User:Derat/MusicBrainzServerDevelopmentNotes

Here are some personal notes about trying to do MusicBrainz server development in June 2023.

Getting the code and setting up my local environment

I cloned the musicbrainz-server and musicbrainz-docker repositories.

Next, I followed the instructions in the "Local development of MusicBrainz Server" section of musicbrainz-docker's README.md. I encountered a DateTime::Locale version error the first time I ran the createdb.sh command, but it worked when I ran it again.

I stepped away from the code for a few weeks at this point. When I came back, I synced both repositories and ran the following command to recreate the database:

sudo docker-compose run --rm musicbrainz recreatedb.sh -sample -fetch

I ran the following to start the containers (without detaching from the terminal, so I could watch the logs):

sudo docker-compose up

At this point, I was able to access my local server at http://localhost:5000/.

The server doesn't seem to have search indexes by default (I think there are more steps for getting that working), so I had to look up an MBID on the real MB site: http://localhost:5000/release/15f5c2cb-41ea-3630-a0f6-2f86785cf608

I edited root/release/add_cover_art.tt in the musicbrainz-server repo and verified that my changes showed up at http://localhost:5000/release/15f5c2cb-41ea-3630-a0f6-2f86785cf608/add-cover-art.

Creating an account

I added a user account via the web interface but my server wasn't able to send email messages, so I wasn't able to verify my email address (needed to perform edits).

I ran the following to connect to PostgreSQL:

sudo docker-compose run musicbrainz psql postgres -U musicbrainz -h db

Next, I ran the following to manually mark my account as being verified:

\l                -- list databases
\c musicbrainz_db -- change DB
\dt               -- list tables
UPDATE EDITOR SET email = 'user@example.org', email_confirm_date = now() WHERE name = 'my_username';

At this point, the server viewed my account as having been verified.

The following will set the account to be an auto-editor:

sudo docker-compose exec db psql -d musicbrainz_db -U musicbrainz -c "UPDATE editor SET privs = privs | 1 WHERE name = 'my_username'"

Linting code

I run the following to lint JavaScript changes:

./node_modules/.bin/eslint $(git diff --name-only master | grep '\.js$')

This will type-check JavaScript files:

./node_modules/.bin/flow

I get a few persistent Cannot resolve module `../../typeInfo.js`. errors unrelated to my changes. I haven't figured out how to suppress those yet.

Running tests

JavaScript unit tests can be run by visiting http://localhost:5000/static/scripts/tests/web.html. I had trouble getting resources to be rebuild so that a new test file would be executed (after adding it to root/static/scripts/tests/index-web.js); I think that running this might've done the trick:

sudo docker-compose run --rm musicbrainz script/compile_resources.sh

I didn't have any luck running Selenium tests against my local installation when following the instructions from the "Selenium" section of musicbrainz-server's HACKING.md. The setup commands seemed to complete successfully:

sudo docker-compose run --rm musicbrainz ./script/create_test_db.sh SELENIUM
sudo docker-compose run --rm musicbrainz ./script/compile_resources.sh

Running ./t/selenium.js --help outside of Docker just produced an error, though:

node:fs:1396
  handleErrorFromBinding(ctx);
  ^

Error: ENOENT: no such file or directory, mkdir '/musicbrainz-server/.nyc_output'
    at Object.mkdirSync (node:fs:1396:3)
    at file:///home/.../temp/src/musicbrainz-server/root/utility/writeCoverage.mjs:18:6
    at ModuleJob.run (node:internal/modules/esm/module_job:194:25) {
  errno: -2,
  syscall: 'mkdir',
  code: 'ENOENT',
  path: '/musicbrainz-server/.nyc_output'
}

Node.js v18.16.1

I couldn't figure out where MB_SERVER_ROOT was getting set incorrectly, and I didn't expect the test script to work within Docker (since I assume it'd have no way to access Chrome), so I just relied on Jenkins to run my tests after I uploaded a PR.

Enabling indexed searches

This was just a matter of running the following in my musicbrainz-docker checkout:

sudo docker-compose exec indexer python -m sir reindex

It died after several hours while building the recordings index (my system only had ~6.6 GB of RAM available), but I was just interested in testing artist search, so that was good enough for me.

Exercising cover art code

I was working on a change to the add-cover-art form, and I had trouble figuring out how to exercise it manually. HACKING-CAA.md describes how to emulate the Cover Art Archive locally, but I couldn't get it to work in conjunction with musicbrainz-docker. I eventually just hacked the code to report success without uploading to the CAA.

I commented out a bunch of code in lib/MusicBrainz/Server/Controller/WS/js.pm by adding =begin and =cut lines:

sub cover_art_upload : Chained('root') PathPart('cover-art-upload') Args(1)
{
    // ...
    my $context = $c->model('MB')->context;

=begin
    unless ($c->model('CoverArtArchive')->exists_for_release_gid($gid)) {
    // ...
            $self->_detach_with_ia_server_error($c, $response->decoded_content);
        }
    }
=cut

    my $id = $c->request->params->{image_id} // $c->model('CoverArtArchive')->fresh_id;
    // ...

I also updated root/static/scripts/edit/MB/CoverArt.js to return early without actually uploading images:

MB.CoverArt.upload_image = function (postfields, file) {
  var deferred = $.Deferred();

  window.setTimeout(() => {
    deferred.notify(50);
  }, 500);
  window.setTimeout(() => {
    deferred.notify(100);
    deferred.resolve();
  }, 1000);
  return deferred.promise();

  var formdata = new window.FormData();
  // ...