discovery/lxd: Remove lxdhelpers

[jtopjian]

This commit removes the dependency of the external lxdhelpers package. The core functionality of the lxdhelpers package has been integrated into the upstream LXD client API and so the lxdhelpers package is no longer useful.

The additional functions that are added are specific to the LXD discovery plugin - it does not make sense to abstract them into an external package.

Also, Travis has been modified to no longer install the libacl1-dev package since this was resolved a month ago (#105).

Just like with #102, I have Terraform configurations here which can help with testing. At a minimum, the deploy.sh script can be used to easily create an LXD+gobetween environment.

[yyyar]

Hi @jtopjian, thanks for the PR!

Unfortunately I don't have enough time to do extensive testing by myself. Your changes look good and I can't see any problems there and to speed up the process, please just confirm you tested it on your envs both with https and non-https, and it works, and I'll be happy to merge!

[jtopjian]

@yyyar No problem at all.

I've tested this to the best of my ability and all looks good. Here's some debug output from a recent test balancing two containers:

2017-10-20 03:56:01 [INFO ] (manager): Initializing...
2017-10-20 03:56:01 [INFO ] (server): Creating 'web_servers': :80 weight lxd none
2017-10-20 03:56:01 [INFO ] (scheduler): Starting scheduler
2017-10-20 03:56:01 [INFO ] (api): Starting up API
2017-10-20 03:56:01 [INFO ] (api): Using HTTP Basic Auth
2017-10-20 03:56:01 [INFO ] (api): Starting HTTP server :8888
2017-10-20 03:56:01 [INFO ] (manager): Initialized
2017-10-20 03:56:01 [DEBUG] (lxdBuildConfig): Using API: https://gb:8443
2017-10-20 03:56:01 [DEBUG] (lxdBuildClient): Generating LXD client certificates
2017-10-20 03:56:05 [DEBUG] (lxdBuildClient): Retrieving LXD server certificate
2017-10-20 03:56:05 [INFO ] (lxdBuildClient): Authenticating to LXD server
2017-10-20 03:56:05 [INFO ] (lxdBuildClient): Authentication successful
2017-10-20 03:56:05 [DEBUG] (lxdBuildConfig): Using API: https://gb:8443
2017-10-20 03:56:05 [DEBUG] (lxdFetch): Fetching containers from https://gb:8443
2017-10-20 03:56:12 [DEBUG] (server.handle [:80]): Accepted 127.0.0.1:47086 -> [::]:80
2017-10-20 03:56:12 [DEBUG] (server.handle [:80]): Begin 127.0.0.1:47086 -> [::]:80 -> 192.168.244.127:80
2017-10-20 03:56:12 [DEBUG] (server.handle [:80]): End 127.0.0.1:47086 -> [::]:80 -> 192.168.244.127:80
2017-10-20 03:56:15 [DEBUG] (server.handle [:80]): Accepted 127.0.0.1:47090 -> [::]:80
2017-10-20 03:56:15 [DEBUG] (server.handle [:80]): Begin 127.0.0.1:47090 -> [::]:80 -> 192.168.244.220:80
2017-10-20 03:56:15 [DEBUG] (server.handle [:80]): End 127.0.0.1:47090 -> [::]:80 -> 192.168.244.220:80
2017-10-20 03:56:17 [DEBUG] (server.handle [:80]): Accepted 127.0.0.1:47094 -> [::]:80
2017-10-20 03:56:17 [DEBUG] (server.handle [:80]): Begin 127.0.0.1:47094 -> [::]:80 -> 192.168.244.220:80
2017-10-20 03:56:17 [DEBUG] (server.handle [:80]): End 127.0.0.1:47094 -> [::]:80 -> 192.168.244.220:80

With regard to https/non-https: did you mean communicating with LXD over http/https? If so, https is mandatory with LXD - no way to communicate over http.

[yyyar]

@jtopjian, thanks!

With regard to https/non-https: did you mean communicating with LXD over http/https? If so, https is mandatory with LXD - no way to communicate over http.

Sorry, I meant local unix socket and secure https.

Looks good, I'll merge it right now.

[jtopjian]

Sorry, I meant local unix socket and secure https.

Ahh - gotcha. Yup, both work 😄

Thank you!

With 0.5 released, no doubt there will be people trying out LXD. I'll be keeping an eye out for issues.

[yyyar]

@jtopjian thank you so much for your support!