Use VAULT_TOKEN environment variable if it exists

[mark-vieira]

As a follow up to https://github.com/elastic/infra/pull/13780#issuecomment-521025910 we should try and use the VAULT_TOKEN passed into the build from CI when possible.

[elasticmachine]

Pinging @elastic/es-core-infra

[mark-vieira]

This is blocked on elasticsearch/infra#13780.

[alpar-t]

@mark-vieira that issue number looks incorrect.
/cc @flaper87

[mark-vieira]

Thanks, Alpar. I updated that.

[alpar-t]

LGTM

[flaper87]

thanks, I had to do this in my fork too. Was planning to send a patch but I was too slow.

lgtm

[mark-vieira]

It's actually elasticsearch/infra#13907 that needs to be addressed before this. Right now this PR wouldn't actually do anything since we never set VAULT_TOKEN in CI.

[flaper87]

It's actually elastic/infra#13907 that needs to be addressed before this. Right now this PR wouldn't actually do anything since we never set VAULT_TOKEN in CI.

It won't so much but it's a step forward down the right direction. I could also use it in my Zuul tests. I had to hack it in myself but I'd rather use this patch.

[mark-vieira]

There seems to be consensus this is worth happening so I've merged this and backported to all active branches.