fetch-images command (#768)

Implementation of a command to fetch pre-built images from a remote registry, complementing the --push-images option already present on build-containers.

The two subcommands used together allow a stack to be deployed without needing to built its images, provided they have been already built and pushed to the specified container image registry.

This implementation simply picks the newest image with the right name and platform (matches against the platform Python is running on, so watch out for scenarios where Python is an x86 binary on M1 macs).

Reviewed-on: cerc-io/stack-orchestrator#768
Co-authored-by: David Boreham <david@bozemanpass.com>
Co-committed-by: David Boreham <david@bozemanpass.com>

stack_orchestrator/main.py

@@ -17,7 +17,7 @@ import click
 
 from stack_orchestrator.command_types import CommandOptions
 from stack_orchestrator.repos import setup_repositories
-from stack_orchestrator.build import build_containers
+from stack_orchestrator.build import build_containers, fetch_containers
 from stack_orchestrator.build import build_npms
 from stack_orchestrator.build import build_webapp
 from stack_orchestrator.deploy.webapp import (run_webapp,
@@ -52,6 +52,7 @@ def cli(ctx, stack, quiet, verbose, dry_run, local_stack, debug, continue_on_err
 
 cli.add_command(setup_repositories.command, "setup-repositories")
 cli.add_command(build_containers.command, "build-containers")
+cli.add_command(fetch_containers.command, "fetch-containers")
 cli.add_command(build_npms.command, "build-npms")
 cli.add_command(build_webapp.command, "build-webapp")
 cli.add_command(run_webapp.command, "run-webapp")