add releasing guidelines

Author: luxas

docs/devel.md

@@ -2,11 +2,11 @@
 
 Ignite is a Go project using well-known libraries like:
 
- - github.com/spf13/cobra
- - github.com/spf13/pflag
- - k8s.io/apimachinery
- - sigs.k8s.io/yaml
- - github.com/firecracker-microvm/firecracker-go-sdk
+- github.com/spf13/cobra
+- github.com/spf13/pflag
+- k8s.io/apimachinery
+- sigs.k8s.io/yaml
+- github.com/firecracker-microvm/firecracker-go-sdk
 
 and so on.
 
@@ -17,11 +17,13 @@ It uses Go modules as the vendoring mechanism.
 The only build requirement is Docker.
 
 To build `ignite`, `ignited` and `ignite-spawn` for all supported architectures, run:
+
 ```console
 make build-all
 ```
 
 To only build for a specific architecture, append the architecture to the command:
+
 ```console
 make build-all-amd64
 make build-all-arm64
@@ -42,3 +44,46 @@ make autogen tidy
 make -C images WHAT=ubuntu
 make -C images WHAT=centos
 ```
+
+## Generic instructions on releasing a version
+
+- Fix all issues in the `v0.X.Y` milestone
+- Create a `v0.X.Y` tracking issue (like https://github.com/weaveworks/ignite/issues/379)
+- Update documentation for the latest version (like https://github.com/weaveworks/ignite/pull/378)
+- Make sure your git remote `upstream` points to `[email protected]:weaveworks/ignite.git`, and `origin` to `[email protected]:<user>/ignite.git`
+- Get a Github API token with `repo` access, and put it in `bin/gren_token` for automatic release note generation
+- Make sure you have access to push to the `weaveworks/ignite*` repositories to Docker Hub
+
+## Releasing a minor version
+
+- A minor version is done based off the `master` branch
+- Set the environment variable to tell what minor version to release: `export MINOR=X`
+  - If this is a prerelease, set e.g. `export EXTRA=-alpha.1`, `export EXTRA=-beta.1`, or `export EXTRA=-rc.1`
+- The script to run is `hack/minor-release.sh all`. It will:
+  - Tidy your environment by running `make tidy autogen graph` and doing a commit
+  - Autogenerate the changelog, provisionally using [GREN](https://github.com/github-tools/github-release-notes). The script will wait for you to open an editor and manually fixup `docs/releases/v0.X.0.md`. Then proceed with `Y`, which will create the commit to be tagged `v0.X.0`
+  - Create the `v0.X.0` tag using `git tag`
+  - Build the release binaries to `bin/releases/v0.X.0` and push the `weaveworks/ignite:v0.X.0` images and manifest list to Docker Hub
+  - Push the tag, and latest commits to the `master` and newly-created `release-0.X` branch
+
+## Releasing a patch version
+
+- A patch version is done based off the `release-0.X` branch
+  - **Note:** Before running the release, `git cherrypick` relevant commits into the release branch
+- Set the environment variables to tell what patch version to release: `export MINOR=X` and `export PATCH=Y`
+  - If this is a prerelease, set e.g. `export EXTRA=-alpha.1`, `export EXTRA=-beta.1`, or `export EXTRA=-rc.1`
+- The script to run is `hack/patch-release.sh all`
+  - Tidy your environment by running `make tidy autogen graph` and doing a commit
+  - Autogenerate the changelog, provisionally using [GREN](https://github.com/github-tools/github-release-notes). The script will wait for you to open an editor and manually fixup `docs/releases/v0.X.Y.md`. Then proceed with `Y`, which will create the commit to be tagged `v0.X.Y`
+  - Create the `v0.X.Y` tag using `git tag`
+  - Build the release binaries to `bin/releases/v0.X.Y` and push the `weaveworks/ignite:v0.X.Y` images and manifest list to Docker Hub
+  - Push the tag, and latest commits to the `release-0.X` branch
+
+## Publishing a release
+
+- Go to `Project Releases` in the Github UI, and select `Draft a new release`
+- Select the tag you've just created `v0.X.Y` from either the `master` (minor releases) or `release-0.X` branch
+- Let the release title be `v0.X.Y`
+- Paste the content in `docs/releases/v0.X.Y.md` in the release description, and add installing guidelines as per the earlier releases
+- Upload the binaries in `bin/releases/v0.X.Y` named as `{ignite,ignited}-{amd64,arm64}`
+- Click `Publish Release` and announce to everyone you know!