install yarn from apt repo

[pklingem]

we should consider installing yarn from the apt repo as the yarn maintainers suggest. It feels wrong to install via npm anyway. The only downside is that we can't lock the version down if we want to. @articulate/ops what are your thoughts?

[plukevdh]

[tecnobrat]

You actually can lock down the version.

Change your apt-get install line to look like: apt-get install yarn=0.19.1-1

Also, you should break this out into it a separate RUN line:

RUN apt-get update && \
    apt-get install apt-transport-https

RUN curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | apt-key add - && \
    echo "deb https://dl.yarnpkg.com/debian/ stable main" | tee /etc/apt/sources.list.d/yarn.list && \
    apt-get update && \
    apt-get install yarn=0.19.1-1 && \
    apt-get clean

The reason is that docker will cache those separately now, which will speed up the build when all you wanna do is bump the version of yarn. Otherwise you do a apt-get update twice, for no reason.

I'm also going to suggest leaving the consul template lines directly below the FROM node:7 line, again for caching sake. Then when you bump yarn it doesn't need to redo the consul stuff after, it'll be cached from the previous run.

[pklingem]

@tecnobrat good thoughts, I will address those. I wish there was a nice way to prevent the duplication across those Dockerfiles, but I can't think of one.

[pklingem]

addressed @tecnobrat's comments, merging.