WIP: Add templates for generating the variants

[LaurentGoderre]

No description provided.

[LaurentGoderre]

Here is the diff the the dockerfile generated by this
https://gist.github.com/LaurentGoderre/fbf5f44e1310a127ae6638e1d7548188

[chorrell]

I think this PR should be renamed since it's about adding templates for the various existing variants and not does not add an Alpine variant (which presumably will be a separate PR :)

[chorrell]

So I think it's time for me to review the 0.10 and 0.12 image with respect to how the slim variant is built an switch to the method used by 4.x and 5.x. That should help in terms if templating the updates.

[LaurentGoderre]

I'm a bit confused what is needed to get this merge, especially since it's pending other decision. Should I separate the commit into the templates and the script so we could merge the template, keep working on it then update scripts when the template is finalized?

[chorrell]

A couple of things need to happen outside of this PR:

• A resolution to Excessive npm log output in 4.x #57. We need to either drop NPM_CONFIG_LOGLEVEL info or use it consistently with all the images. I get the sense we're leaning towards dropping it (edit: actually, I think most were for it as long as it was clearly documented?) but ultimately the @nodejs/docker needs to make the call here
• A PR to make the slim variants of 0.10 and 0.12 consistent with 4.x and 5.x. I can work on that later this week for review.

Once the above two issues are resolve we should be able to move forward with this PR

[chorrell]

PR to make the 0.10 and 0.12 slim variants consistent: #149

[chorrell]

Also, to answer your previous question, I think it would be better to wait for the other issues to be resolved and then rebase this rather than split up the PR.

[chorrell]

I just merged #149. In terms of #57 I think we should just modify the update.sh script with a sed line to remove ENV NPM_CONFIG_LOGLEVEL info for the 0.10 and 0.12 images until a decision is made.

I'll merge this now and work on a follow update for the update.sh script.

And thanks for this @LaurentGoderre !