Install the version 3 odo client into a directory in your $PATH.

Install the latest oc client into a directory in your $PATH.

Create and change to a new directory. Launch vscode and open the folder that you created.

mkdir demo
cd demo
code .

Open 2 terminals in vscode, launch a web browser and login to the Openshift web console.

In the upper right menu under your name in the Openshift web console, choose Copy Login Command -> Display Token then copy the server and token arguments from the example oc command string.

Perform the following steps using the odo client from a vscode terminal.

Login to the Openshift API server.

odo login --token=sha256~logintoken --server=https://api.ocp.mysandbox.com:6443

Create a new project.

odo create project odo-demo

Example output.

 ✓  Project "odo-demo" is ready for use
 ✓  New project created and now using project: odo-demo

Create a new python flask application named flask-example.

odo init --name flask-example --starter=flask-example --devfile=python

Start developer mode to allow for local interactive development.

odo dev

Example output.

  __
 /  \__     Developing using the flask-example Devfile
 \__/  \    Namespace: odo-demo
 /  \__/    odo version: v3.0.0-rc2
 \__/

↪ Deploying to the cluster in developer mode
 •  Waiting for Kubernetes resources  ...
 ⚠  Pod is Pending
 ✓  Pod is Running
 ✓  Syncing files into the container [891ms]
 ✓  Building your application in container on cluster (command: pip-install-requirements) [3s]
 •  Executing the application (command: run-app)  ...
 -  Forwarding from 127.0.0.1:40001 -> 8080

↪ Dev mode
 Status:
 Watching for changes in the current directory /Users/bkozdemb/demo

 Keyboard Commands:
[Ctrl+c] - Exit and delete resources from the cluster
     [p] - Manually apply local changes to the application on the cluster
Pushing files...

File /Users/bkozdemb/demo/.odo changed
 •  Waiting for Kubernetes resources  ...
 ✓  Syncing files into the container 

↪ Dev mode
 Status:
 Watching for changes in the current directory /Users/bkozdemb/demo

 Keyboard Commands:
[Ctrl+c] - Exit and delete resources from the cluster
     [p] - Manually apply local changes to the application on the cluster

The odo client should set up a port-forwarding rule that will allow access to your application endpoint at http://127.0.0.1:40001. Even though the python application is running in Openshift, it can be accessed via a local IP and port.

curl http://127.0.0.1:40001

Hello World!

In VSCode, edit the app.py file and make a simple code change.

Save the file and odo developer mode will automatically push any changes to the running pod in Openshift. Another curl command may be used to verify the change.

curl http://127.0.0.1:40001

Hello Python World!

Create a postgresql database using a built-in Openshift template. This may be done via the oc CLI or Openshift console.

CLI example

oc new-app --template=postgresql-ephemeral -p POSTGRESQL_USER=postgres -p POSTGRESQL_PASSWORD=postgres -p POSTGRESQL_DATABASE=postgres --dry-run=False

Replace the contents of app.py that was created by the odo template with the version in this repo. It contains basic code to connect to the postgresql database and return the connection IP address.

Initially, the app will error because the psycopg library can't be found. Running curl and examining the logs will reveal this.

curl 127.0.0.1:40001

curl: (52) Empty reply from server

oc logs flask-example-app-<pod-id>

...
File "/projects/app.py", line 3, in <module>
   import psycopg
ModuleNotFoundError: No module named 'psycopg'

Fix this by replacing adding psycopg[binary] to the requirements.txt file that was created by odo init.

We're getting closer. The logs should reveal that the app runs but fails to connect to the database server.

oc logs flask-example-app-<pod-id>

...
INFO:root:POSTGRESQL_DATABASE = None
INFO:root:POSTGRESQL_USER = None
INFO:root:POSTGRESQL_PASSWORD = None
INFO:root:DB Connection Failed!
INFO:root:Exiting.

Notice the environment variables needed for authentication are null. We'll fix this by adding the environment variables to devfile.yaml.

Fixed that by the replacing the contents of devfile.yaml that was created by the odo template with the version in this repo.

After modifying devfile.yaml you should notice that a new pod will get built and deployed. Now the curl should succeed.

curl 127.0.0.1:40001

Connected to postgresql at 172.30.224.110

Congratulations on orchestrating your first Openshift application!

This concludes the demo.