consul/agent/envoyextensions/builtin/wasm/structs.go

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// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package wasm
import (
"fmt"
"net/url"
"time"
envoy_core_v3 "github.com/envoyproxy/go-control-plane/envoy/config/core/v3"
envoy_wasm_v3 "github.com/envoyproxy/go-control-plane/envoy/extensions/wasm/v3"
"github.com/hashicorp/consul/acl"
"github.com/hashicorp/consul/api"
"github.com/hashicorp/consul/envoyextensions/extensioncommon"
"github.com/hashicorp/go-multierror"
"github.com/mitchellh/mapstructure"
"google.golang.org/protobuf/types/known/anypb"
"google.golang.org/protobuf/types/known/durationpb"
"google.golang.org/protobuf/types/known/wrapperspb"
)
// wasmConfig defines the configuration for a Wasm Envoy extension.
type wasmConfig struct {
// Protocol is the type of Wasm filter to apply, "tcp" or "http".
Protocol string
// ProxyType identifies the type of Envoy proxy that this extension applies to.
// The extension will only be configured for proxies that match this type and
// will be ignored for all other proxy types.
ProxyType api.ServiceKind
// ListenerType identifies the listener type the filter will be applied to.
ListenerType string
// PluginConfig holds the configuration for the Wasm plugin.
PluginConfig pluginConfig
}
// pluginConfig defines a Wasm plugin configuration.
type pluginConfig struct {
// Name is the unique name for the filter in a VM. For use in identifying the
// filter if multiple filters are handled by the same VmID and RootID.
// Also used for logging/debugging.
Name string
// RootID is a unique ID for a set of filters in a VM which will share a
// RootContext and Contexts if applicable (e.g. a Wasm HttpFilter and a Wasm AccessLog).
// All filters with the same RootID and VmID will share Context(s).
RootID string
// VmConfig is the configuration for starting or finding the Wasm VM that the
// filter will run in.
VmConfig vmConfig
// Configuration holds the configuration that will be encoded as bytes and passed to
// the plugin on startup (proxy_on_configure).
Configuration string
// CapabilityRestrictionConfiguration controls the Wasm ABI capabilities available
// to the filter.
CapabilityRestrictionConfiguration capabilityRestrictionConfiguration
// failOpen controls the behavior when a runtime error occurs during filter
// processing.
//
// If set to false runtime errors will result in a failed request.
// For TCP filters, the connection will be closed. For HTTP filters a 503
// status is returned.
//
// If set to true, a runtime error will result in the filter being bypassed.
failOpen bool
}
// vmConfig defines a Wasm VM configuration.
type vmConfig struct {
// VmID is an ID which will be used along with a hash of the Wasm code to
// determine which VM will be used for the plugin. All plugins which use
// the same VmID and code will use the same VM. May be left blank.
VmID string
// Runtime is the Wasm runtime type, one of: v8, wasmtime, wamr, or wavm.
Runtime string
// Code references the Wasm code that will run in the filter.
Code dataSource
// Configuration holds the configuration that will be encoded as bytes and
// passed to the plugin during VM startup (proxy_on_vm_start).
Configuration string
// EnvironmentVariables specifies environment variables to be injected to
// this VM which will be available through WASIs environ_get and
// environ_get_sizes system calls.
EnvironmentVariables environmentVariables
}
// dataSource defines a local or remote location where Wasm code will be loaded from.
type dataSource struct {
// Local supports loading files from a local volume.
Local localDataSource
// Remote supports loading files from a remote server.
Remote remoteDataSource
}
// environmentVariables defines the environment variables that will be made available
// to the Wasm filter.
type environmentVariables struct {
// HostEnvKeys holds the keys of Envoys environment variables exposed to this VM.
// If a key exists in Envoys environment variables, then that key-value pair will
// be injected into the Wasm VM. If a key does not exist, it will be ignored.
HostEnvKeys []string
// KeyValues is a list of key-value pairs to be injected to this VM in the form of "KEY=VALUE".
KeyValues map[string]string
}
// localDataSource defines a file from a local file system.
type localDataSource struct {
// Filename is the path to the Wasm file on the local file system.
Filename string
}
// remoteDataSource defines a file from a remote file server.
type remoteDataSource struct {
// HttpURI
HttpURI httpURI
// SHA256 of the remote file. Used to validate the remote file.
SHA256 string
// RetryPolicy determines how retries are handled.
RetryPolicy retryPolicy
}
// httpURI defines a remote file using an HTTP URI.
type httpURI struct {
// Service is the upstream service the Wasm plugin will be fetched from.
Service api.CompoundServiceName
// URI is the location of the Wasm file on the upstream service.
URI string
// Timeout sets the maximum duration that a response can take.
Timeout string
timeout time.Duration
}
// retryPolicy defines how to handle retries when fetching remote files.
type retryPolicy struct {
// RetryBackOff holds parameters that control retry backoff strategy.
RetryBackOff retryBackoff
// NumRetries specifies the allowed number of retries.
NumRetries int
}
// retryBackoff holds parameters that control retry backoff strategy.
type retryBackoff struct {
// BaseInterval is the base interval to be used for the next back off
// computation. It should be greater than zero and less than or equal
// to MaxInterval.
BaseInterval string
// MaxInterval is the maximum interval between retries.
MaxInterval string
baseInterval time.Duration
maxInterval time.Duration
}
// capabilityRestrictionConfiguration controls Wasm capabilities available to modules.
type capabilityRestrictionConfiguration struct {
// AllowedCapabilities specifies the Wasm capabilities which will be allowed.
// Capabilities are mapped by name. The value which each capability maps to is
// currently ignored and should be left empty.
AllowedCapabilities map[string]any
}
// newWasmConfig creates a filterConfig from the given args.
// It starts with the default wasm configuration and merges in the config
// from the given args.
func newWasmConfig(args map[string]any) (*wasmConfig, error) {
cfg := &wasmConfig{}
if err := mapstructure.Decode(args, cfg); err != nil {
return cfg, err
}
cfg.normalize()
return cfg, nil
}
func (p *pluginConfig) asyncDataSource(rtCfg *extensioncommon.RuntimeConfig) (*envoy_core_v3.AsyncDataSource, error) {
// Local data source
if filename := p.VmConfig.Code.Local.Filename; filename != "" {
return &envoy_core_v3.AsyncDataSource{
Specifier: &envoy_core_v3.AsyncDataSource_Local{
Local: &envoy_core_v3.DataSource{
Specifier: &envoy_core_v3.DataSource_Filename{
Filename: filename,
},
},
},
}, nil
}
// Remote data source
// For a remote file, ensure there is an upstream cluster for the host specified in the URL.
// Envoy requires an explicit cluster in order to perform the DNS lookup required to actually
// fetch the data from the upstream source.
remote := &p.VmConfig.Code.Remote
clusterSNI := ""
for service, upstream := range rtCfg.Upstreams {
if service == remote.HttpURI.Service {
for sni := range upstream.SNIs {
clusterSNI = sni
break
}
}
}
if clusterSNI == "" {
return nil, fmt.Errorf("no upstream found for remote service %q", remote.HttpURI.Service.Name)
}
d := time.Second
if remote.HttpURI.timeout > 0 {
d = remote.HttpURI.timeout
}
timeout := &durationpb.Duration{Seconds: int64(d.Seconds())}
return &envoy_core_v3.AsyncDataSource{
Specifier: &envoy_core_v3.AsyncDataSource_Remote{
Remote: &envoy_core_v3.RemoteDataSource{
Sha256: remote.SHA256,
HttpUri: &envoy_core_v3.HttpUri{
Uri: remote.HttpURI.URI,
HttpUpstreamType: &envoy_core_v3.HttpUri_Cluster{
Cluster: clusterSNI,
},
Timeout: timeout,
},
RetryPolicy: p.retryPolicy(),
},
},
}, nil
}
func (p *pluginConfig) capConfig() *envoy_wasm_v3.CapabilityRestrictionConfig {
if len(p.CapabilityRestrictionConfiguration.AllowedCapabilities) == 0 {
return nil
}
allowedCaps := make(map[string]*envoy_wasm_v3.SanitizationConfig)
for key := range p.CapabilityRestrictionConfiguration.AllowedCapabilities {
allowedCaps[key] = &envoy_wasm_v3.SanitizationConfig{}
}
return &envoy_wasm_v3.CapabilityRestrictionConfig{
AllowedCapabilities: allowedCaps,
}
}
func (p *pluginConfig) envoyPluginConfig(rtCfg *extensioncommon.RuntimeConfig) (*envoy_wasm_v3.PluginConfig, error) {
var err error
var pluginCfgData, vmCfgData *anypb.Any
if p.Configuration != "" {
pluginCfgData, err = anypb.New(wrapperspb.String(p.Configuration))
if err != nil {
return nil, fmt.Errorf("failed to encode Wasm plugin configuration: %w", err)
}
}
if p.VmConfig.Configuration != "" {
vmCfgData, err = anypb.New(wrapperspb.String(p.VmConfig.Configuration))
if err != nil {
return nil, fmt.Errorf("failed to encode Wasm VM configuration: %w", err)
}
}
code, err := p.asyncDataSource(rtCfg)
if err != nil {
return nil, fmt.Errorf("failed to encode async data source configuration: %w", err)
}
var envVars *envoy_wasm_v3.EnvironmentVariables
if len(p.VmConfig.EnvironmentVariables.HostEnvKeys) > 0 ||
len(p.VmConfig.EnvironmentVariables.KeyValues) > 0 {
envVars = &envoy_wasm_v3.EnvironmentVariables{
HostEnvKeys: p.VmConfig.EnvironmentVariables.HostEnvKeys,
KeyValues: p.VmConfig.EnvironmentVariables.KeyValues,
}
}
return &envoy_wasm_v3.PluginConfig{
Name: p.Name,
RootId: p.RootID,
Vm: &envoy_wasm_v3.PluginConfig_VmConfig{
VmConfig: &envoy_wasm_v3.VmConfig{
VmId: p.VmConfig.VmID,
Runtime: fmt.Sprintf("envoy.wasm.runtime.%s", p.VmConfig.Runtime),
Code: code,
Configuration: vmCfgData,
EnvironmentVariables: envVars,
},
},
Configuration: pluginCfgData,
CapabilityRestrictionConfig: p.capConfig(),
FailOpen: p.failOpen,
}, nil
}
func (p *pluginConfig) retryPolicy() *envoy_core_v3.RetryPolicy {
remote := &p.VmConfig.Code.Remote
if remote.RetryPolicy.NumRetries <= 0 &&
remote.RetryPolicy.RetryBackOff.BaseInterval == "" &&
remote.RetryPolicy.RetryBackOff.MaxInterval == "" {
return nil
}
retryPolicy := &envoy_core_v3.RetryPolicy{}
if remote.RetryPolicy.NumRetries > 0 {
retryPolicy.NumRetries = wrapperspb.UInt32(uint32(remote.RetryPolicy.NumRetries))
}
var baseInterval, maxInterval *durationpb.Duration
if remote.RetryPolicy.RetryBackOff.baseInterval > 0 {
baseInterval = &durationpb.Duration{Seconds: int64(remote.RetryPolicy.RetryBackOff.baseInterval.Seconds())}
}
if remote.RetryPolicy.RetryBackOff.maxInterval > 0 {
maxInterval = &durationpb.Duration{Seconds: int64(remote.RetryPolicy.RetryBackOff.maxInterval.Seconds())}
}
if baseInterval != nil || maxInterval != nil {
retryPolicy.RetryBackOff = &envoy_core_v3.BackoffStrategy{
BaseInterval: baseInterval,
MaxInterval: maxInterval,
}
}
return retryPolicy
}
func (w *wasmConfig) normalize() {
if w.ProxyType == "" {
w.ProxyType = api.ServiceKindConnectProxy
}
if w.PluginConfig.VmConfig.Runtime == "" {
w.PluginConfig.VmConfig.Runtime = supportedRuntimes[0]
}
httpURI := &w.PluginConfig.VmConfig.Code.Remote.HttpURI
httpURI.Service.Namespace = acl.NamespaceOrDefault(httpURI.Service.Namespace)
httpURI.Service.Partition = acl.PartitionOrDefault(httpURI.Service.Partition)
if httpURI.timeout <= 0 {
httpURI.timeout = time.Second
}
}
// validate ensures the filterConfig is valid or it returns an error.
// This method must be called before using the configuration.
func (w *wasmConfig) validate() error {
var err, resultErr error
if w.Protocol != "tcp" && w.Protocol != "http" {
resultErr = multierror.Append(resultErr, fmt.Errorf(`unsupported Protocol %q, expected "tcp" or "http"`, w.Protocol))
}
if w.ProxyType != api.ServiceKindConnectProxy {
resultErr = multierror.Append(resultErr, fmt.Errorf("unsupported ProxyType %q, only %q is supported", w.ProxyType, api.ServiceKindConnectProxy))
}
if w.ListenerType != "inbound" && w.ListenerType != "outbound" {
resultErr = multierror.Append(resultErr, fmt.Errorf(`unsupported ListenerType %q, expected "inbound" or "outbound"`, w.ListenerType))
}
if err = validateRuntime(w.PluginConfig.VmConfig.Runtime); err != nil {
resultErr = multierror.Append(resultErr, err)
}
httpURI := &w.PluginConfig.VmConfig.Code.Remote.HttpURI
isLocal := w.PluginConfig.VmConfig.Code.Local.Filename != ""
isRemote := httpURI.Service.Name != "" || httpURI.URI != ""
if isLocal == isRemote {
resultErr = multierror.Append(resultErr, fmt.Errorf("VmConfig.Code must provide exactly one of Local or Remote data source"))
}
// If the data source is Local then validation is complete.
if isLocal {
return resultErr
}
// Validate the remote data source fields.
// Both Service and URI are required inputs for remote data sources.
// We could catch this above in the isRemote check; however, we do an explicit check
// here for UX to give the user extra feedback in case they only provide one or the other.
if httpURI.Service.Name == "" || httpURI.URI == "" {
resultErr = multierror.Append(resultErr, fmt.Errorf("both Service and URI are required for Remote data sources"))
}
if w.PluginConfig.VmConfig.Code.Remote.SHA256 == "" {
resultErr = multierror.Append(resultErr, fmt.Errorf("SHA256 checksum is required for Remote data sources"))
}
if _, err := url.Parse(httpURI.URI); err != nil {
resultErr = multierror.Append(resultErr, fmt.Errorf("invalid HttpURI.URI: %w", err))
}
if httpURI.Timeout != "" {
httpURI.timeout, err = time.ParseDuration(httpURI.Timeout)
if err != nil {
resultErr = multierror.Append(resultErr, fmt.Errorf("failed to parse HttpURI.Timeout %q as a duration: %w", httpURI.Timeout, err))
}
}
retryPolicy := &w.PluginConfig.VmConfig.Code.Remote.RetryPolicy
if retryPolicy.NumRetries < 0 {
resultErr = multierror.Append(resultErr, fmt.Errorf("RetryPolicy.NumRetries must be greater than or equal to 0"))
}
if retryPolicy.RetryBackOff.BaseInterval != "" {
retryPolicy.RetryBackOff.baseInterval, err = time.ParseDuration(retryPolicy.RetryBackOff.BaseInterval)
if err != nil {
resultErr = multierror.Append(resultErr, fmt.Errorf("failed to parse RetryBackOff.BaseInterval %q: %w", retryPolicy.RetryBackOff.BaseInterval, err))
}
}
if retryPolicy.RetryBackOff.MaxInterval != "" {
retryPolicy.RetryBackOff.maxInterval, err = time.ParseDuration(retryPolicy.RetryBackOff.MaxInterval)
if err != nil {
resultErr = multierror.Append(resultErr, fmt.Errorf("failed to parse RetryBackOff.MaxInterval %q: %w", retryPolicy.RetryBackOff.MaxInterval, err))
}
}
if retryPolicy.RetryBackOff.BaseInterval != "" && retryPolicy.RetryBackOff.baseInterval <= 0 {
resultErr = multierror.Append(resultErr, fmt.Errorf("RetryBackOff.BaseInterval %q must be greater than zero and less than or equal to RetryBackOff.MaxInterval %q",
retryPolicy.RetryBackOff.BaseInterval,
retryPolicy.RetryBackOff.MaxInterval),
)
}
if retryPolicy.RetryBackOff.MaxInterval != "" &&
retryPolicy.RetryBackOff.maxInterval < retryPolicy.RetryBackOff.baseInterval {
resultErr = multierror.Append(resultErr, fmt.Errorf("RetryBackOff.MaxInterval %q must be greater than or equal to RetryBackOff.BaseInterval %q",
retryPolicy.RetryBackOff.MaxInterval,
retryPolicy.RetryBackOff.BaseInterval),
)
}
return resultErr
}
func validateRuntime(s string) error {
for _, rt := range supportedRuntimes {
if s == rt {
return nil
}
}
return fmt.Errorf("unsupported runtime %q", s)
}