feat(release): add create-release-branch target

Makefile

@@ -615,7 +615,6 @@ hack/release/ut:
 	sh -c '$(GIT_CONFIG_SSH) \
 	gotestsum --format=testname --junitfile report/release/ut.xml $(PACKAGE_NAME)/hack/release'
 
-
 release-from: hack/bin/release var-require-all-VERSION-OPERATOR_BASE_VERSION var-require-one-of-EE_IMAGES_VERSIONS-OS_IMAGES_VERSIONS
 	hack/bin/release from
 
@@ -631,6 +630,9 @@ endif
 release-prep: hack/bin/release hack/bin/gh var-require-all-VERSION var-require-one-of-CALICO_VERSION-ENTERPRISE_VERSION
 	@REPO=$(REPO) hack/bin/release prep
 
+create-release-branch: hack/bin/release var-require-all-STREAM-CALICO_REF-ENTERPRISE_REF
+	RELEASE_STREAM=$(STREAM) hack/bin/release branch
+
 ###############################################################################
 # Utilities
 ###############################################################################

RELEASING.md

@@ -2,57 +2,35 @@
 
 ## Preparing a new release branch
 
-For a major or minor release, you will need to create:
+For a major or minor release, you will need to create a new `release-vX.Y` branch, a dev tag on master,
+and a GitHub milestone for the next release. The `create-release-branch` Makefile target automates creating
+the branch and dev tag; you will create the milestone manually in a later step:
 
-- A new `release-vX.Y` branch based on the target minor version.  We always do releases from a release
-  branch, not from master.
-- An empty commit on the master branch, tagged with the "dev" version for the next minor release.
-  This ensures that `git describe --tags` (which is used to generate versions for CI builds) will
-  produce a version that "makes sense" for master commits after the release branch is created.
-- A new GitHub milestone for the next minor release.  This ensures that new PRs get auto-added to
-  the correct milestone.
-
-To create a new release branch:
-
-1. If needed, fetch the latest changes from the repository remote `<remote>`:
-
-    ```sh
-    git fetch <remote>
-    ```
-
-1. Create a new branch based on the target minor version:
-
-   ```sh
-   git checkout <remote>/master -b release-vX.Y
-   ```
-
-1. Push the new branch to the repository:
+```sh
+make create-release-branch STREAM=vX.Y CALICO_REF=<calico-git-ref> ENTERPRISE_REF=<enterprise-git-ref>
+```
 
-   ```sh
-   git push <remote> release-vX.Y
-   ```
+This command:
 
-To create an empty commit and tag on master; run the following commands.  This will push directly to master,
-bypassing the normal PR process.  This is important to make sure that the tag is directly on the master branch.
-We create an empty commit because, when the release branch is created, it shares its commit history with master.
-So, if we tagged the tip of master, we'd also be tagging the tip of the release branch, which would give
-incorrect results for `git describe --tags` on the release branch.
+- Creates a `release-vX.Y` branch from master
+- Updates `config/calico_versions.yml` and `config/enterprise_versions.yml` to point at the given refs
+- Runs `make fix gen-versions-calico gen-versions-enterprise` to regenerate files
+- Commits the changes to the release branch
+- Switches back to master, creates an empty commit, and tags it `vX.(Y+1).0-0.dev`
+- Pushes the release branch, master, and tag to the remote
 
-   ```sh
-   git checkout <remote>/master
-   git commit --allow-empty -m "Start development on vX.Y"  # Where vX.Y is the next minor version
-   git tag vX.Y.0-0.dev
-   git push <remote> HEAD:master   # Note: if someone updates master before you push, delete the tag and start over from the new tip of master.
-   git push <remote> vX.Y.0-0.dev
-   ```
+**Flags / environment variables:**
 
-*Note* that the tag should have the exact format `vX.Y.0-0.dev` where `X.Y` is the next minor version.
-The `-0.dev` suffix was chosen to produce a semver-compliant version that is less than the
-first release version for the new minor version.
+| Env var                                | Flag                      | Description                                                       |
+| -------------------------------------- | ------------------------- | ----------------------------------------------------------------- |
+| `STREAM` / `RELEASE_STREAM` (required) | `--stream`                | Release stream, e.g., `v1.43`                                     |
+| `CALICO_REF` (required)                | `--calico-ref`            | Calico git ref (branch or tag), e.g., `release-v3.32`             |
+| `ENTERPRISE_REF` (required)            | `--enterprise-ref`        | Enterprise git ref (branch or tag), e.g., `release-calient-v3.22` |
+| `RELEASE_BRANCH_PREFIX`                | `--release-branch-prefix` | Branch name prefix (default: `release`)                           |
 
-Finally, create the next minor release's first milestone at https://github.com/tigera/operator/milestones.
-This would mean if the branch release-v1.30 is being created, then the milestone v1.31.0 should be created too.
-This ensures that new PRs against master will be automatically given the correct tag.
+After the branch is created, create the next minor release's first milestone at
+https://github.com/tigera/operator/milestones (e.g., if `release-v1.43` was created,
+create milestone `v1.44.0`).
 
 ## Preparing for the release
 

hack/release/README.md

@@ -8,18 +8,20 @@
     - [Build and publish a release](#build-and-publish-a-release)
     - [Build and publish a hashrelease](#build-and-publish-a-hashrelease)
   - [Commands](#commands)
-    - [release build](#release-build)
+    - [release branch](#release-branch)
       - [Examples](#examples)
-    - [release publish](#release-publish)
+    - [release build](#release-build)
       - [Examples](#examples-1)
-    - [release prep](#release-prep)
+    - [release publish](#release-publish)
       - [Examples](#examples-2)
-    - [release notes](#release-notes)
+    - [release prep](#release-prep)
       - [Examples](#examples-3)
-    - [release github](#release-github)
+    - [release notes](#release-notes)
       - [Examples](#examples-4)
-    - [release from](#release-from)
+    - [release github](#release-github)
       - [Examples](#examples-5)
+    - [release from](#release-from)
+      - [Examples](#examples-6)
 
 ## Installation
 
@@ -131,6 +133,51 @@ Unlike a release, a hashrelease is typically for either a Calico or Calico Enter
 
 ## Commands
 
+### release branch
+
+This command creates a new release branch for the operator.
+It updates the calico and enterprise version configs on the release branch, regenerates files,
+and commits the changes. It then switches back to master, creates an empty commit tagged
+with `vX.Y.0-0.dev` (so that `git describe --tags` produces sensible versions for subsequent
+master commits), and pushes the release branch, master, and tag to the remote.
+
+Both `--calico-ref` and `--enterprise-ref` are required.
+They specify the git ref (branch or tag) to use for each product's version config.
+
+```sh
+release branch --stream <vX.Y> --calico-ref <git-ref> --enterprise-ref <git-ref>
+```
+
+If the `--local` flag is specified, the branch and tag are created locally without pushing to the remote.
+
+| Flag | Env var | Description |
+|------|---------|-------------|
+| `--stream` | `RELEASE_STREAM` | Release stream (e.g., `v1.43`). Required. |
+| `--calico-ref` | `CALICO_REF` | Calico git ref (branch or tag). Required. |
+| `--enterprise-ref` | `ENTERPRISE_REF` | Enterprise git ref (branch or tag). Required. |
+| `--release-branch-prefix` | `RELEASE_BRANCH_PREFIX` | Branch name prefix (default: `release`). |
+| `--local` | `LOCAL` | Skip pushing to remote. |
+
+There is also a Makefile target:
+
+```sh
+make create-release-branch STREAM=vX.Y CALICO_REF=<ref> ENTERPRISE_REF=<ref>
+```
+
+#### Examples
+
+1. To create a release branch for operator v1.43 with Calico v3.32 and Enterprise v3.22
+
+    ```sh
+    release branch --stream v1.43 --calico-ref release-v3.32 --enterprise-ref release-calient-v3.22
+    ```
+
+1. To create a release branch locally without pushing
+
+    ```sh
+    release branch --stream v1.43 --calico-ref release-v3.32 --enterprise-ref release-calient-v3.22 --local
+    ```
+
 ### release build
 
 This command builds the operator image for a specific operator version.