sysutils/node_exporter: Add license file, tests, docs and examples

[0mp]

Summary

sysutils/node_exporter: Add tests, docs and examples

- Define LICENSE_FILE.
- Sort variables.
- Add a do-test target and prepare a testing environment.  One test is skipped
  at the moment due to a problem with detecting procfs(5) on FreeBSD.
- Install documentation and examples.
- Change pkg-descr to better match upstream's README.

I am not sure about a couple of things, however:

• Is it fine to use USES=gmake instead of TEST_DEPENDS=gmake:devel/gmake? USES=gmake adds a dependency to the build process, which is not ideal.
• The whole pre-test target is rather hacky. I was unable to come up with a prettier solution though. Go is a little bit hard to tame.

Bugzilla: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=234791

Test Plan

• portlint
• poudriere testport:
  • 11.2 & 12.0 on amd64 & i386

In order to try out the test suite:

sh
echo "cd /usr/ports/sysutils/node_exporter/ && make test" | poudriere bulk -j 120i -i sysutils/node_exporter shells/bash textproc/gsed net-mgmt/prometheus2

[dor]

This looks pretty great. I had been wondering about this recently for the prometheus2 port :)

[mat]

sysutils/node_exporter/Makefile

25–28 ↗

(On Diff #52695)

This does not do what you think it does.

First, shebangs are handled during the patch phase, so this would not do anything.

Second, target(x) checks for the existence of the target, and when make is at this point, parsing the Makefile, the do-test target does not exist.

Given the footprint of shebangfix, doing it always is ok.

[0mp]

• Set USES=shebang unconditionally as it has little performance footprint.

[0mp]

Thanks, @mat!