Upload etcd keys by template.

[bheatwole]

Currently the etcd backend only creates a very specific style of key in etcd. If you need etcd to contain more information (such as tags and attributes) or for the format to be different for different types of services, you're stuck.

This pull requests adds an additional etcd backend that creates keys based on templates with access to all the information from docker. For example the template below uses the exposed port from the container as part of the key, but uses the published host IP and port in the value.

/services/{{.Published.ExposedPort}}/{{.Name}} {{.Published.HostIP}}:{{.Published.HostPort}}

Since templates allow if...else, you can write add a template that only adds a key if a specific attribute is present.

{{if .Attrs.proxy}}/proxies/{{.Name}} {{.Published.HostIP}}:{{.Published.HostPort}}{{end}}

Usage: Start registrator with one or more ETCD_TMPL_XXXX environment variables. These variables should contain a template of the key value pair you wish published to etcd. Also be sure to use the 'etcd-tmpl' scheme.

docker run -d -v /var/run/docker.sock:/tmp/docker.sock \
   -e ETCD_TMPL_PROXY="{{if .Attrs.proxy}}/load_balancer/{{.Published.ExposedPort}}/{{.Name}} {{.Published.HostIP}}:{{.Published.HostPort}}{{end}}" \
   -e ETCD_TMPL_HTTP="{{if .Published.HostPort eq 80}}/http/{{.Name}} {{.Published.HostIP}}:{{.Published.HostPort}}{{end}}" \
   -e ETCD_TMPL_ALL="/services/{{.Name}} {{.Published.HostIP}}:{{.Published.HostPort}}" \
   progrium/registrator etcd-tmpl://${PRIVATE_IPV4}:4001/

[bryanlarsen]

I did something similar for consul as a docker plugin: https://github.com/bryanlarsen/docker-plugin-kv-consul

Discussion: https://github.com/progrium/docker-plugins/issues/3

[progrium]

Ah right, that was you. This is a big addition, so it might take even longer to get reviewed. Sorry I'm so backed up!

On Fri, Dec 19, 2014 at 6:46 AM, Bryan Larsen [email protected] wrote:

I did something similar for consul as a docker plugin: https://github.com/bryanlarsen/docker-plugin-kv-consul

Discussion: progrium/docker-plugins#3 https://github.com/progrium/docker-plugins/issues/3

— Reply to this email directly or view it on GitHub https://github.com/progrium/registrator/pull/76#issuecomment-67633949.

Jeff Lindsay http://progrium.com

[tsaikd]

This PR is a good idea. It solve my problem for customizing the etcd K/V rule. :+1:

[subicura]

:+1:

[llinder]

:+1:

[benguillet]

:+1:

[vidarl]

:thumbsup:

[vidarl]

In my option, registrator should definitely have the possibility for storing stuff in a flexible way in etcd like this PR proposes. In addition, this PR makes it possible to store Attrs in etcd too, something the default etcd backend currently does not.

So, why has this PR not been merged yet? Are there objections to the approach? or is it because of the current merge conflicts? or just lack of time?

Is there anything I can do in order to get this merged?

[progrium]

Help write tests for existing code? That's one of our blockers for more active development and frequent releases. Docs are our first priority so help with tests would be great.

On Thu, May 21, 2015 at 3:49 AM, Vidar [email protected] wrote:

In my option, registrator should defiantly have the possibility for storing stuff in a flexible way in etcd like this PR proposes. In addition, this PR makes it possible to store Attrs in etcd too, something the default etcd backend currently does not.

So, why has this PR not been merged yet? Are there objections to the approach? or is it because of the current merge conflicts? or just lack of time?

Is there anything I can do in order to get this merged?

— Reply to this email directly or view it on GitHub https://github.com/gliderlabs/registrator/pull/76#issuecomment-104184713 .

Jeff Lindsay http://progrium.com

[hyperbolic2346]

@progrium I've been thinking about your comment above regarding tests and I'm a little torn by it. It seems that you are holding meaningful features hostage here. I totally understand the desire to have tests and to automate, I don't have any beef there. My concern is that without these features you will push users away and that could ultimately result in a dead branch. Like anyone else looking at these issues and investigating registrator, I don't want that to happen. It is really close to exactly what I need. The only reason I am currently still searching for a solution for service announcement and discovery is this missing feature.

[bheatwole]

I checked to see how far off the current code base my pull request is, and there are some significant issues to work through. However, I will do the work to bring the pull request up to master if there's some hope it will be quickly reviewed.

[aramalipoor]

:+1:

[majidgolshadi]

:+1: