# Traefik & Marathon

Traefik can be configured to use Marathon as a provider.
{: .subtitle }

For additional information, refer to [Marathon user guide](../user-guides/marathon.md).

## Configuration Examples

??? example "Configuring Marathon & Deploying / Exposing Applications"

    Enabling the Marathon provider

    ```toml tab="File (TOML)"
    [providers.marathon]
    ```

    ```yaml tab="File (YAML)"
    providers:
      marathon: {}
    ```

    ```bash tab="CLI"
    --providers.marathon=true
    ```

    Attaching labels to Marathon applications

    ```json
	{
		"id": "/whoami",
		"container": {
			"type": "DOCKER",
			"docker": {
				"image": "traefik/whoami",
				"network": "BRIDGE",
				"portMappings": [
					{
						"containerPort": 80,
						"hostPort": 0,
						"protocol": "tcp"
					}
				]
			}
		},
		"labels": {
			"traefik.http.Routers.app.Rule": "PathPrefix(`/app`)"
		}
	}
    ```

## Routing Configuration

See the dedicated section in [routing](../routing/providers/marathon.md).

## Provider Configuration

### `basic`

_Optional_

Enables Marathon basic authentication.

```toml tab="File (TOML)"
[providers.marathon.basic]
  httpBasicAuthUser = "foo"
  httpBasicPassword = "bar"
```

```yaml tab="File (YAML)"
providers:
  marathon:
    basic:
      httpBasicAuthUser: foo
      httpBasicPassword: bar
```

```bash tab="CLI"
--providers.marathon.basic.httpbasicauthuser=foo
--providers.marathon.basic.httpbasicpassword=bar
```

### `dcosToken`

_Optional_

Datacenter Operating System (DCOS) Token for DCOS environment.

If set, it overrides the Authorization header.

```toml tab="File (TOML)"
[providers.marathon]
  dcosToken = "xxxxxx"
  # ...
```

```toml tab="File (YAML)"
providers:
  marathon:
    dcosToken: "xxxxxx"
    # ...
```

```bash tab="CLI"
--providers.marathon.dcosToken=xxxxxx
```

### `defaultRule`

_Optional, Default=```Host(`{{ normalize .Name }}`)```_

The default host rule for all services.

For a given application, if no routing rule was defined by a label, it is defined by this `defaultRule` instead.

It must be a valid [Go template](https://golang.org/pkg/text/template/),
and can include [sprig template functions](http://masterminds.github.io/sprig/).

The app ID can be accessed with the `Name` identifier,
and the template has access to all the labels defined on this Marathon application.

```toml tab="File (TOML)"
[providers.marathon]
  defaultRule = "Host(`{{ .Name }}.{{ index .Labels \"customLabel\"}}`)"
  # ...
```

```yaml tab="File (YAML)"
providers:
  marathon:
    defaultRule: "Host(`{{ .Name }}.{{ index .Labels \"customLabel\"}}`)"
    # ...
```

```bash tab="CLI"
--providers.marathon.defaultRule=Host(`{{ .Name }}.{{ index .Labels \"customLabel\"}}`)
# ...
```

### `dialerTimeout`

_Optional, Default=5s_

Amount of time the Marathon provider should wait before timing out,
when trying to open a TCP connection to a Marathon master.

The value of `dialerTimeout` should be provided in seconds or as a valid duration format,
see [time.ParseDuration](https://golang.org/pkg/time/#ParseDuration).

```toml tab="File (TOML)"
[providers.marathon]
  dialerTimeout = "10s"
  # ...
```

```toml tab="File (YAML)"
providers:
  marathon:
    dialerTimeout: "10s"
    # ...
```

```bash tab="CLI"
--providers.marathon.dialerTimeout=10s
```

### `endpoint`

_Optional, Default=http://127.0.0.1:8080_

Marathon server endpoint.

You can optionally specify multiple endpoints.

```toml tab="File (TOML)"
[providers.marathon]
  endpoint = "http://10.241.1.71:8080,10.241.1.72:8080,10.241.1.73:8080"
  # ...
```

```toml tab="File (YAML)"
providers:
  marathon:
    endpoint: "http://10.241.1.71:8080,10.241.1.72:8080,10.241.1.73:8080"
    # ...
```

```bash tab="CLI"
--providers.marathon.endpoint=http://10.241.1.71:8080,10.241.1.72:8080,10.241.1.73:8080
```

### `exposedByDefault`

_Optional, Default=true_

Exposes Marathon applications by default through Traefik.

If set to `false`, applications that do not have a `traefik.enable=true` label are ignored from the resulting routing configuration.

For additional information, refer to [Restrict the Scope of Service Discovery](./overview.md#restrict-the-scope-of-service-discovery).

```toml tab="File (TOML)"
[providers.marathon]
  exposedByDefault = false
  # ...
```

```yaml tab="File (YAML)"
providers:
  marathon:
    exposedByDefault: false
    # ...
```

```bash tab="CLI"
--providers.marathon.exposedByDefault=false
# ...
```

### `constraints`

_Optional, Default=""_

The `constraints` option can be set to an expression that Traefik matches against the application labels to determine whether
to create any route for that application. If none of the application labels match the expression, no route for that application is
created. In addition, the expression is also matched against the application constraints, such as described
in [Marathon constraints](https://mesosphere.github.io/marathon/docs/constraints.html).
If the expression is empty, all detected applications are included.

The expression syntax is based on the `Label("key", "value")`, and `LabelRegex("key", "value")` functions, as well as the usual boolean logic.
In addition, to match against Marathon constraints, the function `MarathonConstraint("field:operator:value")` can be used, where the field, operator, and value parts are concatenated in a single string using the `:` separator.

??? example "Constraints Expression Examples"

    ```toml
    # Includes only applications having a label with key `a.label.name` and value `foo`
    constraints = "Label(`a.label.name`, `foo`)"
    ```

    ```toml
    # Excludes applications having any label with key `a.label.name` and value `foo`
    constraints = "!Label(`a.label.name`, `value`)"
    ```

    ```toml
    # With logical AND.
    constraints = "Label(`a.label.name`, `valueA`) && Label(`another.label.name`, `valueB`)"
    ```

    ```toml
    # With logical OR.
    constraints = "Label(`a.label.name`, `valueA`) || Label(`another.label.name`, `valueB`)"
    ```

    ```toml
    # With logical AND and OR, with precedence set by parentheses.
    constraints = "Label(`a.label.name`, `valueA`) && (Label(`another.label.name`, `valueB`) || Label(`yet.another.label.name`, `valueC`))"
    ```

    ```toml
    # Includes only applications having a label with key `a.label.name` and a value matching the `a.+` regular expression.
    constraints = "LabelRegex(`a.label.name`, `a.+`)"
    ```

    ```toml
    # Includes only applications having a Marathon constraint with field `A`, operator `B`, and value `C`.
    constraints = "MarathonConstraint(`A:B:C`)"
    ```

    ```toml
    # Uses both Marathon constraint and application label with logical operator.
    constraints = "MarathonConstraint(`A:B:C`) && Label(`a.label.name`, `value`)"
    ```

For additional information, refer to [Restrict the Scope of Service Discovery](./overview.md#restrict-the-scope-of-service-discovery).

```toml tab="File (TOML)"
[providers.marathon]
  constraints = "Label(`a.label.name`,`foo`)"
  # ...
```

```yaml tab="File (YAML)"
providers:
  marathon:
    constraints: "Label(`a.label.name`,`foo`)"
    # ...
```

```bash tab="CLI"
--providers.marathon.constraints=Label(`a.label.name`,`foo`)
# ...
```

### `forceTaskHostname`

_Optional, Default=false_

By default, the task IP address (as returned by the Marathon API) is used as backend server if an IP-per-task configuration can be found;
otherwise, the name of the host running the task is used.
The latter behavior can be enforced by setting this option to `true`.

```toml tab="File (TOML)"
[providers.marathon]
  forceTaskHostname = true
  # ...
```

```yaml tab="File (YAML)"
providers:
  marathon:
    forceTaskHostname: true
    # ...
```

```bash tab="CLI"
--providers.marathon.forceTaskHostname=true
# ...
```

### `keepAlive`

_Optional, Default=10s_

Set the TCP Keep Alive duration for the Marathon HTTP Client.
The value of `keepAlive` should be provided in seconds or as a valid duration format,
see [time.ParseDuration](https://golang.org/pkg/time/#ParseDuration).

```toml tab="File (TOML)"
[providers.marathon]
  keepAlive = "30s"
  # ...
```

```yaml tab="File (YAML)"
providers:
  marathon:
    keepAlive: "30s"
    # ...
```

```bash tab="CLI"
--providers.marathon.keepAlive=30s
# ...
```

### `respectReadinessChecks`

_Optional, Default=false_

Applications may define readiness checks which are probed by Marathon during deployments periodically, and these check results are exposed via the API.
Enabling `respectReadinessChecks` causes Traefik to filter out tasks whose readiness checks have not succeeded.
Note that the checks are only valid during deployments.

See the Marathon guide for details.

```toml tab="File (TOML)"
[providers.marathon]
  respectReadinessChecks = true
  # ...
```

```yaml tab="File (YAML)"
providers:
  marathon:
    respectReadinessChecks: true
    # ...
```

```bash tab="CLI"
--providers.marathon.respectReadinessChecks=true
# ...
```

### `responseHeaderTimeout`

_Optional, Default=60s_

Amount of time the Marathon provider should wait before timing out when waiting for the first response header
from a Marathon master.

The value of `responseHeaderTimeout` should be provided in seconds or as a valid duration format,
see [time.ParseDuration](https://golang.org/pkg/time/#ParseDuration).

```toml tab="File (TOML)"
[providers.marathon]
  responseHeaderTimeout = "66s"
  # ...
```

```yaml tab="File (YAML)"
providers:
  marathon:
    responseHeaderTimeout: "66s"
    # ...
```

```bash tab="CLI"
--providers.marathon.responseHeaderTimeout=66s
# ...
```

### `tls`

_Optional_

#### `tls.ca`

Certificate Authority used for the secure connection to Marathon.

```toml tab="File (TOML)"
[providers.marathon.tls]
  ca = "path/to/ca.crt"
```

```yaml tab="File (YAML)"
providers:
  marathon:
    tls:
      ca: path/to/ca.crt
```

```bash tab="CLI"
--providers.marathon.tls.ca=path/to/ca.crt
```

#### `tls.caOptional`

The value of `tls.caOptional` defines which policy should be used for the secure connection with TLS Client Authentication to Marathon.

!!! warning ""

    If `tls.ca` is undefined, this option will be ignored, and no client certificate will be requested during the handshake. Any provided certificate will thus never be verified.

When this option is set to `true`, a client certificate is requested during the handshake but is not required. If a certificate is sent, it is required to be valid.

When this option is set to `false`, a client certificate is requested during the handshake, and at least one valid certificate should be sent by the client.

```toml tab="File (TOML)"
[providers.marathon.tls]
  caOptional = true
```

```yaml tab="File (YAML)"
providers:
  marathon:
    tls:
      caOptional: true
```

```bash tab="CLI"
--providers.marathon.tls.caOptional=true
```

#### `tls.cert`

Public certificate used for the secure connection to Marathon.

```toml tab="File (TOML)"
[providers.marathon.tls]
  cert = "path/to/foo.cert"
  key = "path/to/foo.key"
```

```yaml tab="File (YAML)"
providers:
  marathon:
    tls:
      cert: path/to/foo.cert
      key: path/to/foo.key
```

```bash tab="CLI"
--providers.marathon.tls.cert=path/to/foo.cert
--providers.marathon.tls.key=path/to/foo.key
```

#### `tls.key`

Private certificate used for the secure connection to Marathon.

```toml tab="File (TOML)"
[providers.marathon.tls]
  cert = "path/to/foo.cert"
  key = "path/to/foo.key"
```

```yaml tab="File (YAML)"
providers:
  marathon:
    tls:
      cert: path/to/foo.cert
      key: path/to/foo.key
```

```bash tab="CLI"
--providers.marathon.tls.cert=path/to/foo.cert
--providers.marathon.tls.key=path/to/foo.key
```

#### `tls.insecureSkipVerify`

If `insecureSkipVerify` is `true`, the TLS connection to Marathon accepts any certificate presented by the server regardless of the hostnames it covers.

```toml tab="File (TOML)"
[providers.marathon.tls]
  insecureSkipVerify = true
```

```yaml tab="File (YAML)"
providers:
  marathon:
    tls:
      insecureSkipVerify: true
```

```bash tab="CLI"
--providers.marathon.tls.insecureSkipVerify=true
```

### `tlsHandshakeTimeout`

_Optional, Default=5s_

Amount of time the Marathon provider should wait before timing out,
when waiting for the TLS handshake to complete.

The value of `tlsHandshakeTimeout` should be provided in seconds or as a valid duration format,
see [time.ParseDuration](https://golang.org/pkg/time/#ParseDuration).

```toml tab="File (TOML)"
[providers.marathon]
  responseHeaderTimeout = "10s"
  # ...
```

```yaml tab="File (YAML)"
providers:
  marathon:
    responseHeaderTimeout: "10s"
    # ...
```

```bash tab="CLI"
--providers.marathon.responseHeaderTimeout=10s
# ...
```

### `trace`

_Optional, Default=false_

Displays additional provider logs when available.

```toml tab="File (TOML)"
[providers.marathon]
  trace = true
  # ...
```

```yaml tab="File (YAML)"
providers:
  marathon:
    trace: true
    # ...
```

```bash tab="CLI"
--providers.marathon.trace=true
# ...
```

### `watch`

_Optional, Default=true_

When set to `true`, watches for Marathon changes.

```toml tab="File (TOML)"
[providers.marathon]
  watch = false
  # ...
```

```yaml tab="File (YAML)"
providers:
  marathon:
    watch: false
    # ...
```

```bash tab="CLI"
--providers.marathon.watch=false
# ...
```
