From 26dfa3266bcda58148e1e78d7b519968a048ad27 Mon Sep 17 00:00:00 2001
From: Puneeth Chaganti <punchagan@muse-amuse.in>
Date: Sun, 1 Apr 2018 02:11:06 +0530
Subject: [PATCH] ci: Make cache keys depend on checksums of dependency
 manifests

Caches in Circle are immutable -- even if a path in a cache changes in builds
after the cache was created, the cache is not updated if it already exists. This
was making the zulip-venv-cache and zulip-npm-cache directories useless on
Circle.

This commit changes the cache keys to depend on the checksums of the dependency
manifests (requirements/{dev,thumbor}.txt, package.json and yarn.lock). This
would ensure that the caches are updated when the environments change. It may
result in the occasional build being "uncached" -- when a dependency manifest
changes -- but builds without such changes will be much faster, and such builds
are a majority.
---
 .circleci/config.yml | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index b36218b21e..16c079605f 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -22,10 +22,10 @@ jobs:
 
       - restore_cache:
           keys:
-          - v1-npm-base.trusty.1
+          - v1-npm-base.trusty-{{ checksum "package.json" }}-{{ checksum "yarn.lock" }}
       - restore_cache:
           keys:
-          - v1-venv-base.trusty.1
+          - v1-venv-base.trusty-{{ checksum "requirements/thumbor.txt" }}-{{ checksum "requirements/dev.txt" }}
 
       - run:
           name: install dependencies
@@ -51,11 +51,11 @@ jobs:
       - save_cache:
           paths:
             - /srv/zulip-npm-cache
-          key: v1-npm-base.trusty.1
+          key: v1-npm-base.trusty-{{ checksum "package.json" }}-{{ checksum "yarn.lock" }}
       - save_cache:
           paths:
             - /srv/zulip-venv-cache
-          key: v1-venv-base.trusty.1
+          key: v1-venv-base.trusty-{{ checksum "requirements/thumbor.txt" }}-{{ checksum "requirements/dev.txt" }}
       # TODO: in Travis we also cache ~/zulip-emoji-cache, ~/node, ~/misc
 
       # The moment of truth!  Run the tests.
@@ -103,10 +103,10 @@ jobs:
 
       - restore_cache:
           keys:
-          - v1-npm-base.xenial.1
+          - v1-npm-base.xenial-{{ checksum "package.json" }}-{{ checksum "yarn.lock" }}
       - restore_cache:
           keys:
-          - v1-venv-base.xenial.1
+          - v1-venv-base.xenial-{{ checksum "requirements/thumbor.txt" }}-{{ checksum "requirements/dev.txt" }}
 
       - run:
           name: install dependencies
@@ -118,11 +118,11 @@ jobs:
       - save_cache:
           paths:
             - /srv/zulip-npm-cache
-          key: v1-npm-base.xenial.1
+          key: v1-npm-base.xenial-{{ checksum "package.json" }}-{{ checksum "yarn.lock" }}
       - save_cache:
           paths:
             - /srv/zulip-venv-cache
-          key: v1-venv-base.xenial.1
+          key: v1-venv-base.xenial-{{ checksum "requirements/thumbor.txt" }}-{{ checksum "requirements/dev.txt" }}
 
       - run:
           name: run backend tests