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Add Support for Consul Connect

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Co-authored-by: Florian Apolloner <apollo13@users.noreply.github.com>
This commit is contained in:
Mohammad Gufran 2021-07-15 17:32:11 +05:30 • committed by GitHub
parent 3a180e2afc
commit 7e43e5615e
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GPG key ID: 4AEE18F83AFDEB23
36 changed files with 2118 additions and 644 deletions
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335
pkg/provider/consulcatalog/consul_catalog.go
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@ -4,12 +4,14 @@ import (
"context"
"fmt"
"strconv"
"strings"
"text/template"
"time"
"github.com/cenkalti/backoff/v4"
"github.com/hashicorp/consul/api"
"github.com/hashicorp/consul/api/watch"
"github.com/hashicorp/go-hclog"
"github.com/sirupsen/logrus"
ptypes "github.com/traefik/paerser/types"
"github.com/traefik/traefik/v2/pkg/config/dynamic"
"github.com/traefik/traefik/v2/pkg/job"
@ -26,15 +28,17 @@ const DefaultTemplateRule = "Host(`{{ normalize .Name }}`)"
var _ provider.Provider = (*Provider)(nil)
type itemData struct {
ID string
Node string
Name string
Address string
Port string
Status string
Labels map[string]string
Tags []string
ExtraConf configuration
ID string
Node string
Datacenter string
Name string
Namespace string
Address string
Port string
Status string
Labels map[string]string
Tags []string
ExtraConf configuration
}
// Provider holds configurations of the provider.
@ -48,9 +52,13 @@ type Provider struct {
Cache bool `description:"Use local agent caching for catalog reads." json:"cache,omitempty" toml:"cache,omitempty" yaml:"cache,omitempty" export:"true"`
ExposedByDefault bool `description:"Expose containers by default." json:"exposedByDefault,omitempty" toml:"exposedByDefault,omitempty" yaml:"exposedByDefault,omitempty" export:"true"`
DefaultRule string `description:"Default rule." json:"defaultRule,omitempty" toml:"defaultRule,omitempty" yaml:"defaultRule,omitempty"`
ConnectAware bool `description:"Enable Consul Connect support." json:"connectAware,omitempty" toml:"connectAware,omitempty" yaml:"connectAware,omitempty" export:"true"`
ConnectByDefault bool `description:"Consider every service as Connect capable by default." json:"connectByDefault,omitempty" toml:"connectByDefault,omitempty" yaml:"connectByDefault,omitempty" export:"true"`
ServiceName string `description:"Name of the Traefik service in Consul Catalog (needs to be registered via the orchestrator or manually)." json:"serviceName,omitempty" toml:"serviceName,omitempty" yaml:"serviceName,omitempty" export:"true"`
client *api.Client
defaultRuleTpl *template.Template
certChan chan *connectCert
}
// EndpointConfig holds configurations of the endpoint.
@ -64,11 +72,6 @@ type EndpointConfig struct {
EndpointWaitTime ptypes.Duration `description:"WaitTime limits how long a Watch will block. If not provided, the agent default values will be used" json:"endpointWaitTime,omitempty" toml:"endpointWaitTime,omitempty" yaml:"endpointWaitTime,omitempty" export:"true"`
}
// SetDefaults sets the default values.
func (c *EndpointConfig) SetDefaults() {
c.Address = "127.0.0.1:8500"
}
// EndpointHTTPAuthConfig holds configurations of the authentication.
type EndpointHTTPAuthConfig struct {
Username string `description:"Basic Auth username" json:"username,omitempty" toml:"username,omitempty" yaml:"username,omitempty"`
@ -78,12 +81,13 @@ type EndpointHTTPAuthConfig struct {
// SetDefaults sets the default values.
func (p *Provider) SetDefaults() {
endpoint := &EndpointConfig{}
endpoint.SetDefaults()
p.Endpoint = endpoint
p.RefreshInterval = ptypes.Duration(15 * time.Second)
p.Prefix = "traefik"
p.ExposedByDefault = true
p.DefaultRule = DefaultTemplateRule
p.ServiceName = "traefik"
p.certChan = make(chan *connectCert)
}
// Init the provider.
@ -99,6 +103,24 @@ func (p *Provider) Init() error {
// Provide allows the consul catalog provider to provide configurations to traefik using the given configuration channel.
func (p *Provider) Provide(configurationChan chan<- dynamic.Message, pool *safe.Pool) error {
var err error
p.client, err = createClient(p.Endpoint)
if err != nil {
return fmt.Errorf("unable to create consul client: %w", err)
}
if p.ConnectAware {
leafWatcher, rootWatcher, err := p.createConnectTLSWatchers()
if err != nil {
return fmt.Errorf("unable to create consul watch plans: %w", err)
}
pool.GoCtx(func(routineCtx context.Context) {
p.watchConnectTLS(routineCtx, leafWatcher, rootWatcher)
})
}
var certInfo *connectCert
pool.GoCtx(func(routineCtx context.Context) {
ctxLog := log.With(routineCtx, log.Str(log.ProviderName, "consulcatalog"))
logger := log.FromContext(ctxLog)
@ -106,13 +128,25 @@ func (p *Provider) Provide(configurationChan chan<- dynamic.Message, pool *safe.
operation := func() error {
var err error
p.client, err = createClient(p.Endpoint)
if err != nil {
return fmt.Errorf("unable to create consul client: %w", err)
// If we are running in connect aware mode then we need to
// make sure that we obtain the certificates before starting
// the service watcher, otherwise a connect enabled service
// that gets resolved before the certificates are available
// will cause an error condition.
if p.ConnectAware && !certInfo.isReady() {
logger.Infof("Waiting for Connect certificate before building first configuration")
select {
case <-routineCtx.Done():
return nil
case certInfo = <-p.certChan:
if certInfo.err != nil {
return backoff.Permanent(err)
}
}
}
// get configuration at the provider's startup.
err = p.loadConfiguration(routineCtx, configurationChan)
err = p.loadConfiguration(ctxLog, certInfo, configurationChan)
if err != nil {
return fmt.Errorf("failed to get consul catalog data: %w", err)
}
@ -123,14 +157,17 @@ func (p *Provider) Provide(configurationChan chan<- dynamic.Message, pool *safe.
for {
select {
case <-ticker.C:
err = p.loadConfiguration(routineCtx, configurationChan)
if err != nil {
return fmt.Errorf("failed to refresh consul catalog data: %w", err)
}
case <-routineCtx.Done():
return nil
case <-ticker.C:
case certInfo = <-p.certChan:
if certInfo.err != nil {
return backoff.Permanent(err)
}
}
err = p.loadConfiguration(ctxLog, certInfo, configurationChan)
if err != nil {
return fmt.Errorf("failed to refresh consul catalog data: %w", err)
}
}
}
@ -148,7 +185,7 @@ func (p *Provider) Provide(configurationChan chan<- dynamic.Message, pool *safe.
return nil
}
func (p *Provider) loadConfiguration(ctx context.Context, configurationChan chan<- dynamic.Message) error {
func (p *Provider) loadConfiguration(ctx context.Context, certInfo *connectCert, configurationChan chan<- dynamic.Message) error {
data, err := p.getConsulServicesData(ctx)
if err != nil {
return err
@ -156,21 +193,53 @@ func (p *Provider) loadConfiguration(ctx context.Context, configurationChan chan
configurationChan <- dynamic.Message{
ProviderName: "consulcatalog",
Configuration: p.buildConfiguration(ctx, data),
Configuration: p.buildConfiguration(ctx, data, certInfo),
}
return nil
}
func (p *Provider) getConsulServicesData(ctx context.Context) ([]itemData, error) {
consulServiceNames, err := p.fetchServices(ctx)
// The query option "Filter" is not supported by /catalog/services.
// https://www.consul.io/api/catalog.html#list-services
opts := &api.QueryOptions{AllowStale: p.Stale, RequireConsistent: p.RequireConsistent, UseCache: p.Cache}
serviceNames, _, err := p.client.Catalog().Services(opts)
if err != nil {
return nil, err
}
var data []itemData
for _, name := range consulServiceNames {
consulServices, statuses, err := p.fetchService(ctx, name)
for name, tags := range serviceNames {
logger := log.FromContext(log.With(ctx, log.Str("serviceName", name)))
svcCfg, err := p.getConfiguration(tagsToNeutralLabels(tags, p.Prefix))
if err != nil {
logger.Errorf("Skip service: %v", err)
continue
}
if !svcCfg.Enable {
logger.Debug("Filtering disabled item")
continue
}
matches, err := constraints.MatchTags(tags, p.Constraints)
if err != nil {
logger.Errorf("Error matching constraint expressions: %v", err)
continue
}
if !matches {
logger.Debugf("Container pruned by constraint expressions: %q", p.Constraints)
continue
}
if !p.ConnectAware && svcCfg.ConsulCatalog.Connect {
logger.Debugf("Filtering out Connect aware item, Connect support is not enabled")
continue
}
consulServices, statuses, err := p.fetchService(ctx, name, svcCfg.ConsulCatalog.Connect)
if err != nil {
return nil, err
}
@ -181,23 +250,30 @@ func (p *Provider) getConsulServicesData(ctx context.Context) ([]itemData, error
address = consulService.Address
}
namespace := consulService.Namespace
if namespace == "" {
namespace = "default"
}
status, exists := statuses[consulService.ID+consulService.ServiceID]
if !exists {
status = api.HealthAny
}
item := itemData{
ID: consulService.ServiceID,
Node: consulService.Node,
Name: consulService.ServiceName,
Address: address,
Port: strconv.Itoa(consulService.ServicePort),
Labels: tagsToNeutralLabels(consulService.ServiceTags, p.Prefix),
Tags: consulService.ServiceTags,
Status: status,
ID: consulService.ServiceID,
Node: consulService.Node,
Datacenter: consulService.Datacenter,
Namespace: namespace,
Name: name,
Address: address,
Port: strconv.Itoa(consulService.ServicePort),
Labels: tagsToNeutralLabels(consulService.ServiceTags, p.Prefix),
Tags: consulService.ServiceTags,
Status: status,
}
extraConf, err := p.getConfiguration(item)
extraConf, err := p.getConfiguration(item.Labels)
if err != nil {
log.FromContext(ctx).Errorf("Skip item %s: %v", item.Name, err)
continue
@ -207,10 +283,11 @@ func (p *Provider) getConsulServicesData(ctx context.Context) ([]itemData, error
data = append(data, item)
}
}
return data, nil
}
func (p *Provider) fetchService(ctx context.Context, name string) ([]*api.CatalogService, map[string]string, error) {
func (p *Provider) fetchService(ctx context.Context, name string, connectEnabled bool) ([]*api.CatalogService, map[string]string, error) {
var tagFilter string
if !p.ExposedByDefault {
tagFilter = p.Prefix + ".enable=true"
@ -219,12 +296,19 @@ func (p *Provider) fetchService(ctx context.Context, name string) ([]*api.Catalo
opts := &api.QueryOptions{AllowStale: p.Stale, RequireConsistent: p.RequireConsistent, UseCache: p.Cache}
opts = opts.WithContext(ctx)
consulServices, _, err := p.client.Catalog().Service(name, tagFilter, opts)
catalogFunc := p.client.Catalog().Service
healthFunc := p.client.Health().Service
if connectEnabled {
catalogFunc = p.client.Catalog().Connect
healthFunc = p.client.Health().Connect
}
consulServices, _, err := catalogFunc(name, tagFilter, opts)
if err != nil {
return nil, nil, err
}
healthServices, _, err := p.client.Health().Service(name, tagFilter, false, opts)
healthServices, _, err := healthFunc(name, tagFilter, false, opts)
if err != nil {
return nil, nil, err
}
@ -243,55 +327,132 @@ func (p *Provider) fetchService(ctx context.Context, name string) ([]*api.Catalo
return consulServices, statuses, err
}
func (p *Provider) fetchServices(ctx context.Context) ([]string, error) {
// The query option "Filter" is not supported by /catalog/services.
// https://www.consul.io/api/catalog.html#list-services
opts := &api.QueryOptions{AllowStale: p.Stale, RequireConsistent: p.RequireConsistent, UseCache: p.Cache}
serviceNames, _, err := p.client.Catalog().Services(opts)
if err != nil {
return nil, err
func rootsWatchHandler(ctx context.Context, dest chan<- []string) func(watch.BlockingParamVal, interface{}) {
return func(_ watch.BlockingParamVal, raw interface{}) {
if raw == nil {
log.FromContext(ctx).Errorf("Root certificate watcher called with nil")
return
}
v, ok := raw.(*api.CARootList)
if !ok || v == nil {
log.FromContext(ctx).Errorf("Invalid result for root certificate watcher")
return
}
roots := make([]string, 0, len(v.Roots))
for _, root := range v.Roots {
roots = append(roots, root.RootCertPEM)
}
dest <- roots
}
// The keys are the service names, and the array values provide all known tags for a given service.
// https://www.consul.io/api/catalog.html#list-services
var filtered []string
for svcName, tags := range serviceNames {
logger := log.FromContext(log.With(ctx, log.Str("serviceName", svcName)))
if !p.ExposedByDefault && !contains(tags, p.Prefix+".enable=true") {
logger.Debug("Filtering disabled item")
continue
}
if contains(tags, p.Prefix+".enable=false") {
logger.Debug("Filtering disabled item")
continue
}
matches, err := constraints.MatchTags(tags, p.Constraints)
if err != nil {
logger.Errorf("Error matching constraints expression: %v", err)
continue
}
if !matches {
logger.Debugf("Container pruned by constraint expression: %q", p.Constraints)
continue
}
filtered = append(filtered, svcName)
}
return filtered, err
}
func contains(values []string, val string) bool {
for _, value := range values {
if strings.EqualFold(value, val) {
return true
type keyPair struct {
cert string
key string
}
func leafWatcherHandler(ctx context.Context, dest chan<- keyPair) func(watch.BlockingParamVal, interface{}) {
return func(_ watch.BlockingParamVal, raw interface{}) {
if raw == nil {
log.FromContext(ctx).Errorf("Leaf certificate watcher called with nil")
return
}
v, ok := raw.(*api.LeafCert)
if !ok || v == nil {
log.FromContext(ctx).Errorf("Invalid result for leaf certificate watcher")
return
}
dest <- keyPair{
cert: v.CertPEM,
key: v.PrivateKeyPEM,
}
}
}
func (p *Provider) createConnectTLSWatchers() (*watch.Plan, *watch.Plan, error) {
leafWatcher, err := watch.Parse(map[string]interface{}{
"type": "connect_leaf",
"service": p.ServiceName,
})
if err != nil {
return nil, nil, fmt.Errorf("failed to create leaf cert watcher plan: %w", err)
}
rootWatcher, err := watch.Parse(map[string]interface{}{
"type": "connect_roots",
})
if err != nil {
return nil, nil, fmt.Errorf("failed to create root cert watcher plan: %w", err)
}
return leafWatcher, rootWatcher, nil
}
// watchConnectTLS watches for updates of the root certificate or the leaf
// certificate, and transmits them to the caller via p.certChan. Any error is also
// propagated up through p.certChan, in connectCert.err.
func (p *Provider) watchConnectTLS(ctx context.Context, leafWatcher *watch.Plan, rootWatcher *watch.Plan) {
ctxLog := log.With(ctx, log.Str(log.ProviderName, "consulcatalog"))
logger := log.FromContext(ctxLog)
leafChan := make(chan keyPair)
rootChan := make(chan []string)
leafWatcher.HybridHandler = leafWatcherHandler(ctx, leafChan)
rootWatcher.HybridHandler = rootsWatchHandler(ctx, rootChan)
logOpts := &hclog.LoggerOptions{
Name: "consulcatalog",
Level: hclog.LevelFromString(logrus.GetLevel().String()),
JSONFormat: true,
}
hclogger := hclog.New(logOpts)
go func() {
err := leafWatcher.RunWithClientAndHclog(p.client, hclogger)
if err != nil {
p.certChan <- &connectCert{err: err}
}
}()
go func() {
err := rootWatcher.RunWithClientAndHclog(p.client, hclogger)
if err != nil {
p.certChan <- &connectCert{err: err}
}
}()
var (
certInfo *connectCert
leafCerts keyPair
rootCerts []string
)
for {
select {
case <-ctx.Done():
leafWatcher.Stop()
rootWatcher.Stop()
return
case rootCerts = <-rootChan:
case leafCerts = <-leafChan:
}
newCertInfo := &connectCert{
root: rootCerts,
leaf: leafCerts,
}
if newCertInfo.isReady() && !newCertInfo.equals(certInfo) {
logger.Debugf("Updating connect certs for service %s", p.ServiceName)
certInfo = newCertInfo
p.certChan <- newCertInfo
}
}
return false
}
func createClient(cfg *EndpointConfig) (*api.Client, error) {