Openshift quickstart: Django

The steps in this document assume that you have access to an OpenShift deployment that you can deploy applications on.

Deploying to OpenShift

To follow the next steps, you need to be logged in to an OpenShift cluster and have an OpenShift project where you can work on.

The template django.json contains just a minimal set of components to get your Django application into OpenShift.

Copy/Download the okd warrior template: django.json from the root folder of the project

A) Deploy using Openshift Web Console:

Login to openshift web-console.

Create a new namespace in the Openshift Web Console Browse or Paste the okd template in the created namespace

Adjust the parameter values to suit your configuration. Most times you can just accept the default values, however you will probably want to set the GIT_REPOSITORY parameter to point to your fork and the DATABASE_* parameters to match your database configuration.

In the web console, the overview tab shows you a service, by default called "django-example", that encapsulates all pods running your Django application. You can access your application by browsing to the service's IP address and port. You can determine these by running

oc get svc

B) Deploy using command line of okd cluster:

oc login to openshift command line.

create a namespace using oc new-project <your-app-name>

Deploy the template using following command in the cli oc new-app -f <template_name.json

The aplication is configured to access in node port:30199 , so it can accessed with the : Ex: http://django-example-hw-dj.apps.openshift.com:30199

Logs

By default your Django application is served with gunicorn and configured to output its access log to stderr. You can look at the combined stdout and stderr of a given pod with this command:

oc get pods         # list all pods in your project
oc logs <pod-name>

This can be useful to observe the correct functioning of your application.

Special environment variables

APP_CONFIG

You can fine tune the gunicorn configuration through the environment variable APP_CONFIG that, when set, should point to a config file as documented here.

DJANGO_SECRET_KEY

When using one of the templates provided in this repository, this environment variable has its value automatically generated. For security purposes, make sure to set this to a random string as documented here.

One-off command execution

At times you might want to manually execute some command in the context of a running application in OpenShift. You can drop into a Python shell for debugging, create a new user for the Django Admin interface, or perform any other task.

You can do all that by using regular CLI commands from OpenShift. To make it a little more convenient, you can use the script openshift/scripts/run-in-container.sh that wraps some calls to oc. In the future, the oc CLI tool might incorporate changes that make this script obsolete.

Here is how you would run a command in a pod specified by label:

1. Inspect the output of the command below to find the name of a pod that matches a given label:

    oc get pods -l <your-label-selector>
   

2. Open a shell in the pod of your choice. Because of how the images produced with CentOS and RHEL work currently, we need to wrap commands with bash to enable any Software Collections that may be used (done automatically inside every bash shell).

    oc exec -p <pod-name> -it -- bash
   

3. Finally, execute any command that you need and exit the shell.