[OSS] feat: add experiments flag for v2 dns and skeleton interfaces (#20115)

feat: add experiments flag for v2 dns and skeleton interfaces
This commit is contained in:
Dan Stough 2024-01-10 11:19:20 -05:00 committed by GitHub
parent fa6eb61f70
commit d52e80b619
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GPG Key ID: 4AEE18F83AFDEB23
22 changed files with 817 additions and 145 deletions

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@ -47,6 +47,7 @@ import (
"github.com/hashicorp/consul/agent/consul"
rpcRate "github.com/hashicorp/consul/agent/consul/rate"
"github.com/hashicorp/consul/agent/consul/servercert"
"github.com/hashicorp/consul/agent/discovery"
"github.com/hashicorp/consul/agent/dns"
external "github.com/hashicorp/consul/agent/grpc-external"
grpcDNS "github.com/hashicorp/consul/agent/grpc-external/services/dns"
@ -67,6 +68,7 @@ import (
"github.com/hashicorp/consul/agent/xds"
"github.com/hashicorp/consul/api"
"github.com/hashicorp/consul/api/watch"
libdns "github.com/hashicorp/consul/internal/dnsutil"
proxytracker "github.com/hashicorp/consul/internal/mesh/proxy-tracker"
"github.com/hashicorp/consul/ipaddr"
"github.com/hashicorp/consul/lib"
@ -217,6 +219,14 @@ type notifier interface {
Notify(string) error
}
// dnsServer abstracts the V1 and V2 implementations of the DNS server.
type dnsServer interface {
GetAddr() string
ListenAndServe(string, string, func()) error
ReloadConfig(*config.RuntimeConfig) error
Shutdown()
}
// Agent is the long running process that is run on every machine.
// It exposes an RPC interface that is used by the CLI to control the
// agent. The agent runs the query interfaces like HTTP, DNS, and RPC.
@ -336,7 +346,11 @@ type Agent struct {
endpointsLock sync.RWMutex
// dnsServer provides the DNS API
dnsServers []*DNSServer
dnsServers []dnsServer
// catalogDataFetcher is used as an interface to the catalog for service discovery
// (aka DNS). Only applicable to the V2 DNS server (agent/dns).
catalogDataFetcher discovery.CatalogDataFetcher
// apiServers listening for connections. If any of these server goroutines
// fail, the agent will be shutdown.
@ -397,7 +411,7 @@ type Agent struct {
// they can update their internal state.
configReloaders []ConfigReloader
// TODO: pass directly to HTTPHandlers and DNSServer once those are passed
// TODO: pass directly to HTTPHandlers and dnsServer once those are passed
// into Agent, which will allow us to remove this field.
rpcClientHealth *health.Client
rpcClientConfigEntry *configentry.Client
@ -729,6 +743,10 @@ func (a *Agent) Start(ctx context.Context) error {
}
}
} else {
if a.baseDeps.UseV2Resources() {
return fmt.Errorf("can't start agent: client agents are not supported with v2 resources")
}
a.externalGRPCServer = external.NewServer(
a.logger.Named("grpc.external"),
metrics.Default(),
@ -836,9 +854,16 @@ func (a *Agent) Start(ctx context.Context) error {
}
// start DNS servers
if err := a.listenAndServeDNS(); err != nil {
if a.baseDeps.UseV2DNS() {
a.logger.Warn("DNS v2 is under construction")
if err := a.listenAndServeV2DNS(); err != nil {
return err
}
} else {
if err := a.listenAndServeV1DNS(); err != nil {
return err
}
}
// Configure the http connection limiter.
a.httpConnLimiter.SetConfig(connlimit.Config{
@ -1016,7 +1041,7 @@ func (a *Agent) listenAndServeGRPC(proxyTracker *proxytracker.ProxyTracker, serv
return nil
}
func (a *Agent) listenAndServeDNS() error {
func (a *Agent) listenAndServeV1DNS() error {
notif := make(chan net.Addr, len(a.config.DNSAddrs))
errCh := make(chan error, len(a.config.DNSAddrs))
for _, addr := range a.config.DNSAddrs {
@ -1068,6 +1093,80 @@ func (a *Agent) listenAndServeDNS() error {
return merr.ErrorOrNil()
}
func (a *Agent) listenAndServeV2DNS() error {
// Check the catalog version and decide which implementation of the data fetcher to implement
if a.baseDeps.UseV2Resources() {
a.catalogDataFetcher = discovery.NewV2DataFetcher(a.config)
} else {
a.catalogDataFetcher = discovery.NewV1DataFetcher(a.config)
}
// Generate a Query Processor with the appropriate data fetcher
processor := discovery.NewQueryProcessor(a.catalogDataFetcher)
notif := make(chan net.Addr, len(a.config.DNSAddrs))
errCh := make(chan error, len(a.config.DNSAddrs))
// create server
cfg := dns.Config{
AgentConfig: a.config,
EntMeta: a.AgentEnterpriseMeta(), // TODO (v2-dns): does this even work for v2 tenancy?
Logger: a.logger,
Processor: processor,
TokenFunc: a.getTokenFunc(),
}
for _, addr := range a.config.DNSAddrs {
s, err := dns.NewServer(cfg)
if err != nil {
return err
}
a.dnsServers = append(a.dnsServers, s)
// start server
a.wgServers.Add(1)
go func(addr net.Addr) {
defer a.wgServers.Done()
err := s.ListenAndServe(addr.Network(), addr.String(), func() { notif <- addr })
if err != nil && !strings.Contains(err.Error(), "accept") {
errCh <- err
}
}(addr)
}
// TODO(v2-dns): implement a new grpcDNS proxy that takes in the new Router object.
//s, _ := dns.NewServer(cfg)
//
//grpcDNS.NewServer(grpcDNS.Config{
// Logger: a.logger.Named("grpc-api.dns"),
// DNSServeMux: s.mux,
// LocalAddr: grpcDNS.LocalAddr{IP: net.IPv4(127, 0, 0, 1), Port: a.config.GRPCPort},
//}).Register(a.externalGRPCServer)
//
//a.dnsServers = append(a.dnsServers, s)
// wait for servers to be up
timeout := time.After(time.Second)
var merr *multierror.Error
for range a.config.DNSAddrs {
select {
case addr := <-notif:
a.logger.Info("Started DNS server",
"address", addr.String(),
"network", addr.Network(),
)
case err := <-errCh:
merr = multierror.Append(merr, err)
case <-timeout:
merr = multierror.Append(merr, fmt.Errorf("agent: timeout starting DNS servers"))
return merr.ErrorOrNil()
}
}
return merr.ErrorOrNil()
}
// startListeners will return a net.Listener for every address unless an
// error is encountered, in which case it will close all previously opened
// listeners and return the error.
@ -1803,15 +1902,8 @@ func (a *Agent) ShutdownEndpoints() {
ctx := context.TODO()
for _, srv := range a.dnsServers {
if srv.Server != nil {
a.logger.Info("Stopping server",
"protocol", "DNS",
"address", srv.Server.Addr,
"network", srv.Server.Net,
)
srv.Shutdown()
}
}
a.dnsServers = nil
a.apiServers.Shutdown(ctx)
@ -2645,13 +2737,13 @@ func (a *Agent) validateService(service *structs.NodeService, chkTypes []*struct
}
// Warn if the service name is incompatible with DNS
if dns.InvalidNameRe.MatchString(service.Service) {
if libdns.InvalidNameRe.MatchString(service.Service) {
a.logger.Warn("Service name will not be discoverable "+
"via DNS due to invalid characters. Valid characters include "+
"all alpha-numerics and dashes.",
"service", service.Service,
)
} else if len(service.Service) > dns.MaxLabelLength {
} else if len(service.Service) > libdns.MaxLabelLength {
a.logger.Warn("Service name will not be discoverable "+
"via DNS due to it being too long. Valid lengths are between "+
"1 and 63 bytes.",
@ -2661,13 +2753,13 @@ func (a *Agent) validateService(service *structs.NodeService, chkTypes []*struct
// Warn if any tags are incompatible with DNS
for _, tag := range service.Tags {
if dns.InvalidNameRe.MatchString(tag) {
if libdns.InvalidNameRe.MatchString(tag) {
a.logger.Debug("Service tag will not be discoverable "+
"via DNS due to invalid characters. Valid characters include "+
"all alpha-numerics and dashes.",
"tag", tag,
)
} else if len(tag) > dns.MaxLabelLength {
} else if len(tag) > libdns.MaxLabelLength {
a.logger.Debug("Service tag will not be discoverable "+
"via DNS due to it being too long. Valid lengths are between "+
"1 and 63 bytes.",
@ -4286,6 +4378,10 @@ func (a *Agent) reloadConfigInternal(newCfg *config.RuntimeConfig) error {
return fmt.Errorf("Failed reloading dns config : %v", err)
}
}
// This field is only populated for the V2 DNS server
if a.catalogDataFetcher != nil {
a.catalogDataFetcher.LoadConfig(newCfg)
}
err := a.reloadEnterprise(newCfg)
if err != nil {
@ -4751,3 +4847,13 @@ func defaultIfEmpty(val, defaultVal string) string {
}
return defaultVal
}
func (a *Agent) getTokenFunc() func() string {
return func() string {
if a.tokens.DNSToken() != "" {
return a.tokens.DNSToken()
} else {
return a.tokens.UserToken()
}
}
}

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@ -34,11 +34,11 @@ import (
"github.com/hashicorp/consul/agent/consul"
"github.com/hashicorp/consul/agent/consul/authmethod/ssoauth"
consulrate "github.com/hashicorp/consul/agent/consul/rate"
"github.com/hashicorp/consul/agent/dns"
hcpconfig "github.com/hashicorp/consul/agent/hcp/config"
"github.com/hashicorp/consul/agent/rpc/middleware"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/consul/agent/token"
"github.com/hashicorp/consul/internal/dnsutil"
"github.com/hashicorp/consul/ipaddr"
"github.com/hashicorp/consul/lib"
"github.com/hashicorp/consul/lib/stringslice"
@ -1287,7 +1287,7 @@ func (b *builder) validate(rt RuntimeConfig) error {
switch {
case rt.NodeName == "":
return fmt.Errorf("node_name cannot be empty")
case dns.InvalidNameRe.MatchString(rt.NodeName):
case dnsutil.InvalidNameRe.MatchString(rt.NodeName):
b.warn("Node name %q will not be discoverable "+
"via DNS due to invalid characters. Valid characters include "+
"all alpha-numerics and dashes.", rt.NodeName)
@ -1295,7 +1295,7 @@ func (b *builder) validate(rt RuntimeConfig) error {
// todo(kyhavlov): Add stronger validation here for node names.
b.warn("Found invalid characters in node name %q - whitespace and quotes "+
"(', \", `) cannot be used with auto-config.", rt.NodeName)
case len(rt.NodeName) > dns.MaxLabelLength:
case len(rt.NodeName) > dnsutil.MaxLabelLength:
b.warn("Node name %q will not be discoverable "+
"via DNS due to it being too long. Valid lengths are between "+
"1 and 63 bytes.", rt.NodeName)
@ -1827,14 +1827,14 @@ func (b *builder) meshGatewayConfVal(mgConf *MeshGatewayConfig) structs.MeshGate
return cfg
}
func (b *builder) dnsRecursorStrategyVal(v string) dns.RecursorStrategy {
var out dns.RecursorStrategy
func (b *builder) dnsRecursorStrategyVal(v string) structs.RecursorStrategy {
var out structs.RecursorStrategy
switch dns.RecursorStrategy(v) {
case dns.RecursorStrategyRandom:
out = dns.RecursorStrategyRandom
case dns.RecursorStrategySequential, "":
out = dns.RecursorStrategySequential
switch structs.RecursorStrategy(v) {
case structs.RecursorStrategyRandom:
out = structs.RecursorStrategyRandom
case structs.RecursorStrategySequential, "":
out = structs.RecursorStrategySequential
default:
b.err = multierror.Append(b.err, fmt.Errorf("dns_config.recursor_strategy: invalid strategy: %q", v))
}

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@ -16,7 +16,6 @@ import (
"github.com/hashicorp/consul/agent/cache"
"github.com/hashicorp/consul/agent/consul"
consulrate "github.com/hashicorp/consul/agent/consul/rate"
"github.com/hashicorp/consul/agent/dns"
hcpconfig "github.com/hashicorp/consul/agent/hcp/config"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/consul/agent/token"
@ -253,7 +252,7 @@ type RuntimeConfig struct {
// client agents try the first server in the list every time.
//
// hcl: dns_config { recursor_strategy = "(random|sequential)" }
DNSRecursorStrategy dns.RecursorStrategy
DNSRecursorStrategy structs.RecursorStrategy
// DNSRecursorTimeout specifies the timeout in seconds
// for Consul's internal dns client used for recursion.

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@ -11,12 +11,12 @@ import (
"regexp"
"github.com/hashicorp/consul/acl"
"github.com/hashicorp/consul/internal/dnsutil"
bexpr "github.com/hashicorp/go-bexpr"
"github.com/hashicorp/consul/agent/connect"
"github.com/hashicorp/consul/agent/consul/authmethod/ssoauth"
"github.com/hashicorp/consul/agent/dns"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/consul/lib/template"
"github.com/hashicorp/consul/proto/private/pbautoconf"
@ -80,7 +80,7 @@ func (a *jwtAuthorizer) Authorize(req *pbautoconf.AutoConfigRequest) (AutoConfig
if invalidSegmentName.MatchString(req.Segment) {
return AutoConfigOptions{}, fmt.Errorf("Invalid request field. %v = `%v`", "segment", req.Segment)
}
if req.Partition != "" && !dns.IsValidLabel(req.Partition) {
if req.Partition != "" && !dnsutil.IsValidLabel(req.Partition) {
return AutoConfigOptions{}, fmt.Errorf("Invalid request field. %v = `%v`", "partition", req.Partition)
}

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@ -4,9 +4,10 @@
package consul
import (
"github.com/hashicorp/consul/lib/stringslice"
"google.golang.org/grpc"
"github.com/hashicorp/consul/lib/stringslice"
"github.com/hashicorp/consul-net-rpc/net/rpc"
"github.com/hashicorp/go-hclog"
@ -49,6 +50,15 @@ type Deps struct {
EnterpriseDeps
}
// UseV2DNS returns true if "v2-dns" is present in the Experiments
// array of the agent config. It is assumed if the v2 resource APIs are enabled.
func (d Deps) UseV2DNS() bool {
if stringslice.Contains(d.Experiments, V2DNSExperimentName) || d.UseV2Resources() {
return true
}
return false
}
// UseV2Resources returns true if "resource-apis" is present in the Experiments
// array of the agent config.
func (d Deps) UseV2Resources() bool {

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@ -142,6 +142,7 @@ const (
LeaderTransferMinVersion = "1.6.0"
CatalogResourceExperimentName = "resource-apis"
V2DNSExperimentName = "v2dns"
V2TenancyExperimentName = "v2tenancy"
HCPAllowV2ResourceAPIs = "hcp-v2-resource-apis"
)

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@ -0,0 +1,157 @@
// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package discovery
import (
"fmt"
"net"
"github.com/hashicorp/consul/agent/config"
"github.com/hashicorp/consul/agent/structs"
)
// Query is used to request a name-based Service Discovery lookup.
type Query struct {
QueryType QueryType
QueryPayload QueryPayload
}
// QueryType is used to filter service endpoints.
// This is needed by the V1 catalog because of the
// overlapping lookups through the service endpoint.
type QueryType string
const (
QueryTypeConnect QueryType = "CONNECT" // deprecated: use for V1 only
QueryTypeIngress QueryType = "INGRESS" // deprecated: use for V1 only
QueryTypeNode QueryType = "NODE"
QueryTypePreparedQuery QueryType = "PREPARED_QUERY" // deprecated: use for V1 only
QueryTypeService QueryType = "SERVICE"
QueryTypeVirtual QueryType = "VIRTUAL"
QueryTypeWorkload QueryType = "WORKLOAD" // V2-only
)
type Context struct {
Token string
DefaultPartition string
DefaultNamespace string
DefaultLocality *structs.Locality
}
type QueryTenancy struct {
Partition string
Namespace string
SamenessGroup string
Peer string
Datacenter string
}
// QueryPayload represents all information needed by the data backend
// to decide which records to include.
type QueryPayload struct {
Name string
PortName string // v1 - this could optionally be "connect" or "ingress"; v2 - this is the service port name
Tag string // deprecated: use for V1 only
RemoteAddr net.Addr // deprecated: used for prepared queries
Tenancy QueryTenancy // tenancy includes any additional labels specified before the domain
// v2 fields only
DisableFailover bool
}
// Result is a generic format of targets that could be returned in a query.
// It is the responsibility of the DNS encoder to know what to do with
// each Result, based on the query type.
type Result struct {
Address string // A/AAAA/CNAME records - could be used in the Extra section. CNAME is required to handle hostname addresses in workloads & nodes.
Weight uint32 // SRV queries
Port uint32 // SRV queries
TTL uint32
Metadata []string // Used to collect metadata into TXT Records
// Used in SRV & PTR queries to point at an A/AAAA Record.
// In V1, this could be a full-qualified Service or Node name.
// In V2, this is generally a fully-qualified Workload name.
Target string
}
type LookupType string
const (
LookupTypeService LookupType = "SERVICE"
LookupTypeConnect LookupType = "CONNECT"
LookupTypeIngress LookupType = "INGRESS"
)
// CatalogDataFetcher is an interface that abstracts data collection
// for Discovery queries. It is assumed that the instantiation also
// includes any agent configuration that influences catalog queries.
type CatalogDataFetcher interface {
// LoadConfig is used to hot-reload the data fetcher with new agent config.
LoadConfig(config *config.RuntimeConfig)
// FetchNodes fetches A/AAAA/CNAME
FetchNodes(ctx Context, req *QueryPayload) ([]*Result, error)
// FetchEndpoints fetches records for A/AAAA/CNAME or SRV requests for services
FetchEndpoints(ctx Context, req *QueryPayload, lookupType LookupType) ([]*Result, error)
// FetchVirtualIP fetches A/AAAA records for virtual IPs
FetchVirtualIP(ctx Context, req *QueryPayload) (*Result, error)
// FetchRecordsByIp is used for PTR requests
// to look up a service/node from an IP.
FetchRecordsByIp(ctx Context, ip net.IP) ([]*Result, error)
// FetchWorkload fetches a single Result associated with
// V2 Workload. V2-only.
FetchWorkload(ctx Context, req *QueryPayload) (*Result, error)
// FetchPreparedQuery evaluates the results of a prepared query.
// deprecated in V2
FetchPreparedQuery(ctx Context, req *QueryPayload) ([]*Result, error)
}
type QueryProcessor struct {
dataFetcher CatalogDataFetcher
}
func NewQueryProcessor(dataFetcher CatalogDataFetcher) *QueryProcessor {
return &QueryProcessor{
dataFetcher: dataFetcher,
}
}
func (p *QueryProcessor) QueryByName(query *Query, ctx Context) ([]*Result, error) {
switch query.QueryType {
case QueryTypeNode:
return p.dataFetcher.FetchNodes(ctx, &query.QueryPayload)
case QueryTypeService:
return p.dataFetcher.FetchEndpoints(ctx, &query.QueryPayload, LookupTypeService)
case QueryTypeConnect:
return p.dataFetcher.FetchEndpoints(ctx, &query.QueryPayload, LookupTypeConnect)
case QueryTypeIngress:
return p.dataFetcher.FetchEndpoints(ctx, &query.QueryPayload, LookupTypeIngress)
case QueryTypeVirtual:
result, err := p.dataFetcher.FetchVirtualIP(ctx, &query.QueryPayload)
if err != nil {
return nil, err
}
return []*Result{result}, nil
case QueryTypeWorkload:
result, err := p.dataFetcher.FetchWorkload(ctx, &query.QueryPayload)
if err != nil {
return nil, err
}
return []*Result{result}, nil
case QueryTypePreparedQuery:
return p.dataFetcher.FetchPreparedQuery(ctx, &query.QueryPayload)
default:
return nil, fmt.Errorf("unknown query type: %s", query.QueryType)
}
}
func (p *QueryProcessor) QueryByIP(ip net.IP, ctx Context) ([]*Result, error) {
return p.dataFetcher.FetchRecordsByIp(ctx, ip)
}

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@ -0,0 +1,73 @@
// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package discovery
import (
"net"
"sync/atomic"
"time"
"github.com/hashicorp/consul/agent/config"
)
const (
// TODO (v2-dns): can we move the recursion into the data fetcher?
maxRecursionLevelDefault = 3 // This field comes from the V1 DNS server and affects V1 catalog lookups
maxRecurseRecords = 5
)
type v1DataFetcherDynamicConfig struct {
allowStale bool
maxStale time.Duration
useCache bool
cacheMaxAge time.Duration
onlyPassing bool
}
type V1DataFetcher struct {
dynamicConfig atomic.Value
}
func NewV1DataFetcher(config *config.RuntimeConfig) *V1DataFetcher {
f := &V1DataFetcher{}
f.LoadConfig(config)
return f
}
func (f *V1DataFetcher) LoadConfig(config *config.RuntimeConfig) {
dynamicConfig := &v1DataFetcherDynamicConfig{
allowStale: config.DNSAllowStale,
maxStale: config.DNSMaxStale,
useCache: config.DNSUseCache,
cacheMaxAge: config.DNSCacheMaxAge,
onlyPassing: config.DNSOnlyPassing,
}
f.dynamicConfig.Store(dynamicConfig)
}
// TODO (v2-dns): Implementation of the V1 data fetcher
func (f *V1DataFetcher) FetchNodes(ctx Context, req *QueryPayload) ([]*Result, error) {
return nil, nil
}
func (f *V1DataFetcher) FetchEndpoints(ctx Context, req *QueryPayload, lookupType LookupType) ([]*Result, error) {
return nil, nil
}
func (f *V1DataFetcher) FetchVirtualIP(ctx Context, req *QueryPayload) (*Result, error) {
return nil, nil
}
func (f *V1DataFetcher) FetchRecordsByIp(ctx Context, ip net.IP) ([]*Result, error) {
return nil, nil
}
func (f *V1DataFetcher) FetchWorkload(ctx Context, req *QueryPayload) (*Result, error) {
return nil, nil
}
func (f *V1DataFetcher) FetchPreparedQuery(ctx Context, req *QueryPayload) ([]*Result, error) {
return nil, nil
}

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@ -0,0 +1,58 @@
// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package discovery
import (
"net"
"sync/atomic"
"github.com/hashicorp/consul/agent/config"
)
type v2DataFetcherDynamicConfig struct {
onlyPassing bool
}
type V2DataFetcher struct {
dynamicConfig atomic.Value
}
func NewV2DataFetcher(config *config.RuntimeConfig) *V2DataFetcher {
f := &V2DataFetcher{}
f.LoadConfig(config)
return f
}
func (f *V2DataFetcher) LoadConfig(config *config.RuntimeConfig) {
dynamicConfig := &v2DataFetcherDynamicConfig{
onlyPassing: config.DNSOnlyPassing,
}
f.dynamicConfig.Store(dynamicConfig)
}
// TODO (v2-dns): Implementation of the V2 data fetcher
func (f *V2DataFetcher) FetchNodes(ctx Context, req *QueryPayload) ([]*Result, error) {
return nil, nil
}
func (f *V2DataFetcher) FetchEndpoints(ctx Context, req *QueryPayload, lookupType LookupType) ([]*Result, error) {
return nil, nil
}
func (f *V2DataFetcher) FetchVirtualIP(ctx Context, req *QueryPayload) (*Result, error) {
return nil, nil
}
func (f *V2DataFetcher) FetchRecordsByIp(ctx Context, ip net.IP) ([]*Result, error) {
return nil, nil
}
func (f *V2DataFetcher) FetchWorkload(ctx Context, req *QueryPayload) (*Result, error) {
return nil, nil
}
func (f *V2DataFetcher) FetchPreparedQuery(ctx Context, req *QueryPayload) ([]*Result, error) {
return nil, nil
}

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@ -25,9 +25,9 @@ import (
"github.com/hashicorp/consul/acl"
cachetype "github.com/hashicorp/consul/agent/cache-types"
"github.com/hashicorp/consul/agent/config"
agentdns "github.com/hashicorp/consul/agent/dns"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/consul/api"
libdns "github.com/hashicorp/consul/internal/dnsutil"
"github.com/hashicorp/consul/ipaddr"
"github.com/hashicorp/consul/lib"
"github.com/hashicorp/consul/logging"
@ -90,7 +90,7 @@ type dnsConfig struct {
NodeName string
NodeTTL time.Duration
OnlyPassing bool
RecursorStrategy agentdns.RecursorStrategy
RecursorStrategy structs.RecursorStrategy
RecursorTimeout time.Duration
Recursors []string
SegmentName string
@ -264,6 +264,28 @@ func (d *DNSServer) ListenAndServe(network, addr string, notif func()) error {
return d.Server.ListenAndServe()
}
func (d *DNSServer) Shutdown() {
if d.Server != nil {
d.logger.Info("Stopping server",
"protocol", "DNS",
"address", d.Server.Addr,
"network", d.Server.Net,
)
err := d.Server.Shutdown()
if err != nil {
d.logger.Error("Error stopping DNS server", "error", err)
}
}
}
// GetAddr is a function to return the server address if is not nil.
func (d *DNSServer) GetAddr() string {
if d.Server != nil {
return d.Server.Addr
}
return ""
}
// toggleRecursorHandlerFromConfig enables or disables the recursor handler based on config idempotently
func (d *DNSServer) toggleRecursorHandlerFromConfig(cfg *dnsConfig) {
shouldEnable := len(cfg.Recursors) > 0
@ -613,7 +635,7 @@ func (d *DNSServer) nameservers(questionName string, cfg *dnsConfig, maxRecursio
for _, o := range out.Nodes {
name, dc := o.Node.Node, o.Node.Datacenter
if agentdns.InvalidNameRe.MatchString(name) {
if libdns.InvalidNameRe.MatchString(name) {
d.logger.Warn("Skipping invalid node for NS records", "node", name)
continue
}

148
agent/dns/router.go Normal file
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@ -0,0 +1,148 @@
// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package dns
import (
"fmt"
"net"
"sync/atomic"
"time"
"github.com/armon/go-radix"
"github.com/hashicorp/go-hclog"
"github.com/miekg/dns"
"github.com/hashicorp/consul/agent/config"
"github.com/hashicorp/consul/agent/discovery"
"github.com/hashicorp/consul/agent/structs"
)
// TODO (v2-dns): metrics
// RouterDynamicConfig is the dynamic configuration that can be hot-reloaded
type RouterDynamicConfig struct {
ARecordLimit int
DisableCompression bool
EnableDefaultFailover bool // TODO (v2-dns): plumbing required for this new V2 setting. This is the agent configured default
EnableTruncate bool
NodeMetaTXT bool
NodeTTL time.Duration
Recursors []string
RecursorTimeout time.Duration
RecursorStrategy structs.RecursorStrategy
SOAConfig SOAConfig
// TTLRadix sets service TTLs by prefix, eg: "database-*"
TTLRadix *radix.Tree
// TTLStrict sets TTLs to service by full name match. It Has higher priority than TTLRadix
TTLStrict map[string]time.Duration
UDPAnswerLimit int
}
type SOAConfig struct {
Refresh uint32 // 3600 by default
Retry uint32 // 600
Expire uint32 // 86400
Minttl uint32 // 0
}
// DiscoveryQueryProcessor is an interface that can be used by any consumer requesting Service Discovery results.
// This could be attached to a gRPC endpoint in the future in addition to DNS.
// Making this an interface means testing the router with a mock is trivial.
type DiscoveryQueryProcessor interface {
QueryByName(*discovery.Query, discovery.Context) ([]*discovery.Result, error)
QueryByIP(net.IP, discovery.Context) ([]*discovery.Result, error)
}
// Router replaces miekg/dns.ServeMux with a simpler router that only checks for the 2-3 valid domains
// that Consul supports and forwards to a single DiscoveryQueryProcessor handler. If there is no match, it will recurse.
type Router struct {
processor DiscoveryQueryProcessor
domain string
altDomain string
logger hclog.Logger
tokenFunc func() string
defaultNamespace string
defaultPartition string
// TODO (v2-dns): default locality for request context?
// dynamicConfig stores the config as an atomic value (for hot-reloading).
// It is always of type *RouterDynamicConfig
dynamicConfig atomic.Value
}
var _ = dns.Handler(&Router{})
func NewRouter(cfg Config) (*Router, error) {
router := &Router{
// TODO (v2-dns): implement stub
}
if err := router.ReloadConfig(cfg.AgentConfig); err != nil {
return nil, err
}
return router, nil
}
// HandleRequest is used to process and individual DNS request. It returns a message in success or fail cases.
func (r Router) HandleRequest(req *dns.Msg, reqCtx discovery.Context, remoteAddress net.Addr) *dns.Msg {
cfg := r.dynamicConfig.Load().(*RouterDynamicConfig)
// TODO (v2-dns): implement HandleRequest. This is just temporary
return createServerFailureResponse(req, cfg, false)
// Parse fields of the message
// Route the request to the appropriate destination
// 1. r.processor.QueryByName
// 2. r.processor.QueryByIP
// 3. recurse
// Serialize the output
}
// ServeDNS implements the miekg/dns.Handler interface
func (r Router) ServeDNS(w dns.ResponseWriter, req *dns.Msg) {
reqCtx := r.defaultAgentDNSRequestContext()
out := r.HandleRequest(req, reqCtx, w.RemoteAddr())
w.WriteMsg(out)
}
// GetDynamicRouterConfig takes global config and creates the config used by DNS server
func GetDynamicRouterConfig(conf *config.RuntimeConfig) (*RouterDynamicConfig, error) {
cfg := &RouterDynamicConfig{
// TODO (v2-dns)
}
return cfg, nil
}
// ReloadConfig hot-reloads the router config with new parameters
func (r Router) ReloadConfig(newCfg *config.RuntimeConfig) error {
cfg, err := GetDynamicRouterConfig(newCfg)
if err != nil {
return fmt.Errorf("error loading DNS config: %w", err)
}
r.dynamicConfig.Store(cfg)
return nil
}
func (r Router) defaultAgentDNSRequestContext() discovery.Context {
return discovery.Context{
// TODO (v2-dns): implement stub
}
}
func createServerFailureResponse(req *dns.Msg, cfg *RouterDynamicConfig, recursionAvailable bool) *dns.Msg {
// Return a SERVFAIL message
m := &dns.Msg{}
m.SetReply(req)
m.Compress = !cfg.DisableCompression
m.SetRcode(req, dns.RcodeServerFailure)
m.RecursionAvailable = recursionAvailable
return m
}

6
agent/dns/router_test.go Normal file
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@ -0,0 +1,6 @@
// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package dns
// TODO (v2-dns)

86
agent/dns/server.go Normal file
View File

@ -0,0 +1,86 @@
// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package dns
import (
"fmt"
"github.com/hashicorp/go-hclog"
"github.com/miekg/dns"
"github.com/hashicorp/consul/acl"
"github.com/hashicorp/consul/agent/config"
"github.com/hashicorp/consul/logging"
)
// Server is used to expose service discovery queries using a DNS interface.
// It implements the agent.dnsServer interface.
type Server struct {
*dns.Server // Used for setting up listeners
Router *Router // Used to routes and parse DNS requests
logger hclog.Logger
}
// Config represent all the DNS configuration required to construct a DNS server.
type Config struct {
AgentConfig *config.RuntimeConfig
EntMeta *acl.EnterpriseMeta
Logger hclog.Logger
Processor DiscoveryQueryProcessor
TokenFunc func() string
}
func NewServer(config Config) (*Server, error) {
router, err := NewRouter(config)
if err != nil {
return nil, fmt.Errorf("error creating DNS router: %w", err)
}
srv := &Server{
Router: router,
logger: config.Logger.Named(logging.DNS),
}
return srv, nil
}
func (d *Server) ListenAndServe(network, addr string, notif func()) error {
d.Server = &dns.Server{
Addr: addr,
Net: network,
Handler: d.Router,
NotifyStartedFunc: notif,
}
if network == "udp" {
d.UDPSize = 65535
}
return d.Server.ListenAndServe()
}
// ReloadConfig hot-reloads the server config with new parameters under config.RuntimeConfig.DNS*
func (d *Server) ReloadConfig(newCfg *config.RuntimeConfig) error {
return d.Router.ReloadConfig(newCfg)
}
func (d *Server) Shutdown() {
if d.Server != nil {
d.logger.Info("Stopping server",
"protocol", "DNS",
"address", d.Server.Addr,
"network", d.Server.Net,
)
err := d.Server.Shutdown()
if err != nil {
d.logger.Error("Error stopping DNS server", "error", err)
}
}
}
// GetAddr is a function to return the server address if is not nil.
func (d *Server) GetAddr() string {
if d.Server != nil {
return d.Server.Addr
}
return ""
}

6
agent/dns/server_test.go Normal file
View File

@ -0,0 +1,6 @@
// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package dns
// TODO (v2-dns): add at least one test to listen and serve with a dummy router.

View File

@ -31,8 +31,8 @@ import (
"github.com/hashicorp/consul/agent/config"
"github.com/hashicorp/consul/agent/consul"
agentdns "github.com/hashicorp/consul/agent/dns"
"github.com/hashicorp/consul/agent/structs"
libdns "github.com/hashicorp/consul/internal/dnsutil"
"github.com/hashicorp/consul/lib"
"github.com/hashicorp/consul/sdk/testutil/retry"
"github.com/hashicorp/consul/testrpc"
@ -3550,7 +3550,7 @@ func TestDNSInvalidRegex(t *testing.T) {
}
for _, test := range tests {
t.Run(test.desc, func(t *testing.T) {
if got, want := agentdns.InvalidNameRe.MatchString(test.in), test.invalid; got != want {
if got, want := libdns.InvalidNameRe.MatchString(test.in), test.invalid; got != want {
t.Fatalf("Expected %v to return %v", test.in, want)
}
})
@ -3558,16 +3558,13 @@ func TestDNSInvalidRegex(t *testing.T) {
}
}
func TestDNS_ConfigReload(t *testing.T) {
func TestDNS_V1ConfigReload(t *testing.T) {
if testing.Short() {
t.Skip("too slow for testing.Short")
}
t.Parallel()
for name, experimentsHCL := range versionHCL {
t.Run(name, func(t *testing.T) {
a := NewTestAgent(t, `
recursors = ["8.8.8.8:53"]
dns_config = {
@ -3592,14 +3589,17 @@ func TestDNS_ConfigReload(t *testing.T) {
min_ttl = 4
}
}
`+experimentsHCL)
`)
defer a.Shutdown()
testrpc.WaitForLeader(t, a.RPC, "dc1")
for _, s := range a.dnsServers {
cfg := s.config.Load().(*dnsConfig)
server, ok := s.(*DNSServer)
require.True(t, ok)
cfg := server.config.Load().(*dnsConfig)
require.Equal(t, []string{"8.8.8.8:53"}, cfg.Recursors)
require.Equal(t, agentdns.RecursorStrategy("sequential"), cfg.RecursorStrategy)
require.Equal(t, structs.RecursorStrategy("sequential"), cfg.RecursorStrategy)
require.False(t, cfg.AllowStale)
require.Equal(t, 20*time.Second, cfg.MaxStale)
require.Equal(t, 10*time.Second, cfg.NodeTTL)
@ -3644,9 +3644,12 @@ func TestDNS_ConfigReload(t *testing.T) {
require.NoError(t, err)
for _, s := range a.dnsServers {
cfg := s.config.Load().(*dnsConfig)
server, ok := s.(*DNSServer)
require.True(t, ok)
cfg := server.config.Load().(*dnsConfig)
require.Equal(t, []string{"1.1.1.1:53"}, cfg.Recursors)
require.Equal(t, agentdns.RecursorStrategy("random"), cfg.RecursorStrategy)
require.Equal(t, structs.RecursorStrategy("random"), cfg.RecursorStrategy)
require.True(t, cfg.AllowStale)
require.Equal(t, 21*time.Second, cfg.MaxStale)
require.Equal(t, 11*time.Second, cfg.NodeTTL)
@ -3669,10 +3672,11 @@ func TestDNS_ConfigReload(t *testing.T) {
require.Equal(t, uint32(30), cfg.SOAConfig.Expire)
require.Equal(t, uint32(40), cfg.SOAConfig.Minttl)
}
})
}
}
// TODO (v2-dns) add a test for checking the V2 DNS Server reloads the config
func TestDNS_ReloadConfig_DuringQuery(t *testing.T) {
if testing.Short() {
t.Skip("too slow for testing.Short")

View File

@ -1,19 +1,9 @@
// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package dns
package structs
import (
"math/rand"
"regexp"
)
// MaxLabelLength is the maximum length for a name that can be used in DNS.
const MaxLabelLength = 63
// InvalidNameRe is a regex that matches characters which can not be included in
// a DNS name.
var InvalidNameRe = regexp.MustCompile(`[^A-Za-z0-9\\-]+`)
import "math/rand"
type RecursorStrategy string

View File

@ -1,7 +1,7 @@
// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package dns
package structs
import (
"testing"

View File

@ -74,7 +74,7 @@ type TestAgent struct {
// dns is a reference to the first started DNS endpoint.
// It is valid after Start().
dns *DNSServer
dns dnsServer
// srv is an HTTPHandlers that may be used to test http endpoints.
srv *HTTPHandlers
@ -362,7 +362,7 @@ func (a *TestAgent) DNSAddr() string {
if a.dns == nil {
return ""
}
return a.dns.Addr
return a.dns.GetAddr()
}
func (a *TestAgent) HTTPAddr() string {

View File

@ -1,13 +1,20 @@
// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package dns
package dnsutil
import (
"errors"
"regexp"
)
// MaxLabelLength is the maximum length for a name that can be used in DNS.
const MaxLabelLength = 63
// InvalidNameRe is a regex that matches characters which can not be included in
// a DNS name.
var InvalidNameRe = regexp.MustCompile(`[^A-Za-z0-9\\-]+`)
// matches valid DNS labels according to RFC 1123, should be at most 63
// characters according to the RFC
var validLabel = regexp.MustCompile(`^[a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?$`)

View File

@ -1,12 +1,11 @@
// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package dns_test
package dnsutil
import (
"testing"
"github.com/hashicorp/consul/agent/dns"
"github.com/stretchr/testify/require"
)
@ -29,23 +28,23 @@ func TestValidLabel(t *testing.T) {
t.Run("*", func(t *testing.T) {
t.Run("IsValidLabel", func(t *testing.T) {
require.False(t, dns.IsValidLabel("*"))
require.False(t, IsValidLabel("*"))
})
t.Run("ValidateLabel", func(t *testing.T) {
require.Error(t, dns.ValidateLabel("*"))
require.Error(t, ValidateLabel("*"))
})
})
for name, expect := range cases {
t.Run(name, func(t *testing.T) {
t.Run("IsValidDNSLabel", func(t *testing.T) {
require.Equal(t, expect, dns.IsValidLabel(name))
require.Equal(t, expect, IsValidLabel(name))
})
t.Run("ValidateLabel", func(t *testing.T) {
if expect {
require.NoError(t, dns.ValidateLabel(name))
require.NoError(t, ValidateLabel(name))
} else {
require.Error(t, dns.ValidateLabel(name))
require.Error(t, ValidateLabel(name))
}
})
})

View File

@ -9,7 +9,7 @@ import (
mapset "github.com/deckarep/golang-set/v2"
"github.com/hashicorp/consul/agent/dns"
"github.com/hashicorp/consul/internal/dnsutil"
"github.com/hashicorp/consul/proto-public/pbresource"
)
@ -27,7 +27,7 @@ const FinalizerKey = "finalizers"
// ValidateName returns an error a name is not a valid resource name.
// The error will contain reference to what constitutes a valid resource name.
func ValidateName(name string) error {
if !dns.IsValidLabel(name) || strings.ToLower(name) != name || len(name) > MaxNameLength {
if !dnsutil.IsValidLabel(name) || strings.ToLower(name) != name || len(name) > MaxNameLength {
return fmt.Errorf("a resource name must consist of lower case alphanumeric characters or '-', must start and end with an alphanumeric character and be less than %d characters, got: %q", MaxNameLength+1, name)
}
return nil

View File

@ -9,7 +9,7 @@ import (
"google.golang.org/protobuf/types/known/anypb"
"github.com/hashicorp/consul/agent/dns"
"github.com/hashicorp/consul/internal/dnsutil"
"github.com/hashicorp/consul/internal/resource"
"github.com/hashicorp/consul/proto-public/pbresource"
pbtenancy "github.com/hashicorp/consul/proto-public/pbtenancy/v2beta1"
@ -55,7 +55,7 @@ func ValidateNamespace(res *pbresource.Resource) error {
return errInvalidName
}
if !dns.IsValidLabel(res.Id.Name) {
if !dnsutil.IsValidLabel(res.Id.Name) {
return fmt.Errorf("namespace name %q is not a valid DNS hostname", res.Id.Name)
}