Getting started with logging: Lokistack

This tutorial explains how to view the logs of an application on Openshift.

Requirements

To follow this guide, please make sure that you have the following tools installed:

oc: You can download the OpenShift command directly from OpenShift Web Console. Open the help menu (marked as a question mark at the top right) and select the "Command line tools" entry.

Step 1: Deploy Fortune application

Create a new namespace called demo-fortune

oc new-project demo-fortune

If you get an error that the namespace already exists, please pick another name and try again. We recommend prefixing the name with the name of your organization to minimize potential for name collisions.

Create Fortune application manifest

Manifest for Fortune application

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: fortune-cookie
  name: fortune-cookie
spec:
  replicas: 1
  selector:
    matchLabels:
      app: fortune-cookie
  template:
    metadata:
      labels:
        app: fortune-cookie
    spec:
      containers:
      - image: registry.gitlab.com/vshn/applications/fortune-go:latest
        imagePullPolicy: IfNotPresent
        name: fortune-cookie
---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: fortune-cookie
  name: fortune-cookie
spec:
  ports:
  - port: 8080
    protocol: TCP
    targetPort: 8080
    name: web
  selector:
    app: fortune-cookie
  type: ClusterIP

Deploy Fortune application manifest
```
oc apply -f fortune.yaml
```
Expose Fortune application
```
oc expose svc/fortune-cookie
```

Step 2: View Fortune application logs

The current / live logs can be viewed from the logs tab of the pod
To access the aggregated logs from all pods, change to the aggregated logs tab
```
{ kubernetes_container_name="fortune-cookie" } | json
```