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

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

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