Kubernetes : Create Pods

Kubernetes : Create Pods 2015/12/13

Containers in Kubernetes Cluster are managed as a Pod. It's possible to run Containers to create Pods. This example is based on the environment like follows. +---------------------+ | [ Admin Node ] | | dlp.server.world | | | +----------+----------+ | +----------------------+ | +----------------------+ | [ Node01 ] |10.0.0.51 | 10.0.0.52| [ Node02 ] | | node01.server.world +----------+----------+ node02.server.world | | | | | +----------------------+ +----------------------+

	For example, Create a Pod with single container which httpd is installed.
[1]	Create a Container image which httpd is installed on a Node, refer to here. The image name is "web_server" for configuratuion on this exmaple.
[2]	Copy a container image just created above to all other Nodes like follows.

# output container image to a file [root@node01 ~]#  docker save web_server > web_server.tar # copy the image to other Nodes [root@node01 ~]#  scp web_server.tar node02:/root/web_server.tar

[3]	Load the comtainer image just copied.

[root@node02 ~]#  docker load < web_server.tar  [root@node02 ~]#  docker images  REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE web_server latest 084ef53f3d83 11 minutes ago 283.9 MB docker.io/centos latest ce20c473cd8a 8 weeks ago 172.3 MB

[4]	Create a Pod on Admin Node.

[root@dlp ~]#  vi pod-webserver.yaml apiVersion: v1 kind: Pod metadata: # name of Pod name: httpd labels: # rabel of Pod app: web_server spec: containers: # name of Container - name: httpd # Container image image: web_server ports: # Container Port - containerPort: 80 # create Pod [root@dlp ~]#  kubectl create -f pod-webserver.yaml  pods/httpd # show Pods list [root@dlp ~]#  kubectl get pods -o wide  NAME READY STATUS RESTARTS AGE NODE httpd 0/1 Running 0 8s node01 # display assigned IP address on the Pod [root@dlp ~]#  kubectl get pod httpd -o yaml | grep "podIP"  podIP: 172.16.35.10 # access to the Pod [root@dlp ~]#  curl http://172.16.35.10/  Hello DockerFile

[5]	If you'd like to remove a Pod, do like follows.

[root@dlp ~]#  kubectl delete pod httpd  pods/httpd