--- title: "Traefik Nomad Service Discovery Routing" description: "Learn how to use Nomad Service Discovery as a provider for routing configurations in Traefik Proxy. Read the technical documentation." --- # Traefik and Nomad Service Discovery A story of Tags, Services & Nomads {: .subtitle } ![Nomad](../../assets/img/providers/nomad.png) Attach tags to your Nomad services and let Traefik do the rest! One of the best feature of Traefik is to delegate the routing configuration to the application level. With Nomad, Traefik can leverage tags attached to a service to generate routing rules. !!! warning "Tags & sensitive data" We recommend to *not* use tags to store sensitive data (certificates, credentials, etc). Instead, we recommend to store sensitive data in a safer storage (secrets, file, etc). ## Routing Configuration !!! info "tags" - tags are case insensitive. - The complete list of tags can be found [the reference page](../../reference/dynamic-configuration/nomad.md) ### General Traefik creates, for each Nomad service, a corresponding Traefik [service](../services/index.md) and [router](../routers/index.md). The Traefik service automatically gets a server per instance in this Nomad service, and the router gets a default rule attached to it, based on the Nomad service name. ### Routers To update the configuration of the Router automatically attached to the service, add tags starting with `traefik.routers.{name-of-your-choice}.` and followed by the option you want to change. For example, to change the rule, you could add the tag ```traefik.http.routers.my-service.rule=Host(`example.com`)```. ??? info "`traefik.http.routers..rule`" See [rule](../routers/index.md#rule) for more information. ```yaml traefik.http.routers.myrouter.rule=Host(`example.com`) ``` ??? info "`traefik.http.routers..entrypoints`" See [entry points](../routers/index.md#entrypoints) for more information. ```yaml traefik.http.routers.myrouter.entrypoints=web,websecure ``` ??? info "`traefik.http.routers..middlewares`" See [middlewares](../routers/index.md#middlewares) and [middlewares overview](../../middlewares/overview.md) for more information. ```yaml traefik.http.routers.myrouter.middlewares=auth,prefix,cb ``` ??? info "`traefik.http.routers..service`" See [rule](../routers/index.md#service) for more information. ```yaml traefik.http.routers.myrouter.service=myservice ``` ??? info "`traefik.http.routers..tls`" See [tls](../routers/index.md#tls) for more information. ```yaml traefik.http.routers.myrouter.tls=true ``` ??? info "`traefik.http.routers..tls.certresolver`" See [certResolver](../routers/index.md#certresolver) for more information. ```yaml traefik.http.routers.myrouter.tls.certresolver=myresolver ``` ??? info "`traefik.http.routers..tls.domains[n].main`" See [domains](../routers/index.md#domains) for more information. ```yaml traefik.http.routers.myrouter.tls.domains[0].main=example.org ``` ??? info "`traefik.http.routers..tls.domains[n].sans`" See [domains](../routers/index.md#domains) for more information. ```yaml traefik.http.routers.myrouter.tls.domains[0].sans=test.example.org,dev.example.org ``` ??? info "`traefik.http.routers..tls.options`" See [options](../routers/index.md#options) for more information. ```yaml traefik.http.routers.myrouter.tls.options=foobar ``` ??? info "`traefik.http.routers..priority`" See [priority](../routers/index.md#priority) for more information. ```yaml traefik.http.routers.myrouter.priority=42 ``` ### Services To update the configuration of the Service automatically attached to the service, add tags starting with `traefik.http.services.{name-of-your-choice}.`, followed by the option you want to change. For example, to change the `passHostHeader` behavior, you'd add the tag `traefik.http.services.{name-of-your-choice}.loadbalancer.passhostheader=false`. ??? info "`traefik.http.services..loadbalancer.server.port`" Registers a port. Useful when the service exposes multiples ports. ```yaml traefik.http.services.myservice.loadbalancer.server.port=8080 ``` ??? info "`traefik.http.services..loadbalancer.server.scheme`" Overrides the default scheme. ```yaml traefik.http.services.myservice.loadbalancer.server.scheme=http ``` ??? info "`traefik.http.services..loadbalancer.serverstransport`" Allows to reference a ServersTransport resource that is defined either with the File provider or the Kubernetes CRD one. See [serverstransport](../services/index.md#serverstransport) for more information. ```yaml traefik.http.services.myservice.loadbalancer.serverstransport=foobar@file ``` ??? info "`traefik.http.services..loadbalancer.passhostheader`" See [pass Host header](../services/index.md#pass-host-header) for more information. ```yaml traefik.http.services.myservice.loadbalancer.passhostheader=true ``` ??? info "`traefik.http.services..loadbalancer.healthcheck.headers.`" See [health check](../services/index.md#health-check) for more information. ```yaml traefik.http.services.myservice.loadbalancer.healthcheck.headers.X-Foo=foobar ``` ??? info "`traefik.http.services..loadbalancer.healthcheck.hostname`" See [health check](../services/index.md#health-check) for more information. ```yaml traefik.http.services.myservice.loadbalancer.healthcheck.hostname=example.org ``` ??? info "`traefik.http.services..loadbalancer.healthcheck.interval`" See [health check](../services/index.md#health-check) for more information. ```yaml traefik.http.services.myservice.loadbalancer.healthcheck.interval=10 ``` ??? info "`traefik.http.services..loadbalancer.healthcheck.path`" See [health check](../services/index.md#health-check) for more information. ```yaml traefik.http.services.myservice.loadbalancer.healthcheck.path=/foo ``` ??? info "`traefik.http.services..loadbalancer.healthcheck.status`" See [health check](../services/index.md#health-check) for more information. ```yaml traefik.http.services.myservice.loadbalancer.healthcheck.status=42 ``` ??? info "`traefik.http.services..loadbalancer.healthcheck.port`" See [health check](../services/index.md#health-check) for more information. ```yaml traefik.http.services.myservice.loadbalancer.healthcheck.port=42 ``` ??? info "`traefik.http.services..loadbalancer.healthcheck.scheme`" See [health check](../services/index.md#health-check) for more information. ```yaml traefik.http.services.myservice.loadbalancer.healthcheck.scheme=http ``` ??? info "`traefik.http.services..loadbalancer.healthcheck.timeout`" See [health check](../services/index.md#health-check) for more information. ```yaml traefik.http.services.myservice.loadbalancer.healthcheck.timeout=10 ``` ??? info "`traefik.http.services..loadbalancer.healthcheck.followredirects`" See [health check](../services/index.md#health-check) for more information. ```yaml traefik.http.services.myservice.loadbalancer.healthcheck.followredirects=true ``` ??? info "`traefik.http.services..loadbalancer.sticky.cookie`" See [sticky sessions](../services/index.md#sticky-sessions) for more information. ```yaml traefik.http.services.myservice.loadbalancer.sticky.cookie=true ``` ??? info "`traefik.http.services..loadbalancer.sticky.cookie.httponly`" See [sticky sessions](../services/index.md#sticky-sessions) for more information. ```yaml traefik.http.services.myservice.loadbalancer.sticky.cookie.httponly=true ``` ??? info "`traefik.http.services..loadbalancer.sticky.cookie.name`" See [sticky sessions](../services/index.md#sticky-sessions) for more information. ```yaml traefik.http.services.myservice.loadbalancer.sticky.cookie.name=foobar ``` ??? info "`traefik.http.services..loadbalancer.sticky.cookie.secure`" See [sticky sessions](../services/index.md#sticky-sessions) for more information. ```yaml traefik.http.services.myservice.loadbalancer.sticky.cookie.secure=true ``` ??? info "`traefik.http.services..loadbalancer.sticky.cookie.samesite`" See [sticky sessions](../services/index.md#sticky-sessions) for more information. ```yaml traefik.http.services.myservice.loadbalancer.sticky.cookie.samesite=none ``` ??? info "`traefik.http.services..loadbalancer.sticky.cookie.maxage`" See [sticky sessions](../services/index.md#sticky-sessions) for more information. ```yaml traefik.http.services.myservice.loadbalancer.sticky.cookie.maxage=42 ``` ??? info "`traefik.http.services..loadbalancer.responseforwarding.flushinterval`" See [response forwarding](../services/index.md#response-forwarding) for more information. ```yaml traefik.http.services.myservice.loadbalancer.responseforwarding.flushinterval=10 ``` ### Middleware You can declare pieces of middleware using tags starting with `traefik.http.middlewares.{name-of-your-choice}.`, followed by the middleware type/options. For example, to declare a middleware [`redirectscheme`](../../middlewares/http/redirectscheme.md) named `my-redirect`, you'd write `traefik.http.middlewares.my-redirect.redirectscheme.scheme: https`. More information about available middlewares in the dedicated [middlewares section](../../middlewares/overview.md). ??? example "Declaring and Referencing a Middleware" ```yaml # ... # Declaring a middleware traefik.http.middlewares.my-redirect.redirectscheme.scheme=https # Referencing a middleware traefik.http.routers.my-service.middlewares=my-redirect ``` !!! warning "Conflicts in Declaration" If you declare multiple middleware with the same name but with different parameters, the middleware fails to be declared. ### TCP You can declare TCP Routers and/or Services using tags. ??? example "Declaring TCP Routers and Services" ```yaml traefik.tcp.routers.my-router.rule=HostSNI(`example.com`) traefik.tcp.routers.my-router.tls=true traefik.tcp.services.my-service.loadbalancer.server.port=4123 ``` !!! warning "TCP and HTTP" If you declare a TCP Router/Service, it will prevent Traefik from automatically creating an HTTP Router/Service (like it does by default if no TCP Router/Service is defined). You can declare both a TCP Router/Service and an HTTP Router/Service for the same Nomad service (but you have to do so manually). #### TCP Routers ??? info "`traefik.tcp.routers..entrypoints`" See [entry points](../routers/index.md#entrypoints_1) for more information. ```yaml traefik.tcp.routers.mytcprouter.entrypoints=ep1,ep2 ``` ??? info "`traefik.tcp.routers..rule`" See [rule](../routers/index.md#rule_1) for more information. ```yaml traefik.tcp.routers.mytcprouter.rule=HostSNI(`example.com`) ``` ??? info "`traefik.tcp.routers..service`" See [service](../routers/index.md#services) for more information. ```yaml traefik.tcp.routers.mytcprouter.service=myservice ``` ??? info "`traefik.tcp.routers..tls`" See [TLS](../routers/index.md#tls_1) for more information. ```yaml traefik.tcp.routers.mytcprouter.tls=true ``` ??? info "`traefik.tcp.routers..tls.certresolver`" See [certResolver](../routers/index.md#certresolver_1) for more information. ```yaml traefik.tcp.routers.mytcprouter.tls.certresolver=myresolver ``` ??? info "`traefik.tcp.routers..tls.domains[n].main`" See [domains](../routers/index.md#domains_1) for more information. ```yaml traefik.tcp.routers.mytcprouter.tls.domains[0].main=example.org ``` ??? info "`traefik.tcp.routers..tls.domains[n].sans`" See [domains](../routers/index.md#domains_1) for more information. ```yaml traefik.tcp.routers.mytcprouter.tls.domains[0].sans=test.example.org,dev.example.org ``` ??? info "`traefik.tcp.routers..tls.options`" See [options](../routers/index.md#options_1) for more information. ```yaml traefik.tcp.routers.mytcprouter.tls.options=myoptions ``` ??? info "`traefik.tcp.routers..tls.passthrough`" See [TLS](../routers/index.md#tls_1) for more information. ```yaml traefik.tcp.routers.mytcprouter.tls.passthrough=true ``` #### TCP Services ??? info "`traefik.tcp.services..loadbalancer.server.port`" Registers a port of the application. ```yaml traefik.tcp.services.mytcpservice.loadbalancer.server.port=423 ``` ??? info "`traefik.tcp.services..loadbalancer.server.tls`" Determines whether to use TLS when dialing with the backend. ```yaml traefik.tcp.services.mytcpservice.loadbalancer.server.tls=true ``` ??? info "`traefik.tcp.services..loadbalancer.proxyprotocol.version`" See [PROXY protocol](../services/index.md#proxy-protocol) for more information. ```yaml traefik.tcp.services.mytcpservice.loadbalancer.proxyprotocol.version=1 ``` ??? info "`traefik.tcp.services..loadbalancer.serverstransport`" Allows to reference a ServersTransport resource that is defined either with the File provider or the Kubernetes CRD one. See [serverstransport](../services/index.md#serverstransport_2) for more information. ```yaml traefik.tcp.services.myservice.loadbalancer.serverstransport=foobar@file ``` ### UDP You can declare UDP Routers and/or Services using tags. ??? example "Declaring UDP Routers and Services" ```yaml traefik.udp.routers.my-router.entrypoints=udp traefik.udp.services.my-service.loadbalancer.server.port=4123 ``` !!! warning "UDP and HTTP" If you declare a UDP Router/Service, it will prevent Traefik from automatically creating an HTTP Router/Service (like it does by default if no UDP Router/Service is defined). You can declare both a UDP Router/Service and an HTTP Router/Service for the same Nomad service (but you have to do so manually). #### UDP Routers ??? info "`traefik.udp.routers..entrypoints`" See [entry points](../routers/index.md#entrypoints_2) for more information. ```yaml traefik.udp.routers.myudprouter.entrypoints=ep1,ep2 ``` ??? info "`traefik.udp.routers..service`" See [service](../routers/index.md#services_1) for more information. ```yaml traefik.udp.routers.myudprouter.service=myservice ``` #### UDP Services ??? info "`traefik.udp.services..loadbalancer.server.port`" Registers a port of the application. ```yaml traefik.udp.services.myudpservice.loadbalancer.server.port=423 ``` ### Specific Provider Options #### `traefik.enable` ```yaml traefik.enable=true ``` You can tell Traefik to consider (or not) the service by setting `traefik.enable` to true or false. 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. That means, if you just expose lets say port `:1337` on the Nomad job, traefik will pick up this port and use it.