Generate Gomu files after the fact (#2258)

* Move file generation to new package

* Use text/template instead of html/template

* Make config variables more consistent

* Combine generate files and print comments there

* Add gomu generate command

* Refactor project templating to file library

* Determine client earlier

cmd/gomu/cmd/cli/cli.go

@@ -3,6 +3,7 @@ package cli
 import (
 	_ "github.com/asim/go-micro/cmd/gomu/cmd/cli/call"
 	_ "github.com/asim/go-micro/cmd/gomu/cmd/cli/describe"
+	_ "github.com/asim/go-micro/cmd/gomu/cmd/cli/generate"
 	_ "github.com/asim/go-micro/cmd/gomu/cmd/cli/new"
 	_ "github.com/asim/go-micro/cmd/gomu/cmd/cli/run"
 	_ "github.com/asim/go-micro/cmd/gomu/cmd/cli/services"

cmd/gomu/cmd/cli/generate/generate.go

@@ -0,0 +1,98 @@
+package generate
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/asim/go-micro/cmd/gomu/cmd"
+	"github.com/asim/go-micro/cmd/gomu/file"
+	"github.com/asim/go-micro/cmd/gomu/file/generator"
+	tmpl "github.com/asim/go-micro/cmd/gomu/file/template"
+	"github.com/urfave/cli/v2"
+)
+
+func init() {
+	cmd.Register(&cli.Command{
+		Name:  "generate",
+		Usage: "Generate project template files after the fact",
+		Subcommands: []*cli.Command{
+			{
+				Name:   "skaffold",
+				Usage:  "Generate Skaffold project template files",
+				Action: Skaffold,
+			},
+		},
+	})
+}
+
+// Skaffold generates Skaffold project template files in the current directory.
+// Exits on error.
+func Skaffold(ctx *cli.Context) error {
+	dir, err := os.Getwd()
+	if err != nil {
+		return err
+	}
+	service := dir[strings.LastIndex(dir, "/")+1:]
+
+	vendor, err := getServiceVendor(service)
+	if err != nil {
+		return err
+	}
+
+	g := generator.New(
+		generator.Service(service),
+		generator.Vendor(vendor),
+		generator.Directory("."),
+		generator.Client(strings.HasSuffix(service, "-client")),
+		generator.Skaffold(true),
+	)
+
+	files := []file.File{
+		{".dockerignore", tmpl.DockerIgnore},
+		{"go.mod", tmpl.Module},
+		{"plugins.go", tmpl.Plugins},
+		{"resources/clusterrole.yaml", tmpl.KubernetesClusterRole},
+		{"resources/configmap.yaml", tmpl.KubernetesEnv},
+		{"resources/deployment.yaml", tmpl.KubernetesDeployment},
+		{"resources/rolebinding.yaml", tmpl.KubernetesRoleBinding},
+		{"skaffold.yaml", tmpl.SkaffoldCFG},
+	}
+
+	if err := g.Generate(files); err != nil {
+		return err
+	}
+
+	fmt.Println("skaffold project template files generated")
+
+	return nil
+}
+
+func getServiceVendor(s string) (string, error) {
+	f, err := os.Open("go.mod")
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+
+	line := ""
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		if strings.HasPrefix(scanner.Text(), "module ") {
+			line = scanner.Text()
+			break
+
+		}
+	}
+	if line == "" {
+		return "", nil
+	}
+
+	module := line[strings.LastIndex(line, " ")+1:]
+	if module == s {
+		return "", nil
+	}
+
+	return module[:strings.LastIndex(module, "/")] + "/", nil
+}

cmd/gomu/cmd/cli/new/new.go

@@ -4,12 +4,12 @@ import (
 	"fmt"
 	"os"
 	"path"
-	"path/filepath"
 	"strings"
-	"text/template"
 
 	"github.com/asim/go-micro/cmd/gomu/cmd"
-	tmpl "github.com/asim/go-micro/cmd/gomu/cmd/cli/new/template"
+	"github.com/asim/go-micro/cmd/gomu/file"
+	"github.com/asim/go-micro/cmd/gomu/file/generator"
+	tmpl "github.com/asim/go-micro/cmd/gomu/file/template"
 	"github.com/urfave/cli/v2"
 )
 
@@ -24,21 +24,6 @@ var flags []cli.Flag = []cli.Flag{
 	},
 }
 
-type config struct {
-	Alias    string
-	Comments []string
-	Dir      string
-	Vendor   string
-	Client   bool
-	Jaeger   bool
-	Skaffold bool
-}
-
-type file struct {
-	Path string
-	Tmpl string
-}
-
 // NewCommand returns a new new cli command.
 func init() {
 	cmd.Register(&cli.Command{
@@ -87,10 +72,11 @@ func createProject(ctx *cli.Context, pt string) error {
 		return cli.ShowSubcommandHelp(ctx)
 	}
 
+	client := pt == "client"
 	name, vendor := getNameAndVendor(arg)
 
 	dir := name
-	if pt == "client" {
+	if client {
 		dir += "-client"
 	}
 
@@ -105,7 +91,16 @@ func createProject(ctx *cli.Context, pt string) error {
 
 	fmt.Printf("creating %s %s\n", pt, name)
 
-	files := []file{
+	g := generator.New(
+		generator.Service(name),
+		generator.Vendor(vendor),
+		generator.Directory(dir),
+		generator.Client(client),
+		generator.Jaeger(ctx.Bool("jaeger")),
+		generator.Skaffold(ctx.Bool("skaffold")),
+	)
+
+	files := []file.File{
 		{".dockerignore", tmpl.DockerIgnore},
 		{".gitignore", tmpl.GitIgnore},
 		{"Dockerfile", tmpl.Dockerfile},
@@ -115,17 +110,17 @@ func createProject(ctx *cli.Context, pt string) error {
 
 	switch pt {
 	case "client":
-		files = append(files, []file{
+		files = append(files, []file.File{
 			{"main.go", tmpl.MainCLT},
 		}...)
 	case "function":
-		files = append(files, []file{
+		files = append(files, []file.File{
 			{"handler/" + name + ".go", tmpl.HandlerFNC},
 			{"main.go", tmpl.MainFNC},
 			{"proto/" + name + ".proto", tmpl.ProtoFNC},
 		}...)
 	case "service":
-		files = append(files, []file{
+		files = append(files, []file.File{
 			{"handler/" + name + ".go", tmpl.HandlerSRV},
 			{"main.go", tmpl.MainSRV},
 			{"proto/" + name + ".proto", tmpl.ProtoSRV},
@@ -135,7 +130,7 @@ func createProject(ctx *cli.Context, pt string) error {
 	}
 
 	if ctx.Bool("skaffold") {
-		files = append(files, []file{
+		files = append(files, []file.File{
 			{"plugins.go", tmpl.Plugins},
 			{"resources/clusterrole.yaml", tmpl.KubernetesClusterRole},
 			{"resources/configmap.yaml", tmpl.KubernetesEnv},
@@ -145,22 +140,22 @@ func createProject(ctx *cli.Context, pt string) error {
 		}...)
 	}
 
-	c := config{
-		Alias:    name,
-		Dir:      dir,
-		Vendor:   vendor,
-		Client:   pt == "client",
-		Jaeger:   ctx.Bool("jaeger"),
-		Skaffold: ctx.Bool("skaffold"),
+	if err := g.Generate(files); err != nil {
+		return err
 	}
 
-	if pt == "client" {
-		c.Comments = clientComments(name, dir)
+	var comments []string
+	if client {
+		comments = clientComments(name, dir)
 	} else {
-		c.Comments = protoComments(name, dir)
+		comments = protoComments(name, dir)
 	}
 
-	return create(files, c)
+	for _, comment := range comments {
+		fmt.Println(comment)
+	}
+
+	return nil
 }
 
 func clientComments(name, dir string) []string {
@@ -184,49 +179,6 @@ func protoComments(name, dir string) []string {
 	}
 }
 
-func create(files []file, c config) error {
-	for _, file := range files {
-		fp := filepath.Join(c.Dir, file.Path)
-		dir := filepath.Dir(fp)
-
-		if _, err := os.Stat(dir); os.IsNotExist(err) {
-			if err := os.MkdirAll(dir, 0755); err != nil {
-				return err
-			}
-		}
-
-		f, err := os.Create(fp)
-		if err != nil {
-			return err
-		}
-
-		fn := template.FuncMap{
-			"dehyphen": func(s string) string {
-				return strings.ReplaceAll(s, "-", "")
-			},
-			"lower": strings.ToLower,
-			"title": func(s string) string {
-				return strings.ReplaceAll(strings.Title(s), "-", "")
-			},
-		}
-		t, err := template.New(fp).Funcs(fn).Parse(file.Tmpl)
-		if err != nil {
-			return err
-		}
-
-		err = t.Execute(f, c)
-		if err != nil {
-			return err
-		}
-	}
-
-	for _, comment := range c.Comments {
-		fmt.Println(comment)
-	}
-
-	return nil
-}
-
 func getNameAndVendor(s string) (string, string) {
 	var n string
 	var v string

cmd/gomu/file/file.go

@@ -0,0 +1,6 @@
+package file
+
+type File struct {
+	Path     string
+	Template string
+}

cmd/gomu/file/generator/generator.go

@@ -0,0 +1,70 @@
+package generator
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"text/template"
+
+	"github.com/asim/go-micro/cmd/gomu/file"
+)
+
+type Generator interface {
+	Generate([]file.File) error
+}
+
+type generator struct {
+	opts Options
+}
+
+// Generate generates project template files.
+func (g *generator) Generate(files []file.File) error {
+	for _, file := range files {
+		fp := filepath.Join(g.opts.Directory, file.Path)
+		dir := filepath.Dir(fp)
+
+		if _, err := os.Stat(dir); os.IsNotExist(err) {
+			if err := os.MkdirAll(dir, 0755); err != nil {
+				return err
+			}
+		}
+
+		f, err := os.Create(fp)
+		if err != nil {
+			return err
+		}
+
+		fn := template.FuncMap{
+			"dehyphen": func(s string) string {
+				return strings.ReplaceAll(s, "-", "")
+			},
+			"lower": strings.ToLower,
+			"title": func(s string) string {
+				return strings.ReplaceAll(strings.Title(s), "-", "")
+			},
+		}
+		t, err := template.New(fp).Funcs(fn).Parse(file.Template)
+		if err != nil {
+			return err
+		}
+
+		err = t.Execute(f, g.opts)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// New returns a new generator struct.
+func New(opts ...Option) Generator {
+	var options Options
+	for _, o := range opts {
+		o(&options)
+	}
+
+	return &generator{
+		opts: options,
+	}
+}

cmd/gomu/file/generator/options.go

@@ -0,0 +1,49 @@
+package generator
+
+type Options struct {
+	Service   string
+	Vendor    string
+	Directory string
+
+	Client   bool
+	Jaeger   bool
+	Skaffold bool
+}
+
+type Option func(o *Options)
+
+func Service(s string) Option {
+	return func(o *Options) {
+		o.Service = s
+	}
+}
+
+func Vendor(v string) Option {
+	return func(o *Options) {
+		o.Vendor = v
+	}
+}
+
+func Directory(d string) Option {
+	return func(o *Options) {
+		o.Directory = d
+	}
+}
+
+func Client(c bool) Option {
+	return func(o *Options) {
+		o.Client = c
+	}
+}
+
+func Jaeger(j bool) Option {
+	return func(o *Options) {
+		o.Jaeger = j
+	}
+}
+
+func Skaffold(s bool) Option {
+	return func(o *Options) {
+		o.Skaffold = s
+	}
+}

cmd/gomu/file/template/docker.go

@@ -3,7 +3,7 @@ package template
 // Dockerfile is the Dockerfile template used for new projects.
 var Dockerfile = `FROM golang:alpine AS builder
 ENV CGO_ENABLED=0 GOOS=linux
-WORKDIR /go/src/{{.Alias}}
+WORKDIR /go/src/{{.Service}}{{if .Client}}-client{{end}}
 RUN apk --update --no-cache add ca-certificates gcc libtool make musl-dev protoc
 COPY {{if not .Client}}Makefile {{end}}go.mod go.sum ./
 RUN {{if not .Client}}make init && {{end}}go mod download
@@ -12,8 +12,8 @@ RUN make {{if not .Client}}proto {{end}}tidy build
 
 FROM scratch
 COPY --from=builder /etc/ssl/certs /etc/ssl/certs
-COPY --from=builder /go/src/{{.Alias}}/{{.Alias}} /{{.Alias}}
-ENTRYPOINT ["/{{.Alias}}"]
+COPY --from=builder /go/src/{{.Service}}{{if .Client}}-client{{end}}/{{.Service}}{{if .Client}}-client{{end}} /{{.Service}}{{if .Client}}-client{{end}}
+ENTRYPOINT ["/{{.Service}}{{if .Client}}-client{{end}}"]
 CMD []
 `
 

cmd/gomu/file/template/gitignore.go

@@ -2,5 +2,5 @@ package template
 
 // GitIgnore is the .gitignore template used for new projects.
 var GitIgnore = `# don't commit the service binary to vcs
-{{.Alias}}
+{{.Service}}{{if .Client}}-client{{end}}
 `

cmd/gomu/file/template/handler.go

@@ -8,13 +8,13 @@ import (
 
 	log "github.com/asim/go-micro/v3/logger"
 
-	pb "{{.Vendor}}{{.Dir}}/proto"
+	pb "{{.Vendor}}{{.Service}}/proto"
 )
 
-type {{title .Alias}} struct{}
+type {{title .Service}} struct{}
 
-func (e *{{title .Alias}}) Call(ctx context.Context, req *pb.CallRequest, rsp *pb.CallResponse) error {
-	log.Infof("Received {{title .Alias}}.Call request: %v", req)
+func (e *{{title .Service}}) Call(ctx context.Context, req *pb.CallRequest, rsp *pb.CallResponse) error {
+	log.Infof("Received {{title .Service}}.Call request: %v", req)
 	rsp.Msg = "Hello " + req.Name
 	return nil
 }
@@ -30,18 +30,18 @@ import (
 
 	log "github.com/asim/go-micro/v3/logger"
 
-	pb "{{.Vendor}}{{.Dir}}/proto"
+	pb "{{.Vendor}}{{.Service}}/proto"
 )
 
-type {{title .Alias}} struct{}
+type {{title .Service}} struct{}
 
-func (e *{{title .Alias}}) Call(ctx context.Context, req *pb.CallRequest, rsp *pb.CallResponse) error {
-	log.Infof("Received {{title .Alias}}.Call request: %v", req)
+func (e *{{title .Service}}) Call(ctx context.Context, req *pb.CallRequest, rsp *pb.CallResponse) error {
+	log.Infof("Received {{title .Service}}.Call request: %v", req)
 	rsp.Msg = "Hello " + req.Name
 	return nil
 }
 
-func (e *{{title .Alias}}) ClientStream(ctx context.Context, stream pb.{{title .Alias}}_ClientStreamStream) error {
+func (e *{{title .Service}}) ClientStream(ctx context.Context, stream pb.{{title .Service}}_ClientStreamStream) error {
 	var count int64
 	for {
 		req, err := stream.Recv()
@@ -57,8 +57,8 @@ func (e *{{title .Alias}}) ClientStream(ctx context.Context, stream pb.{{title .
 	}
 }
 
-func (e *{{title .Alias}}) ServerStream(ctx context.Context, req *pb.ServerStreamRequest, stream pb.{{title .Alias}}_ServerStreamStream) error {
-	log.Infof("Received {{title .Alias}}.ServerStream request: %v", req)
+func (e *{{title .Service}}) ServerStream(ctx context.Context, req *pb.ServerStreamRequest, stream pb.{{title .Service}}_ServerStreamStream) error {
+	log.Infof("Received {{title .Service}}.ServerStream request: %v", req)
 	for i := 0; i < int(req.Count); i++ {
 		log.Infof("Sending %d", i)
 		if err := stream.Send(&pb.ServerStreamResponse{
@@ -71,7 +71,7 @@ func (e *{{title .Alias}}) ServerStream(ctx context.Context, req *pb.ServerStrea
 	return nil
 }
 
-func (e *{{title .Alias}}) BidiStream(ctx context.Context, stream pb.{{title .Alias}}_BidiStreamStream) error {
+func (e *{{title .Service}}) BidiStream(ctx context.Context, stream pb.{{title .Service}}_BidiStreamStream) error {
 	for {
 		req, err := stream.Recv()
 		if err == io.EOF {

cmd/gomu/file/template/kubernetes.go

@@ -7,7 +7,7 @@ var KubernetesEnv = `---
 apiVersion: v1
 kind: ConfigMap
 metadata:
-  name: {{.Dir}}-env
+  name: {{.Service}}{{if .Client}}-client{{end}}-env
 data:
   MICRO_REGISTRY: kubernetes
 `
@@ -56,23 +56,23 @@ var KubernetesDeployment = `---
 apiVersion: apps/v1
 kind: Deployment
 metadata:
-  name: {{.Dir}}
+  name: {{.Service}}{{if .Client}}-client{{end}}
   labels:
-    app: {{.Dir}}
+    app: {{.Service}}{{if .Client}}-client{{end}}
 spec:
   replicas: 1
   selector:
     matchLabels:
-      app: {{.Dir}}
+      app: {{.Service}}{{if .Client}}-client{{end}}
   template:
     metadata:
       labels:
-        app: {{.Dir}}
+        app: {{.Service}}{{if .Client}}-client{{end}}
     spec:
       containers:
-      - name: {{.Dir}}
-        image: {{.Dir}}:latest
+      - name: {{.Service}}{{if .Client}}-client{{end}}
+        image: {{.Service}}{{if .Client}}-client{{end}}:latest
         envFrom:
         - configMapRef:
-            name: {{.Dir}}-env
+            name: {{.Service}}{{if .Client}}-client{{end}}-env
 `

cmd/gomu/file/template/main.go

@@ -7,14 +7,14 @@ import (
 	"context"
 	"time"
 
-	pb "{{.Vendor}}{{lower .Alias}}/proto"
+	pb "{{.Vendor}}{{lower .Service}}/proto"
 
 	"github.com/asim/go-micro/v3"
 	log "github.com/asim/go-micro/v3/logger"
 )
 
 var (
-	service = "{{lower .Alias}}"
+	service = "{{lower .Service}}"
 	version = "latest"
 )
 
@@ -44,7 +44,7 @@ func main() {
 var MainFNC = `package main
 
 import (
-	"{{.Vendor}}{{.Dir}}/handler"
+	"{{.Vendor}}{{.Service}}/handler"
 
 {{if .Jaeger}}	ot "github.com/asim/go-micro/plugins/wrapper/trace/opentracing/v3"
 {{end}}	"github.com/asim/go-micro/v3"
@@ -54,7 +54,7 @@ import (
 )
 
 var (
-	service = "{{lower .Alias}}"
+	service = "{{lower .Service}}"
 	version = "latest"
 )
 
@@ -82,7 +82,7 @@ func main() {
 	fnc.Init()
 
 	// Handle function
-	fnc.Handle(new(handler.{{title .Alias}}))
+	fnc.Handle(new(handler.{{title .Service}}))
 
 	// Run function
 	if err := fnc.Run(); err != nil {
@@ -95,8 +95,8 @@ func main() {
 var MainSRV = `package main
 
 import (
-	"{{.Vendor}}{{.Dir}}/handler"
-	pb "{{.Vendor}}{{.Dir}}/proto"
+	"{{.Vendor}}{{.Service}}/handler"
+	pb "{{.Vendor}}{{.Service}}/proto"
 
 {{if .Jaeger}}	ot "github.com/asim/go-micro/plugins/wrapper/trace/opentracing/v3"
 {{end}}	"github.com/asim/go-micro/v3"
@@ -106,7 +106,7 @@ import (
 )
 
 var (
-	service = "{{lower .Alias}}"
+	service = "{{lower .Service}}"
 	version = "latest"
 )
 
@@ -134,7 +134,7 @@ func main() {
 	srv.Init()
 
 	// Register handler
-	pb.Register{{title .Alias}}Handler(srv.Server(), new(handler.{{title .Alias}}))
+	pb.Register{{title .Service}}Handler(srv.Server(), new(handler.{{title .Service}}))
 
 	// Run service
 	if err := srv.Run(); err != nil {

cmd/gomu/file/template/makefile.go

@@ -11,7 +11,7 @@ init:
 
 .PHONY: proto
 proto:
-	@protoc --proto_path=. --micro_out=. --go_out=:. proto/{{.Alias}}.proto
+	@protoc --proto_path=. --micro_out=. --go_out=:. proto/{{.Service}}.proto
 
 .PHONY: tidy
 tidy:
@@ -19,7 +19,7 @@ tidy:
 
 .PHONY: build
 build:
-	@go build -o {{.Alias}} *.go
+	@go build -o {{.Service}}{{if .Client}}-client{{end}} *.go
 
 .PHONY: test
 test:
@@ -27,5 +27,5 @@ test:
 
 .PHONY: docker
 docker:
-	@docker build -t {{.Alias}}:latest .
+	@docker build -t {{.Service}}{{if .Client}}-client{{end}}:latest .
 `

cmd/gomu/file/template/module.go

@@ -1,7 +1,7 @@
 package template
 
 // Module is the go.mod template used for new projects.
-var Module = `module {{.Vendor}}{{.Dir}}
+var Module = `module {{.Vendor}}{{.Service}}{{if .Client}}-client{{end}}
 
 go 1.16
 
@@ -13,5 +13,5 @@ require (
 // see https://github.com/etcd-io/etcd/issues/11154 and https://github.com/etcd-io/etcd/issues/11931.
 replace google.golang.org/grpc => google.golang.org/grpc v1.26.0{{if .Vendor}}{{if not .Skaffold}}
 
-replace {{.Vendor}}{{lower .Alias}} => ../{{lower .Alias}}{{end}}{{end}}
+replace {{.Vendor}}{{lower .Service}} => ../{{lower .Service}}{{end}}{{end}}
 `

cmd/gomu/file/template/proto.go

@@ -3,11 +3,11 @@ package template
 // ProtoFNC is the .proto file template used for new function projects.
 var ProtoFNC = `syntax = "proto3";
 
-package {{dehyphen .Alias}};
+package {{dehyphen .Service}};
 
-option go_package = "./proto;{{dehyphen .Alias}}";
+option go_package = "./proto;{{dehyphen .Service}}";
 
-service {{title .Alias}} {
+service {{title .Service}} {
 	rpc Call(CallRequest) returns (CallResponse) {}
 }
 
@@ -23,11 +23,11 @@ message CallResponse {
 // ProtoSRV is the .proto file template used for new service projects.
 var ProtoSRV = `syntax = "proto3";
 
-package {{dehyphen .Alias}};
+package {{dehyphen .Service}};
 
-option go_package = "./proto;{{dehyphen .Alias}}";
+option go_package = "./proto;{{dehyphen .Service}}";
 
-service {{title .Alias}} {
+service {{title .Service}} {
 	rpc Call(CallRequest) returns (CallResponse) {}
 	rpc ClientStream(stream ClientStreamRequest) returns (ClientStreamResponse) {}
 	rpc ServerStream(ServerStreamRequest) returns (stream ServerStreamResponse) {}

cmd/gomu/file/template/skaffold.go

@@ -6,10 +6,10 @@ var SkaffoldCFG = `---
 apiVersion: skaffold/v2beta21
 kind: Config
 metadata:
-  name: {{.Dir}}
+  name: {{.Service}}{{if .Client}}-client{{end}}
 build:
   artifacts:
-  - image: {{.Dir}}
+  - image: {{.Service}}{{if .Client}}-client{{end}}
 deploy:
   kubectl:
     manifests: