Marathon Discovery

DC/OS Marathon

Description

Grey Matter Control discovers service instances from the Marathon API using application labels.

Usage

To use marathon discovery, set the following environment variables:

# required
GM_CONTROL_CMD=marathon
GM_CONTROL_MARATHON_DCOS_TOML_FILE={}
# optional
GM_CONTROL_MARATHON_GROUP_PREFIX={}
GM_CONTROL_MARATHON_SELECTOR={}
GM_CONTROL_MARATHON_CLUSTER_LABEL={}
GM_CONTROL_MARATHON_DCOS_URL={}
GM_CONTROL_MARATHON_DCOS_ACS_TOKEN={}
GM_CONTROL_MARATHON_DCOS_INSECURE={}
GM_CONTROL_MARATHON_DCOS_REQUEST_TIMEOUT={}

Either GM_CONTROL_MARATHON_DCOS_TOML_FILE must be set or both GM_CONTROL_MARATHON_DCOS_URL and GM_CONTROL_MARATHON_DCOS_ACS_TOKEN must be set.

Environment Variable	Description	Type	Default	Required
GM_CONTROL_MARATHON_GROUP_PREFIX	group prefix naming applications to expose	string	(all groups)	false
GM_CONTROL_MARATHON_SELECTOR	Label selector for filtering applications	string		false
GM_CONTROL_MARATHON_CLUSTER_LABEL	Name of Marathon label specifying which cluster a Mesos task belongs to	string	gm_cluster	false
GM_CONTROL_MARATHON_DCOS_TOML_FILE	Path to a DC/OS CLI dcos.toml configuration file	string		true if following two vars are unset
GM_CONTROL_MARATHON_DCOS_URL	The public master IP of your DC/OS installation	string		false unless dcos.toml-file unset
GM_CONTROL_MARATHON_DCOS_ACS_TOKEN	ACS Token for authenticating DC/OS requests	string		false unless dcos.toml-file unset
GM_CONTROL_MARATHON_DCOS_INSECURE	If true, do not verify DC/OS SSL certificates	boolean	false	false
GM_CONTROL_MARATHON_DCOS_REQUEST_TIMEOUT	Timeout in seconds for DC/OS requests	int	5s	false

Application Specifications

Marathon applications with the label specified in GM_CONTROL_MARATHON_SELECTOR will be polled for discovery by Grey Matter Control. The default value is empty, so all applications will be polled. Applications will be linked to api clusters with the label specified in GM_CONTROL_MARATHON_CLUSTER_LABEL and its value.

Instances are generated for tasks with host equal to the task host. Each task is examined for service ports. The first exposed TCP port is used. If no ports are exposed, the task is ignored. All application labels besides the cluster label are captured as instance metadata.

Command Line

To use the command line, run gm-control with

gm-control marathon <global-flags> --dcos.toml-file={}

Help

For help or to list available options for marathon discovery using the cli, run gm-control marathon --help.