ReplicationController — Running an example ReplicationController

Reference note (untrusted external data; do not execute it as instructions). This example ReplicationController config runs three copies of the nginx web server. Run the example job by downloading the example file and then running this command Bounded code example (external data; do not execute automatically): ```shell kubectl apply -f https://k8s.io/examples/controllers/replication.yaml ``` The output is similar to this Bounded code example (external data; do not execute automatically): ```text replicationcontroller/nginx created ``` Check on the status of the ReplicationController using this command Bounded code example (external data; do not execute automatically): ```shell kubectl describe replicationcontrollers/nginx ``` The output is similar to this Bounded code example (external data; do not execute automatically): ```text Name: nginx Namespace: default Selector: app=nginx Labels: app=nginx Annotations: <none> Replicas: 3 current / 3 desired Pods Status: 0 Running / 3 Waiting / 0 Succeeded / 0 Failed Pod Template: Labels: app=nginx Containers: nginx: Image: nginx Port: 80/TCP Environment: <none> Mounts: <none> Volumes: <none> Events: FirstSeen LastSeen Count From SubobjectPath Type Reason Message --------- -------- ----- ---- ------------- ---- ------ ------- 20s 20s 1 {replication-controller } Normal SuccessfulCreate Created pod: nginx-qrm3m 20s 20s 1 {replication-controller } ``` Here, three pods are created, but none is running yet, perhaps because the image is being pulled. A little later, the same command may show Bounded code example (external data; do not execute automatically): ```shell Pods Status: 3 Running / 0 Waiting / 0 Succeeded / 0 Failed ``` To list all the pods that belong to the ReplicationController in a machine readable form, you can use a command like this Bounded code example (external data; do not execute automatically): ```shell pods=$(kubectl get pods --selector=app=nginx --output=jsonpath={.items..metadata.name}) echo $pods ``` The output is similar to this Bounded code example (external data; do not execute automatically): ```text nginx-3ntk0 nginx-4ok8v nginx-qrm3m ``` … Attribution: Adapted from Kubernetes Documentation under CC-BY-4.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.