github.com/openshift/installer@v1.4.17/docs/dev/pinned-coreos.md (about)

     1  # CoreOS and the installer
     2  
     3  A key decision made before the release of OpenShift 4 is to pin the CoreOS bootimage in
     4  the installer: https://github.com/openshift/installer/commit/e080f0494708b2674fe37af02f670c8030c32bf6
     5  
     6  That is still the case today; when one gets an `openshift-install` binary, that
     7  binary contains the 2-tuple `(CoreOS, release image)`, meaning the result of an
     8  install will be the same thing each time.
     9  
    10  More background:
    11  
    12   - https://github.com/openshift/enhancements/pull/201
    13   - https://github.com/openshift/machine-config-operator/blob/master/docs/OSUpgrades.md
    14  
    15  ## Stream metadata
    16  
    17  As of 4.8 the [stream metadata enhancement](https://github.com/openshift/enhancements/blob/master/enhancements/coreos-bootimages.md)
    18  is in progress which provides a standardized JSON format and injects
    19  that data into the cluster as well.
    20  
    21  ### Updating pinned stream metadata
    22  
    23  
    24  To update the bootimage for one or more architectures, use e.g.
    25  
    26  ```
    27  $ plume cosa2stream --target data/data/coreos/rhcos.json --distro rhcos  x86_64=48.83.202102230316-0 s390x=47.83.202102090311-0 ppc64le=47.83.202102091015-0 --url https://rhcos-redirector.apps.art.xq1c.p1.openshiftapps.com/art/storage/releases --no-signatures
    28  ```
    29  
    30  For more information on this command, see:
    31  
    32  - https://github.com/coreos/coreos-assembler/pull/2000 
    33  - https://github.com/coreos/coreos-assembler/pull/2052
    34  ### Origin of stream metadata
    35  
    36  
    37  For historical reference, the initial file `data/data/rhcos-stream.json` was generated this way:
    38  
    39  ```
    40  $ plume cosa2stream --name rhcos-4.8 --distro rhcos  x86_64=48.83.202102230316-0 s390x=47.83.202102090311-0 ppc64le=47.83.202102091015-0 > data/data/rhcos-stream.json
    41  ```
    42  NOTE: the data for `data/data/rhcos-stream.json` now lives in `data/data/coreos/rhcos.json`