UpdatePod

⚠️ DO NOT USE IN PRODUCTION

UpdatePod is a background service that monitors a running pod in a Kubernetes cluster and automatically restarts its managing Deployment based on environment configuration.

This is useful for triggering image pull/update without replacing the image tag — especially when imagePullPolicy: Always is used.

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📦 Docker Image

Pull from Docker Hub:

docker pull aanilkay/updatepod:latest

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⚙️ Environment Variables

Variable Name	Description	Example
POD_NAMESPACE	Namespace of the pod	default
POD_NAME_PREFIX	Prefix of the pod name to match	my-app
POD_CONTAINER_NAME	(Optional) Container name inside the pod	web
RESTART_INTERVAL_MINUTES	Interval in minutes for auto-check and restart	10

All values are case-sensitive. If a pod with the given prefix is not found, nothing will happen.

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🚀 What It Does

1. On start, reads environment variables.

2. Finds the first pod that starts with the provided prefix.

3. Follows the chain:

   • Pod → ReplicaSet → Deployment

4. Patches the Deployment to add a restart annotation:

   spec:
     template:
       metadata:
         annotations:
           kubectl.kubernetes.io/restartedAt: <timestamp>

5. Waits for the given interval, then repeats.

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🧪 Local Testing with launchSettings.json

"profiles": {
  "UpdatePod": {
    "commandName": "Project",
    "environmentVariables": {
      "POD_NAMESPACE": "default",
      "POD_NAME_PREFIX": "my-app",
      "POD_CONTAINER_NAME": "web",
      "HARBOR_ROBOT_USER": "robot$yourproject",
      "HARBOR_ROBOT_TOKEN": "your-harbor-token",
      "DOCKER_HUB_TOKEN": "your-docker-hub-token"
    }
  }
}

How to Add Harbor Robot User and Token

To use Harbor robot credentials, follow these steps:

1. Create a Robot Account in your Harbor project:

• Go to your Harbor project.
• Navigate to Robot Accounts.
• Click New Robot Account and set permissions.
• Copy the generated username (e.g., robot$yourproject) and token.

2. Add to launchSettings.json:

• Set HARBOR_ROBOT_USER to the robot username.
• Set HARBOR_ROBOT_TOKEN to the robot token.

Example:

"environmentVariables": {
  "HARBOR_ROBOT_USER": "robot$yourproject",
  "HARBOR_ROBOT_TOKEN": "your-harbor-token"
}

Keep robot credentials secure and do not share them publicly.

How to get Docker Hub Token

To obtain a Docker Hub token for API authentication, follow these steps:

1. Send a POST request to the Docker Hub login endpoint:

https://hub.docker.com/v2/users/login/

2. Include your Docker Hub username and password in the request body as JSON:

{
  "username": "your_dockerhub_username",
  "password": "your_dockerhub_password"
}

3. Example using curl:

curl -X POST -H "Content-Type: application/json" \
  -d '{"username": "your_dockerhub_username", "password": "your_dockerhub_password"}' \
  https://hub.docker.com/v2/users/login/

4. The response will contain a token:

{
  "token": "your_dockerhub_token"
}

5. Use this token as a Bearer token in the Authorization header for subsequent Docker Hub API requests.

Note: Keep your token secure and do not share it publicly.

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☸️ Kubernetes Deployment Example

apiVersion: apps/v1
kind: Deployment
metadata:
  name: updatepod
  namespace: your-namespace
spec:
  replicas: 1
  selector:
    matchLabels:
      app: updatepod
  template:
    metadata:
      labels:
        app: updatepod
    spec:
      serviceAccountName: updatepod-sa
      containers:
        - name: updatepod
          image: aanilkay/updatepod:latest
          env:
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
            - name: POD_NAME_PREFIX
              value: my-app
            - name: POD_CONTAINER_NAME
              value: web
            - name: RESTART_INTERVAL_MINUTES
              value: "10"

---

🔐 Minimal Required RBAC Permissions

apiVersion: v1
kind: ServiceAccount
metadata:
  name: updatepod-sa
  namespace: your-namespace
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: updatepod-role
  namespace: your-namespace
rules:
  - apiGroups: [""]
    resources: ["pods"]
    verbs: ["get", "list"]
  - apiGroups: ["apps"]
    resources: ["replicasets"]
    verbs: ["get"]
  - apiGroups: ["apps"]
    resources: ["deployments"]
    verbs: ["get", "patch"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: updatepod-binding
  namespace: your-namespace
subjects:
  - kind: ServiceAccount
    name: updatepod-sa
    namespace: your-namespace
roleRef:
  kind: Role
  name: updatepod-role
  apiGroup: rbac.authorization.k8s.io

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❗ Disclaimer

This tool is intended for internal development/testing purposes only.

Do not use in production environments.

It does not include any validation, security handling, or error isolation. Use at your own risk.