Document the release process (#550)

Author: mkumatag

docs/book/src/developer/release.md

@@ -1 +1,51 @@
 # Release Process
+
+## Alpha/Beta releases
+- Create a tag and push
+    ```shell
+    git clone [email protected]:kubernetes-sigs/cluster-api-provider-ibmcloud.git
+    git tag -s -m "v0.2.0-alpha.3" v0.2.0-alpha.3
+    git push origin v0.2.0-alpha.3
+    ```
+- Wait for the google cloud build to be finished 
+- Create a draft release with release notes for the tag
+- Tick the prerelease checkbox
+- Download the artifacts once cloud build is finished
+     ```shell
+    gsutil -m cp \
+      "gs://artifacts.k8s-staging-capi-ibmcloud.appspot.com/components/v0.2.0-alpha.3/cluster-template-powervs.yaml" \
+      "gs://artifacts.k8s-staging-capi-ibmcloud.appspot.com/components/v0.2.0-alpha.3/cluster-template.yaml" \
+      "gs://artifacts.k8s-staging-capi-ibmcloud.appspot.com/components/v0.2.0-alpha.3/infrastructure-components.yaml" \
+      "gs://artifacts.k8s-staging-capi-ibmcloud.appspot.com/components/v0.2.0-alpha.3/metadata.yaml" \
+      .
+    ```
+- Upload the downloaded artifacts into the release asset
+- Publish the drafted release
+> Note: In the above instructions, `v0.2.0-alpha.3` is the version/tag is being released
+
+## GA Releases
+- Create a tag and push
+    ```shell
+    git clone [email protected]:kubernetes-sigs/cluster-api-provider-ibmcloud.git
+    git tag -s -m "v0.1.0" v0.1.0
+    git push origin v0.1.0
+    ```
+- Wait for the google cloud build to be finished
+- Create a draft release with release notes for the tag
+- Perform the [image promotion process](https://github.com/kubernetes/k8s.io/tree/main/k8s.gcr.io#image-promoter):
+  - Clone and pull down the latest from [kubernetes/k8s.io](https://github.com/kubernetes/k8s.io)
+  - Create a new branch in your fork of `kubernetes/k8s.io`. 
+  - The staging repository is [here](https://console.cloud.google.com/gcr/images/k8s-staging-capi-ibmcloud/GLOBAL).
+  - Once image is present in the above staging repository, find the sha256 tag for the image by following instructions
+  ```shell
+  $ manifest-tool inspect --raw gcr.io/k8s-staging-capi-ibmcloud/cluster-api-ibmcloud-controller:v0.1.0 | jq '.[0].Digest'
+  "sha256:6c92a6a337ca5152eda855ac27c9e4ca1f30bba0aa4de5c3a0b937270ead4363"
+  ```
+  - In your `kubernetes/k8s.io` branch edit `k8s.gcr.io/images/k8s-staging-capi-ibmcloud/images.yaml` and add an entry for the version using the sha256 value got from the above command. For example: `"sha256:6c92a6a337ca5152eda855ac27c9e4ca1f30bba0aa4de5c3a0b937270ead4363": ["v0.1.0"]`
+  - You can use [this PR](https://github.com/kubernetes/k8s.io/pull/3185) as example 
+  - Wait for the PR to be approved and merged
+  - Run `make release` command
+  - Copy the content from `out` directory to release asset 
+  - Publish the drafted release
+
+> Note: In the above instructions, `v0.1.0` is the version/tag is being released