Upgrade alpine in node@8 to 3.6

[SimenB]

Just 8.0, right?

This does not update Dockerfile-alpine.template, which means running update.sh will rollback the version in this dockerfile. Is that expected/wanted?

[Starefossen]

All green build in Travis: https://travis-ci.org/nodejs/docker-node/builds/237802125

[pesho]

This does not update Dockerfile-alpine.template, which means running update.sh will rollback the version in this dockerfile. Is that expected/wanted?

For the record (personal opinion, not WG policy) - the template should be updated, and update.sh without parameters should not be used, but only run with a specific version, like update.sh 8.0.

[SimenB]

If the template is updated, that would mean node 4 and 6 would get the new alpine version.

[pesho]

If the template is updated, that would mean node 4 and 6 would get the new alpine version.

When they see new releases, yes, that's a weakness in the current setup. They would require manual cleanup after update.sh then. Either that, or the current branch (8.x) would require manual fixing (present state). I think the better option is if the template matches the current branch, as it would see more frequent releases from now on.