Merge pull request #381 from defang-io/lio-templates

Instantiate a project from a sample

Author: acote88

src/cmd/cli/command/commands.go

@@ -424,16 +424,47 @@ var generateCmd = &cobra.Command{
 			return errors.New("cannot run in non-interactive mode")
 		}
 
+		var language string
+		if err := survey.AskOne(&survey.Select{
+			Message: "Choose the language you'd like to use:",
+			Options: []string{"Nodejs", "Golang", "Python"},
+			Default: "Nodejs",
+			Help:    "The project code will be in the language you choose here.",
+		}, &language); err != nil {
+			return err
+		}
+
+		var category, sample string
+
+		// Fetch the list of samples from the Defang repository
+		if samples, err := cli.FetchSamples(cmd.Context()); err != nil {
+			term.Debug(" - unable to fetch samples:", err)
+		} else if len(samples) > 0 {
+			const generateWithAI = "Generate with AI"
+
+			category = strings.ToLower(language)
+			sampleNames := []string{generateWithAI}
+			// sampleDescriptions := []string{"Generate a sample from scratch using a language prompt"}
+			for _, sample := range samples {
+				if sample.Category == category {
+					sampleNames = append(sampleNames, sample.Name)
+					// sampleDescriptions = append(sampleDescriptions, sample.Readme)
+				}
+			}
+
+			if err := survey.AskOne(&survey.Select{
+				Message: "Choose a sample service:",
+				Options: sampleNames,
+				Help:    "The project code will be based on the sample you choose here.",
+			}, &sample); err != nil {
+				return err
+			}
+			if sample == generateWithAI {
+				sample = ""
+			}
+		}
+
 		var qs = []*survey.Question{
-			{
-				Name: "language",
-				Prompt: &survey.Select{
-					Message: "Choose the language you'd like to use:",
-					Options: []string{"Nodejs", "Golang", "Python"},
-					Default: "Nodejs",
-					Help:    "The generated code will be in the language you choose here.",
-				},
-			},
 			{
 				Name: "description",
 				Prompt: &survey.Input{
@@ -457,13 +488,16 @@ Generate will write files in the current folder. You can edit them and then depl
 			},
 		}
 
+		if sample != "" {
+			qs = qs[1:] // user picked a sample, so we skip the description question
+		}
+
 		prompt := struct {
-			Language    string // or you can tag fields to match a specific name
-			Description string
+			Description string // or you can tag fields to match a specific name
 			Folder      string
 		}{}
 
-		// ask the questions
+		// ask the remaining questions
 		err := survey.Ask(qs, &prompt)
 		if err != nil {
 			return err
@@ -479,7 +513,7 @@ Generate will write files in the current folder. You can edit them and then depl
 			}
 		}
 
-		Track("Generate Started", P{"language", prompt.Language}, P{"description", prompt.Description}, P{"folder", prompt.Folder})
+		Track("Generate Started", P{"language", language}, P{"sample", sample}, P{"description", prompt.Description}, P{"folder", prompt.Folder})
 
 		// create the folder if needed
 		cd := ""
@@ -496,10 +530,18 @@ Generate will write files in the current folder. You can edit them and then depl
 			term.Warn(" ! The folder is not empty. Files may be overwritten. Press Ctrl+C to abort.")
 		}
 
-		term.Info(" * Working on it. This may take 1 or 2 minutes...")
-		_, err = cli.Generate(cmd.Context(), client, prompt.Language, prompt.Description)
-		if err != nil {
-			return err
+		if prompt.Description != "" {
+			term.Info(" * Working on it. This may take 1 or 2 minutes...")
+			_, err := cli.GenerateWithAI(cmd.Context(), client, language, prompt.Description)
+			if err != nil {
+				return err
+			}
+		} else {
+			term.Info(" * Fetching sample from the Defang repository...")
+			err := cli.InitFromSample(cmd.Context(), category, sample)
+			if err != nil {
+				return err
+			}
 		}
 
 		term.Info(" * Code generated successfully in folder", prompt.Folder)

src/pkg/cli/generate.go

@@ -10,7 +10,7 @@ import (
 	defangv1 "github.com/defang-io/defang/src/protos/io/defang/v1"
 )
 
-func Generate(ctx context.Context, client client.Client, language string, description string) ([]string, error) {
+func GenerateWithAI(ctx context.Context, client client.Client, language string, description string) ([]string, error) {
 	if DoDryRun {
 		term.Warn(" ! Dry run, not generating files")
 		return nil, ErrDryRun

src/pkg/cli/init.go

@@ -0,0 +1,89 @@
+package cli
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+
+	"github.com/defang-io/defang/src/pkg/http"
+	"github.com/defang-io/defang/src/pkg/term"
+)
+
+type Sample struct {
+	Name     string `json:"name"`
+	Category string `json:"category"` // language
+	Readme   string `json:"readme"`
+}
+
+func FetchSamples(ctx context.Context) ([]Sample, error) {
+	resp, err := http.GetWithHeader(ctx, "https://docs.defang.io/samples.json", http.Header{"Accept-Encoding": []string{"gzip"}})
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	term.Debug(resp.Header)
+	reader := resp.Body
+	if resp.Header.Get("Content-Encoding") == "gzip" {
+		reader, err = gzip.NewReader(resp.Body)
+		if err != nil {
+			return nil, err
+		}
+		defer reader.Close()
+	}
+	var samples []Sample
+	err = json.NewDecoder(reader).Decode(&samples)
+	return samples, err
+}
+
+func InitFromSample(ctx context.Context, category, sample string) error {
+	const repo = "defang"
+	const branch = "main"
+
+	prefix := fmt.Sprintf("%s-%s/samples/%s/%s/", repo, branch, category, sample)
+	resp, err := http.GetWithContext(ctx, "https://github.com/defang-io/"+repo+"/archive/refs/heads/"+branch+".tar.gz")
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	term.Debug(resp.Header)
+	body, err := gzip.NewReader(resp.Body)
+	if err != nil {
+		return err
+	}
+	defer body.Close()
+	tarReader := tar.NewReader(body)
+	term.Info(" * Writing files to disk...")
+	for {
+		h, err := tarReader.Next()
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			return err
+		}
+
+		if base, ok := strings.CutPrefix(h.Name, prefix); ok && len(base) > 0 {
+			fmt.Println("   -", base)
+			if h.FileInfo().IsDir() {
+				if err := os.MkdirAll(base, 0755); err != nil {
+					return err
+				}
+				continue
+			}
+			// Like os.Create, but with the same mode as the original file (so scripts are executable, etc.)
+			file, err := os.OpenFile(base, os.O_RDWR|os.O_CREATE|os.O_TRUNC, h.FileInfo().Mode())
+			if err != nil {
+				return err
+			}
+			if _, err := io.Copy(file, tarReader); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}

src/pkg/http/get.go

@@ -5,11 +5,25 @@ import (
 	"net/http"
 )
 
-func GetWithAuth(ctx context.Context, url, auth string) (*http.Response, error) {
+type Header = http.Header
+
+func GetWithContext(ctx context.Context, url string) (*http.Response, error) {
+	hreq, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	if err != nil {
+		return nil, err
+	}
+	return http.DefaultClient.Do(hreq)
+}
+
+func GetWithHeader(ctx context.Context, url string, header http.Header) (*http.Response, error) {
 	hreq, err := http.NewRequestWithContext(ctx, "GET", url, nil)
 	if err != nil {
 		return nil, err
 	}
-	hreq.Header.Set("Authorization", auth)
+	hreq.Header = header
 	return http.DefaultClient.Do(hreq)
 }
+
+func GetWithAuth(ctx context.Context, url, auth string) (*http.Response, error) {
+	return GetWithHeader(ctx, url, http.Header{"Authorization": []string{auth}})
+}