Add container_from_explicit

Author: dh-seanmurphy

cmd/drone-docker/main.go

@@ -183,6 +183,11 @@ func main() {
 			Usage:  "images to consider as cache sources",
 			EnvVar: "PLUGIN_CACHE_FROM",
 		},
+		cli.StringFlag{
+			Name:   "cache-from-explicit",
+			Usage:  "image to consider as cache source fully specified",
+			EnvVar: "PLUGIN_CACHE_FROM_EXPLICIT",
+		},
 		cli.StringFlag{
 			Name:   "cache-to",
 			Usage:  "images to consider as cache stores",

docker.go

@@ -61,6 +61,7 @@ type (
 		Squash              bool     // Docker build squash
 		Pull                bool     // Docker build pull
 		CacheFrom           []string // Docker build cache-from
+		CacheFromExplicit   string   // Docker build cache-from with comma support
 		CacheTo             string   // Docker build cache-to
 		Compress            bool     // Docker build compress
 		Repo                string   // Docker build repository
@@ -415,6 +416,9 @@ func commandBuild(build Build) *exec.Cmd {
 	for _, arg := range build.CacheFrom {
 		args = append(args, "--cache-from", arg)
 	}
+	if build.CacheFromExplicit != "" {
+		args = append(args, "--cache-from", build.CacheFromExplicit)
+	}
 	if build.CacheTo != "" {
 		args = append(args, "--cache-to", build.CacheTo)
 	}