ansible,jenkins: install gcc-7 on ubuntu1604 machines, use on node>12

[rvagg]

Ref: #1970

This will build Node >=13 with GCC 7 on Ubuntu 16.04 and the default GCC 5 compiler below that.

I've tried out the ansible config on one of the ubuntu1604-x64 machines and it works fine, leaves the default compiler as 5 but 7 is available.

I've not tested the select-compiler.sh script that's included here, we've not used it beyond the IBM machines but it's probably time to get some of the logic out of Jenkins and into GitHub for the other machines. Some sanity checking before I attempt to test it out would be helpful.

[sam-github]

Looks reasonable, and I think select-compiler is a pretty transparent and useful way to describe the compiler version requirements per/node release.

[mhdawson]

Is gcc7 easier to install than gcc6. Just wondering why that version versus the 6.x which is listed as the mininum level for Node 12 and greater. Is this a step towards moving up the minimum?

[rvagg]

yeah, good question @mhdawson, I had a list in front of me and 6 wasn't on it, can't recall where that list was from but 6 is in the toolchains repo.
I've downgraded in the latest commit. I'll assume approval and merge and start testing this a bit later.

[rvagg]

A couple of minor tweaks to select-compiler.sh once I got it into CI but it's working as expected and selecting the right compilers for Ubuntu 16.04 across supported release lines as well as CentOS 6 and 7 and the small amount of Bash in Jenkins that was doing that job has been removed in favour of this. This is what's node-test-commit-linux now:

curl -sLO https://raw.githubusercontent.com/nodejs/build/master/jenkins/scripts/select-compiler.sh
. ./select-compiler.sh

node-test-commit-v8-linux got updated too so this is run in all cases, not just the IBM platforms, so it should be doing the right thing with Ubuntu 16.04 but I haven't tested that yet.

[rvagg]

btw I ran this playbook against:

test-nearform_intel-ubuntu1604-x64-1
test-nearform_intel-ubuntu1604-x64-2
test-packetnet-ubuntu1604-x64-1 jenkins-workspace-1
test-packetnet-ubuntu1604-x64-2 jenkins-workspace-2
test-softlayer-ubuntu1604-x64-1 jenkins-workspace-3
test-rackspace-ubuntu1604-x64-1
test-rackspace-ubuntu1604-x64-2

The two packet.net Jenkins workspaces had Node 8 installed on them from the NodeSource repos, it was removed from the playbook. I can't think of what this might be. The binary_tmp repo runs on each of these but is hardwired to the softlayer machine at the moment which I don't think had it. Running the playbook on the softlayer machine did mess up the binary_tmp repo though, it had dangling refs in it that wouldn't clean up automatically. I resorted to removing the files from refs/ and it seems to be working again.

[targos]

This broke citgm-smoker on AIX: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/2075/nodes=aix61-ppc64/console

15:06:50 /tmp/jenkins3289696872254253027.sh[4]: 0403-057 Syntax error at line 125 : `=~' is not expected.

[richardlau]

This broke citgm-smoker on AIX: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/2075/nodes=aix61-ppc64/console

15:06:50 /tmp/jenkins3289696872254253027.sh[4]: 0403-057 Syntax error at line 125 : `=~' is not expected.

Should have been fixed by #1994.

[richardlau]

This broke citgm-smoker on AIX: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/2075/nodes=aix61-ppc64/console

15:06:50 /tmp/jenkins3289696872254253027.sh[4]: 0403-057 Syntax error at line 125 : `=~' is not expected.

Should have been fixed by #1994.

Also one of the "Execute shell" steps was missing #!/bin/bash (the step that failed). I've added the shebang now.