Paul Gschwendtner f6805de8eb build: fix circleci not restoring cache for PRs (#28480)
Currently whenever someone creates a pull request, the NPM dependencies
are downloaded and installed. This is problematic because we have a lot
NPM dependencies with potentially large files that would need to be
downloaded (e.g. the Bazel binaries).

The caches are currently not being restored because we added the
`{Branch}` variable to the CircleCI cache key. Since every PR has a different
branch name (e.g. `devversion/refs/heads/my-banch`), the cache keys would
never match an existing cache key, and the PR would start fresh by
downloading everything.

We can safely remove the `{Branch}` variable from the cache key because
it does not provide any value since the cached files are based on the state
of the `yarn.lock` file and not based on the current branch name. This reduces
our dependency on the slow and sometimes **flaky** Yarn registry. We should
try to depend as few as possible on external services (e.g. see how Saucelabs
flakiness can cause trouble for the caretaker; same applies to flaky Yarn installs)

PR Close #28480
2019-02-04 02:48:48 -08:00
..
2018-12-07 14:29:03 -08:00

Encryption

Based on https://github.com/circleci/encrypted-files

In the CircleCI web UI, we have a secret variable called KEY https://circleci.com/gh/angular/angular/edit#env-vars which is only exposed to non-fork builds (see "Pass secrets to builds from forked pull requests" under https://circleci.com/gh/angular/angular/edit#advanced-settings)

We use this as a symmetric AES encryption key to encrypt tokens like a GitHub token that enables publishing snapshots.

To create the github_token file, we take this approach:

  • Find the angular-builds:token in http://valentine
  • Go inside the CircleCI default docker image so you use the same version of openssl as we will at runtime: docker run --rm -it circleci/node:10.12
  • echo "https://[token]:@github.com" > credentials
  • openssl aes-256-cbc -e -in credentials -out .circleci/github_token -k $KEY
  • If needed, base64-encode the result so you can copy-paste it out of docker: base64 github_token