sample-applications

Sample apps for Redis and PostgreSQL

There are 2 sample applications to start getting metrics into your cluster, postgresql-python-sample and redis-ruby-sample.

Requirements to deploy sample apps

1. AKS cluster up and running.
2. Azure Redis credentials.
3. Azure PostgreSQL credentials.
4. Terminal connected with Kubectl to your cluster.

Deployment

1. Create two folders: postgres-creds and redis-creds. Paste your credentials in them like the instructions suggest.
2. Create a kubernetes secret.
3. Deploy both services: postgresql-python-deployment.yaml and redis-ruby-deployment.yaml
4. Verify they are both up and running.

Here are the details on how to deploy each application.

Deploy PostgreSQL python sample application

To deploy the python app that consumes the PostgreSQL database you can run the following commands from the root of this directory.

Put credentials in a folder

Create secrets for postgreSQL credentials (remember this is not secure for prod environments):

# Create files to avoid escaping character
mkdir postgres-creds
echo -n '< REPLACE WITH POSTGRESQL USERNAME >' > postgres-creds/username-p.txt
echo -n '< REPLACE WITH POSTGRESQL PASS >' > postgres-creds/password-p.txt
echo -n '< REPLACE WITH POSTGRESQL HOSTNAME >' > postgres-creds/hostname-p.txt

Create k8s secret with that folder

kubectl create secret generic postgresql-user-pass --from-file=postgres-creds

The credentials are now stored in the cluster. You can delete them from your computer

rm -rf postgres-creds

Deploy the application to your cluster

kubectl apply -f sample-applications/postgresql-python-client/postgresql-python-deployment.yaml

Verify the installation

See the progress of the deployment in the describe:

kubectl describe po -l app=postgresql-sample
  Type    Reason     Age   From                               Message
  ----    ------     ----  ----                               -------
  Normal  Scheduled  74s   default-scheduler                  Successfully assigned default/postgresql-sample-deployment-86b9d655f-mzqpj to aks-agentpool-31039371-1
  Normal  Pulling    72s   kubelet, aks-agentpool-31039371-1  pulling image "brusmx/postgresql-python-sample:1.0"
  Normal  Pulled     70s   kubelet, aks-agentpool-31039371-1  Successfully pulled image "brusmx/postgresql-python-sample:1.0"
  Normal  Created    69s   kubelet, aks-agentpool-31039371-1  Created container
  Normal  Started    69s   kubelet, aks-agentpool-31039371-1  Started container

And then after a few seconds you will see it consuming the database:

kubectl logs -l app=postgresql-sample

Obtained credentials .
Inserted 163 individuals
1516 rows. Sleeping for 300 seconds...

7 individuals deleted
1509 rows. Sleeping for 300 seconds...

Redis ruby sample application

To deploy the ruby app that consumes Redis you can run the following commands from the root of this directory.

Store credentials in a folder

Create secrets for Redis credentials:

mkdir redis-creds
# Create files to avoid escaping character
echo -n '< REPLACE WITH REDIS PASS >' > redis-creds/password-r.txt
echo -n '< REPLACE WITH POSTGRESQL HOSTNAME >' > redis-creds/hostname-r.txt

Create a k8s secret with that folder

kubectl create secret generic redis-creds --from-file=redis-creds

And remove the folder from your filesystem:

rm -rf redis-creds

Deploy your redis application

If you have port 6379 as default you can leave the yaml as is. If your port is different, please change it in the yaml file.

NOTE: SSL enforced is not currently supported

kubectl apply -f sample-applications/redis-ruby-client/redis-ruby-deployment.yaml

After your pod is running, and if it's your first time running the application you will need to create the database schemas. Run the following command:

kubectl exec -it <<REDIS SAMPL POD NAME>> -- rails db:migrate

Verify the deployment

Wait for your pod to be up and running:

kubectl get pods -l app=redis-sample
---
NAME                                       READY   STATUS    RESTARTS   AGE
redis-sample-deployment-7f95f4b86c-ttj6b   1/1     Running   0          6m32s

You can use forward your local port 9090 to connect to that service.

kubectl port-forward redis-sample-deployment-7f95f4b86c-ttj6b 9090:3000

Visit 127.0.0.1:9090 where you willl see a list of articles. Create a few and that will upload them to Redis.