ci: double our cores on CircleCI (#22641)

This should cut our build time in ~half, assuming it's widely parallel.
See
https://circleci.com/docs/2.0/configuration-reference/#resource_class

Also enable bazel repository caching, and store the external
repositories in the CircleCI cache for later builds.

PR Close #22641

.circleci/bazel.rc

@@ -15,11 +15,16 @@ build --experimental_remote_spawn_cache --remote_rest_cache=http://localhost:764
 # Prevent unstable environment variables from tainting cache keys
 build --experimental_strict_action_env
 
+# Save downloaded repositories such as the go toolchain
+# This directory can then be included in the CircleCI cache
+# It should save time running the first build
+build --experimental_repository_cache=/home/circleci/bazel_repository_cache
+
 # Workaround https://github.com/bazelbuild/bazel/issues/3645
 # Bazel doesn't calculate the memory ceiling correctly when running under Docker.
-# Limit Bazel to consuming resources that fit in CircleCI "medium" class which is the default:
+# Limit Bazel to consuming resources that fit in CircleCI "xlarge" class
 # https://circleci.com/docs/2.0/configuration-reference/#resource_class
-build --local_resources=3072,2.0,1.0
+build --local_resources=14336,8.0,1.0
 
 # Retry in the event of flakes, eg. https://circleci.com/gh/angular/angular/31309
 test --flaky_test_attempts=2

.circleci/config.yml

@@ -13,7 +13,7 @@
 # If you change the `docker_image` version, also change the `cache_key` suffix and the version of
 # `com_github_bazelbuild_buildtools` in the `/WORKSPACE` file.
 var_1: &docker_image angular/ngcontainer:0.1.0
-var_2: &cache_key angular-{{ .Branch }}-{{ checksum "yarn.lock" }}-0.1.0
+var_2: &cache_key v2-angular-{{ .Branch }}-{{ checksum "yarn.lock" }}-0.1.0
 
 # See remote cache documentation in /docs/BAZEL.md
 var_3: &setup-bazel-remote-cache
@@ -59,7 +59,7 @@ jobs:
 
   build:
     <<: *job_defaults
-    resource_class: large
+    resource_class: xlarge
     steps:
       - checkout:
           <<: *post_checkout
@@ -71,6 +71,7 @@ jobs:
       - restore_cache:
           key: *cache_key
 
+      - run: ls /home/circleci/bazel_repository_cache || true
       - run: bazel info release
       - run: bazel run @yarn//:yarn
       # Use bazel query so that we explicitly ask for all buildable targets to be built as well
@@ -91,6 +92,7 @@ jobs:
           key: *cache_key
           paths:
             - "node_modules"
+            - "~/bazel_repository_cache"
 
 workflows:
   version: 2