Declarative Config Migrator (DCM)

dcm is a purpose-built command line tool meant to help existing users of opm who build sqlite-based index images to gracefully transition to Declarative Config-based index images using imperative workflow commands similar to what exists in opm.

Support

This tool is jointly maintained for internal use by Red Hat's OpenShift OLM team and EXD Container Pipelines team, and is tied to the lifecycle of the sqlite-to-DC operator catalog transition.

This tool tracks the deprecation and EoL timelines of OLM's sqlite support. As of 5/11/2021, the tentative plan is:

Deprecation in OpenShift 4.9
EoL in OpenShift 4.11

Install

Releases

Binary downloads are available on the releases page.

From source

( 
  TMPDIR=$(mktemp -d)
  git clone https://github.com/release-engineering/dcm $TMPDIR
  make -C $TMPDIR install
  rm -rf $TMPDIR
)

Features

The features supported by dcm are a subset of the features supported by opm that focus on the existing modes that are supported for migration to declarative config. At a high level these features are:

Migrating an existing index images

To avoid the problem of needing to build a DC index from scratch, dcm supports migrating an existing SQLite-based index image to DC and writing out a DC index directory to the local filesystem.

NOTE: Building a new DC index image is out of scope for dcm. opm's roadmap includes a feature to help users build an index image from a DC directory.

$ dcm migrate -h
Migrate an index image to a declarative config directory

Usage:
  dcm migrate <indexImage> [flags]

  Flags:
    -h, --help                help for migrate
    -d, --output-dir string   Directory in which to migrated index as declarative config (default "index")

Adding bundles

One of the primary uses of opm is to add bundles to indices, so this command is carried over to dcm. However, it only supports a subset of what the opm index add command supports.

It hardcodes replaces mode semantics. The semver and semver-skippatch modes are not supported. This includes the replaces mode behavior of automatically promoting bundles (and bundles in their replaces chain) when they are referenced in the replaces field in new channels' bundles.
It supports the --overwrite-latest flag when adding a bundle that already exists in the index and is a channel head in every channel it is a member of.
It supports adding bundles that use the olm.substitutesFor CSV annotation and making the appropriate graph updates to insert them in the correct place.

$ dcm add -h
Add a bundle to a declarative config directory

Usage:
  dcm add <dcDir> <bundleImage> [flags]

  Flags:
    -h, --help               help for add
        --overwrite-latest   Allow bundles that are channel heads to be overwritten

Deprecating bundles

There are cases when existing bundles in an index need to be marked as deprecated so that they cannot be installed on a cluster. This is a DC implementation of opm's deprecatetruncate subcommand.

Deprecate a bundle from a declarative config directory

Usage:
  dcm deprecatetruncate <dcDir> <bundleImage> [flags]

  Flags:
    -h, --help   help for deprecatetruncate

# README