Istio Release

This repository defines the release process for Istio.

The release process is split into two phases, the build and publish

Build

The build step will pull down all needed sources to build a release. Generally this is from GitHub, but local files can be used as well for private builds or local testing.

Next, it will build a variety of different artifacts, including a manifest.yaml which defines what dependencies were a part of the build.

While not completely possible today, the goal is for the build process to be runnable in an air gapped environment once all dependencies have been downloaded.

Manifest

A build takes a manifest.yaml to determine what to build. See below for possible values:

# Version specifies which version is being built
# This is use for `--version`, metrics, and determining proxy capabilities.
# Note that since this determines proxy capabilities, it is desirable to follow Istio semver
version: 1.2.3

# Some of the artifacts have a docker hub built in - currently this is the operator and Helm charts
# The specified docker hub will be used there. Note - this does not effect where the images are published,
# but if the images are not later published to this hub the charts will not pull a valid image
docker: docker.io/istio

# Directory specifies the working directory to build in
directory: /tmp/istio-release

# Dependencies specifies dependencies of the build
# Note - only istio, cni, and operator are strictly required
# Other dependencies are only required to grab licenses and publish tags to Github.
# Fields:
#   localpath: rather than pull from git, copy a local git repository
#
#   git: specifies the git source to pull from
#     branch: branch to pull from git
#     sha: sha to pull from git
#     auto: rather than a static branch/sha, determine the sha to use from istio/istio.
#           possible values are `deps` to check istio.deps, and `modules` to check go.mod
dependencies:
  istio:
    git: https://github.com/istio/istio
    branch: release-1.4
  cni:
    git: https://github.com/istio/cni
    auto: deps
  operator:
    git: https://github.com/istio/operator
    auto: modules
# Extra dependencies, just for publish
  api:
    git: https://github.com/istio/api
    auto: modules
  proxy:
    git: https://github.com/istio/proxy
    auto: deps
# proxyOverride specifies an Envoy binary to use, instead of pulling one from GCS
proxyOverride: /path/to/envoy

Publish

The publish step takes in the build artifacts as an input, and publishes them to a variety of places:

• Copy artifacts to GCS
• Push docker images
• Tag all Github source repositories
• Publish a Github release

All of these steps can be done in isolation. For example, a daily build will first publish to a staging GCS and dockerhub, then once testing has completed publish again to all locations.

Credentials

The following credentials are needed

• Github token: as environment variable GITHUB_TOKEN or --githubtoken file.
• Docker credentials (TODO - how to set these).
• GCP credentials for GCS (TODO - how to set these).

Running a build

To ensure a consistent environment, the build should run in a docker container, gcr.io/istio-testing/build-tools.

The exact config used, including the specific docker tag, for Istio builds can be found at https://github.com/istio/test-infra/blob/master/prow/config/jobs/release-builder.yaml.