From a1c406a4795e3f91963676f923ca607df975a2c7 Mon Sep 17 00:00:00 2001
From: Paulo Castro <paulo@balena.io>
Date: Wed, 12 Feb 2020 11:35:03 +0000
Subject: [PATCH] Add '--cache-from' option to balena build and deploy commands

It implements the same feature as the "docker build --cache-from" option.

Resolves: #1616
Change-type: minor
---
 doc/cli.markdown               | 8 ++++++++
 lib/utils/docker-coffee.coffee | 9 +++++++++
 2 files changed, 17 insertions(+)

diff --git a/doc/cli.markdown b/doc/cli.markdown
index 1aaccd0d..76101b4f 100644
--- a/doc/cli.markdown
+++ b/doc/cli.markdown
@@ -1968,6 +1968,10 @@ The alias to the generated image
 
 Set a build-time variable (eg. "-B 'ARG=value'"). Can be specified multiple times.
 
+#### --cache-from &#60;image-list&#62;
+
+Comma-separated list (no spaces) of image names for build cache resolution. Implements the same feature as the "docker build --cache-from" option.
+
 #### --nocache
 
 Don't use docker layer caching when building
@@ -2097,6 +2101,10 @@ The alias to the generated image
 
 Set a build-time variable (eg. "-B 'ARG=value'"). Can be specified multiple times.
 
+#### --cache-from &#60;image-list&#62;
+
+Comma-separated list (no spaces) of image names for build cache resolution. Implements the same feature as the "docker build --cache-from" option.
+
 #### --nocache
 
 Don't use docker layer caching when building
diff --git a/lib/utils/docker-coffee.coffee b/lib/utils/docker-coffee.coffee
index 064cb45d..e79aaa2a 100644
--- a/lib/utils/docker-coffee.coffee
+++ b/lib/utils/docker-coffee.coffee
@@ -83,6 +83,13 @@ exports.appendOptions = (opts) ->
 			description: 'Set a build-time variable (eg. "-B \'ARG=value\'"). Can be specified multiple times.'
 			alias: 'B'
 		},
+		{
+			signature: 'cache-from'
+			parameter: 'image-list'
+			description: '
+				Comma-separated list (no spaces) of image names for build cache resolution.
+				Implements the same feature as the "docker build --cache-from" option.'
+		},
 		{
 			signature: 'nocache'
 			description: "Don't use docker layer caching when building"
@@ -160,6 +167,8 @@ exports.generateBuildOpts = (options) ->
 		opts.t = options.tag
 	if options.nocache?
 		opts.nocache = true
+	if options['cache-from']?.trim()
+		opts.cachefrom = options['cache-from'].split(',').filter((i) -> !!i.trim())
 	if options.squash?
 		opts.squash = true
 	if options.buildArg?