The controller works by adding immutability to all the secrets that are currently being used by pods however it restricts it to a set of images that are specified by the ImmutableImages custom resource. However it doesn't actually tag the secret as immutable, rather it keeps a list of such secrets in a Custom Resource and a validating webhook for secrets is triggered on any updates which checks if the particular secret is part of the ImmutableSecrets list of the CR or not.

Upon any updates to to ImmutableImages or creation of a new pod, the reconciliation occurs, it looks for all the new secrets that should be marked as immutable by looking for the various ways in which a secret is attached to containers.

Preventing changes to the data of an existing Secret has the following benefits:

• protects you from accidental (or unwanted) updates that could cause applications outages
• improves cluster performance by reducing apiserver load (not applicable with our webhook)

Ref: Secrets

• Check when secret is deleted and a pod is created that refers it (secret Get failure)
• Add namespace to the CR as well
• Check if it's possible to edit the secret from the pod itself!
• Remove statefulness from the CR to allow for updates to the list. Think about doing it without the map somehow (if the webhook thing happens, what we can do is every reconcile, create the spec and status, so that there's no state to keep track of)
• Check for pod deletion updating the CR as well, since the image that is tracked in the CR could be only referred by the deleted pod.

• go version v1.22.0+
• docker version 17.03+.
• kubectl version v1.11.3+.
• Access to a Kubernetes v1.11.3+ cluster.

Build and push your image to the location specified by IMG:

make docker-build docker-push IMG=<some-registry>/secret-controller:tag

NOTE: This image ought to be published in the personal registry you specified. And it is required to have access to pull the image from the working environment. Make sure you have the proper permission to the registry if the above commands don’t work.

Install the CRDs into the cluster:

make install

Deploy the Manager to the cluster with the image specified by IMG:

make deploy IMG=<some-registry>/secret-controller:tag

NOTE: If you encounter RBAC errors, you may need to grant yourself cluster-admin privileges or be logged in as admin.

Create instances of your solution You can apply the samples (examples) from the config/sample:

kubectl apply -k config/samples/

NOTE: Ensure that the samples has default values to test it out.

Delete the instances (CRs) from the cluster:

kubectl delete -k config/samples/

Delete the APIs(CRDs) from the cluster:

make uninstall

UnDeploy the controller from the cluster:

make undeploy

Following are the steps to build the installer and distribute this project to users.

1. Build the installer for the image built and published in the registry:

make build-installer IMG=<some-registry>/secret-controller:tag

NOTE: The makefile target mentioned above generates an 'install.yaml' file in the dist directory. This file contains all the resources built with Kustomize, which are necessary to install this project without its dependencies.

2. Using the installer

Users can just run kubectl apply -f to install the project, i.e.:

kubectl apply -f https://raw.githubusercontent.com/<org>/secret-controller/<tag or branch>/dist/install.yaml

// TODO(user): Add detailed information on how you would like others to contribute to this project

NOTE: Run make help for more information on all potential make targets

More information can be found via the Kubebuilder Documentation

Copyright 2024.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.