Travis CI cache a single file at a specified location

问题

I am building a Ruby project on Travis CI and I use Gemfile ans Bundler to manage dependencies. My .travis.yml contains only one line about caching:

cache: bundler

And I rely on this in other places (Travis's default install command, cache directories, plus an extra bundle clean before uploading cache).

By default, Gemfile.lock is not cached. I want to cache it to make Bundler to skip dependency resolution and use the cached Gemfile.lock. I haven't found a valid solution for this.

Any ideas?

回答1:

I noticed the only comment under this question and came up with an idea, but I think it's more a workaround than a solution.

Copy Gemfile.lock from /tmp/cached in before_install phase. The copy Gemfile.lock to /tmp/cached in before_script phase. This way it'll be cached by Travis CI and the cache will be used by Bundler.

I'm still looking for a real solution.

回答2:

AFAICS from Travis' cacher implementation,

it will work if you specify a file name rather than a directory name under cache: directories:.¹

With one caveat:

Initially, when there's no cache (thus the file doesn't yet exist), the cache restore step will create an empty directory with this name.
- You need to manually detect and delete this directory early in your build

Example .travis.yml (using an evvar for the file's path to avoid repeating it everywhere):

env:
  global:
    - FILE=<path>
cache:
  directories:
    - $FILE
before_install:
  - if [[ -d $FILE ]]; then rm -rf "$FILE"; fi

# create and/or use the file

¹_{That's because they use tar to make and extract cache archives, and tar doesn't care if you pass a file or a directory to it}

来源：https://stackoverflow.com/questions/50492750/travis-ci-cache-a-single-file-at-a-specified-location

标签

caching

bundler

travis-ci