jenkins: new "release-sources" labels for source, headers, docs

[rvagg]

Ref #1730

We need to switch to Linux for creation of our generic tarballs and 12 is the time to get it done. Here's my strategy and I'd like some sanity checking before I put it into effect for nightlies.

• Current strategy piggy-backs the osx1010-release-tar and osx1011-release-tar labels, these are also used for creating the darwin binary tarballs so we'll leave them as they are
• I've added labels osx1010-release-sources and osx1011-release-sources to the existing osx release machines, I've also added centos7-release-sources to the new centos7-64 release machine.
• I'll add all 3 of these new labels to iojs+release and VersionSelectorScript here should take care of selecting the right one.
• The iojs+release job has a dedicated block for doing this work, it comes under a label match for osx10\d\d-release-tar and runs 3 separate items for tar-upload, doc-upload and tar-headers-upload. I'll change that to .*-release-sources and leave the rest alone, I don't see anything that's macOS specific.

That should leave <12 working as it does now and switch to CentOS 7 x64 for making these assets for Node >= 12.

Can I get some sanity checking please?

I'm also noticing as I do this that osx1011 can be removed entirely from ci-release when we drop Node 11, assuming we get 10.13 in place in time.

[richardlau]

SGTM.

[mhdawson]

LGTM seems resonable.

[rvagg]

this turned out to be more complicated: by uncoupling this from the osx-release-tar label we end up with non-deterministic run order and with a clean workspace. The tar-upload, doc-upload and tar-headers-upload all depend on $(NODE_EXE) but don't go through the motions of configuring and building like binary does. Previously we could rely on the osx-release-tar builder to do a binary-upload before going through these other stages so everything would be ready to go. But now the same machine is re-used but as an entirely separate run.

So, in the release-sources jobs I've had to do a make binary before anything else and rely on ccache to do the heavy lifting, but it means lots more copypasta which is unfortunate. On top of this we need devtoolset-6 enabled for centos7 for all of the make calls, so more copypasta and conditionals. Then, I also discovered that ccache isn't even activated for the devtoolset jobs (centos6/devtoolset-2 as well) because we're relying on $PATH to do that work on these machines. So even more copypasta from the nice block of Bash in node-test-commit-linux that sets CC and CXX prepended with ccache.

Anyway, it appears to be working now. I re-ran a 10.x nightly and a master nightly and they used the right builders, so I think we can call this solved for now. iojs+release (maybe the whole ci-release) really needs an overhaul though, it's getting out of hand but it's such a critical piece that it's difficult to do major surgery on.