Getting Started

• Install Marathon
• Setup Recommendations
• High Availability Mode

Using Marathon

• Application Basics
• Application Deployments
• Application Groups
• Authorization and Access Control
• Blue-Green Deployment
• Constraints
• Event Bus
• Health Checks
• Marathon Web Interface
• Networking
• Pods
• Recipes
• Provisioning Containers
• Stateful Applications Using Local Persistent Volumes
• Stateful Applications Using External Persistent Volumes
• Task Environment Variables
• Task Handling
• Task Handling Configuration
• Secret Configuration
• Unreachable Strategy

Administration

• Command Line Flags
• Backup and Restore
• Data Migration
• Framework Authentication
• High Availability
• Metrics
• Deprecated Metrics
• Readiness Checks
• Checks
• Service Discovery and Load Balancing
• SSL and Basic Authentication
• Seccomp
• Using a Private Docker Registry
• Maintenance mode
• Compatibility with Mesos

Upgrading

• Upgrading to a new Version
• Migrating Apps to the 1.5 Networking API
• Migrating Tools to the 1.5 Networking API
• Versioning

Troubleshooting

• Stuck App or Pod Deployments
• No new instances are starting
• An App Requires a Specific Host Port
• Error Using HTTPS with local CA Certificate
• Error Reading Authentication Secret
• Slow Docker apps and deployments
• Exit Codes

Development

• Contributor Guidelines
• Current Marathon Development
• Extend Marathon with Plugins
• Run a Local Version of Marathon

API Reference

• REST API Reference

Docs for Previous Versions

Task Environment Variables

Marathon sets up some environment variables for each task it launches in addition to those set by Mesos.

User-defined Data

Each element of the env field of each task’s app definition describes an environment variable.

Note: No custom prefix will be added to these variable names, even if one is specified via the --env_vars_prefix command line flag.

Host Ports

Host ports are the ports at which the application is reachable on the host running the Mesos agent.

For the Mesos executor, these are also the ports that the application should listen to. In both container and container/bridge modes, the application should actually bind to the containerPort, which is typically the same for each task since the containers use their own network stack.

Two environment variables are set for each assigned port resource. One is by-index and the other is by-name. Referencing ports by name is strongly encouraged.

By-index variables are named PORT0 through PORT{N-1} where N is the number of assigned ports. In addition, provided there is at least one assigned port, then PORT has the same value as PORT0.

By-name variables are named PORT_xxx where xxx is the name of some portDefinition or portMapping. See the networking docs for details.

The PORTS variable contains a comma-separated list of all assigned host ports.

Note: It is possible to specify a custom prefix for these variable names through the --env_vars_prefix command line flag.

App Metadata

• MARATHON_APP_ID contains the complete path of the corresponding app definition. For example /httpServer, or /webshop/db.
• MARATHON_APP_VERSION contains the version of the app definition which was used to start this task. For example 2015-04-02T09:37:00.596Z.
• MARATHON_APP_DOCKER_IMAGE contains the value of the app definition container.docker.image value. For example mesosphere/marathon:latest, nginx or nginx:1.9.3.
• MARATHON_APP_RESOURCE_CPUS contains the value of the app definition cpus value.
• MARATHON_APP_RESOURCE_MEM contains the value of the app definition mem value, expressed in megabytes.
• MARATHON_APP_RESOURCE_DISK value of the app definition disk value, expressed in megabytes.
• MARATHON_APP_LABELS contains list of labels of the corresponding app definition. For example: label1 label2 label3
• MARATHON_APP_LABEL_NAME contains value of label “NAME” of the corresponding app definition.

Note: No custom prefix will be added to these variable names, even if one is specified via the --env_vars_prefix command line flag.

Note: Label name will be sanitized: all characters except a-z A-Z 0-9 _ will be replaced with _. All keys and values longer than 512 chars will be omitted.

Task Metadata

• MESOS_TASK_ID contains the ID of this task as used by Mesos. For example test3.d10caa92-d91b-11e4-b351-56847afe9799

Values Set by Mesos

This is by no means exhaustive!

• MESOS_SANDBOX Path within the container to the mount point of the sandbox directory.