Deploy and update Marathon applications based on Docker containers

Initial deploy

Generate JSON config file for your new application

deploy.py --generate awesome-app.example.com

Edit your application's config to match its needs

The new config file lives in a folder matching its name in the 'deploy/apps' dir in the docker.git repo

vi apps/awesome-app.example.com/awesome-app.example.com.json

Deploy your app to the Marathon cluster

deploy.py <marathon_cluster_hostname>

Commit and push your applications config to the docker.git repo

git commit apps/awesome-app.example.com/awesome-app.example.com.json
git push

** Please respect the following rules when deploying a new application **

• the name (ID) of your app should be a FQDN under which that app should be running (eg: 'awesome-app.example.com). This is used to configure your application in the load balancer. If it is a HTTP based application it will be used to configure the 'virtual host' in the load balancer that will distribute the requests to your container
• the network type needs to be 'BRIDGED', otherwise your containers won't be available
• after you create a new application or modify an existing one, please commit your changes to this git repo so we have a log of changes and a backup of the cluster config - the applications' configs are not saved anywhere else besides this git repo, so be careful!

Update application

If you want your application to use a new version of your container or change your application's config (CPU, Mem, no. of instances etc), the procedure is very similar to the deploy one

Modify your apps JSON config in the docker.git repo

vi apps/awesome-app.example.com/awesome-app.example.com.json

Use the same deploy command.

This is will overwrite the config in Marathon and trigger a new deployment of your application based on the 'upgradeStrategy' defined in your config

deploy.py awesome-app.example.com

Restart application

If for any reason you would like to do a rolling restart of your application, using the currently running config, use the following command. It will trigger a new deployment of your application also based on the configured 'upgradeStrategy'.

deploy.py --restart awesome-app.example.com

Generate the Nginx configs

This repository contains another tool, that can be used to generate a Nginx config for each application running in Marathon. It will be used to load balance the traffic to all the Docker instances (Host IP + Container port) running under the application.

The script is meant to be run in a loop, either as a cron job or a Supervisor program (recommended). You can find the 'generate_nginxconfig_marathon.py' under the 'proxy' directory. It assumes it runs on the same host(s) that run Nginx, the load balancing hosts / instances / servers.