RFC: Take ownership of composer-cli tool

[msehnout]

Motivation:

The only CLI client for Weldr API is composer-cli from the lorax repository. Given that osbuild-composer became available in both the latest RHEL and the latest Fedora, it would make sense for the osbuild organization to take ownership of the command line client so that we can quickly respond to reported issues.

These are examples from Red Hat Bugzilla and Github issues:

1. composer-cli does not communicate with the user and if it does, it does not contain anything useful [1]:

# composer-cli blueprints list
# composer-cli blueprints save
# composer-cli blueprints save /
# composer-cli blueprints save /foo
2020-11-23 15:42:03,866: foo:
zsh: exit 1     composer-cli blueprints save /foo
# composer-cli blueprints save base.toml
2020-11-23 15:42:14,427: base.toml:
zsh: exit 1     composer-cli blueprints save base.toml
# composer-cli blueprints save fail.toml
2020-11-23 15:42:19,773: fail.toml:
zsh: exit 1     composer-cli blueprints save fail.toml

2. The same issue reported again [2]:

Additionally, executing "composer-cli sources add" without any file name doesn't report an error.

3. Structure of the output is chaotic and it is not clear what it means [3]:

[fedora@ip-172-31-39-140 ~]$ sudo composer-cli compose start --size 12000 rpmci-runner-with-cloudinit ami rpmci-runner-20G provider.conf 

Compose 1bffda7a-ee0c-4b80-a711-171620ba62cc added to the queue
[fedora@ip-172-31-39-140 ~]$ 
[fedora@ip-172-31-39-140 ~]$ sudo composer-cli compose info 1bffda7a-ee0c-4b80-a711-171620ba62cc
1bffda7a-ee0c-4b80-a711-171620ba62cc FAILED   rpmci-runner-with-cloudinit 0.0.1 ami              12582912000
Packages:
2020-11-26 10:31:06,493: 'version'

We should solve these problem as soon as possible because there is no alternative client (Cockpit does not have all the features composer-cli has).

[1] composer-cli poor error handling and messages: https://bugzilla.redhat.com/show_bug.cgi?id=1900659
[2] composer-cli needs to have some decent examples: https://bugzilla.redhat.com/show_bug.cgi?id=1915353
[3] composer-cli has a poor user experience: osbuild/osbuild-composer#1105

Approach

Create a new repository with composer-cli only. Make an RPM package out of it, for example osbuild-composer-cli which would provide the composer-cli binary and it would conflict with composer-cli RPM package which is built as a subpackage of lorax.

Draft new user interface with helpful messages and implement it in the current code base. For example:

# composer-cli blueprints list
There are no blueprints. Start by creating a new one. For more information invoke: composer-cli blueprints help
# composer-cli blueprints save
You need to specify a blueprint to save: composer-cli blueprints save <BLUEPRINT.toml>
# sudo composer-cli compose start --size 12000 rpmci-runner-with-cloudinit ami rpmci-runner-20G provider.conf
Successfully created new compose and added it to the queue.
Compose UUID: 1bffda7a-ee0c-4b80-a711-171620ba62cc
Invoke composer-cli compose info 1bffda7a-ee0c-4b80-a711-171620ba62cc to monitor the progress.
# sudo composer-cli compose info 1bffda7a-ee0c-4b80-a711-171620ba62cc
Compose UUID: 1bffda7a-ee0c-4b80-a711-171620ba62cc
The compose has FAILED
Invoke composer-cli compose logs 1bffda7a-ee0c-4b80-a711-171620ba62cc to download build log.

Keep the current output format when invoked with --json as that one works fine.

Alternatives

Write a completely new client, for example https://github.com/bcl/weldr-client. If we started from scratch and took our time to do a proper research on available libraries, we could generate most of the code like parsing command line arguments (this is only partial in composer-cli), bash/zsh/fish completions, HTTP client code (if we wrote OpenAPI spec for Weldr API) and probably more. The clear downside of this approach is that we would for sure broke someone's workflow by changing some details in how composer-cli works. Nevertheless we can start by the approach described in the section above and continue with this alternative in the future.

Prototype

Ripping only composer-cli from the lorax repository should be straight forward as the repo is well structured and the code for client and server part is separate. I tried it myself and I can execute composer-cli from the src directory:
https://github.com/msehnout/osbuild-composer-cli

$ sudo python3 bin/composer-cli sources list
fedora
updates
fedora-modular
updates-modular

[bcl]

We clearly need to improve documentation for some of the commands (eg. sources which I somehow missed adding to the docs). But I don't think we can (or should) move it someplace else for RHEL8. Continue to improve what's needed in the rhel8-branch of lorax.

In Fedora 34 lorax-composer has been dropped, but the composer-cli subpackage remains. We should move that to osbuild in Fedora 34, and add my new go version as a branch to that repo so it can be worked on in the same place as the existing code.

ETA: Do we want to rename it? Now would be the best time, but I don't have any better suggestions.

[msehnout]

Oh no, naming. composerctl?

[ondrejbudai]

composerctl doesn't sound that bad. Btw it would be nice if we can do the change in RHEL 9. :)

[bcl]

I ended up moving it and rewriting it :) https://github.com/osbuild/weldr-client