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Reference

Components

discovery

discovery.marathon

Open source

discovery.marathon

discovery.marathon allows you to retrieve scrape targets from Marathon’s Service API.

Usage

discovery.marathon "LABEL" {
  servers = [MARATHON_SERVER1, MARATHON_SERVER2...]
}

Arguments

The following arguments are supported:

Name	Type	Description	Default	Required
`servers`	`list(string)`	List of Marathon servers.		yes
`refresh_interval`	`duration`	Interval at which to refresh the list of targets.	`"30s"`	no
`auth_token`	`secret`	Auth token to authenticate with.		no
`auth_token_file`	`string`	File containing an auth token to authenticate with.		no
`bearer_token_file`	`string`	File containing a bearer token to authenticate with.		no
`bearer_token`	`secret`	Bearer token to authenticate with.		no
`enable_http2`	`bool`	Whether HTTP2 is supported for requests.	`true`	no
`follow_redirects`	`bool`	Whether redirects returned by the server should be followed.	`true`	no
`proxy_url`	`string`	HTTP proxy to send requests through.		no
`no_proxy`	`string`	Comma-separated list of IP addresses, CIDR notations, and domain names to exclude from proxying.		no
`proxy_from_environment`	`bool`	Use the proxy URL indicated by environment variables.	`false`	no
`proxy_connect_header`	`map(list(secret))`	Specifies headers to send to proxies during CONNECT requests.		no

At most, one of the following can be provided:

auth_token argument.
auth_token_file argument.
bearer_token_file argument.
bearer_token argument.
basic_auth block.
authorization block.
oauth2 block.

no_proxy can contain IPs, CIDR notations, and domain names. IP and domain names can contain port numbers. proxy_url must be configured if no_proxy is configured.

proxy_from_environment uses the environment variables HTTP_PROXY, HTTPS_PROXY, and NO_PROXY (or the lowercase versions thereof). Requests use the proxy from the environment variable matching their scheme, unless excluded by NO_PROXY. proxy_url and no_proxy must not be configured if proxy_from_environment is configured.

proxy_connect_header should only be configured if proxy_url or proxy_from_environment are configured.

Blocks

The following blocks are supported inside the definition of discovery.marathon:

Hierarchy	Block	Description	Required
basic_auth	basic_auth	Configure basic_auth for authenticating to the endpoint.	no
authorization	authorization	Configure generic authorization to the endpoint.	no
oauth2	oauth2	Configure OAuth2 for authenticating to the endpoint.	no
oauth2 > tls_config	tls_config	Configure TLS settings for connecting to the endpoint.	no
tls_config	tls_config	Configure TLS settings for connecting to the endpoint.	no

The > symbol indicates deeper levels of nesting. For example, oauth2 > tls_config refers to a tls_config block defined inside an oauth2 block.

basic_auth block

Name	Type	Description	Required
`password_file`	`string`	File containing the basic auth password.	no
`password`	`secret`	Basic auth password.	no
`username`	`string`	Basic auth username.	no

password and password_file are mutually exclusive, and only one can be provided inside a basic_auth block.

authorization block

Name	Type	Description	Required
`credentials_file`	`string`	File containing the secret value.	no
`credentials`	`secret`	Secret value.	no
`type`	`string`	Authorization type, for example, “Bearer”.	no

credential and credentials_file are mutually exclusive, and only one can be provided inside an authorization block.

oauth2 block

Name	Type	Description	Default	Required
`client_id`	`string`	OAuth2 client ID.		no
`client_secret_file`	`string`	File containing the OAuth2 client secret.		no
`client_secret`	`secret`	OAuth2 client secret.		no
`endpoint_params`	`map(string)`	Optional parameters to append to the token URL.		no
`proxy_url`	`string`	HTTP proxy to send requests through.		no
`no_proxy`	`string`	Comma-separated list of IP addresses, CIDR notations, and domain names to exclude from proxying.		no
`proxy_from_environment`	`bool`	Use the proxy URL indicated by environment variables.	`false`	no
`proxy_connect_header`	`map(list(secret))`	Specifies headers to send to proxies during CONNECT requests.		no
`scopes`	`list(string)`	List of scopes to authenticate with.		no
`token_url`	`string`	URL to fetch the token from.		no

client_secret and client_secret_file are mutually exclusive, and only one can be provided inside an oauth2 block.

The oauth2 block may also contain a separate tls_config sub-block.

no_proxy can contain IPs, CIDR notations, and domain names. IP and domain names can contain port numbers. proxy_url must be configured if no_proxy is configured.

proxy_connect_header should only be configured if proxy_url or proxy_from_environment are configured.

tls_config block

Name	Type	Description	Required
`ca_pem`	`string`	CA PEM-encoded text to validate the server with.	no
`ca_file`	`string`	CA certificate to validate the server with.	no
`cert_pem`	`string`	Certificate PEM-encoded text for client authentication.	no
`cert_file`	`string`	Certificate file for client authentication.	no
`insecure_skip_verify`	`bool`	Disables validation of the server certificate.	no
`key_file`	`string`	Key file for client authentication.	no
`key_pem`	`secret`	Key PEM-encoded text for client authentication.	no
`min_version`	`string`	Minimum acceptable TLS version.	no
`server_name`	`string`	ServerName extension to indicate the name of the server.	no

The following pairs of arguments are mutually exclusive and can’t both be set simultaneously:

ca_pem and ca_file
cert_pem and cert_file
key_pem and key_file

When configuring client authentication, both the client certificate (using cert_pem or cert_file) and the client key (using key_pem or key_file) must be provided.

When min_version isn’t provided, the minimum acceptable TLS version is inherited from Go’s default minimum version, TLS 1.2. If min_version is provided, it must be set to one of the following strings:

"TLS10" (TLS 1.0)
"TLS11" (TLS 1.1)
"TLS12" (TLS 1.2)
"TLS13" (TLS 1.3)

Exported fields

The following fields are exported and can be referenced by other components:

Name	Type	Description
`targets`	`list(map(string))`	The set of targets discovered from the Marathon servers.

Each target includes the following labels:

__meta_marathon_app: the name of the app (with slashes replaced by dashes).
__meta_marathon_image: the name of the Docker image used (if available).
__meta_marathon_task: the ID of the Mesos task.
__meta_marathon_app_label_<labelname>: any Marathon labels attached to the app.
__meta_marathon_port_definition_label_<labelname>: the port definition labels.
__meta_marathon_port_mapping_label_<labelname>: the port mapping labels.
__meta_marathon_port_index: the port index number (e.g. 1 for PORT1).

Component health

discovery.marathon is only reported as unhealthy when given an invalid configuration. In those cases, exported fields retain their last healthy values.

Debug information

discovery.marathon does not expose any component-specific debug information.

Debug metrics

discovery.marathon does not expose any component-specific debug metrics.

Example

This example discovers targets from a Marathon server:

discovery.marathon "example" {
  servers = ["localhost:8500"]
}

prometheus.scrape "demo" {
  targets    = discovery.marathon.example.targets
  forward_to = [prometheus.remote_write.demo.receiver]
}

prometheus.remote_write "demo" {
  endpoint {
    url = PROMETHEUS_REMOTE_WRITE_URL

    basic_auth {
      username = USERNAME
      password = PASSWORD
    }
  }
}

Replace the following:

PROMETHEUS_REMOTE_WRITE_URL: The URL of the Prometheus remote_write-compatible server to send metrics to.
USERNAME: The username to use for authentication to the remote_write API.
PASSWORD: The password to use for authentication to the remote_write API.

Compatible components

discovery.marathon has exports that can be consumed by the following components:

Components that consume Targets

Note
Connecting some components may not be sensible or components may require further configuration to make the connection work correctly. Refer to the linked documentation for more details.

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