The OpenShift team cuts 4 different types of releases, all of them available from the download mirrors. However they differ on naming and location:
- Stable: highest quality release and intended for customer use.
- Release Candidate: early customer access for staging environments and integration testing.
- Dev preview: very early customer access for feature assessment and dev environments.
- Nightly: for inter-op and continuous testing.
Some differences:
- Stable builds are stored in the main download location
- RC and Development/nightly builds are stored in a different location
- Stable and RC builds publish their container images to this quay namespace
- Development builds publish to this quay namespace, but it is protected and you will need to authenticate using your cloud.redhat.com pull secret.
- Nightly builds published to openshiftapps.com. Accessible only through DCI.
For more information about the available builds, please reference the OpenShift Release Types documentation.
DCI uses component tags (in this case, an OCP build maps to a component in the
DCI control server) to identify tags, DCI uses build:ga (or "general
availability") for stable builds, build:candidate for RC builds and
build:dev for dev preview and build:nightly for nightlies.
Here's a table to summarize the changes in URLs across all versions we have identified:
| Build type | DCI Tag | OCP Mirror Base URL | Quay.io Namespace |
|---|---|---|---|
| Stable | build:ga |
mirror.openshift.com/pub/openshift-v4/clients/ocp | quay.io/openshift-release-dev/ocp-release |
| Candidate | build:candidate |
mirror.openshift.com/pub/openshift-v4/clients/ocp-dev-preview | quay.io/openshift-release-dev/ocp-release |
| Dev | build:dev |
mirror.openshift.com/pub/openshift-v4/clients/ocp-dev-preview | quay.io/openshift-release-dev/ocp-release-nightly |
| Nightly | build:nightly |
openshiftapps.com | registry.ci.openshift.org |
The DCI OCP agent fetches the release.txt file from the OCP mirror and then
parses it to figure out the SHA256 for the image to pull from Quay. This way
there is no ambiguity on what image to download.