Merge pull request #2352 from superfly/rails-processes

Enable Rails scanner to define [processes] in fly.toml

internal/command/launch/srcinfo.go

@@ -264,8 +264,17 @@ func setAppconfigFromSrcinfo(ctx context.Context, srcInfo *scanner.SourceInfo, a
 		appConfig.SetMounts(appVolumes)
 	}
 
-	for procName, procCommand := range srcInfo.Processes {
-		appConfig.SetProcess(procName, procCommand)
+	if len(srcInfo.Processes) > 0 {
+		for procName, procCommand := range srcInfo.Processes {
+			appConfig.SetProcess(procName, procCommand)
+
+			// if processes are defined, associate HTTPService with the app service
+			// (if defined) or the first service if no app service is defined.
+			if appConfig.HTTPService != nil &&
+				(procName == "app" || appConfig.HTTPService.Processes == nil) {
+				appConfig.HTTPService.Processes = []string{procName}
+			}
+		}
 	}
 
 	if srcInfo.ReleaseCmd != "" {
@@ -309,7 +318,25 @@ func runCallback(ctx context.Context, srcInfo *scanner.SourceInfo, options map[s
 	if srcInfo == nil || srcInfo.Callback == nil {
 		return nil
 	}
-	return srcInfo.Callback(srcInfo, options)
+
+	err := srcInfo.Callback(srcInfo, options)
+
+	if srcInfo.MergeConfig != nil {
+		if err == nil {
+			cfg, err := appconfig.LoadConfig(srcInfo.MergeConfig.Name)
+			if err == nil {
+				// In theory, any part of the configuration could be merged here, but for now
+				// we will only copy over the processes
+				srcInfo.Processes = cfg.Processes
+			}
+		}
+
+		if srcInfo.MergeConfig.Temporary {
+			_ = os.Remove(srcInfo.MergeConfig.Name)
+		}
+	}
+
+	return err
 }
 
 func runInitCommands(ctx context.Context, srcInfo *scanner.SourceInfo) error {

scanner/rails.go

@@ -2,6 +2,7 @@ package scanner
 
 import (
 	"io/fs"
+	"log"
 	"os"
 	"os/exec"
 	"regexp"
@@ -128,6 +129,23 @@ func RailsCallback(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) {
+		flyToml := "fly.toml"
+		_, err := os.Stat(flyToml)
+		if os.IsNotExist(err) {
+			// "touch" fly.toml
+			file, err := os.Create("fly.toml")
+			if err != nil {
+				log.Fatal(err)
+			}
+			file.Close()
+
+			// inform caller of the presence of this file
+			srcInfo.MergeConfig = &MergeConfigStruct{
+				Name:      "fly.toml",
+				Temporary: true,
+			}
+		}
+
 		args := []string{"./bin/rails", "generate", "dockerfile",
 			"--label=fly_launch_runtime:rails"}
 

scanner/scanner.go

@@ -27,6 +27,11 @@ type Secret struct {
 	Generate func() (string, error)
 }
 
+type MergeConfigStruct struct {
+	Name      string
+	Temporary bool
+}
+
 type SourceInfo struct {
 	Family                       string
 	Version                      string
@@ -57,6 +62,7 @@ type SourceInfo struct {
 	Callback                     func(srcInfo *SourceInfo, options map[string]bool) error
 	HttpCheckPath                string
 	ConsoleCommand               string
+	MergeConfig                  *MergeConfigStruct
 }
 
 type SourceFile struct {