kubectl wait for pod readiness¶

kubectl wait for pod readiness refers to the use of the kubectl wait command to block the command line session until one or more [[Pods]] reach a specific condition, such as ready.^[400-devops__06-Kubernetes__k8s-learning__06.ingress__README.md]

This is typically used in automation scripts or deployment workflows to ensure that a service has fully started before proceeding with subsequent steps, such as running integration tests or configuring Ingress rules.

Syntax¶

The general syntax for waiting on a pod to become ready involves specifying the target resource type, the desired condition, and a timeout duration^[400-devops__06-Kubernetes__k8s-learning__06.ingress__README.md]:

[kubectl](<./kubectl.md>) wait --namespace <namespace> \
  --for=condition=ready pod \
  --selector=<label-selector> \
  --timeout=<duration>

Key Parameters¶

• --for=condition=ready: Specifies that the command should wait until the status.condition of the pod is Ready.^[400-devops__06-Kubernetes__k8s-learning__06.ingress__README.md]
• --selector: Filters the pods to wait for based on label selectors (e.g., app.kubernetes.io/component=controller).^[400-devops__06-Kubernetes__k8s-learning__06.ingress__README.md]
• --timeout: Defines the maximum time to wait before the command fails and exits. If the condition is not met within this time, the command will return a non-zero exit code.^[400-devops__06-Kubernetes__k8s-learning__06.ingress__README.md]

Examples¶

Waiting for Ingress Controller¶

When deploying an Ingress controller like NGINX, it is common practice to wait until the controller pods are ready before creating Ingress resources^[400-devops__06-Kubernetes__k8s-learning__06.ingress__README.md].

[kubectl](<./kubectl.md>) wait --namespace ingress-nginx \
  --for=condition=ready pod \
  --selector=app.kubernetes.io/component=controller \
  --timeout=120s

In this example, the command pauses execution until a pod with the label app.kubernetes.io/component=controller in the ingress-nginx namespace reports as Ready, or until 120 seconds have passed^[400-devops__06-Kubernetes__k8s-learning__06.ingress__README.md].

Related Concepts¶

• kubectl
• Pod
• Ingress
• [[Deployment]]

Sources¶

^[400-devops__06-Kubernetes__k8s-learning__06.ingress__README.md]