Support Nomad canary deployment

docs/content/routing/providers/consul-catalog.md

@@ -470,6 +470,20 @@ You can tell Traefik to consider (or not) the service as a Connect capable one b
 
 This option overrides the value of `connectByDefault`.
 
+#### `traefik.consulcatalog.canary`
+
+```yaml
+traefik.consulcatalog.canary=true
+```
+
+When ConsulCatalog, in the context of a Nomad orchestrator,
+is a provider (of service registration) for Traefik,
+one might have the need to distinguish within Traefik between a [Canary](https://learn.hashicorp.com/tutorials/nomad/job-blue-green-and-canary-deployments#deploy-with-canaries) instance of a service, or a production one.
+For example if one does not want them to be part of the same load-balancer.
+
+Therefore, this option, which is meant to be provided as one of the values of the `canary_tags` field in the Nomad [service stanza](https://www.nomadproject.io/docs/job-specification/service#canary_tags),
+allows Traefik to identify that the associated instance is a canary one.
+
 #### Port Lookup
 
 Traefik is capable of detecting the port to use, by following the default consul Catalog flow.

docs/content/routing/providers/nomad.md

@@ -460,6 +460,19 @@ You can tell Traefik to consider (or not) the service by setting `traefik.enable
 
 This option overrides the value of `exposedByDefault`.
 
+#### `traefik.nomad.canary`
+
+```yaml
+traefik.nomad.canary=true
+```
+
+When Nomad orchestrator is a provider (of service registration) for Traefik,
+one might have the need to distinguish within Traefik between a [Canary](https://learn.hashicorp.com/tutorials/nomad/job-blue-green-and-canary-deployments#deploy-with-canaries) instance of a service, or a production one.
+For example if one does not want them to be part of the same load-balancer.
+
+Therefore, this option, which is meant to be provided as one of the values of the `canary_tags` field in the Nomad [service stanza](https://www.nomadproject.io/docs/job-specification/service#canary_tags),
+allows Traefik to identify that the associated instance is a canary one.
+
 #### Port Lookup
 
 Traefik is capable of detecting the port to use, by following the default Nomad Service Discovery flow.

pkg/provider/consulcatalog/config.go

@@ -4,7 +4,10 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"hash/fnv"
 	"net"
+	"sort"
+	"strings"
 
 	"github.com/hashicorp/consul/api"
 	"github.com/traefik/traefik/v2/pkg/config/dynamic"
@@ -37,8 +40,7 @@ func (p *Provider) buildConfiguration(ctx context.Context, items []itemData, cer
 		if len(confFromLabel.TCP.Routers) > 0 || len(confFromLabel.TCP.Services) > 0 {
 			tcpOrUDP = true
 
-			err := p.buildTCPServiceConfiguration(ctxSvc, item, confFromLabel.TCP)
-			if err != nil {
+			if err := p.buildTCPServiceConfiguration(item, confFromLabel.TCP); err != nil {
 				logger.Error(err)
 				continue
 			}
@@ -49,8 +51,7 @@ func (p *Provider) buildConfiguration(ctx context.Context, items []itemData, cer
 		if len(confFromLabel.UDP.Routers) > 0 || len(confFromLabel.UDP.Services) > 0 {
 			tcpOrUDP = true
 
-			err := p.buildUDPServiceConfiguration(ctxSvc, item, confFromLabel.UDP)
-			if err != nil {
+			if err := p.buildUDPServiceConfiguration(item, confFromLabel.UDP); err != nil {
 				logger.Error(err)
 				continue
 			}
@@ -75,8 +76,7 @@ func (p *Provider) buildConfiguration(ctx context.Context, items []itemData, cer
 			}
 		}
 
-		err = p.buildServiceConfiguration(ctxSvc, item, confFromLabel.HTTP)
-		if err != nil {
+		if err = p.buildServiceConfiguration(item, confFromLabel.HTTP); err != nil {
 			logger.Error(err)
 			continue
 		}
@@ -89,7 +89,7 @@ func (p *Provider) buildConfiguration(ctx context.Context, items []itemData, cer
 			Labels: item.Labels,
 		}
 
-		provider.BuildRouterConfiguration(ctx, confFromLabel.HTTP, provider.Normalize(item.Name), p.defaultRuleTpl, model)
+		provider.BuildRouterConfiguration(ctx, confFromLabel.HTTP, getName(item), p.defaultRuleTpl, model)
 
 		configurations[svcName] = confFromLabel
 	}
@@ -128,75 +128,69 @@ func (p *Provider) keepContainer(ctx context.Context, item itemData) bool {
 	return true
 }
 
-func (p *Provider) buildTCPServiceConfiguration(ctx context.Context, item itemData, configuration *dynamic.TCPConfiguration) error {
+func (p *Provider) buildTCPServiceConfiguration(item itemData, configuration *dynamic.TCPConfiguration) error {
 	if len(configuration.Services) == 0 {
 		configuration.Services = make(map[string]*dynamic.TCPService)
 
 		lb := &dynamic.TCPServersLoadBalancer{}
 		lb.SetDefaults()
 
-		configuration.Services[provider.Normalize(item.Name)] = &dynamic.TCPService{
+		configuration.Services[getName(item)] = &dynamic.TCPService{
 			LoadBalancer: lb,
 		}
 	}
 
-	for name, service := range configuration.Services {
-		ctxSvc := log.With(ctx, log.Str(log.ServiceName, name))
-		err := p.addServerTCP(ctxSvc, item, service.LoadBalancer)
-		if err != nil {
+	for _, service := range configuration.Services {
+		if err := p.addServerTCP(item, service.LoadBalancer); err != nil {
 			return err
 		}
 	}
 
 	return nil
 }
 
-func (p *Provider) buildUDPServiceConfiguration(ctx context.Context, item itemData, configuration *dynamic.UDPConfiguration) error {
+func (p *Provider) buildUDPServiceConfiguration(item itemData, configuration *dynamic.UDPConfiguration) error {
 	if len(configuration.Services) == 0 {
 		configuration.Services = make(map[string]*dynamic.UDPService)
 
 		lb := &dynamic.UDPServersLoadBalancer{}
 
-		configuration.Services[provider.Normalize(item.Name)] = &dynamic.UDPService{
+		configuration.Services[getName(item)] = &dynamic.UDPService{
 			LoadBalancer: lb,
 		}
 	}
 
-	for name, service := range configuration.Services {
-		ctxSvc := log.With(ctx, log.Str(log.ServiceName, name))
-		err := p.addServerUDP(ctxSvc, item, service.LoadBalancer)
-		if err != nil {
+	for _, service := range configuration.Services {
+		if err := p.addServerUDP(item, service.LoadBalancer); err != nil {
 			return err
 		}
 	}
 
 	return nil
 }
 
-func (p *Provider) buildServiceConfiguration(ctx context.Context, item itemData, configuration *dynamic.HTTPConfiguration) error {
+func (p *Provider) buildServiceConfiguration(item itemData, configuration *dynamic.HTTPConfiguration) error {
 	if len(configuration.Services) == 0 {
 		configuration.Services = make(map[string]*dynamic.Service)
 
 		lb := &dynamic.ServersLoadBalancer{}
 		lb.SetDefaults()
 
-		configuration.Services[provider.Normalize(item.Name)] = &dynamic.Service{
+		configuration.Services[getName(item)] = &dynamic.Service{
 			LoadBalancer: lb,
 		}
 	}
 
-	for name, service := range configuration.Services {
-		ctxSvc := log.With(ctx, log.Str(log.ServiceName, name))
-		err := p.addServer(ctxSvc, item, service.LoadBalancer)
-		if err != nil {
+	for _, service := range configuration.Services {
+		if err := p.addServer(item, service.LoadBalancer); err != nil {
 			return err
 		}
 	}
 
 	return nil
 }
 
-func (p *Provider) addServerTCP(ctx context.Context, item itemData, loadBalancer *dynamic.TCPServersLoadBalancer) error {
+func (p *Provider) addServerTCP(item itemData, loadBalancer *dynamic.TCPServersLoadBalancer) error {
 	if loadBalancer == nil {
 		return errors.New("load-balancer is not defined")
 	}
@@ -227,7 +221,7 @@ func (p *Provider) addServerTCP(ctx context.Context, item itemData, loadBalancer
 	return nil
 }
 
-func (p *Provider) addServerUDP(ctx context.Context, item itemData, loadBalancer *dynamic.UDPServersLoadBalancer) error {
+func (p *Provider) addServerUDP(item itemData, loadBalancer *dynamic.UDPServersLoadBalancer) error {
 	if loadBalancer == nil {
 		return errors.New("load-balancer is not defined")
 	}
@@ -254,7 +248,7 @@ func (p *Provider) addServerUDP(ctx context.Context, item itemData, loadBalancer
 	return nil
 }
 
-func (p *Provider) addServer(ctx context.Context, item itemData, loadBalancer *dynamic.ServersLoadBalancer) error {
+func (p *Provider) addServer(item itemData, loadBalancer *dynamic.ServersLoadBalancer) error {
 	if loadBalancer == nil {
 		return errors.New("load-balancer is not defined")
 	}
@@ -300,3 +294,18 @@ func (p *Provider) addServer(ctx context.Context, item itemData, loadBalancer *d
 func itemServersTransportKey(item itemData) string {
 	return provider.Normalize("tls-" + item.Namespace + "-" + item.Datacenter + "-" + item.Name)
 }
+
+func getName(i itemData) string {
+	if !i.ExtraConf.ConsulCatalog.Canary {
+		return provider.Normalize(i.Name)
+	}
+
+	tags := make([]string, len(i.Tags))
+	copy(tags, i.Tags)
+
+	sort.Strings(tags)
+
+	hasher := fnv.New64()
+	hasher.Write([]byte(strings.Join(tags, "")))
+	return provider.Normalize(fmt.Sprintf("%s-%d", i.Name, hasher.Sum64()))
+}