Update this module so that it can work with Apicast 3.1

[nmasse-itix]

Latest version of Apicast work differently for DNS name resolution. See 3scale/APIcast#324.

Namely, on version 3.1, the module produces this error message:

Nov  7 21:24:42 ip-172-31-31-249.us-east-2.compute.internal dockerd-current[2843]: 2017/11/08 02:24:42 [error] 30#30: *685 [lua] verbose.lua:92: do_log(): failed to log message: try to send log messages to the log server failed after 3 retries: try to connect to the log server failed after 3 retries: no resolver defined to resolve "ec2-52-14-196-66.us-east-2.compute.amazonaws.com" while sending to client, client: 172.17.0.1, server: _, request: "GET /?user_key=d07cc438281c2f088ff72a665870d559 HTTP/1.1", upstream: "https://107.23.177.9:443/?user_key=d07cc438281c2f088ff72a665870d559", host: "echo-api.3scale.net"

It seems that we now have to use the RESOLVER environment variable instead of the resolver directive in the nginx configuration file.

[mikz]

3scale/APIcast#324 shouldn't affect the name resolution itself. It is just about preferences. Basically RESOLVER is used before the servers defined in /etc/resolv.conf.

This error is happening because nginx does not have resolver directive - that means you can't use ngx.socket.tcp:connect with name, but only with IP address. There are few wrappers to do the DNS resolution before doing :connect: https://github.com/3scale/apicast/blob/9bf6358484b295a299263a836c360fe8a27962e2/spec/resty/resolver/socket_spec.lua

But with latest changes (going to be in 3.2) (3scale/APIcast#449) we are able to generate proper resolver directive in the nginx configuration so you can use nginx internal name resolution instead of the APIcast one. Created issue upstream 3scale/APIcast#488 to make this work.

[nmasse-itix]

Thanks for the insights ! I will spend some time updating the module to the new policy framework today.

[mikz]

@nmasse-itix if you'd like to have access to our testing frameworks I'd recommend you to do it like 3scale/APIcast#487 or 3scale/APIcast#497 and open a PR to the APIcast repo.
We plan to expose these tools to be standalone and to work outside APIcast repository, but that might take a while.

[mikz]

We are writing documentation of the new policy chain. Feedback and review much welcomed: 3scale/APIcast#512