fix: add option to set additional build contexts (#116)

_docs/data/data.yaml

@@ -89,6 +89,11 @@ properties:
     type: string
     required: false
 
+  named_context:
+    description: Set additional named [build contexts](https://docs.docker.com/engine/reference/commandline/buildx_build/#build-context) (e.g., name=path).
+    type: list
+    required: false
+
   tags:
     description: Set repository tags to use for the image. Tags can also be loaded from a `.tags` file.
     defaultValue: latest

cmd/drone-docker-buildx/config.go

@@ -128,6 +128,13 @@ func settingsFlags(settings *plugin.Settings, category string) []cli.Flag {
 			Destination: &settings.Build.Context,
 			Category:    category,
 		},
+		&cli.StringSliceFlag{
+			Name:        "named-context",
+			EnvVars:     []string{"PLUGIN_NAMED_CONTEXT"},
+			Usage:       "additional named build context",
+			Destination: &settings.Build.NamedContext,
+			Category:    category,
+		},
 		&cli.StringSliceFlag{
 			Name:        "tags",
 			EnvVars:     []string{"PLUGIN_TAG", "PLUGIN_TAGS"},

plugin/docker.go

@@ -117,6 +117,9 @@ func commandBuild(build Build, dryrun bool) *exec.Cmd {
 	if build.Output != "" {
 		args = append(args, "--output", build.Output)
 	}
+	for _, arg := range build.NamedContext.Value() {
+		args = append(args, "--build-context", arg)
+	}
 
 	if len(build.Platforms.Value()) > 0 {
 		args = append(args, "--platform", strings.Join(build.Platforms.Value(), ","))

plugin/impl.go

@@ -40,25 +40,26 @@ type Login struct {
 
 // Build defines Docker build parameters.
 type Build struct {
-	Ref        string          // Git commit ref
-	Branch     string          // Git repository branch
-	Dockerfile string          // Docker build Dockerfile
-	Context    string          // Docker build context
-	TagsAuto   bool            // Docker build auto tag
-	TagsSuffix string          // Docker build tags with suffix
-	Tags       cli.StringSlice // Docker build tags
-	Platforms  cli.StringSlice // Docker build target platforms
-	Args       cli.StringSlice // Docker build args
-	ArgsEnv    cli.StringSlice // Docker build args from env
-	Target     string          // Docker build target
-	Pull       bool            // Docker build pull
-	CacheFrom  cli.StringSlice // Docker build cache-from
-	Compress   bool            // Docker build compress
-	Repo       string          // Docker build repository
-	NoCache    bool            // Docker build no-cache
-	AddHost    cli.StringSlice // Docker build add-host
-	Quiet      bool            // Docker build quiet
-	Output     string          // Docker build output folder
+	Ref          string          // Git commit ref
+	Branch       string          // Git repository branch
+	Dockerfile   string          // Docker build Dockerfile
+	Context      string          // Docker build context
+	TagsAuto     bool            // Docker build auto tag
+	TagsSuffix   string          // Docker build tags with suffix
+	Tags         cli.StringSlice // Docker build tags
+	Platforms    cli.StringSlice // Docker build target platforms
+	Args         cli.StringSlice // Docker build args
+	ArgsEnv      cli.StringSlice // Docker build args from env
+	Target       string          // Docker build target
+	Pull         bool            // Docker build pull
+	CacheFrom    cli.StringSlice // Docker build cache-from
+	Compress     bool            // Docker build compress
+	Repo         string          // Docker build repository
+	NoCache      bool            // Docker build no-cache
+	AddHost      cli.StringSlice // Docker build add-host
+	Quiet        bool            // Docker build quiet
+	Output       string          // Docker build output folder
+	NamedContext cli.StringSlice // Docker build named context
 }
 
 // Settings for the Plugin.