Merge pull request #4346 from esl/invalidate-circleci-cache-with-plugins

Invalidate CircleCI deps cache if the plugin list changes

This PR addresses MIM-2265.

It is hard to handle updates of plugins, circleci would always use the cached old version. And rebar.lock is not tracking plugins.

Proposed changes include:

Hashing of {plugins, ...}. block. Useful if you are developing or updating plugins
Invalidate CircleCI deps cache if the plugin list changes
We use base circle ci image for initial template generation, which has no Erlang. So we use sed to match plugins block and we hash it.

.circleci/template.yml

@@ -6,7 +6,7 @@ references:
   - &ENTRYPOINT ["/bin/sh", "-c", "eval ${INSTALL_DEPS_CMD:-echo} && echo __INJECT_FILES__ | eval ${BASE32DEC:-base32 --decode} | bash"]
   # Caches created via the save_cache step are stored for up to 15 days
   - &CERT_KEY certs-cache-{{ checksum "certs_cache_key" }}-v3
-  - &DEPS_CACHE_KEY deps-cache-{{ checksum "rebar.lock" }}-{{ checksum "big_tests/rebar.lock" }}-{{ checksum "otp_version" }}-v5
+  - &DEPS_CACHE_KEY deps-cache-{{ checksum "rebar.lock" }}-{{ checksum "big_tests/rebar.lock" }}-__REBAR_PLUGINS_HASH__-{{ checksum "otp_version" }}-v5
   - &BUILD_CACHE_KEY build-cache-{{ .Branch }}-{{ .Revision }}-{{ checksum "otp_version" }}-v6
 
 # list of references to be used inside executors block

tools/circle-generate-config.sh

@@ -35,6 +35,9 @@ CACERT=$(cat32 tools/ssl/ca/cacert.pem)
 
 CERTS_CACHE_KEY=$(cat certs_cache_key)
 
+# Matches plugins list in the rebar.config
+REBAR_PLUGINS_HASH=$(cat rebar.config | sed -n '/^{plugins/,/]}./p' | sha1sum | awk '{print $1}')
+
 sed -e "s/__MYSQL_CNF__/${MYSQL_CNF}/" \
     -e "s/__MYSQL_SQL__/${MYSQL_SQL}/" \
     -e "s/__MYSQL_SETUP__/${MYSQL_SETUP}/" \
@@ -69,5 +72,6 @@ sed -e "s/__MYSQL_CNF__/${MYSQL_CNF}/" \
     -e "s/__PYTHON2_BASE32_DEC__/${PYTHON2_BASE32_DEC}/" \
     -e "s/__PYTHON3_BASE32_DEC__/${PYTHON3_BASE32_DEC}/" \
     -e "s/__CERTS_CACHE_KEY__/${CERTS_CACHE_KEY}/" \
+    -e "s/__REBAR_PLUGINS_HASH__/${REBAR_PLUGINS_HASH}/" \
     .circleci/template.yml \
     > "$OUT_FILE"