Add support for limited build-args

Support for go modules is now active in git-tar and of-builder.
Tested on the community cluster with new images and the
following sample repo:

https://github.com/alexellis/gitops-webinar

Fixes: #652

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

Author: alexellis

git-tar/Dockerfile

@@ -1,6 +1,6 @@
-FROM openfaas/faas-cli:0.11.8 as faas-cli
-FROM openfaas/classic-watchdog:0.18.1 as watchdog
-FROM golang:1.13-alpine3.11 as build
+FROM openfaas/faas-cli:0.12.8 as faas-cli
+FROM openfaas/classic-watchdog:0.18.17 as watchdog
+FROM golang:1.13-alpine3.12 as build
 
 ENV CGO_ENABLED=0
 ENV GO111MODULE=off

git-tar/Gopkg.lock

@@ -1,6 +1,6 @@
 [[constraint]]
   name = "github.com/openfaas/faas-cli"
-  version = "0.9.3"
+  version = "0.12.8"
 
 [[constraint]]
   name = "github.com/openfaas/openfaas-cloud"
@@ -26,4 +26,3 @@
   go-tests = true
   unused-packages = true
 
-

git-tar/Gopkg.toml

@@ -36,11 +36,6 @@ type tarEntry struct {
 	imageName    string
 }
 
-type cfg struct {
-	Ref      string  `json:"ref"`
-	Frontend *string `json:"frontend,omitempty"`
-}
-
 func parseYAML(filePath string) (*stack.Services, error) {
 	envVarSubst := false
 	parsed, err := stack.ParseYAMLFile(path.Join(filePath, "stack.yml"), "", "", envVarSubst)
@@ -123,8 +118,13 @@ func makeTar(pushEvent sdk.PushEvent, filePath string, services *stack.Services)
 		imageName := formatImageShaTag(pushRepositoryURL, &v, pushEvent.AfterCommitID,
 			pushEvent.Repository.Owner.Login, pushEvent.Repository.Name)
 
-		config := cfg{
-			Ref: imageName,
+		allowedBuildArgs := []string{"GO111MODULE"}
+		buildArgs := makeBuildArgs(v.BuildArgs, allowedBuildArgs)
+
+		// Write a config file for the Docker build
+		config := buildConfig{
+			Ref:       imageName,
+			BuildArgs: buildArgs,
 		}
 
 		configBytes, _ := json.Marshal(config)
@@ -797,3 +797,16 @@ func invokeWithHMAC(uri string, payload []byte, payloadSecret string, headers ma
 
 	return res.StatusCode, resOut, nil
 }
+
+func makeBuildArgs(inputArgs map[string]string, allowed []string) map[string]string {
+	args := map[string]string{}
+	for key, value := range inputArgs {
+		for _, allow := range allowed {
+			if key == allow {
+				args[key] = value
+				break
+			}
+		}
+	}
+	return args
+}

git-tar/function/ops.go

@@ -0,0 +1,7 @@
+package function
+
+type buildConfig struct {
+	Ref       string            `json:"ref"`
+	Frontend  string            `json:"frontend,omitempty"`
+	BuildArgs map[string]string `json:"buildArgs,omitempty"`
+}