From 3a6860968a21ada933a0b8bbf7d5d74aa618f5e3 Mon Sep 17 00:00:00 2001
From: Roman Usherenko <roman.usherenko@gmail.com>
Date: Sun, 16 Sep 2018 23:11:40 +0300
Subject: [PATCH] allow multiple cache images for one service

---
 commands/build.sh |  7 ++++++-
 tests/build.bats  | 53 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+), 1 deletion(-)

diff --git a/commands/build.sh b/commands/build.sh
index e0b82db3..34a6b19e 100755
--- a/commands/build.sh
+++ b/commands/build.sh
@@ -15,10 +15,15 @@ for line in $(plugin_read_list CACHE_FROM) ; do
   IFS=':' read -r -a tokens <<< "$line"
   service_name=${tokens[0]}
   service_image=$(IFS=':'; echo "${tokens[*]:1}")
+  cache_image_name="$(service_name_cache_from_var "$service_name")"
+
+  if [[ -n ${!cache_image_name+x} ]]; then
+    continue # skipping since there's already a pulled cache image for this service
+  fi
 
   echo "~~~ :docker: Pulling cache image for $service_name"
   if retry "$pull_retries" plugin_prompt_and_run docker pull "$service_image" ; then
-    printf -v "$(service_name_cache_from_var "$service_name")" "%s" "$service_image"
+    printf -v "$cache_image_name" "%s" "$service_image"
   else
     echo "!!! :docker: Pull failed. $service_image will not be used as a cache for $service_name"
   fi
diff --git a/tests/build.bats b/tests/build.bats
index 3679c9dc..fbb1c297 100644
--- a/tests/build.bats
+++ b/tests/build.bats
@@ -197,6 +197,59 @@ load '../lib/shared'
   unstub docker-compose
 }
 
+@test "Build with several cache-from images for one service" {
+  export BUILDKITE_PLUGIN_DOCKER_COMPOSE_CONFIG="tests/composefiles/docker-compose.v3.2.yml"
+  export BUILDKITE_JOB_ID=1111
+  export BUILDKITE_PLUGIN_DOCKER_COMPOSE_BUILD_0=helloworld
+  export BUILDKITE_PLUGIN_DOCKER_COMPOSE_CACHE_FROM_0=helloworld:my.repository/myservice_cache:branch-name
+  export BUILDKITE_PLUGIN_DOCKER_COMPOSE_CACHE_FROM_1=helloworld:my.repository/myservice_cache:latest
+  export BUILDKITE_PIPELINE_SLUG=test
+  export BUILDKITE_BUILD_NUMBER=1
+
+  stub docker \
+    "pull my.repository/myservice_cache:branch-name : echo pulled cache image"
+
+  stub docker-compose \
+    "-f tests/composefiles/docker-compose.v3.2.yml -p buildkite1111 -f docker-compose.buildkite-1-override.yml build --pull helloworld : echo built helloworld"
+
+  run $PWD/hooks/command
+
+  assert_success
+  assert_output --partial "pulled cache image"
+  assert_output --partial "- my.repository/myservice_cache:branch-name"
+  refute_output --partial "- my.repository/myservice_cache:latest"
+  assert_output --partial "built helloworld"
+  unstub docker
+  unstub docker-compose
+}
+
+@test "Build with several cache-from images for one service with first image being not available" {
+  export BUILDKITE_PLUGIN_DOCKER_COMPOSE_CONFIG="tests/composefiles/docker-compose.v3.2.yml"
+  export BUILDKITE_JOB_ID=1111
+  export BUILDKITE_PLUGIN_DOCKER_COMPOSE_BUILD_0=helloworld
+  export BUILDKITE_PLUGIN_DOCKER_COMPOSE_CACHE_FROM_0=helloworld:my.repository/myservice_cache:branch-name
+  export BUILDKITE_PLUGIN_DOCKER_COMPOSE_CACHE_FROM_1=helloworld:my.repository/myservice_cache:latest
+  export BUILDKITE_PIPELINE_SLUG=test
+  export BUILDKITE_BUILD_NUMBER=1
+
+  stub docker \
+    "pull my.repository/myservice_cache:branch-name : exit 1" \
+    "pull my.repository/myservice_cache:latest : echo pulled cache image"
+
+  stub docker-compose \
+    "-f tests/composefiles/docker-compose.v3.2.yml -p buildkite1111 -f docker-compose.buildkite-1-override.yml build --pull helloworld : echo built helloworld"
+
+  run $PWD/hooks/command
+
+  assert_success
+  assert_output --partial "pulled cache image"
+  refute_output --partial "- my.repository/myservice_cache:branch-name"
+  assert_output --partial "- my.repository/myservice_cache:latest"
+  assert_output --partial "built helloworld"
+  unstub docker
+  unstub docker-compose
+}
+
 @test "Build with a cache-from image when pulling of the cache-from image failed" {
   export BUILDKITE_PLUGIN_DOCKER_COMPOSE_CONFIG="tests/composefiles/docker-compose.v3.2.yml"
   export BUILDKITE_JOB_ID=1111