Working with Kubernetes Cluster using Kubectl Part – 9 – Multi Containers Pods

multicontainer-pod.yaml

apiVersion: v1
kind: Pod
metadata:
  name: multicontainer-pod
spec:
  containers:
  - name: producer
    image: ubuntu
    command: ["/bin/bash"]
    args: ["-c", "while true; do echo $(hostname) $(date) >> /var/log/index.html; sleep 10; done"]
    volumeMounts:
    - name: webcontent
      mountPath: /var/log
  - name: consumer
    image: nginx
    ports:
      - containerPort: 80
    volumeMounts:
    - name: webcontent
      mountPath: /usr/share/nginx/html
  volumes:
  - name: webcontent 
    emptyDir: {}

apiVersion: v1

kind: Pod

metadata:

name: multicontainer-pod

spec:

containers:

- name: producer

image: ubuntu

command: ["/bin/bash"]

args: ["-c", "while true; do echo $(hostname) $(date) >> /var/log/index.html; sleep 10; done"]

volumeMounts:

- name: webcontent

mountPath: /var/log

- name: consumer

image: nginx

ports:

- containerPort: 80

volumeMounts:

- name: webcontent

mountPath: /usr/share/nginx/html

volumes:

- name: webcontent

emptyDir: {}


#Review the code for a multi-container pod, the volume webcontent is an emptyDir...essentially a temporary file system.
#This is mounted in the containers at mountPath, in two different locations inside the container.
#As producer writes data, consumer can see it immediatly since it's a shared file system.
more multicontainer-pod.yaml

#Let's create our multi-container Pod.
kubectl apply -f multicontainer-pod.yaml

#Let's connect to our Pod...not specifying a name defaults to the first container in the configuration
kubectl exec -it multicontainer-pod -- /bin/sh
ls -la /var/log
tail /var/log/index.html
exit

#Let's specify a container name and access the consumer container in our Pod
kubectl exec -it multicontainer-pod --container consumer -- /bin/sh
ls -la /usr/share/nginx/html
tail /usr/share/nginx/html/index.html
exit

#This application listens on port 80, we'll forward from 8080->80
kubectl port-forward multicontainer-pod 8080:80 &amp;
curl http://localhost:8080

#Kill our port-forward.
fg
ctrl+c

kubectl delete pod multicontainer-pod

#Review the code for a multi-container pod, the volume webcontent is an emptyDir...essentially a temporary file system.

#This is mounted in the containers at mountPath, in two different locations inside the container.

#As producer writes data, consumer can see it immediatly since it's a shared file system.

more multicontainer-pod.yaml

#Let's create our multi-container Pod.

kubectl apply -f multicontainer-pod.yaml

#Let's connect to our Pod...not specifying a name defaults to the first container in the configuration

kubectl exec -it multicontainer-pod -- /bin/sh

ls -la /var/log

tail /var/log/index.html

exit

#Let's specify a container name and access the consumer container in our Pod

kubectl exec -it multicontainer-pod --container consumer -- /bin/sh

ls -la /usr/share/nginx/html

tail /usr/share/nginx/html/index.html

exit

#This application listens on port 80, we'll forward from 8080->80

kubectl port-forward multicontainer-pod 8080:80 &

curl http://localhost:8080

#Kill our port-forward.

ctrl+c

kubectl delete pod multicontainer-pod