Powerstrip: prototype Docker extensions today

[progrium]

I'm involved as an independent collaborator again in Docker's internal extension efforts, and after I saw this I got ClusterHQ looped in to that working group. Then we talked about collaborating on a Go port of Powerstrip, so I'm working on that here: https://github.com/ClusterHQ/powerstrip/tree/golang

We're also planning to combine the Docker event stream plugin system I prototyped previously into Powerstrip: https://github.com/progrium/docker-plugins

And ultimately, eventually, we'll have native extension support in Docker that allows much more extensibility, but all this is a good first step IMO.

[michaelsbradley]

Do you know if Powerstrip could be used to extend the entire family of Docker tools: machine, compose (fig), swarm?

I think it would be interesting, for example, to explore development of an extension that "guided" those tools regarding where (virtually speaking) they should re/deploy machines and containers, based on metrics collected by a 3rd party service with which that extension communicated.

I apologize if my question is a bit naïve; at present, I've been spending a lot of time with the porcelain and haven't gotten into the internals enough to understand how all the Docker pieces truly fit together.

[binocarlos]

I've been hacking on a powerstrip adapter for the past few weeks (https://github.com/binocarlos/powerstrip-weave) and have found it a pleasure to work with.

Capturing JSON messages on their way to the docker server is a far more civilised way to extend docker than trying to "wrap" the docker cli.

In my use case - using the cli - I was struggling to separate the docker arguments from the image name and container args. It's better for docker itself to do that and more generally - its better to use the vanilla docker client (because orchestration tools).

As soon as I was working with the JSON messages generated by the docker client - everything became much easier!

[errordeveloper]

If you are looking to build an extension, make sure to checkout the post by @binocarlos [1], it's just the right level of detail for you know and a full-blow implementation indeed!

[1]: http://weaveblog.com/2015/01/29/powerstrip-weave-a-docker-ne...

[SEJeff]

The Wordpress on this site is dead, why don't more people use static html generators these days? It doesn't get more web scale than static html via pelican or Jekyll or something :)

I'm quite happy to see this happening however and see that the batteries included, but removable mantra really is actually happening.

[jodok]

we just moved our very own https://crate.io site from wordpress to cactus (python-based, https://github.com/koenbok/cactus). just opened our github repo: https://github.com/crate/crate-web it also includes a script to pull in existing wordpress blog posts.

[lewq]

We're working on moving to a static site generator :)

That said one emergency mod_rewrite rule later and we fixed the issue - which was that the HN link went to the link without the trailing slash which was hitting the database! :'(

[lewq]

Yes, we are also glad to be involved in making "batteries included but removeable" really happen :)

[dobe]

we at crate switched to https://github.com/koenbok/cactus and are really happy with it. we had a really bad experience with wordpress and are so glad we switched.

[errordeveloper]

An interesting project would be to implement a policy extension, one that would check where container image has the right versions of certain packages and would refuse to start a container with outdate JRE, OpenSSL or anything more recent...

[lewq]

Definitely! We have https://github.com/ClusterHQ/powerstrip#additional-adapter-i... and https://github.com/ClusterHQ/powerstrip/issues/8 for ideas... please add more!