Documentation > Installation > Setup on OpenShift

Setup on OpenShift

OpenShift is Red Hat's Platform-as-a-Service (PaaS), focused on hosting web applications. Resources are mapped as "Gears" and application setup is provided by "Cartridges". Cartridges are the plug-ins that house the framework or components that can be used to create and run an application.

Crossbar.io can be run on OpenShift since they provide a beta WebSocket support on HTTP (8000) and HTTPS (8443).

Pre-requisites

Crossbar.io on OpenShift

To run crossbar.io on OpenShift you will have to use a DIY cartridge. That is because Python cartridges are based on Apache+mod_wsgi so they won't handle Websockets. Using DIY the request is passed from the Openshift Websocket proxy directly into you application local port.

There are two options for deploying Crossbar.io:

  1. Use a a base application to start with
  2. Create your DIY application from scratch

This howto uses option (1.).

Use a a base application to start with

There is an OpenShift application which you can use as a starting point for your Crossbar.io installation. This base application was created to provide a minimal setup to run a standard Crossbar.io installation (based on crossbar init) using Python-3.5.

It also provide a way to easy customize the Crossbar.io instance by editing its configuration file config.{yaml,json}.

To use it you can:

  1. Call rhc app create passing --from-code https://github.com/jvdm/openshift-crossbar.
  2. Use the web console interface on the Add Application page, select Do-It-Yourself 0.1 and set the Source Code field.

Crossbar.io configuration

Crossbar.io configuration on OpenShift can't be static: that's because the ip address and port used must match the ones OpenShift is expecting you to use. OpenShift provides this information through environment variables: OPENSHIFT_DIY_IP and OPENSHIFT_DIY_PORT.

The application will use config.{json,yaml} files in the project's root as a template to create .crossbar/config.{json,yaml}, by evaluating any shell variable expansion inside the file. That's how you have a dynamic crossbar configuration on crossbar.io startup.

If you want to change crossbar.io configuration, you just need to edit the config.yaml file on the project's root. You can change its name to config.json if you prefer working with JSON. But this file will be used only as a "template": the crossbar instance will be run using .crossbar as CROSSBAR_DIR, so adjust your paths.

What will you get

After application deploy (which is done by a git push), you should be able to access the web worker on http://<app-name>-<domain-name>.rhcloud.com.

To connect to the router using websockets you will need to use port :8000: http://<app-name>-<domain-name>.rhcloud.com:8000/ws.