Marathon Deploy

A Marathon command-line deployment tool in Ruby. Takes a json or yaml file describing an application and pushes it to the Marathon REST API

Feature Summary

• Deploy a single application descriptor to multiple marathon endpoints
• Checks for existing deployment of application before starting new deployment
• Polls for Healthcheck results after deployment
• Proper exit codes for easier integration with Jenkins automated pipelines
• Deploy file macro substitution using values from locally set environment (ENV) variables (macros have the format %%MACRO_NAME%% and must match the environment variable name)
• Inject environment variables into a deployment when local environment variables with the format: MARATHON_DEPLOY_FOO=BAR are set (MARATHON_DEPLOY prefix will be removed in final json payload).
• PRODUCTION / PREPRODUCTION modes (specified with --environment)
• Rolling upgrade deployment strategy (Marathon default)

Roadmap Features

• Record actions and json payload to a database (for rollback, history, auditing)
• Deploy a deployment descriptor containing multiple applications
• Specify deployment strategy (using minimumHealthCapacity) as an option. See Marathon Deployment document

Installation

Ensure Ruby (1.9+) and ruby-dev and gem are installed on you system, then run:

$ gem install marathon_deploy

Executables from this gem:

$ marathon_deploy  (client program executable, automatically added to $PATH)
$ json2yaml (convenience utility for converting json to yaml)
$ expand_macros (expands all macros in the form %%MACRO%% with value of ENV[MACRO])

Usage

Help

>marathon_deploy -h
Usage: bin/marathon_deploy [options]
    -u, --url MARATHON_URL(S)             Default: ["http://localhost:8080"]
    -l, --logfile LOGFILE                 Default: STDOUT
    -d, --debug                           Run in debug mode
    -v, --version                         Version info
    -f, --force                           Force deployment when sending same deploy JSON to Marathon
    -n, --noop                            No action. Just display what would be performed.
    -i, --ignore-preproduction-defaults   Ignores the preproduction defaults for cpu, memory, and instance limits
    -R, --retry                           Will retry the deployment if the initial one fails
    -e, --environment ENVIRONMENT         Default: PREPRODUC

Overriding configuration based on environment

By using the -e <ENVIRONMENT> switch you can specify a custom environment which can overwrite the settings in the deploy file. For example, setting -e STAGING and creating a STAGING.yml or STAGING.json file in the same folder with the deploy file will trigger the overwriting process.

See examples/run-with-env-overrides.sh for a demo of this feature. Here we are specifying different memory settings and appending a custom health-check based on environment.

Example Deployfile

By default, a file called 'deploy.yml' is searched for in the current directory where deploy.rb is run from. An alternative file name can be provided with the -f parameter.

The file format must conform to the Marathon API specification

Minimalistic example (using Docker container):

id: python-example-stable
cmd: echo python stable `hostname` > index.html; python3 -m http.server 8080
mem: 16
cpus: 0.1
instances: 5
container:
  type: DOCKER
  docker:
    image: ubuntu:14.04
    network: BRIDGE
    portMappings:
    - containerPort: 8080
      hostPort: 0
      protocol: tcp
env:
  SERVICE_TAGS: python,webapp,http,weight=100
  SERVICE_NAME: python
healthChecks:
- portIndex: 0
  protocol: TCP
  gracePeriodSeconds: 30
  intervalSeconds: 10
  timeoutSeconds: 30
  maxConsecutiveFailures: 3
- path: "/"
  portIndex: 0
  protocol: HTTP
  gracePeriodSeconds: 30
  intervalSeconds: 10
  timeoutSeconds: 30
  maxConsecutiveFailures: 3

JSON to YAML file conversion

As a convenience, the provided json2yaml.rb script can convert a JSON file to the arguably more human-readable YAML format:

$json2yaml marathon-webapp.json  > marathon-webapp.yaml

Parsing a file with macro expansion from ENV variables

A helper script which takes a file and replaces all macros having the format %%MACRO%% with the values from ENV variables. Script will fail if there are no ENV values for macro names contained in the template.

$expand_macros -h
Usage: bin/expand_macros.rb [options]
    -o, --outfile OUTFILE            Default: STDOUT
    -l, --logfile LOGFILE            Default: STDOUT
    -d, --debug                      Run in debug mode
    -v, --version                    Version info
    -f, --force                      force overwrite of existing OUTFILE
    -t, --template TEMPLATE_FILE     Input file. Default: dockerfile.tpl
    -h, --help                       Show this message

Contributing

1. Fork it ( https://github.com/[my-github-username]/marathon_deploy/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request