Support multiple namespaces in the Nomad Provider

.golangci.toml

@@ -178,6 +178,7 @@
     "SA1019: cfg.FeaturePolicy is deprecated",
     "SA1019: c.Providers.ConsulCatalog.Namespace is deprecated",
     "SA1019: c.Providers.Consul.Namespace is deprecated",
+    "SA1019: c.Providers.Nomad.Namespace is deprecated",
   ]
  [[issues.exclude-rules]]
     path = "(.+)_test.go"

docs/content/deprecation/features.md

@@ -7,6 +7,7 @@ This page is maintained and updated periodically to reflect our roadmap and any
 | [Pilot](#pilot)                                             | 2.7        | 2.8            | 2.9     |
 | [Consul Enterprise Namespace](#consul-enterprise-namespace) | 2.8        | N/A            | 3.0     |
 | [TLS 1.0 and 1.1 Support](#tls-10-and-11)                   | N/A        | 2.8            | N/A     |
+| [Nomad Namespace](#nomad-namespace)                         | 2.10       | N/A            | 3.0     |
 
 ## Impact
 
@@ -26,3 +27,8 @@ please use the `namespaces` options instead.
 ### TLS 1.0 and 1.1
 
 Starting on 2.8 the default TLS options will use the minimum version of TLS 1.2. Of course, it can still be overridden with custom configuration.  
+
+### Nomad Namespace
+
+Starting on 2.10 the `namespace` option of the Nomad provider is deprecated,
+please use the `namespaces` options instead.  

docs/content/migration/v2.md

@@ -490,3 +490,9 @@ In `v2.8.2`, Traefik now reject certificates signed with the SHA-1 hash function
 ### Traefik Pilot
 
 In `v2.9`, Traefik Pilot support has been removed.
+
+## v2.10
+
+### Nomad Namespace
+
+In `v2.10`, the `namespace` option of the Nomad provider is deprecated, please use the `namespaces` options instead.

docs/content/providers/nomad.md

@@ -442,10 +442,16 @@ For additional information, refer to [Restrict the Scope of Service Discovery](.
 
 ### `namespace`
 
+??? warning "Deprecated in favor of the [`namespaces`](#namespaces) option."
+
     _Optional, Default=""_
 
     The `namespace` option defines the namespace in which the Nomad services will be discovered.
     
+    !!! warning
+    
+        One should only define either the `namespaces` option or the `namespace` option.
+
     ```yaml tab="File (YAML)"
     providers:
       nomad:
@@ -463,3 +469,38 @@ providers:
     --providers.nomad.namespace=production
     # ...
     ```
+
+### `namespaces`
+
+_Optional, Default=""_
+
+The `namespaces` option defines the namespaces in which the nomad services will be discovered.
+When using the `namespaces` option, the discovered object names will be suffixed as shown below:
+
+```text
+<resource-name>@nomad-<namespace>
+```
+
+!!! warning
+  
+    One should only define either the `namespaces` option or the `namespace` option.
+
+```yaml tab="File (YAML)"
+providers:
+  nomad:
+    namespaces:
+      - "ns1"
+      - "ns2"
+    # ...
+```
+
+```toml tab="File (TOML)"
+[providers.nomad]
+  namespaces = ["ns1", "ns2"]
+  # ...
+```
+
+```bash tab="CLI"
+--providers.nomad.namespaces=ns1,ns2
+# ...
+```

docs/content/reference/static-configuration/cli-ref.md

@@ -855,6 +855,9 @@ Expose Nomad services by default. (Default: ```true```)
 `--providers.nomad.namespace`:  
 Sets the Nomad namespace used to discover services.
 
+`--providers.nomad.namespaces`:  
+Sets the Nomad namespaces used to discover services.
+
 `--providers.nomad.prefix`:  
 Prefix for nomad service tags. (Default: ```traefik```)
 

docs/content/reference/static-configuration/env-ref.md

@@ -855,6 +855,9 @@ Expose Nomad services by default. (Default: ```true```)
 `TRAEFIK_PROVIDERS_NOMAD_NAMESPACE`:  
 Sets the Nomad namespace used to discover services.
 
+`TRAEFIK_PROVIDERS_NOMAD_NAMESPACES`:  
+Sets the Nomad namespaces used to discover services.
+
 `TRAEFIK_PROVIDERS_NOMAD_PREFIX`:  
 Prefix for nomad service tags. (Default: ```traefik```)
 

docs/content/reference/static-configuration/file.toml

@@ -181,6 +181,7 @@
     prefix = "foobar"
     stale = true
     namespace = "foobar"
+    namespaces = ["foobar", "foobar"]
     exposedByDefault = true
     refreshInterval = "42s"
     [providers.nomad.endpoint]

docs/content/reference/static-configuration/file.yaml

@@ -195,6 +195,9 @@ providers:
     prefix: foobar
     stale: true
     namespace: foobar
+    namespaces:
+      - foobar
+      - foobar
     exposedByDefault: true
     refreshInterval: 42s
     endpoint:

pkg/config/static/static_config.go

@@ -186,7 +186,7 @@ type Providers struct {
 	Rest              *rest.Provider                 `description:"Enable Rest backend with default settings." json:"rest,omitempty" toml:"rest,omitempty" yaml:"rest,omitempty" export:"true" label:"allowEmpty" file:"allowEmpty"`
 	Rancher           *rancher.Provider              `description:"Enable Rancher backend with default settings." json:"rancher,omitempty" toml:"rancher,omitempty" yaml:"rancher,omitempty" export:"true" label:"allowEmpty" file:"allowEmpty"`
 	ConsulCatalog     *consulcatalog.ProviderBuilder `description:"Enable ConsulCatalog backend with default settings." json:"consulCatalog,omitempty" toml:"consulCatalog,omitempty" yaml:"consulCatalog,omitempty" label:"allowEmpty" file:"allowEmpty" export:"true"`
-	Nomad             *nomad.Provider                `description:"Enable Nomad backend with default settings." json:"nomad,omitempty" toml:"nomad,omitempty" yaml:"nomad,omitempty" label:"allowEmpty" file:"allowEmpty" export:"true"`
+	Nomad             *nomad.ProviderBuilder         `description:"Enable Nomad backend with default settings." json:"nomad,omitempty" toml:"nomad,omitempty" yaml:"nomad,omitempty" label:"allowEmpty" file:"allowEmpty" export:"true"`
 	Ecs               *ecs.Provider                  `description:"Enable AWS ECS backend with default settings." json:"ecs,omitempty" toml:"ecs,omitempty" yaml:"ecs,omitempty" label:"allowEmpty" file:"allowEmpty" export:"true"`
 
 	Consul    *consul.ProviderBuilder `description:"Enable Consul backend with default settings." json:"consul,omitempty" toml:"consul,omitempty" yaml:"consul,omitempty" label:"allowEmpty" file:"allowEmpty"  export:"true"`
@@ -326,11 +326,15 @@ func (c *Configuration) ValidateConfiguration() error {
 	}
 
 	if c.Providers.ConsulCatalog != nil && c.Providers.ConsulCatalog.Namespace != "" && len(c.Providers.ConsulCatalog.Namespaces) > 0 {
-		return fmt.Errorf("consul catalog provider cannot have both namespace and namespaces options configured")
+		return fmt.Errorf("Consul Catalog provider cannot have both namespace and namespaces options configured")
 	}
 
 	if c.Providers.Consul != nil && c.Providers.Consul.Namespace != "" && len(c.Providers.Consul.Namespaces) > 0 {
-		return fmt.Errorf("consul provider cannot have both namespace and namespaces options configured")
+		return fmt.Errorf("Consul provider cannot have both namespace and namespaces options configured")
+	}
+
+	if c.Providers.Nomad != nil && c.Providers.Nomad.Namespace != "" && len(c.Providers.Nomad.Namespaces) > 0 {
+		return fmt.Errorf("Nomad provider cannot have both namespace and namespaces options configured")
 	}
 
 	return nil

pkg/provider/aggregator/aggregator.go

@@ -115,7 +115,9 @@ func NewProviderAggregator(conf static.Providers) ProviderAggregator {
 	}
 
 	if conf.Nomad != nil {
-		p.quietAddProvider(conf.Nomad)
+		for _, pvd := range conf.Nomad.BuildProviders() {
+			p.quietAddProvider(pvd)
+		}
 	}
 
 	if conf.Consul != nil {

pkg/provider/nomad/config_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"testing"
 
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"github.com/traefik/traefik/v2/pkg/config/dynamic"
 )
@@ -2509,5 +2510,57 @@ func Test_keepItem(t *testing.T) {
 	}
 }
 
+func TestNamespaces(t *testing.T) {
+	testCases := []struct {
+		desc               string
+		namespace          string
+		namespaces         []string
+		expectedNamespaces []string
+	}{
+		{
+			desc:               "no defined namespaces",
+			expectedNamespaces: []string{""},
+		},
+		{
+			desc:               "deprecated: use of defined namespace",
+			namespace:          "test-ns",
+			expectedNamespaces: []string{"test-ns"},
+		},
+		{
+			desc:               "use of 1 defined namespaces",
+			namespaces:         []string{"test-ns"},
+			expectedNamespaces: []string{"test-ns"},
+		},
+		{
+			desc:               "use of multiple defined namespaces",
+			namespaces:         []string{"test-ns1", "test-ns2", "test-ns3", "test-ns4"},
+			expectedNamespaces: []string{"test-ns1", "test-ns2", "test-ns3", "test-ns4"},
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			pb := &ProviderBuilder{
+				Namespace:  test.namespace,
+				Namespaces: test.namespaces,
+			}
+
+			assert.Equal(t, test.expectedNamespaces, extractNamespacesFromProvider(pb.BuildProviders()))
+		})
+	}
+}
+
+func extractNamespacesFromProvider(providers []*Provider) []string {
+	res := make([]string, len(providers))
+	for i, p := range providers {
+		res[i] = p.namespace
+	}
+	return res
+}
+
 func Int(v int) *int    { return &v }
 func Bool(v bool) *bool { return &v }

pkg/provider/nomad/nomad.go

@@ -2,6 +2,7 @@ package nomad
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"strings"
 	"text/template"
@@ -46,17 +47,68 @@ type item struct {
 	ExtraConf configuration // global options
 }
 
-// Provider holds configurations of the provider.
-type Provider struct {
+// ProviderBuilder is responsible for constructing namespaced instances of the Nomad provider.
+type ProviderBuilder struct {
+	Configuration `yaml:",inline" export:"true"`
+
+	// Deprecated: Use Namespaces option instead
+	Namespace  string   `description:"Sets the Nomad namespace used to discover services." json:"namespace,omitempty" toml:"namespace,omitempty" yaml:"namespace,omitempty"`
+	Namespaces []string `description:"Sets the Nomad namespaces used to discover services." json:"namespaces,omitempty" toml:"namespaces,omitempty" yaml:"namespaces,omitempty"`
+}
+
+// BuildProviders builds Nomad provider instances for the given namespaces configuration.
+func (p *ProviderBuilder) BuildProviders() []*Provider {
+	if p.Namespace != "" {
+		log.WithoutContext().Warnf("Namespace option is deprecated, please use the Namespaces option instead.")
+	}
+
+	if len(p.Namespaces) == 0 {
+		return []*Provider{{
+			Configuration: p.Configuration,
+			name:          providerName,
+			// p.Namespace could be empty
+			namespace: p.Namespace,
+		}}
+	}
+
+	var providers []*Provider
+	for _, namespace := range p.Namespaces {
+		providers = append(providers, &Provider{
+			Configuration: p.Configuration,
+			name:          providerName + "-" + namespace,
+			namespace:     namespace,
+		})
+	}
+
+	return providers
+}
+
+// Configuration represents the Nomad provider configuration.
+type Configuration struct {
 	DefaultRule      string          `description:"Default rule." json:"defaultRule,omitempty" toml:"defaultRule,omitempty" yaml:"defaultRule,omitempty"`
 	Constraints      string          `description:"Constraints is an expression that Traefik matches against the Nomad service's tags to determine whether to create route(s) for that service." json:"constraints,omitempty" toml:"constraints,omitempty" yaml:"constraints,omitempty" export:"true"`
 	Endpoint         *EndpointConfig `description:"Nomad endpoint settings" json:"endpoint,omitempty" toml:"endpoint,omitempty" yaml:"endpoint,omitempty" export:"true"`
 	Prefix           string          `description:"Prefix for nomad service tags." json:"prefix,omitempty" toml:"prefix,omitempty" yaml:"prefix,omitempty" export:"true"`
 	Stale            bool            `description:"Use stale consistency for catalog reads." json:"stale,omitempty" toml:"stale,omitempty" yaml:"stale,omitempty" export:"true"`
-	Namespace        string          `description:"Sets the Nomad namespace used to discover services." json:"namespace,omitempty" toml:"namespace,omitempty" yaml:"namespace,omitempty" export:"true"`
 	ExposedByDefault bool            `description:"Expose Nomad services by default." json:"exposedByDefault,omitempty" toml:"exposedByDefault,omitempty" yaml:"exposedByDefault,omitempty" export:"true"`
 	RefreshInterval  ptypes.Duration `description:"Interval for polling Nomad API." json:"refreshInterval,omitempty" toml:"refreshInterval,omitempty" yaml:"refreshInterval,omitempty" export:"true"`
+}
 
+// SetDefaults sets the default values for the Nomad Traefik Provider Configuration.
+func (c *Configuration) SetDefaults() {
+	c.Endpoint = &EndpointConfig{}
+	c.Prefix = defaultPrefix
+	c.ExposedByDefault = true
+	c.RefreshInterval = ptypes.Duration(15 * time.Second)
+	c.DefaultRule = defaultTemplateRule
+}
+
+// Provider holds configuration along with the namespace it will discover services in.
+type Provider struct {
+	Configuration
+
+	name           string
+	namespace      string
 	client         *api.Client        // client for Nomad API
 	defaultRuleTpl *template.Template // default routing rule
 }
@@ -72,22 +124,23 @@ 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 for the Nomad Traefik Provider.
-func (p *Provider) SetDefaults() {
-	p.Endpoint = &EndpointConfig{}
-	p.Prefix = defaultPrefix
-	p.ExposedByDefault = true
-	p.RefreshInterval = ptypes.Duration(15 * time.Second)
-	p.DefaultRule = defaultTemplateRule
-}
-
 // Init the Nomad Traefik Provider.
 func (p *Provider) Init() error {
+	if p.namespace == api.AllNamespacesNamespace {
+		return errors.New("wildcard namespace not supported")
+	}
+
 	defaultRuleTpl, err := provider.MakeDefaultRuleTemplate(p.DefaultRule, nil)
 	if err != nil {
 		return fmt.Errorf("error while parsing default rule: %w", err)
 	}
 	p.defaultRuleTpl = defaultRuleTpl
+
+	// In case they didn't initialize Provider with BuildProviders
+	if p.name == "" {
+		p.name = providerName
+	}
+
 	return nil
 }
 
@@ -95,13 +148,13 @@ func (p *Provider) Init() error {
 // 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.Namespace, p.Endpoint)
+	p.client, err = createClient(p.namespace, p.Endpoint)
 	if err != nil {
 		return fmt.Errorf("failed to create nomad API client: %w", err)
 	}
 
 	pool.GoCtx(func(routineCtx context.Context) {
-		ctxLog := log.With(routineCtx, log.Str(log.ProviderName, providerName))
+		ctxLog := log.With(routineCtx, log.Str(log.ProviderName, p.name))
 		logger := log.FromContext(ctxLog)
 
 		operation := func() error {
@@ -154,7 +207,7 @@ func (p *Provider) loadConfiguration(ctx context.Context, configurationC chan<-
 		return err
 	}
 	configurationC <- dynamic.Message{
-		ProviderName:  providerName,
+		ProviderName:  p.name,
 		Configuration: p.buildConfig(ctx, items),
 	}
 

pkg/provider/nomad/nomad_test.go

@@ -64,7 +64,12 @@ func Test_globalConfig(t *testing.T) {
 
 	for _, test := range cases {
 		t.Run(test.Name, func(t *testing.T) {
-			p := Provider{ExposedByDefault: test.ExposedByDefault, Prefix: test.Prefix}
+			p := Provider{
+				Configuration: Configuration{
+					ExposedByDefault: test.ExposedByDefault,
+					Prefix:           test.Prefix,
+				},
+			}
 			result := p.getExtraConf(test.Tags)
 			require.Equal(t, test.exp, result)
 		})
@@ -91,7 +96,7 @@ func Test_getNomadServiceData(t *testing.T) {
 	require.NoError(t, err)
 
 	// fudge client, avoid starting up via Provide
-	p.client, err = createClient(p.Namespace, p.Endpoint)
+	p.client, err = createClient(p.namespace, p.Endpoint)
 	require.NoError(t, err)
 
 	// make the query for services

webui/src/components/_commons/PanelMiddlewares.vue

@@ -1151,6 +1151,9 @@ export default {
       if (name.startsWith('consulcatalog-')) {
         return `statics/providers/consulcatalog.svg`
       }
+      if (name.startsWith('nomad-')) {
+        return `statics/providers/nomad.svg`
+      }
 
       return `statics/providers/${name}.svg`
     }

webui/src/components/_commons/PanelMirroringServices.vue

@@ -75,6 +75,9 @@ export default {
       if (name.startsWith('consulcatalog-')) {
         return `statics/providers/consulcatalog.svg`
       }
+      if (name.startsWith('nomad-')) {
+        return `statics/providers/nomad.svg`
+      }
 
       return `statics/providers/${name}.svg`
     }

webui/src/components/_commons/PanelRouterDetails.vue

@@ -141,6 +141,9 @@ export default {
       if (name.startsWith('consulcatalog-')) {
         return `statics/providers/consulcatalog.svg`
       }
+      if (name.startsWith('nomad-')) {
+        return `statics/providers/nomad.svg`
+      }
 
       return `statics/providers/${name}.svg`
     }

webui/src/components/_commons/PanelServiceDetails.vue

@@ -155,6 +155,9 @@ export default {
       if (name.startsWith('consulcatalog-')) {
         return `statics/providers/consulcatalog.svg`
       }
+      if (name.startsWith('nomad-')) {
+        return `statics/providers/nomad.svg`
+      }
 
       return `statics/providers/${name}.svg`
     }

webui/src/components/_commons/PanelWeightedServices.vue

@@ -75,6 +75,9 @@ export default {
       if (name.startsWith('consulcatalog-')) {
         return `statics/providers/consulcatalog.svg`
       }
+      if (name.startsWith('nomad-')) {
+        return `statics/providers/nomad.svg`
+      }
 
       return `statics/providers/${name}.svg`
     }

webui/src/components/_commons/ProviderIcon.vue

@@ -20,6 +20,9 @@ export default {
       if (name.startsWith('consulcatalog-')) {
         return `statics/providers/consulcatalog.svg`
       }
+      if (name.startsWith('nomad-')) {
+        return `statics/providers/nomad.svg`
+      }
 
       return `statics/providers/${name}.svg`
     }

webui/src/components/dashboard/PanelProvider.vue

@@ -37,6 +37,9 @@ export default {
       if (name.startsWith('consulcatalog-')) {
         return `statics/providers/consulcatalog.svg`
       }
+      if (name.startsWith('nomad-')) {
+        return `statics/providers/nomad.svg`
+      }
 
       return `statics/providers/${name}.svg`
     }