Merge pull request superfly#2224 from superfly/node-framework-scanner

Create a separate node framework scanner

scanner/nodeFramework.go

@@ -0,0 +1,185 @@
+package scanner
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/fs"
+	"os"
+	"os/exec"
+	"regexp"
+	"strconv"
+	"strings"
+
+	"github.com/blang/semver"
+)
+
+var packageJson map[string]interface{}
+
+// Handle node frameworks separate from other node applications.  Currently the requirements
+// for a framework is pretty low: to have a "start" script.  Because we are actually
+// going to be running a node application to generate a Dockerfile there is one more
+// criteria: the running node version must be at least 16.  If there turns out to be
+// demand for earlier versions of node, we can adjust this requirement.
+func configureNodeFramework(sourceDir string, config *ScannerConfig) (*SourceInfo, error) {
+	// first ensure that there is a package.json
+	if !checksPass(sourceDir, fileExists("package.json")) {
+		return nil, nil
+	}
+
+	// ensure package.json has a start script
+	data, err := os.ReadFile("package.json")
+
+	if err != nil {
+		return nil, nil
+	} else {
+		err = json.Unmarshal(data, &packageJson)
+		if err != nil {
+			return nil, nil
+		}
+
+		scripts, ok := packageJson["scripts"].(map[string]interface{})
+
+		if !ok || scripts["start"] == nil {
+			return nil, nil
+		}
+	}
+
+	// ensure node version is at least 16.0.0
+	out, err := exec.Command("node", "-v").Output()
+	if err != nil {
+		return nil, nil
+	} else {
+		minVersion, err := semver.Make("16.0.0")
+		if err != nil {
+			panic(err)
+		}
+
+		nodeVersionString := strings.TrimSpace(string(out))
+		if nodeVersionString[:1] == "v" {
+			nodeVersionString = nodeVersionString[1:]
+		}
+
+		nodeVersion, err := semver.Make(nodeVersionString)
+
+		if err != nil || nodeVersion.LT(minVersion) {
+			return nil, nil
+		}
+	}
+
+	srcInfo := &SourceInfo{
+		Family:     "NodeJS",
+		SkipDeploy: true,
+		Callback:   NodeFrameworkCallback,
+	}
+
+	return srcInfo, nil
+}
+
+func NodeFrameworkCallback(srcInfo *SourceInfo, options map[string]bool) error {
+	// generate Dockerfile if it doesn't already exist
+	_, err := os.Stat("Dockerfile")
+	if errors.Is(err, fs.ErrNotExist) {
+		var args []string
+
+		_, err = os.Stat("node_modules")
+		if errors.Is(err, fs.ErrNotExist) {
+			// no existing node_modules directory: run package directly
+			args = []string{"npx", "--yes", "@flydotio/dockerfile@latest"}
+		} else {
+			// build command to install package using preferred package manager
+			args = []string{"npm", "install", "@flydotio/dockerfile", "--save-dev"}
+
+			_, err = os.Stat("yarn.lock")
+			if !errors.Is(err, fs.ErrNotExist) {
+				args = []string{"yarn", "add", "@flydotio/dockerfile", "--dev"}
+			}
+
+			_, err = os.Stat("pnpm-lock.yaml")
+			if !errors.Is(err, fs.ErrNotExist) {
+				args = []string{"pnpm", "add", "-D", "@flydotio/dockerfile"}
+			}
+		}
+
+		// check first to see if the package is already installed
+		installed := false
+
+		deps, ok := packageJson["dependencies"].(map[string]interface{})
+		if ok && deps["@flydotio/dockerfile"] != nil {
+			installed = true
+		}
+
+		deps, ok = packageJson["devDependencies"].(map[string]interface{})
+		if ok && deps["@flydotio/dockerfile"] != nil {
+			installed = true
+		}
+
+		// install/run command
+		if !installed || args[0] == "npx" {
+			cmd := exec.Command(args[0], args[1:]...)
+			cmd.Stdin = nil
+			cmd.Stdout = os.Stdout
+			cmd.Stderr = os.Stderr
+
+			if err := cmd.Run(); err != nil {
+				return fmt.Errorf("failed to install @flydotio/dockerfile: %w", err)
+			}
+		}
+
+		// run the package if we haven't already
+		if args[0] != "npx" {
+			cmd := exec.Command("npx", "dockerfile")
+			cmd.Stdin = nil
+			cmd.Stdout = os.Stdout
+			cmd.Stderr = os.Stderr
+
+			if err := cmd.Run(); err != nil {
+				return fmt.Errorf("failed to generate Dockerfile: %w", err)
+			}
+		}
+	}
+
+	// read dockerfile
+	dockerfile, err := os.ReadFile("Dockerfile")
+	if err != nil {
+		return err
+	}
+
+	// extract family
+	family := "NodeJS"
+	re := regexp.MustCompile(`(?m)^LABEL\s+fly_launch_runtime="(?P<family>.+?)"`)
+	m := re.FindStringSubmatch(string(dockerfile))
+
+	for i, name := range re.SubexpNames() {
+		if len(m) > 0 && name == "family" {
+			family = m[i]
+		}
+	}
+	srcInfo.Family = family
+
+	// extract port
+	port := 3000
+	re = regexp.MustCompile(`(?m)^EXPOSE\s+(?P<port>\d+)`)
+	m = re.FindStringSubmatch(string(dockerfile))
+
+	for i, name := range re.SubexpNames() {
+		if len(m) > 0 && name == "port" {
+			port, err = strconv.Atoi(m[i])
+			if err != nil {
+				panic(err)
+			}
+		}
+	}
+	srcInfo.Port = port
+
+	// provide some advice
+	srcInfo.DeployDocs += `
+If you need custom packages installed, or have problems with your deployment
+build, you may need to edit the Dockerfile for app-specific changes. If you
+need help, please post on https://community.fly.io.
+
+Now: run 'fly deploy' to deploy your Node app.
+`
+
+	return nil
+}

scanner/scanner.go

@@ -83,6 +83,7 @@ func Scan(sourceDir string, config *ScannerConfig) (*SourceInfo, error) {
 		configurePhoenix,
 		configureRails,
 		configureRedwood,
+		configureNodeFramework,
 		/* frameworks scanners are placed before generic scanners,
 		   since they might mix languages or have a Dockerfile that
 			 doesn't work with Fly */