Manually delete namespace with a finalizer

Problem

Sometimes you need to delete a namespace, but the deletion is stuck because of the finalizer. When you depleted all other options and you cannot move forward without deleting the namespace, you can consider removing it forcibly.

Solution

1. View the namespaces that are stuck in the Terminating state:

   kubectl get namespaces

2. Select a terminating namespace and view the contents of the namespace to find out the finalizer:

   kubectl get namespace <terminating-namespace> -o yaml

   Your YAML contents might resemble the following output:

    apiVersion: v1
    kind: Namespace
    metadata:
      creationTimestamp: 2018-11-19T18:48:30Z
      deletionTimestamp: 2018-11-19T18:59:36Z
      name: <terminating-namespace>
      resourceVersion: "1385077"
      selfLink: /api/v1/namespaces/<terminating-namespace>
      uid: b50c9ea4-ec2b-11e8-a0be-fa163eeb47a5
    spec:
      finalizers:
      - kubernetes
    status:
      phase: Terminating

3. Create a temporary JSON file:

   kubectl get namespace <terminating-namespace> -o json > tmp.json

   Edit your tmp.json file. Replace the value of the finalizers field with null.

   Your tmp.json file might resemble the following output:

   {
     "apiVersion": "v1",
     "kind": "Namespace",
     "metadata": {
        "creationTimestamp": "2018-11-19T18:48:30Z",
        "deletionTimestamp": "2018-11-19T18:59:36Z",
        "name": "<terminating-namespace>",
        "resourceVersion": "1385077",
        "selfLink": "/api/v1/namespaces/<terminating-namespace>",
        "uid": "b50c9ea4-ec2b-11e8-a0be-fa163eeb47a5"
     },
     "spec": {
        "finalizers": null
     },
     "status": {
        "phase": "Terminating"
     }
   }

4. Set a temporary proxy IP and port. If the command recommends using the --append-server-path flag, follow the recommendation. Be sure to keep your terminal window open until you delete the stuck namespace:

   kubectl proxy

   Your proxy IP and port might resemble the following output:

   Starting to serve on 127.0.0.1:8001

5. From a new terminal window, make an API call with your temporary proxy IP and port:

   curl -k -H "Content-Type: application/json" -X PUT --data-binary @tmp.json http://127.0.0.1:8001/api/v1/namespaces/<terminating-namespace>/finalize

   Your output might resemble the following content:

   {
      "kind": "Namespace",
      "apiVersion": "v1",
      "metadata": {
          "name": "<terminating-namespace>",
          "selfLink": "/api/v1/namespaces/<terminating-namespace>/finalize",
          "uid": "b50c9ea4-ec2b-11e8-a0be-fa163eeb47a5",
          "resourceVersion": "1602981",
          "creationTimestamp": "2018-11-19T18:48:30Z",
          "deletionTimestamp": "2018-11-19T18:59:36Z"
      },
      "spec": {
      },
      "status": {
          "phase": "Terminating"
      }
   }

   Note: The finalizer parameter is removed.

6. Verify that the terminating namespace is removed:

   kubectl get namespaces