie: true, HashPolicyQueryParam: true, } ) // ServiceRouterConfigEntry defines L7 (e.g. http) routing rules for a named // service exposed in Connect. // // This config entry represents the topmost part of the discovery chain. Only // one router config will be used per resolved discovery chain and is not // otherwise discovered recursively (unlike splitter and resolver config // entries). // // Router config entries will be restricted to only services that define their // protocol as http-based (in centralized configuration). type ServiceRouterConfigEntry struct { Kind string Name string // Routes is the list of routes to consider when processing L7 requests. // The first rule to match in the list is terminal and stops further // evaluation. // // Traffic that fails to match any of the provided routes will be routed to // the default service. Routes []ServiceRoute Meta map[string]string `json:",omitempty"` Hash uint64 `json:",omitempty" hash:"ignore"` acl.EnterpriseMeta `hcl:",squash" mapstructure:",squash"` RaftIndex `hash:"ignore"` } func (e *ServiceRouterConfigEntry) SetHash(h uint64) { e.Hash = h } func (e *ServiceRouterConfigEntry) GetHash() uint64 { return e.Hash } func (e *ServiceRouterConfigEntry) GetKind() string { return ServiceRouter } func (e *ServiceRouterConfigEntry) GetName() string { if e == nil { return "" } return e.Name } func (e *ServiceRouterConfigEntry) GetMeta() map[string]string { if e == nil { return nil } return e.Meta } func (e *ServiceRouterConfigEntry) Normalize() error { if e == nil { return fmt.Errorf("config entry is nil") } e.Kind = ServiceRouter e.EnterpriseMeta.Normalize() for _, route := range e.Routes { if route.Match == nil || route.Match.HTTP == nil { continue } httpMatch := route.Match.HTTP for j := 0; j < len(httpMatch.Methods); j++ { httpMatch.Methods[j] = strings.ToUpper(httpMatch.Methods[j]) } if route.Destination != nil && route.Destination.Namespace == "" { route.Destination.Namespace = e.EnterpriseMeta.NamespaceOrEmpty() } if route.Destination != nil && route.Destination.Partition == "" { route.Destination.Partition = e.EnterpriseMeta.PartitionOrEmpty() } } h, err := HashConfigEntry(e) if err != nil { return err } e.Hash = h return nil } func (e *ServiceRouterConfigEntry) Validate() error { if e.Name == "" { return fmt.Errorf("Name is required") } if err := validateConfigEntryMeta(e.Meta); err != nil { return err } // Technically you can have no explicit routes at all where just the // catch-all is configured for you, but at that point maybe you should just // delete it so it will default? for i, route := range e.Routes { eligibleForPrefixRewrite := false if route.Match != nil && route.Match.HTTP != nil { pathParts := 0 if route.Match.HTTP.PathExact != "" { eligibleForPrefixRewrite = true pathParts++ if !strings.HasPrefix(route.Match.HTTP.PathExact, "/") { return fmt.Errorf("Route[%d] PathExact doesn't start with '/': %q", i, route.Match.HTTP.PathExact) } } if route.Match.HTTP.PathPrefix != "" { eligibleForPrefixRewrite = true pathParts++ if !strings.HasPrefix(route.Match.HTTP.PathPrefix, "/") { return fmt.Errorf("Route[%d] PathPrefix doesn't start with '/': %q", i, route.Match.HTTP.PathPrefix) } } if route.Match.HTTP.PathRegex != "" { pathParts++ } if pathParts > 1 { return fmt.Errorf("Route[%d] should only contain at most one of PathExact, PathPrefix, or PathRegex", i) } for j, hdr := range route.Match.HTTP.Header { if hdr.Name == "" { return fmt.Errorf("Route[%d] Header[%d] missing required Name field", i, j) } hdrParts := 0 if hdr.Present { hdrParts++ } if hdr.Exact != "" { hdrParts++ } if hdr.Regex != "" { hdrParts++ } if hdr.Prefix != "" { hdrParts++ } if hdr.Suffix != "" { hdrParts++ } if hdrParts != 1 { return fmt.Errorf("Route[%d] Header[%d] should only contain one of Present, Exact, Prefix, Suffix, or Regex", i, j) } } for j, qm := range route.Match.HTTP.QueryParam { if qm.Name == "" { return fmt.Errorf("Route[%d] QueryParam[%d] missing required Name field", i, j) } qmParts := 0 if qm.Present { qmParts++ } if qm.Exact != "" { qmParts++ } if qm.Regex != "" { qmParts++ } if qmParts != 1 { return fmt.Errorf("Route[%d] QueryParam[%d] should only contain one of Present, Exact, or Regex", i, j) } } if len(route.Match.HTTP.Methods) > 0 { found := make(map[string]struct{}) for _, m := range route.Match.HTTP.Methods { if !isValidHTTPMethod(m) { return fmt.Errorf("Route[%d] Methods contains an invalid method %q", i, m) } if _, ok := found[m]; ok { return fmt.Errorf("Route[%d] Methods contains %q more than once", i, m) } found[m] = struct{}{} } } } if route.Destination != nil { if route.Destination.PrefixRewrite != "" && !eligibleForPrefixRewrite { return fmt.Errorf("Route[%d] cannot make use of PrefixRewrite without configuring either PathExact or PathPrefix", i) } for _, r := range route.Destination.RetryOn { if !isValidRetryCondition(r) { return fmt.Errorf("Route[%d] contains an invalid retry condition: %q", i, r) } } } } return nil } func isValidHTTPMethod(method string) bool { switch method { case http.MethodGet, http.MethodHead, http.MethodPost, http.MethodPut, http.MethodPatch, http.MethodDelete, http.MethodConnect, http.MethodOptions, http.MethodTrace: return true default: return false } } func isValidRetryCondition(retryOn string) bool { switch retryOn { case "5xx", "gateway-error", "reset", "connect-failure", "envoy-ratelimited", "retriable-4xx", "refused-stream", "cancelled", "deadline-exceeded", "internal", "resource-exhausted", "unavailable": return true default: return false } } func (e *ServiceRouterConfigEntry) CanRead(authz acl.Authorizer) error { return canReadDiscoveryChain(e, authz) } func (e *ServiceRouterConfigEntry) CanWrite(authz acl.Authorizer) error { return canWriteDiscoveryChain(e, authz) } func (e *ServiceRouterConfigEntry) GetRaftIndex() *RaftIndex { if e == nil { return &RaftIndex{} } return &e.RaftIndex } func (e *ServiceRouterConfigEntry) ListRelatedServices() []ServiceID { found := make(map[ServiceID]struct{}) // We always inject a default catch-all route to the same service as the router. svcID := NewServiceID(e.Name, &e.EnterpriseMeta) found[svcID] = struct{}{} for _, route := range e.Routes { if route.Destination != nil { destID := NewServiceID(defaultIfEmpty(route.Destination.Service, e.Name), route.Destination.GetEnterpriseMeta(&e.EnterpriseMeta)) if destID != svcID { found[destID] = struct{}{} } } } if len(found) == 0 { return nil } out := make([]ServiceID, 0, len(found)) for svc := range found { out = append(out, svc) } sort.Slice(out, func(i, j int) bool { return out[i].EnterpriseMeta.LessThan(&out[j].EnterpriseMeta) || out[i].ID < out[j].ID }) return out } func (e *ServiceRouterConfigEntry) GetEnterpriseMeta() *acl.EnterpriseMeta { if e == nil { return nil } return &e.EnterpriseMeta } // ServiceRoute is a single routing rule that routes traffic to the destination // when the match criteria applies. type ServiceRoute struct { Match *ServiceRouteMatch `json:",omitempty"` Destination *ServiceRouteDestination `json:",omitempty"` } // ServiceRouteMatch is a set of criteria that can match incoming L7 requests. type ServiceRouteMatch struct { HTTP *ServiceRouteHTTPMatch `json:",omitempty"` // If we have non-http match criteria for other protocols in the future // (gRPC, redis, etc) they can go here. } func (m *ServiceRouteMatch) IsEmpty() bool { return m.HTTP == nil || m.HTTP.IsEmpty() } // ServiceRouteHTTPMatch is a set of http-specific match criteria. type ServiceRouteHTTPMatch struct { PathExact string `json:",omitempty" alias:"path_exact"` PathPrefix string `json:",omitempty" alias:"path_prefix"` PathRegex string `json:",omitempty" alias:"path_regex"` CaseInsensitive bool `json:",omitempty" alias:"case_insensitive"` Header []ServiceRouteHTTPMatchHeader `json:",omitempty"` QueryParam []ServiceRouteHTTPMatchQueryParam `json:",omitempty" alias:"query_param"` Methods []string `json:",omitempty"` } func (m *ServiceRouteHTTPMatch) IsEmpty() bool { return m.PathExact == "" && m.PathPrefix == "" && m.PathRegex == "" && !m.CaseInsensitive && len(m.Header) == 0 && len(m.QueryParam) == 0 && len(m.Methods) == 0 } type ServiceRouteHTTPMatchHeader struct { Name string Present bool `json:",omitempty"` Exact string `json:",omitempty"` Prefix string `json:",omitempty"` Suffix string `json:",omitempty"` Regex string `json:",omitempty"` Invert bool `json:",omitempty"` } type ServiceRouteHTTPMatchQueryParam struct { Name string Present bool `json:",omitempty"` Exact string `json:",omitempty"` Regex string `json:",omitempty"` } // ServiceRouteDestination describes how to proxy the actual matching request // to a service. type ServiceRouteDestination struct { // Service is the service to resolve instead of the default service. If // empty then the default discovery chain service name is used. Service string `json:",omitempty"` // ServiceSubset is a named subset of the given service to resolve instead // of one defined as that service's DefaultSubset. If empty the default // subset is used. // // If this field is specified then this route is ineligible for further // splitting. ServiceSubset string `json:",omitempty" alias:"service_subset"` // Namespace is the namespace to resolve the service from instead of the // current namespace. If empty the current namespace is assumed. // // If this field is specified then this route is ineligible for further // splitting. Namespace string `json:",omitempty"` // Partition is the partition to resolve the service from instead of the // current partition. If empty the current partition is assumed. // // If this field is specified then this route is ineligible for further // splitting. Partition string `json:",omitempty"` // PrefixRewrite allows for the proxied request to have its matching path // prefix modified before being sent to the destination. Described more // below in the envoy implementation section. PrefixRewrite string `json:",omitempty" alias:"prefix_rewrite"` // RequestTimeout is the total amount of time permitted for the entire // downstream request (and retries) to be processed. RequestTimeout time.Duration `json:",omitempty" alias:"request_timeout"` // IdleTimeout is The total amount of time permitted for the request stream // to be idle IdleTimeout time.Duration `json:",omitempty" alias:"idle_timeout"` // NumRetries is the number of times to retry the request when a retryable // result occurs. This seems fairly proxy agnostic. NumRetries uint32 `json:",omitempty" alias:"num_retries"` // RetryOnConnectFailure allows for connection failure errors to trigger a // retry. This should be expressible in other proxies as it's just a layer // 4 failure bubbling up to layer 7. RetryOnConnectFailure bool `json:",omitempty" alias:"retry_on_connect_failure"` // RetryOn allows setting envoy specific conditions when a request should // be automatically retried. RetryOn []string `json:",omitempty" alias:"retry_on"` // RetryOnStatusCodes is a flat list of http response status codes that are // eligible for retry. This again should be feasible in any reasonable proxy. RetryOnStatusCodes []uint32 `json:",omitempty" alias:"retry_on_status_codes"` // Allow HTTP header manipulation to be configured. RequestHeaders *HTTPHeaderModifiers `json:",omitempty" alias:"request_headers"` ResponseHeaders *HTTPHeaderModifiers `json:",omitempty" alias:"response_headers"` } func (e *ServiceRouteDestination) MarshalJSON() ([]byte, error) { type Alias ServiceRouteDestination exported := &struct { RequestTimeout string `json:",omitempty"` IdleTimeout string `json:",omitempty"` *Alias }{ RequestTimeout: e.RequestTimeout.String(), IdleTimeout: e.IdleTimeout.String(), Alias: (*Alias)(e), } if e.RequestTimeout == 0 { exported.RequestTimeout = "" } if e.IdleTimeout == 0 { exported.IdleTimeout = "" } return json.Marshal(exported) } func (e *ServiceRouteDestination) UnmarshalJSON(data []byte) error { type Alias ServiceRouteDestination aux := &struct { RequestTimeout string IdleTimeout string *Alias }{ Alias: (*Alias)(e), } if err := lib.UnmarshalJSON(data, &aux); err != nil { return err } var err error if aux.RequestTimeout != "" { if e.RequestTimeout, err = time.ParseDuration(aux.RequestTimeout); err != nil { return err } } if aux.IdleTimeout != "" { if e.IdleTimeout, err = time.ParseDuration(aux.IdleTimeout); err != nil { return err } } return nil } func (d *ServiceRouteDestination) HasRetryFeatures() bool { return d.NumRetries > 0 || d.RetryOnConnectFailure || len(d.RetryOnStatusCodes) > 0 || len(d.RetryOn) > 0 } // ServiceSplitterConfigEntry defines how incoming requests are split across // different subsets of a single service (like during staged canary rollouts), // or perhaps across different services (like during a v2 rewrite or other type // of codebase migration). // // This config entry represents the next hop of the discovery chain after // routing. If no splitter config is defined the chain assumes 100% of traffic // goes to the default service and discovery continues on to the resolution // hop. // // Splitter configs are recursively collected while walking the discovery // chain. // // Splitter config entries will be restricted to only services that define // their protocol as http-based (in centralized configuration). type ServiceSplitterConfigEntry struct { Kind string Name string // Splits is the configurations for the details of the traffic splitting. // // The sum of weights across all splits must add up to 100. // // If the split is within epsilon of 100 then the remainder is attributed // to the FIRST split. Splits []ServiceSplit Meta map[string]string `json:",omitempty"` Hash uint64 `json:",omitempty" hash:"ignore"` acl.EnterpriseMeta `hcl:",squash" mapstructure:",squash"` RaftIndex `hash:"ignore"` } func (e *ServiceSplitterConfigEntry) SetHash(h uint64) { e.Hash = h } func (e *ServiceSplitterConfigEntry) GetHash() uint64 { return e.Hash } func (e *ServiceSplitterConfigEntry) GetKind() string { return ServiceSplitter } func (e *ServiceSplitterConfigEntry) GetName() string { if e == nil { return "" } return e.Name } func (e *ServiceSplitterConfigEntry) GetMeta() map[string]string { if e == nil { return nil } return e.Meta } func (e *ServiceSplitterConfigEntry) Normalize() error { if e == nil { return fmt.Errorf("config entry is nil") } e.Kind = ServiceSplitter // This slightly massages inputs to enforce that the smallest representable // weight is 1/10000 or .01% e.EnterpriseMeta.Normalize() if len(e.Splits) > 0 { for i, split := range e.Splits { if split.Namespace == "" { split.Namespace = e.EnterpriseMeta.NamespaceOrDefault() } e.Splits[i].Weight = NormalizeServiceSplitWeight(split.Weight) } } h, err := HashConfigEntry(e) if err != nil { return err } e.Hash = h return nil } func NormalizeServiceSplitWeight(weight float32) float32 { weightScaled := scaleWeight(weight) return float32(weightScaled) / 100.0 } func (e *ServiceSplitterConfigEntry) Validate() error { if e.Name == "" { return fmt.Errorf("Name is required") } if len(e.Splits) == 0 { return fmt.Errorf("no splits configured") } if err := validateConfigEntryMeta(e.Meta); err != nil { return err } const maxScaledWeight = 100 * 100 copyAsKey := func(s ServiceSplit) ServiceSplit { s.Weight = 0 return s } // Make sure we didn't refer to the same thing twice. found := make(map[ServiceSplit]struct{}) for _, split := range e.Splits { splitKey := copyAsKey(split) if splitKey.Service == "" { splitKey.Service = e.Name } if _, ok := found[splitKey]; ok { return fmt.Errorf( "split destination occurs more than once: service=%q, subset=%q, namespace=%q, partition=%q", splitKey.Service, splitKey.ServiceSubset, splitKey.Namespace, splitKey.Partition, ) } found[splitKey] = struct{}{} } sumScaled := 0 for _, split := range e.Splits { sumScaled += scaleWeight(split.Weight) } if sumScaled != maxScaledWeight { return fmt.Errorf("the sum of all split weights must be 100, not %f", float32(sumScaled)/100) } return nil } // scaleWeight assumes the input is a value between 0 and 100 representing // shares out of a percentile range. The function will convert to a unit // representing 0.01% units in the same manner as you may convert $0.98 to 98 // cents. func scaleWeight(v float32) int { return int(math.Round(float64(v * 100.0))) } func (e *ServiceSplitterConfigEntry) CanRead(authz acl.Authorizer) error { return canReadDiscoveryChain(e, authz) } func (e *ServiceSplitterConfigEntry) CanWrite(authz acl.Authorizer) error { return canWriteDiscoveryChain(e, authz) } func (e *ServiceSplitterConfigEntry) GetRaftIndex() *RaftIndex { if e == nil { return &RaftIndex{} } return &e.RaftIndex } func (e *ServiceSplitterConfigEntry) GetEnterpriseMeta() *acl.EnterpriseMeta { if e == nil { return nil } return &e.EnterpriseMeta } func (e *ServiceSplitterConfigEntry) ListRelatedServices() []ServiceID { found := make(map[ServiceID]struct{}) svcID := NewServiceID(e.Name, &e.EnterpriseMeta) for _, split := range e.Splits { splitID := NewServiceID(defaultIfEmpty(split.Service, e.Name), split.GetEnterpriseMeta(&e.EnterpriseMeta)) if splitID != svcID { found[splitID] = struct{}{} } } if len(found) == 0 { return nil } out := make([]ServiceID, 0, len(found)) for svc := range found { out = append(out, svc) } sort.Slice(out, func(i, j int) bool { return out[i].EnterpriseMeta.LessThan(&out[j].EnterpriseMeta) || out[i].ID < out[j].ID }) return out } // ServiceSplit defines how much traffic to send to which set of service // instances during a traffic split. type ServiceSplit struct { // A value between 0 and 100 reflecting what portion of traffic should be // directed to this split. // // The smallest representable weight is 1/10000 or .01% // // If the split is within epsilon of 100 then the remainder is attributed // to the FIRST split. Weight float32 // Service is the service to resolve instead of the default (optional). Service string `json:",omitempty"` // ServiceSubset is a named subset of the given service to resolve instead // of one defined as that service's DefaultSubset. If empty the default // subset is used (optional). // // If this field is specified then this route is ineligible for further // splitting. ServiceSubset string `json:",omitempty" alias:"service_subset"` // Namespace is the namespace to resolve the service from instead of the // current namespace. If empty the current namespace is assumed (optional). // // If this field is specified then this route is ineligible for further // splitting. Namespace string `json:",omitempty"` // Partition is the partition to resolve the service from instead of the // current partition. If empty the current partition is assumed (optional). // // If this field is specified then this route is ineligible for further // splitting. Partition string `json:",omitempty"` // NOTE: Any configuration added to Splits that needs to be passed to the // proxy needs special handling MergeParent below. // Allow HTTP header manipulation to be configured. RequestHeaders *HTTPHeaderModifiers `json:",omitempty" alias:"request_headers"` ResponseHeaders *HTTPHeaderModifiers `json:",omitempty" alias:"response_headers"` } // MergeParent is called by the discovery chain compiler when a split directs to // another splitter. We refer to the first ServiceSplit as the parent and the // ServiceSplits of the second splitter as its children. The parent ends up // "flattened" by the compiler, i.e. replaced with its children recursively with // the weights modified as necessary. // // Since the parent is never included in the output, any request processing // config attached to it (e.g. header manipulation) would be lost and not take // affect when splitters direct to other splitters. To avoid that, we define a // MergeParent operation which is called by the compiler on each child split // during flattening. It must merge any request processing configuration from // the passed parent into the child such that the end result is equivalent to a // request first passing through the parent and then the child. Response // handling must occur as if the request first passed through the through the // child to the parent. // // MergeDefaults leaves both s and parent unchanged and returns a deep copy to // avoid confusing issues where config changes after being compiled. func (s *ServiceSplit) MergeParent(parent *ServiceSplit) (*ServiceSplit, error) { if s == nil && parent == nil { return nil, nil } var err error var copy ServiceSplit if s == nil { copy = *parent copy.RequestHeaders, err = parent.RequestHeaders.Clone() if err != nil { return nil, err } copy.ResponseHeaders, err = parent.ResponseHeaders.Clone() if err != nil { return nil, err } return ©, nil } else { copy = *s } var parentReq *HTTPHeaderModifiers if parent != nil { parentReq = parent.RequestHeaders } // Merge any request handling from parent _unless_ it's overridden by us. copy.RequestHeaders, err = MergeHTTPHeaderModifiers(parentReq, s.RequestHeaders) if err != nil { return nil, err } var parentResp *HTTPHeaderModifiers if parent != nil { parentResp = parent.ResponseHeaders } // Merge any response handling. Note that we allow parent to override this // time since responses flow the other way so the unflattened behavior would // be that the parent processing happens _after_ ours potentially overriding // it. copy.ResponseHeaders, err = MergeHTTPHeaderModifiers(s.ResponseHeaders, parentResp) if err != nil { return nil, err } return ©, nil } // ServiceResolverConfigEntry defines which instances of a service should // satisfy discovery requests for a given named service. // // This config entry represents the next hop of the discovery chain after // splitting. If no resolver config is defined the chain assumes 100% of // traffic goes to the healthy instances of the default service in the current // datacenter+namespace and discovery terminates. // // Resolver configs are recursively collected while walking the chain. // // Resolver config entries will be valid for services defined with any protocol // (in centralized configuration). type ServiceResolverConfigEntry struct { Kind string Name string // DefaultSubset is the subset to use when no explicit subset is // requested. If empty the unnamed subset is used. DefaultSubset string `json:",omitempty" alias:"default_subset"` // Subsets is a map of subset name to subset definition for all // usable named subsets of this service. The map key is the name // of the subset and all names must be valid DNS subdomain elements // so they can be used in SNI FQDN headers for the Connect Gateways // feature. // // This may be empty, in which case only the unnamed default subset // will be usable. Subsets map[string]ServiceResolverSubset `json:",omitempty"` // Redirect is a service/subset/datacenter/namespace to resolve // instead of the requested service (optional). // // When configured, all occurrences of this resolver in any discovery // chain evaluation will be substituted for the supplied redirect // EXCEPT when the redirect has already been applied. // // When substituting the supplied redirect into the discovery chain // all other fields beside Kind/Name/Redirect will be ignored. Redirect *ServiceResolverRedirect `json:",omitempty"` // Failover controls when and how to reroute traffic to an alternate pool // of service instances. // // The map is keyed by the service subset it applies to, and the special // string "*" is a wildcard that applies to any subset not otherwise // specified here. Failover map[string]ServiceResolverFailover `json:",omitempty"` // PrioritizeByLocality controls whether the locality of services within the // local partition will be used to prioritize connectivity. PrioritizeByLocality *ServiceResolverPrioritizeByLocality `json:",omitempty" alias:"prioritize_by_locality"` // ConnectTimeout is the timeout for establishing new network connections // to this service. ConnectTimeout time.Duration `json:",omitempty" alias:"connect_timeout"` // RequestTimeout is the timeout for an HTTP request to complete before // the connection is automatically terminated. If unspecified, defaults // to 15 seconds. RequestTimeout time.Duration `json:",omitempty" alias:"request_timeout"` // LoadBalancer determines the load balancing policy and configuration for services // issuing requests to this upstream service. LoadBalancer *LoadBalancer `json:",omitempty" alias:"load_balancer"` Meta map[string]string `json:",omitempty"` Hash uint64 `json:",omitempty" hash:"ignore"` acl.EnterpriseMeta `hcl:",squash" mapstructure:",squash"` RaftIndex `hash:"ignore"` } func (e *ServiceResolverConfigEntry) SetHash(h uint64) { e.Hash = h } func (e *ServiceResolverConfigEntry) GetHash() uint64 { return e.Hash } func (e *ServiceResolverConfigEntry) RelatedPeers() []string { peers := make(map[string]struct{}) if r := e.Redirect; r != nil && r.Peer != "" { peers[r.Peer] = struct{}{} } if e.Failover != nil { for _, f := range e.Failover { for _, t := range f.Targets { if t.Peer != "" { peers[t.Peer] = struct{}{} } } } } return maps.SliceOfKeys(peers) } func (e *ServiceResolverConfigEntry) MarshalJSON() ([]byte, error) { type Alias ServiceResolverConfigEntry exported := &struct { ConnectTimeout string `json:",omitempty"` RequestTimeout string `json:",omitempty"` *Alias }{ ConnectTimeout: e.ConnectTimeout.String(), RequestTimeout: e.RequestTimeout.String(), Alias: (*Alias)(e), } if e.ConnectTimeout == 0 { exported.ConnectTimeout = "" } if e.RequestTimeout == 0 { exported.RequestTimeout = "" } return json.Marshal(exported) } func (e *ServiceResolverConfigEntry) UnmarshalJSON(data []byte) error { type Alias ServiceResolverConfigEntry aux := &struct { ConnectTimeout string RequestTimeout string *Alias }{ Alias: (*Alias)(e), } var err error if err = lib.UnmarshalJSON(data, &aux); err != nil { return err } var merr *multierror.Error if aux.ConnectTimeout != "" { if e.ConnectTimeout, err = time.ParseDuration(aux.ConnectTimeout); err != nil { merr = multierror.Append(merr, err) } } if aux.RequestTimeout != "" { if e.RequestTimeout, err = time.ParseDuration(aux.RequestTimeout); err != nil { merr = multierror.Append(merr, err) } } return merr.ErrorOrNil() } func (e *ServiceResolverConfigEntry) SubsetExists(name string) bool { if name == "" { return true } if len(e.Subsets) == 0 { return false } _, ok := e.Subsets[name] return ok } func (e *ServiceResolverConfigEntry) IsDefault() bool { return e.DefaultSubset == "" && len(e.Subsets) == 0 && e.Redirect == nil && len(e.Failover) == 0 && e.ConnectTimeout == 0 && e.RequestTimeout == 0 && e.LoadBalancer == nil && e.PrioritizeByLocality == nil } func (e *ServiceResolverConfigEntry) GetKind() string { return ServiceResolver } func (e *ServiceResolverConfigEntry) GetName() string { if e == nil { return "" } return e.Name } func (e *ServiceResolverConfigEntry) GetMeta() map[string]string { if e == nil { return nil } return e.Meta } func (e *ServiceResolverConfigEntry) Normalize() error { if e == nil { return fmt.Errorf("config entry is nil") } e.Kind = ServiceResolver e.EnterpriseMeta.Normalize() h, err := HashConfigEntry(e) if err != nil { return err } e.Hash = h return nil } func (e *ServiceResolverConfigEntry) Validate() error { if e.Name == "" { return fmt.Errorf("Name is required") } if err := validateConfigEntryMeta(e.Meta); err != nil { return err } if len(e.Subsets) > 0 { for name, subset := range e.Subsets { if name == "" { return fmt.Errorf("Subset defined with empty name") } if err := validateServiceSubset(name); err != nil { return fmt.Errorf("Subset %q is invalid: %v", name, err) } if subset.Filter != "" { if _, err := bexpr.CreateEvaluator(subset.Filter, nil); err != nil { return fmt.Errorf("Filter for subset %q is not a valid expression: %v", name, err) } } } } isSubset := func(subset string) bool { if len(e.Subsets) > 0 { _, ok := e.Subsets[subset] return ok } return false } if e.DefaultSubset != "" && !isSubset(e.DefaultSubset) { return fmt.Errorf("DefaultSubset %q is not a valid subset", e.DefaultSubset) } if err := e.PrioritizeByLocality.validate(); err != nil { return err } if e.Redirect != nil { if !e.InDefaultPartition() && e.Redirect.Datacenter != "" { return fmt.Errorf("Cross-datacenter redirect is only supported in the default partition") } if acl.PartitionOrDefault(e.Redirect.Partition) != e.PartitionOrDefault() && e.Redirect.Datacenter != "" { return fmt.Errorf("Cross-datacenter and cross-partition redirect is not supported") } r := e.Redirect if err := r.ValidateEnterprise(); err != nil { return fmt.Errorf("Redirect: %s", err.Error()) } if len(e.Failover) > 0 { return fmt.Errorf("Redirect and Failover cannot both be set") } // TODO(rb): prevent subsets and default subsets from being defined? if r.isEmpty() { return fmt.Errorf("Redirect is empty") } switch { case r.SamenessGroup != "" && r.ServiceSubset != "": return fmt.Errorf("Redirect.SamenessGroup cannot be set with Redirect.ServiceSubset") case r.SamenessGroup != "" && r.Partition != "": return fmt.Errorf("Redirect.Partition cannot be set with Redirect.SamenessGroup") case r.SamenessGroup != "" && r.Datacenter != "": return fmt.Errorf("Redirect.SamenessGroup cannot be set with Redirect.Datacenter") case r.Peer != "" && r.ServiceSubset != "": return fmt.Errorf("Redirect.Peer cannot be set with Redirect.ServiceSubset") case r.Peer != "" && r.Partition != "": return fmt.Errorf("Redirect.Partition cannot be set with Redirect.Peer") case r.Peer != "" && r.Datacenter != "": return fmt.Errorf("Redirect.Peer cannot be set with Redirect.Datacenter") case r.Service == "": if r.ServiceSubset != "" { return fmt.Errorf("Redirect.ServiceSubset defined without Redirect.Service") } if r.Namespace != "" { return fmt.Errorf("Redirect.Namespace defined without Redirect.Service") } if r.Partition != "" { return fmt.Errorf("Redirect.Partition defined without Redirect.Service") } if r.Peer != "" { return fmt.Errorf("Redirect.Peer defined without Redirect.Service") } case r.ServiceSubset != "" && (r.Service == "" || r.Service == e.Name): if !isSubset(r.ServiceSubset) { return fmt.Errorf("Redirect.ServiceSubset %q is not a valid subset of %q", r.ServiceSubset, e.Name) } } } if len(e.Failover) > 0 { for subset, f := range e.Failover { if !e.InDefaultPartition() && len(f.Datacenters) != 0 { return fmt.Errorf("Cross-datacenter failover is only supported in the default partition") } errorPrefix := fmt.Sprintf("Bad Failover[%q]: ", subset) if err := f.ValidateEnterprise(); err != nil { return fmt.Errorf(errorPrefix + err.Error()) } if subset != "*" && !isSubset(subset) { return fmt.Errorf(errorPrefix + "not a valid subset subset") } if f.isEmpty() { return fmt.Errorf(errorPrefix + "one of Service, ServiceSubset, Namespace, Targets, SamenessGroup, or Datacenters is required") } if err := f.Policy.ValidateEnterprise(); err != nil { return fmt.Errorf("Bad Failover[%q]: %s", subset, err) } if err := f.Policy.validate(); err != nil { return fmt.Errorf("Bad Failover[%q]: %w", subset, err) } if f.ServiceSubset != "" { if f.Service == "" || f.Service == e.Name { if !isSubset(f.ServiceSubset) { return fmt.Errorf("%sServiceSubset %q is not a valid subset of %q", errorPrefix, f.ServiceSubset, f.Service) } } } if f.SamenessGroup != "" { switch { case len(f.Datacenters) > 0: return fmt.Errorf("Bad Failover[%q]: SamenessGroup cannot be set with Datacenters", subset) case f.ServiceSubset != "": return fmt.Errorf("Bad Failover[%q]: SamenessGroup cannot be set with ServiceSubset", subset) case len(f.Targets) > 0: return fmt.Errorf("Bad Failover[%q]: SamenessGroup cannot be set with Targets", subset) } } if len(f.Datacenters) != 0 && len(f.Targets) != 0 { return fmt.Errorf("Bad Failover[%q]: Targets cannot be set with Datacenters", subset) } if f.ServiceSubset != "" && len(f.Targets) != 0 { return fmt.Errorf("Bad Failover[%q]: Targets cannot be set with ServiceSubset", subset) } if f.Service != "" && len(f.Targets) != 0 { return fmt.Errorf("Bad Failover[%q]: Targets cannot be set with Service", subset) } for i, target := range f.Targets { errorPrefix := fmt.Sprintf("Bad Failover[%q].Targets[%d]: ", subset, i) if err := target.ValidateEnterprise(); err != nil { return fmt.Errorf(errorPrefix + err.Error()) } switch { case target.Peer != "" && target.ServiceSubset != "": return fmt.Errorf(errorPrefix + "Peer cannot be set with ServiceSubset") case target.Peer != "" && target.Partition != "": return fmt.Errorf(errorPrefix + "Partition cannot be set with Peer") case target.Peer != "" && target.Datacenter != "": return fmt.Errorf(errorPrefix + "Peer cannot be set with Datacenter") case target.Partition != "" && target.Datacenter != "": return fmt.Errorf(errorPrefix + "Partition cannot be set with Datacenter") case target.ServiceSubset != "" && (target.Service == "" || target.Service == e.Name): if !isSubset(target.ServiceSubset) { return fmt.Errorf("%sServiceSubset %q is not a valid subset of %q", errorPrefix, target.ServiceSubset, e.Name) } } } for _, dc := range f.Datacenters { if dc == "" { return fmt.Errorf("Bad Failover[%q].Datacenters: found empty datacenter", subset) } } } } if e.ConnectTimeout < 0 { return fmt.Errorf("Bad ConnectTimeout '%s', must be >= 0", e.ConnectTimeout) } if e.RequestTimeout < 0 { return fmt.Errorf("Bad RequestTimeout '%s', must be >= 0", e.RequestTimeout) } if e.LoadBalancer != nil { lb := e.LoadBalancer if ok := validLBPolicies[lb.Policy]; !ok { return fmt.Errorf("Bad LoadBalancer policy: %q is not supported", lb.Policy) } if lb.Policy != LBPolicyRingHash && lb.RingHashConfig != nil { return fmt.Errorf("Bad LoadBalancer configuration. "+ "RingHashConfig specified for incompatible load balancing policy %q", lb.Policy) } if lb.Policy != LBPolicyLeastRequest && lb.LeastRequestConfig != nil { return fmt.Errorf("Bad LoadBalancer configuration. "+ "LeastRequestConfig specified for incompatible load balancing policy %q", lb.Policy) } if !lb.IsHashBased() && len(lb.HashPolicies) > 0 { return fmt.Errorf("Bad LoadBalancer configuration: "+ "HashPolicies specified for non-hash-based Policy: %q", lb.Policy) } for i, hp := range lb.HashPolicies { if ok := validHashPolicies[hp.Field]; hp.Field != "" && !ok { return fmt.Errorf("Bad LoadBalancer HashPolicy[%d]: %q is not a supported field", i, hp.Field) } if hp.SourceIP && hp.Field != "" { return fmt.Errorf("Bad LoadBalancer HashPolicy[%d]: "+ "A single hash policy cannot hash both a source address and a %q", i, hp.Field) } if hp.SourceIP && hp.FieldValue != "" { return fmt.Errorf("Bad LoadBalancer HashPolicy[%d]: "+ "A FieldValue cannot be specified when hashing SourceIP", i) } if hp.Field != "" && hp.FieldValue == "" { return fmt.Errorf("Bad LoadBalancer HashPolicy[%d]: Field %q was specified without a FieldValue", i, hp.Field) } if hp.FieldValue != "" && hp.Field == "" { return fmt.Errorf("Bad LoadBalancer HashPolicy[%d]: FieldValue requires a Field to apply to", i) } if hp.CookieConfig != nil { if hp.Field != HashPolicyCookie { return fmt.Errorf("Bad LoadBalancer HashPolicy[%d]: cookie_config provided for %q", i, hp.Field) } if hp.CookieConfig.Session && hp.CookieConfig.TTL != 0*time.Second { return fmt.Errorf("Bad LoadBalancer HashPolicy[%d]: a session cookie cannot have an associated TTL", i) } } } } return nil } func (e *ServiceResolverConfigEntry) CanRead(authz acl.Authorizer) error { return canReadDiscoveryChain(e, authz) } func (e *ServiceResolverConfigEntry) CanWrite(authz acl.Authorizer) error { return canWriteDiscoveryChain(e, authz) } func (e *ServiceResolverConfigEntry) GetRaftIndex() *RaftIndex { if e == nil { return &RaftIndex{} } return &e.RaftIndex } func (e *ServiceResolverConfigEntry) GetEnterpriseMeta() *acl.EnterpriseMeta { if e == nil { return nil } return &e.EnterpriseMeta } func (e *ServiceResolverConfigEntry) ListRelatedServices() []ServiceID { found := make(map[ServiceID]struct{}) svcID := NewServiceID(e.Name, &e.EnterpriseMeta) if e.Redirect != nil { redirectID := NewServiceID(defaultIfEmpty(e.Redirect.Service, e.Name), e.Redirect.GetEnterpriseMeta(&e.EnterpriseMeta)) if redirectID != svcID { found[redirectID] = struct{}{} } } if len(e.Failover) > 0 { for _, failover := range e.Failover { if len(failover.Targets) == 0 { failoverID := NewServiceID(defaultIfEmpty(failover.Service, e.Name), failover.GetEnterpriseMeta(&e.EnterpriseMeta)) if failoverID != svcID { found[failoverID] = struct{}{} } continue } for _, target := range failover.Targets { // We can't know about related services on cluster peers. if target.Peer != "" { continue } failoverID := NewServiceID(defaultIfEmpty(target.Service, e.Name), target.GetEnterpriseMeta(failover.GetEnterpriseMeta(&e.EnterpriseMeta))) if failoverID != svcID { found[failoverID] = struct{}{} } } } } if len(found) == 0 { return nil } out := make([]ServiceID, 0, len(found)) for svc := range found { out = append(out, svc) } sort.Slice(out, func(i, j int) bool { return out[i].EnterpriseMeta.LessThan(&out[j].EnterpriseMeta) || out[i].ID < out[j].ID }) return out } // ServiceResolverSubset defines a way to select a portion of the Consul // catalog during service discovery. Anything that affects the ultimate catalog // query performed OR post-processing on the results of that sort of query // should be defined here. type ServiceResolverSubset struct { // Filter specifies the go-bexpr filter expression to be used for selecting // instances of the requested service. Filter string `json:",omitempty"` // OnlyPassing - Specifies the behavior of the resolver's health check // filtering. If this is set to false, the results will include instances // with checks in the passing as well as the warning states. If this is set // to true, only instances with checks in the passing state will be // returned. (behaves identically to the similarly named field on prepared // queries). OnlyPassing bool `json:",omitempty" alias:"only_passing"` } type ServiceResolverRedirect struct { // Service is a service to resolve instead of the current service // (optional). Service string `json:",omitempty"` // ServiceSubset is a named subset of the given service to resolve instead // of one defined as that service's DefaultSubset If empty the default // subset is used (optional). // // If this is specified at least one of Service, Datacenter, or Namespace // should be configured. ServiceSubset string `json:",omitempty" alias:"service_subset"` // Namespace is the namespace to resolve the service from instead of the // current one (optional). Namespace string `json:",omitempty"` // Partition is the partition to resolve the service from instead of the // current one (optional). Partition string `json:",omitempty"` // Datacenter is the datacenter to resolve the service from instead of the // current one (optional). Datacenter string `json:",omitempty"` // Peer is the name of the cluster peer to resolve the service from instead // of the current one (optional). Peer string `json:",omitempty"` // SamenessGroup is the name of the sameness group to resolve the service from instead // of the local partition. SamenessGroup string `json:",omitempty"` } // ToSamenessDiscoveryTargetOpts returns the options required for sameness failover and redirects. // These operations should preserve the service name and namespace. func (r *ServiceResolverConfigEntry) ToSamenessDiscoveryTargetOpts() DiscoveryTargetOpts { return DiscoveryTargetOpts{ Service: r.Name, Namespace: r.NamespaceOrDefault(), Partition: r.PartitionOrDefault(), } } func (r *ServiceResolverRedirect) ToDiscoveryTargetOpts() DiscoveryTargetOpts { return DiscoveryTargetOpts{ Service: r.Service, ServiceSubset: r.ServiceSubset, Namespace: r.Namespace, Partition: r.Partition, Datacenter: r.Datacenter, Peer: r.Peer, } } func (r *ServiceResolverRedirect) isEmpty() bool { return r.Service == "" && r.ServiceSubset == "" && r.Namespace == "" && r.Partition == "" && r.Datacenter == "" && r.Peer == "" && r.SamenessGroup == "" } // There are some restrictions on what is allowed in here: // // - Service, ServiceSubset, Namespace, Datacenters, and Targets cannot all be // empty at once. When Targets is defined, the other fields should not be // populated. type ServiceResolverFailover struct { // Service is the service to resolve instead of the default as the failover // group of instances (optional). // // This is a DESTINATION during failover. Service string `json:",omitempty"` // ServiceSubset is the named subset of the requested service to resolve as // the failover group of instances. If empty the default subset for the // requested service is used (optional). // // This is a DESTINATION during failover. ServiceSubset string `json:",omitempty" alias:"service_subset"` // Namespace is the namespace to resolve the requested service from to form // the failover group of instances. If empty the current namespace is used // (optional). // // This is a DESTINATION during failover. Namespace string `json:",omitempty"` // Datacenters is a fixed list of datacenters to try. We never try a // datacenter multiple times, so those are subtracted from this list before // proceeding. // // This is a DESTINATION during failover. Datacenters []string `json:",omitempty"` // Targets specifies a fixed list of failover targets to try. We never try a // target multiple times, so those are subtracted from this list before // proceeding. // // This is a DESTINATION during failover. Targets []ServiceResolverFailoverTarget `json:",omitempty"` // Policy specifies the exact mechanism used for failover. Policy *ServiceResolverFailoverPolicy `json:",omitempty"` // SamenessGroup specifies the sameness group to failover to. SamenessGroup string `json:",omitempty"` } func (f *ServiceResolverFailover) ToDiscoveryTargetOpts() DiscoveryTargetOpts { return DiscoveryTargetOpts{ Service: f.Service, ServiceSubset: f.ServiceSubset, Namespace: f.Namespace, } } func (f *ServiceResolverFailover) isEmpty() bool { return f.Service == "" && f.ServiceSubset == "" && f.Namespace == "" && len(f.Datacenters) == 0 && len(f.Targets) == 0 && f.SamenessGroup == "" } type ServiceResolverFailoverPolicy struct { // Mode specifies the type of failover that will be performed. Valid values are // "sequential", "" (equivalent to "sequential") and "order-by-locality". Mode string `json:",omitempty"` Regions []string `json:",omitempty"` } func (fp *ServiceResolverFailoverPolicy) validate() error { if fp == nil { return nil } switch fp.Mode { case "": case "sequential": case "order-by-locality": default: return fmt.Errorf("Failover-policy mode must be one of '', 'sequential', or 'order-by-locality'") } return nil } type ServiceResolverPrioritizeByLocality struct { // Mode specifies the type of prioritization that will be performed // when selecting nodes in the local partition. // Valid values are: "" (default "none"), "none", and "failover". Mode string `json:",omitempty"` } type ServiceResolverFailoverTarget struct { // Service specifies the name of the service to try during failover. Service string `json:",omitempty"` // ServiceSubset specifies the service subset to try during failover. ServiceSubset string `json:",omitempty" alias:"service_subset"` // Partition specifies the partition to try during failover. Partition string `json:",omitempty"` // Namespace specifies the namespace to try during failover. Namespace string `json:",omitempty"` // Datacenter specifies the datacenter to try during failover. Datacenter string `json:",omitempty"` // Peer specifies the name of the cluster peer to try during failover. Peer string `json:",omitempty"` } func (t *ServiceResolverFailoverTarget) ToDiscoveryTargetOpts() DiscoveryTargetOpts { return DiscoveryTargetOpts{ Service: t.Service, ServiceSubset: t.ServiceSubset, Namespace: t.Namespace, Partition: t.Partition, Datacenter: t.Datacenter, Peer: t.Peer, } } // LoadBalancer determines the load balancing policy and configuration for services // issuing requests to this upstream service. type LoadBalancer struct { // Policy is the load balancing policy used to select a host Policy string `json:",omitempty"` // RingHashConfig contains configuration for the "ring_hash" policy type RingHashConfig *RingHashConfig `json:",omitempty" alias:"ring_hash_config"` // LeastRequestConfig contains configuration for the "least_request" policy type LeastRequestConfig *LeastRequestConfig `json:",omitempty" alias:"least_request_config"` // HashPolicies is a list of hash policies to use for hashing load balancing algorithms. // Hash policies are evaluated individually and combined such that identical lists // result in the same hash. // If no hash policies are present, or none are successfully evaluated, // then a random backend host will be selected. HashPolicies []HashPolicy `json:",omitempty" alias:"hash_policies"` } // RingHashConfig contains configuration for the "ring_hash" policy type type RingHashConfig struct { // MinimumRingSize determines the minimum number of entries in the hash ring MinimumRingSize uint64 `json:",omitempty" alias:"minimum_ring_size"` // MaximumRingSize determines the maximum number of entries in the hash ring MaximumRingSize uint64 `json:",omitempty" alias:"maximum_ring_size"` } // LeastRequestConfig contains configuration for the "least_request" policy type type LeastRequestConfig struct { // ChoiceCount determines the number of random healthy hosts from which to select the one with the least requests. ChoiceCount uint32 `json:",omitempty" alias:"choice_count"` } // HashPolicy defines which attributes will be hashed by hash-based LB algorithms type HashPolicy struct { // Field is the attribute type to hash on. // Must be one of "header","cookie", or "query_parameter". // Cannot be specified along with SourceIP. Field string `json:",omitempty"` // FieldValue is the value to hash. // ie. header name, cookie name, URL query parameter name // Cannot be specified along with SourceIP. FieldValue string `json:",omitempty" alias:"field_value"` // CookieConfig contains configuration for the "cookie" hash policy type. CookieConfig *CookieConfig `json:",omitempty" alias:"cookie_config"` // SourceIP determines whether the hash should be of the source IP rather than of a field and field value. // Cannot be specified along with Field or FieldValue. SourceIP bool `json:",omitempty" alias:"source_ip"` // Terminal will short circuit the computation of the hash when multiple hash policies are present. // If a hash is computed when a Terminal policy is evaluated, // then that hash will be used and subsequent hash policies will be ignored. Terminal bool `json:",omitempty"` } // CookieConfig contains configuration for the "cookie" hash policy type. // This is specified to have Envoy generate a cookie for a client on its first request. type CookieConfig struct { // Generates a session cookie with no expiration. Session bool `json:",omitempty"` // TTL for generated cookies. Cannot be specified for session cookies. TTL time.Duration `json:",omitempty"` // The path to set for the cookie Path string `json:",omitempty"` } func (lb *LoadBalancer) IsHashBased() bool { if lb == nil { return false } switch lb.Policy { case LBPolicyMaglev, LBPolicyRingHash: return true default: return false } } type discoveryChainConfigEntry interface { ConfigEntry // ListRelatedServices returns a list of other names of services referenced // in this config entry. ListRelatedServices() []ServiceID } func canReadDiscoveryChain(entry discoveryChainConfigEntry, authz acl.Authorizer) error { var authzContext acl.AuthorizerContext entry.GetEnterpriseMeta().FillAuthzContext(&authzContext) return authz.ToAllowAuthorizer().ServiceReadAllowed(entry.GetName(), &authzContext) } func canWriteDiscoveryChain(entry discoveryChainConfigEntry, authz acl.Authorizer) error { entryID := NewServiceID(entry.GetName(), entry.GetEnterpriseMeta()) var authzContext acl.AuthorizerContext entryID.FillAuthzContext(&authzContext) name := entry.GetName() if err := authz.ToAllowAuthorizer().ServiceWriteAllowed(name, &authzContext); err != nil { return err } for _, svc := range entry.ListRelatedServices() { if entryID == svc { continue } svc.FillAuthzContext(&authzContext) // You only need read on related services to redirect traffic flow for // your own service. if err := authz.ToAllowAuthorizer().ServiceReadAllowed(svc.ID, &authzContext); err != nil { return err } } return nil } // DiscoveryChainRequest is used when requesting the discovery chain for a // service. type DiscoveryChainRequest struct { Name string EvaluateInDatacenter string EvaluateInNamespace string EvaluateInPartition string // OverrideMeshGateway allows for the mesh gateway setting to be overridden // for any resolver in the compiled chain. OverrideMeshGateway MeshGatewayConfig // OverrideProtocol allows for the final protocol for the chain to be // altered. // // - If the chain ordinarily would be TCP and an L7 protocol is passed here // the chain will not include Routers or Splitters. // // - If the chain ordinarily would be L7 and TCP is passed here the chain // will not include Routers or Splitters. OverrideProtocol string // OverrideConnectTimeout allows for the ConnectTimeout setting to be // overridden for any resolver in the compiled chain. OverrideConnectTimeout time.Duration Datacenter string // where to route the RPC QueryOptions } func (r *DiscoveryChainRequest) RequestDatacenter() string { return r.Datacenter } func (r *DiscoveryChainRequest) CacheInfo() cache.RequestInfo { info := cache.RequestInfo{ Token: r.Token, Datacenter: r.Datacenter, MinIndex: r.MinQueryIndex, Timeout: r.MaxQueryTime, MaxAge: r.MaxAge, MustRevalidate: r.MustRevalidate, } v, err := hashstructure.Hash(struct { Name string EvaluateInDatacenter string EvaluateInNamespace string EvaluateInPartition string OverrideMeshGateway MeshGatewayConfig OverrideProtocol string OverrideConnectTimeout time.Duration Filter string }{ Name: r.Name, EvaluateInDatacenter: r.EvaluateInDatacenter, EvaluateInNamespace: r.EvaluateInNamespace, EvaluateInPartition: r.EvaluateInPartition, OverrideMeshGateway: r.OverrideMeshGateway, OverrideProtocol: r.OverrideProtocol, OverrideConnectTimeout: r.OverrideConnectTimeout, Filter: r.QueryOptions.Filter, }, nil) if err == nil { // If there is an error, we don't set the key. A blank key forces // no cache for this request so the request is forwarded directly // to the server. info.Key = strconv.FormatUint(v, 10) } return info } type DiscoveryChainResponse struct { Chain *CompiledDiscoveryChain QueryMeta } type ConfigEntryGraphError struct { // one of Message or Err should be set Message string Err error } func (e *ConfigEntryGraphError) Error() string { if e.Err != nil { return e.Err.Error() } return e.Message } var ( validServiceSubset = regexp.MustCompile(`^[a-z0-9]([a-z0-9-]*[a-z0-9])?$`) serviceSubsetMaxLength = 63 ) // validateServiceSubset checks if the provided name can be used as an service // subset. Because these are used in SNI headers they must a DNS label per // RFC-1035/RFC-1123. func validateServiceSubset(subset string) error { if subset == "" || len(subset) > serviceSubsetMaxLength { return fmt.Errorf("must be non-empty and 63 characters or fewer") } if !validServiceSubset.MatchString(subset) { return fmt.Errorf("must be 63 characters or fewer, begin or end with lower case alphanumeric characters, and contain lower case alphanumeric characters or '-' in between") } return nil } func defaultIfEmpty(val, defaultVal string) string { if val != "" { return val } return defaultVal } func IsProtocolHTTPLike(protocol string) bool { switch protocol { case "http", "http2", "grpc": return true default: return false } } // HTTPHeaderModifiers is a set of rules for HTTP header modification that // should be performed by proxies as the request passes through them. It can // operate on either request or response headers depending on the context in // which it is used. type HTTPHeaderModifiers struct { // Add is a set of name -> value pairs that should be appended to the request // or response (i.e. allowing duplicates if the same header already exists). Add map[string]string `json:",omitempty"` // Set is a set of name -> value pairs that should be added to the request or // response, overwriting any existing header values of the same name. Set map[string]string `json:",omitempty"` // Remove is the set of header names that should be stripped from the request // or response. Remove []string `json:",omitempty"` } func (m *HTTPHeaderModifiers) IsZero() bool { if m == nil { return true } return len(m.Add) == 0 && len(m.Set) == 0 && len(m.Remove) == 0 } func (m *HTTPHeaderModifiers) Validate(protocol string) error { if m.IsZero() { return nil } if !IsProtocolHTTPLike(protocol) { // Non nil but context is not an httpish protocol return fmt.Errorf("only valid for http, http2 and grpc protocols") } return nil } // Clone returns a deep-copy of m unless m is nil func (m *HTTPHeaderModifiers) Clone() (*HTTPHeaderModifiers, error) { if m == nil { return nil, nil } cpy, err := copystructure.Copy(m) if err != nil { return nil, err } m = cpy.(*HTTPHeaderModifiers) return m, nil } // MergeHTTPHeaderModifiers takes a base HTTPHeaderModifiers and merges in field // defined in overrides. Precedence is given to the overrides field if there is // a collision. The resulting object is returned leaving both base and overrides // unchanged. The `Add` field in override also replaces same-named keys of base // since we have no way to express multiple adds to the same key. We could // change that, but it makes the config syntax more complex for a huge edgecase. func MergeHTTPHeaderModifiers(base, overrides *HTTPHeaderModifiers) (*HTTPHeaderModifiers, error) { if base.IsZero() { return overrides.Clone() } merged, err := base.Clone() if err != nil { return nil, err } if overrides.IsZero() { return merged, nil } for k, v := range overrides.Add { merged.Add[k] = v } for k, v := range overrides.Set { merged.Set[k] = v } // Deduplicate removes. removed := make(map[string]struct{}) for _, k := range merged.Remove { removed[k] = struct{}{} } for _, k := range overrides.Remove { if _, ok := removed[k]; !ok { merged.Remove = append(merged.Remove, k) } } return merged, nil }