external-snapshotter/release-tools

csi-release-tools

These build and test rules can be shared between different Go projects without modifications. Customization for the different projects happen in the top-level Makefile.

The rules include support for building and pushing Docker images, with the following features:

• one or more command and image per project
• push canary and/or tagged release images
• automatically derive the image tag(s) from repo tags
• the source code revision is stored in a "revision" image label
• never overwrites an existing release image

Usage

The expected repository layout is:

• cmd/*/*.go - source code for each command
• cmd/*/Dockerfile - docker file for each command or Dockerfile in the root when only building a single command
• Makefile - includes release-tools/build.make and sets configuration variables
• .travis.yml - a symlink to release-tools/.travis.yml

To create a release, tag a certain revision with a name that starts with v, for example v1.0.0, then make push while that commit is checked out.

It does not matter on which branch that revision exists, i.e. it is possible to create releases directly from master. A release branch can still be created for maintenance releases later if needed.

Release branches are expected to be named release-x.y for releases x.y.z. Building from such a branch creates x.y-canary images. Building from master creates the main canary image.

Sharing and updating

git subtree is the recommended way of maintaining a copy of the rules inside the release-tools directory of a project. This way, it is possible to make changes also locally, test them and then push them back to the shared repository at a later time.

Cheat sheet:

• git subtree add --prefix=release-tools https://github.com/kubernetes-csi/csi-release-tools.git master - add release tools to a repo which does not have them yet (only once)
• git subtree pull --prefix=release-tools https://github.com/kubernetes-csi/csi-release-tools.git master - update local copy to latest upstream (whenever upstream changes)
• edit, git commit, git subtree push --prefix=release-tools git@github.com:<user>/csi-release-tools.git <my-new-or-existing-branch> - push to a new branch before submitting a PR

verify-shellcheck.sh

The verify-shellcheck.sh script in this repo is a stripped down copy of the corresponding script in the Kubernetes repository. It can be used to check for certain errors shell scripts, like missing quotation marks. The default test-shellcheck target in build.make only checks the scripts in this directory. Components can add more directories to TEST_SHELLCHECK_DIRS to check also other scripts.

End-to-end testing

A repo that wants to opt into testing via Prow must set up a top-level .prow.sh. Typically that will source prow.sh and then transfer control to it:

#! /bin/bash -e

. release-tools/prow.sh
main

All Kubernetes-CSI repos are expected to switch to Prow. For details on what is enabled in Prow, see https://github.com/kubernetes/test-infra/tree/master/config/jobs/kubernetes-csi

Test results for periodic jobs are visible in https://testgrid.k8s.io/sig-storage-csi-ci

It is possible to reproduce the Prow testing locally on a suitable machine:

• Linux host
• Docker installed
• code to be tested checkout out in $GOPATH/src/<import path>
• cd $GOPATH/src/<import path> && ./.prow.sh

Beware that the script intentionally doesn't clean up after itself and modifies the content of $GOPATH, in particular the kubernetes and kind repositories there. Better run it in an empty, disposable $GOPATH.

When it terminates, the following command can be used to get access to the Kubernetes cluster that was brought up for testing (assuming that this step succeeded):

export KUBECONFIG="$(kind get kubeconfig-path --name="csi-prow")"

It is possible to control the execution via environment variables. See prow.sh for details. Particularly useful is testing against different Kubernetes releases:

CSI_PROW_KUBERNETES_VERSION=1.13.3 ./.prow.sh
CSI_PROW_KUBERNETES_VERSION=latest ./.prow.sh

Dependencies and vendoring

Most projects will (eventually) use go mod to manage dependencies. dep is also still supported by csi-release-tools, but not documented here because it's not recommended anymore.

The usual instructions for using go modules apply. Here's a cheat sheet for some of the relevant commands:

• list available updates: GO111MODULE=on go list -u -m all
• update or add a single dependency: GO111MODULE=on go get <package>
• update all dependencies to their next minor or patch release: GO111MODULE=on go get ./... (add -u=patch to limit to patch releases)
• lock onto a specific version: GO111MODULE=on go get <package>@<version>
• clean up go.mod: GO111MODULE=on go mod tidy
• update vendor directory: GO111MODULE=on go mod vendor

GO111MODULE=on can be left out when using Go >= 1.13 or when the source is checked out outside of $GOPATH.

go mod tidy must be used to ensure that the listed dependencies are really still needed. Changing import statements or a tentative go get can result in stale dependencies.

The test-vendor verifies that it was used when run locally or in a pre-merge CI job. If a vendor directory is present, it will also verify that it's content is up-to-date.

The vendor directory is optional. It is still present in projects because it avoids downloading sources during CI builds. If this is no longer deemed necessary, then a project can also remove the directory.

Conversion of a repository that uses dep to go mod can be done with:

GO111MODULE=on go mod init
release-tools/go-get-kubernetes.sh <current Kubernetes version from Gopkg.toml>
GO111MODULE=on go mod tidy
GO111MODULE=on go mod vendor
git rm -f Gopkg.toml Gopkg.lock
git add go.mod go.sum vendor

Updating Kubernetes dependencies

When using packages that are part of the Kubernetes source code, the commands above are not enough because the lack of semantic versioning prevents go mod from finding newer releases. Importing directly from kubernetes/kubernetes also needs replace statements to override the fake v0.0.0 versions (https://github.com/kubernetes/kubernetes/issues/79384). The go-get-kubernetes.sh script can be used to update all packages in lockstep to a different Kubernetes version. Example usage:

$ ./release-tools/go-get-kubernetes.sh 1.16.4