feat: ability for users to specify custom builders (knative#147)

* refactor: functionWithOverrides
* feat: custom Buildpacks builder
* fix: namespaces

buildpacks/builder.go

@@ -36,6 +36,10 @@ func (builder *Builder) Build(f faas.Function) (err error) {
 	var packBuilder string
 	if f.Builder != "" {
 		packBuilder = f.Builder
+		pb, ok := f.BuilderMap[packBuilder]
+		if ok {
+			packBuilder = pb
+		}
 	} else {
 		packBuilder = RuntimeToBuildpack[f.Runtime]
 		if packBuilder == "" {

client.go

@@ -360,6 +360,7 @@ func (c *Client) Initialize(cfg Function) (err error) {
 			if c.verbose {
 				fmt.Printf("Builder: %s\n", f.Builder)
 			}
+			f.BuilderMap = builders
 		}
 		// Remove the builders.yaml file so the user is not confused by a
 		// configuration file that is only used for project creation/initialization

cmd/build.go

@@ -13,10 +13,16 @@ import (
 
 func init() {
 	root.AddCommand(buildCmd)
+	buildCmd.Flags().StringP("builder", "b", "default", "Buildpacks builder")
 	buildCmd.Flags().BoolP("confirm", "c", false, "Prompt to confirm all configuration options - $FAAS_CONFIRM")
 	buildCmd.Flags().StringP("image", "i", "", "Optional full image name, in form [registry]/[namespace]/[name]:[tag] for example quay.io/myrepo/project.name:latest (overrides --repository) - $FAAS_IMAGE")
 	buildCmd.Flags().StringP("path", "p", cwd(), "Path to the Function project directory - $FAAS_PATH")
 	buildCmd.Flags().StringP("repository", "r", "", "Repository for built images, ex 'docker.io/myuser' or just 'myuser'.  Optional if --image provided. - $FAAS_REPOSITORY")
+
+	err := buildCmd.RegisterFlagCompletionFunc("builder", CompleteBuilderList)
+	if err != nil {
+		fmt.Println("Error while calling RegisterFlagCompletionFunc: ", err)
+	}
 }
 
 var buildCmd = &cobra.Command{
@@ -33,15 +39,19 @@ name will be derived from the project name.
 Any value provided for --image or --repository will be persisted in the
 faas.yaml configuration file. On subsequent invocations of the "build" command
 these values will be read from the configuration file.
+
+It's possible to use a custom Buildpack builder with the --builder flag.
+The value may be image name e.g. "cnbs/sample-builder:bionic",
+or reference to builderMaps in the config file e.g. "default".
 `,
 	SuggestFor: []string{"biuld", "buidl", "built"},
-	PreRunE:    bindEnv("image", "path", "repository", "confirm"),
+	PreRunE:    bindEnv("image", "path", "builder", "repository", "confirm"),
 	RunE:       runBuild,
 }
 
 func runBuild(cmd *cobra.Command, _ []string) (err error) {
 	config := newBuildConfig()
-	function, err := functionWithOverrides(config.Path, "", config.Image)
+	function, err := functionWithOverrides(config.Path, functionOverrides{Builder: config.Builder, Image: config.Image})
 	if err != nil {
 		return
 	}
@@ -94,6 +104,7 @@ type buildConfig struct {
 	// Confirm: confirm values arrived upon from environment plus flags plus defaults,
 	// with interactive prompting (only applicable when attached to a TTY).
 	Confirm bool
+	Builder string
 }
 
 func newBuildConfig() buildConfig {
@@ -103,6 +114,7 @@ func newBuildConfig() buildConfig {
 		Repository: viper.GetString("repository"),
 		Verbose:    viper.GetBool("verbose"), // defined on root
 		Confirm:    viper.GetBool("confirm"),
+		Builder:    viper.GetString("builder"),
 	}
 }
 

cmd/completion_util.go

@@ -2,6 +2,7 @@ package cmd
 
 import (
 	"encoding/json"
+	"github.com/boson-project/faas"
 	"os"
 	"os/user"
 	"path"
@@ -67,3 +68,31 @@ func CompleteRegistryList(cmd *cobra.Command, args []string, toComplete string)
 	directive = cobra.ShellCompDirectiveDefault
 	return
 }
+
+func CompleteBuilderList(cmd *cobra.Command, args []string, complete string) (strings []string, directive cobra.ShellCompDirective) {
+	directive = cobra.ShellCompDirectiveError
+
+	var (
+		err  error
+		path string
+		f    faas.Function
+	)
+
+	path, err = cmd.Flags().GetString("path")
+	if err != nil {
+		return
+	}
+
+	f, err = faas.NewFunction(path)
+	if err != nil {
+		return
+	}
+
+	strings = make([]string, 0, len(f.BuilderMap))
+	for name := range f.BuilderMap {
+		strings = append(strings, name)
+	}
+
+	directive = cobra.ShellCompDirectiveDefault
+	return
+}

cmd/delete.go

@@ -42,6 +42,7 @@ func runDelete(cmd *cobra.Command, args []string) (err error) {
 
 	remover := knative.NewRemover(config.Namespace)
 	remover.Verbose = config.Verbose
+	remover.Namespace = config.Namespace
 
 	function := faas.Function{Root: config.Path, Name: config.Name}
 

cmd/deploy.go

@@ -41,7 +41,7 @@ or -n flag, and if so this will overwrite the value in the faas.yaml file.
 
 func runDeploy(cmd *cobra.Command, _ []string) (err error) {
 	config := newDeployConfig()
-	function, err := functionWithOverrides(config.Path, config.Namespace, "")
+	function, err := functionWithOverrides(config.Path, functionOverrides{Namespace: config.Namespace})
 	if err != nil {
 		return err
 	}
@@ -57,6 +57,7 @@ func runDeploy(cmd *cobra.Command, _ []string) (err error) {
 
 	deployer := knative.NewDeployer()
 	deployer.Verbose = config.Verbose
+	deployer.Namespace = function.Namespace
 
 	client := faas.New(
 		faas.WithVerbose(config.Verbose),

cmd/root.go

@@ -120,48 +120,44 @@ func bindEnv(flags ...string) bindFunc {
 	}
 }
 
-// overrideImage overwrites (or sets) the value of the Function's .Image
-// property, which preempts the default functionality of deriving the value as:
-// Deafult:  [config.Repository]/[config.Name]:latest
-func overrideImage(root, override string) (err error) {
-	if override == "" {
-		return
-	}
-	f, err := faas.NewFunction(root)
-	if err != nil {
-		return err
-	}
-	f.Image = override
-	return f.WriteConfig()
-}
-
-// overrideNamespace overwrites (or sets) the value of the Function's .Namespace
-// property, which preempts the default functionality of using the underlying
-// platform configuration (if supported).  In the case of Kubernetes, this
-// overrides the configured namespace (usually) set in ~/.kube.config.
-func overrideNamespace(root, override string) (err error) {
-	if override == "" {
-		return
-	}
-	f, err := faas.NewFunction(root)
-	if err != nil {
-		return err
-	}
-	f.Namespace = override
-	return f.WriteConfig()
+type functionOverrides struct {
+	Image     string
+	Namespace string
+	Builder   string
 }
 
 // functionWithOverrides sets the namespace and image strings for the
 // Function project at root, if provided, and returns the Function
 // configuration values
-func functionWithOverrides(root, namespace, image string) (f faas.Function, err error) {
-	if err = overrideNamespace(root, namespace); err != nil {
+func functionWithOverrides(root string, overrides functionOverrides) (f faas.Function, err error) {
+	f, err = faas.NewFunction(root)
+	if err != nil {
 		return
 	}
-	if err = overrideImage(root, image); err != nil {
+
+	overrideMapping := []struct{
+		src  string
+		dest *string
+	} {
+		{overrides.Builder, &f.Builder},
+		{overrides.Image, &f.Image},
+		{overrides.Namespace, &f.Namespace},
+	}
+
+	for _, m := range overrideMapping {
+		if m.src != "" {
+			*m.dest = m.src
+		}
+	}
+
+	err =  f.WriteConfig()
+	if err != nil {
 		return
 	}
-	return faas.NewFunction(root)
+
+	f, err = faas.NewFunction(root)
+	return
+
 }
 
 // deriveName returns the explicit value (if provided) or attempts to derive

cmd/update.go

@@ -50,7 +50,7 @@ update is run, a new container image is always built.
 
 func runUpdate(cmd *cobra.Command, args []string) (err error) {
 	config := newUpdateConfig()
-	function, err := functionWithOverrides(config.Path, config.Namespace, "")
+	function, err := functionWithOverrides(config.Path, functionOverrides{Namespace: config.Namespace})
 	if err != nil {
 		return err
 	}

config.go

@@ -14,12 +14,13 @@ const ConfigFile = "faas.yaml"
 // Config represents the serialized state of a Function's metadata.
 // See the Function struct for attribute documentation.
 type config struct {
-	Name      string `yaml:"name"`
-	Namespace string `yaml:"namespace"`
-	Runtime   string `yaml:"runtime"`
-	Image     string `yaml:"image"`
-	Trigger   string `yaml:"trigger"`
-	Builder   string `yaml:"builder"`
+	Name       string            `yaml:"name"`
+	Namespace  string            `yaml:"namespace"`
+	Runtime    string            `yaml:"runtime"`
+	Image      string            `yaml:"image"`
+	Trigger    string            `yaml:"trigger"`
+	Builder    string            `yaml:"builder"`
+	BuilderMap map[string]string `yaml:"builderMap"`
 	// Add new values to the toConfig/fromConfig functions.
 }
 
@@ -49,24 +50,26 @@ func newConfig(root string) (c config, err error) {
 // Note that config does not include ancillary fields not serialized, such as Root.
 func fromConfig(c config) (f Function) {
 	return Function{
-		Name:      c.Name,
-		Namespace: c.Namespace,
-		Runtime:   c.Runtime,
-		Image:     c.Image,
-		Trigger:   c.Trigger,
-		Builder:   c.Builder,
+		Name:       c.Name,
+		Namespace:  c.Namespace,
+		Runtime:    c.Runtime,
+		Image:      c.Image,
+		Trigger:    c.Trigger,
+		Builder:    c.Builder,
+		BuilderMap: c.BuilderMap,
 	}
 }
 
 // toConfig serializes a Function to a config object.
 func toConfig(f Function) config {
 	return config{
-		Name:      f.Name,
-		Namespace: f.Namespace,
-		Runtime:   f.Runtime,
-		Image:     f.Image,
-		Trigger:   f.Trigger,
-		Builder:   f.Builder,
+		Name:       f.Name,
+		Namespace:  f.Namespace,
+		Runtime:    f.Runtime,
+		Image:      f.Image,
+		Trigger:    f.Trigger,
+		Builder:    f.Builder,
+		BuilderMap: f.BuilderMap,
 	}
 }
 

function.go

@@ -41,8 +41,13 @@ type Function struct {
 	// "Repo+Name:latest" to derive the Image.
 	Image string
 
-	// Builder represents the CNCF Buildpack builder image for a function
-	Builder string
+	// Builder represents the CNCF Buildpack builder image for a function,
+	// or it might be reference to `BuilderMap`.
+	Builder    string
+
+	// Map containing known builders.
+	// e.g. { "jvm": "docker.io/example/quarkus-jvm-builder" }
+	BuilderMap map[string]string
 }
 
 // NewFunction loads a Function from a path on disk. use .Initialized() to determine if

templates/quarkus/events/.builders.yaml

@@ -1 +1,3 @@
-default: quay.io/boson/faas-quarkus-builder
+default: quay.io/boson/faas-quarkus-jvm-builder
+jvm: quay.io/boson/faas-quarkus-jvm-builder
+native: quay.io/boson/faas-quarkus-native-builder

templates/quarkus/http/.builders.yaml

@@ -1 +1,3 @@
-default: quay.io/boson/faas-quarkus-builder
+default: quay.io/boson/faas-quarkus-jvm-builder
+jvm: quay.io/boson/faas-quarkus-jvm-builder
+native: quay.io/boson/faas-quarkus-native-builder