Search API Solr - Add Ludwig integration

Interesting. But why does a module maintainer need to take care about where to get the download from?
Why doesn't Ludwig simply get the requirements from composer.json and uses packagist to find the download?
Where does Ludwig put the libraries and how does it deal with the autoloader?
One thing I'm really afraid of is the conflict management. I faced that so many times before composer was usable with drupal ...

I read the blog post. But to be honest, I'm still not a fan of ludwig.
I'm still of the opinion that the module maintainer should not be responsible to provide an exact download link.
As a module maintainer, I don't want to be responsible for taking care about security releases of 3rd party libraries and to be forced to react that quickly.

+1 for this.

@bojanz: I committed the additional check for solarium during the install phase.

I had the chance to talk to some developers about ludwig. Nobody felt enthusiastic about it. But I'm aware that they are not "end users".
But due to the fact that even end-users will have to deal with the command line anyway, I still prefer to only promote this:
composer require drupal/search_api_solr

Thanks for committing that change.

even end-users will have to deal with the command line anyway

They don't, and that's a key reason why Ludwig is useful to a large portion of Drupal users.

I added a note about ludwig in the release notes of 8.x-1.1 to get some more feedback on this topic.

+1 for adding Ludwig as an option to the module.

+another 1 for this

Adding Ludwig as an option +1!!!

For our use case, we have 21 sites built through Pantheon upstream. In order to use Solr for multi-site search we would have to completely rebuild every site from the ground up using composer. Using Ludwig would be a perfect option for us. For now, we are using a custom google search as a work around.

OK, I consider (experimental) support for ludwig for 8.x-2.x. But the patch needs to adjusted.
We already committed a part of the original patch that needs to be removed.
And maennchen/zipstream-php is missing as dependency.

I support having also the ludwig option.

Patch?

Here is an updated patch, which adds Ludwig integration. After installing the Ludwig module, I successfully installed the two libraries, required by Search API Solr Search:

$ drush ludwig-download
Downloaded package "solarium/solarium".
Downloaded package "maennchen/zipstream-php".

What about the requirements of solarium?

composer handles them:

    "require": {
        "php": "^7.0",
        "symfony/event-dispatcher": "^2.7 || ^3.0 || ^4.0"
    },

Solarium 5 might require HTTPlug.

And the next version of zipstream will add dependencies as well:

 "require": {
    "php": ">= 7.1",
    "ext-mbstring": "*",
    "psr/http-message": "^1.0",
    "myclabs/php-enum": "^1.5"
  },

I'm still not a fan of that ludwig thing. It puts additional load on me to do things manually composer would solve automatically. And I'm afraid of additional support request, too.

+1 for ludwig

Just write a doc and let developer do it manually for complex dependencies.

Ludwig integration is officially abandoned by Search API Solr module maintainers in the meantime.

For those who need to use Search API Solr module without Composer - there is a working D9 ludwig.json file example here:

#3082582-12: Search API Solr - Dropped Ludwig support