[services] MVP process manager (#659)

## Summary

Very simple implementation of using a third party process manager to
launch and manage services. Only implemented for nginx, but trivial to
add new services. It first installs `process-compose` as a global
package (if necessary). If any of the installed services contain a
process-compose.yaml it references it and starts the manager.

TODO:
- [ ] Doesn't work with auto-forwarding

## How was it tested?

`devbox services manager`

<img width="1398" alt="image"
src="https://user-images.githubusercontent.com/544948/220255227-91bcd48e-faf1-4319-ac7c-312f4fab043f.png">

Author: mikeland73

devbox.go

@@ -48,6 +48,7 @@ type Devbox interface {
 	// ShellPlan creates a plan of the actions that devbox will take to generate its
 	// shell environment.
 	ShellPlan() (*plansdk.ShellPlan, error)
+	StartProcessManager(ctx context.Context) error
 	StartServices(ctx context.Context, services ...string) error
 	StopServices(ctx context.Context, services ...string) error
 }

internal/boxcli/services.go

@@ -53,8 +53,17 @@ func ServicesCmd() *cobra.Command {
 		},
 	}
 
+	processManagerCommand := &cobra.Command{
+		Use:   "manager",
+		Short: "Starts process manager with all supported services",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return startProcessManager(cmd, flags)
+		},
+	}
+
 	flags.config.register(servicesCommand)
 	servicesCommand.AddCommand(lsCommand)
+	servicesCommand.AddCommand(processManagerCommand)
 	servicesCommand.AddCommand(restartCommand)
 	servicesCommand.AddCommand(startCommand)
 	servicesCommand.AddCommand(stopCommand)
@@ -132,3 +141,11 @@ func restartServices(
 	_ = stopServices(cmd, services, flags)
 	return startServices(cmd, services, flags)
 }
+
+func startProcessManager(cmd *cobra.Command, flags servicesCmdFlags) error {
+	box, err := devbox.Open(flags.config.path, cmd.ErrOrStderr())
+	if err != nil {
+		return errors.WithStack(err)
+	}
+	return box.StartProcessManager(cmd.Context())
+}

internal/impl/devbox.go

@@ -611,6 +611,34 @@ func (d *Devbox) StartServices(ctx context.Context, serviceNames ...string) erro
 	return services.Start(ctx, d.packages(), serviceNames, d.projectDir, d.writer)
 }
 
+func (d *Devbox) StartProcessManager(ctx context.Context) error {
+	svcs, err := d.Services()
+	if err != nil {
+		return err
+	}
+	hasServiceWithProcessCompose := false
+	for _, s := range svcs {
+		if _, hasComposeYaml := s.ProcessComposeYaml(); hasComposeYaml {
+			hasServiceWithProcessCompose = true
+			break
+		}
+	}
+	if !hasServiceWithProcessCompose {
+		return usererr.New("No services with process-compose.yaml found")
+	}
+	processComposePath, err := utilityLookPath("process-compose")
+	if err != nil {
+		if err = addDevboxUtilityPackage("process-compose"); err != nil {
+			return err
+		}
+	}
+	if !IsDevboxShellEnabled() {
+		return d.Exec("devbox", "services", "manager")
+	}
+
+	return services.StartProcessManager(ctx, processComposePath, svcs)
+}
+
 func (d *Devbox) StopServices(ctx context.Context, serviceNames ...string) error {
 	if !IsDevboxShellEnabled() {
 		return d.Exec(append([]string{"devbox", "services", "stop"}, serviceNames...)...)

internal/impl/global.go

@@ -19,6 +19,14 @@ import (
 	"go.jetpack.io/devbox/internal/xdg"
 )
 
+var warningNotInPath = usererr.NewWarning(`the devbox global profile is not in your $PATH.
+
+Add the following line to your shell's rcfile (e.g., ~/.bashrc or ~/.zshrc)
+and restart your shell to fix this:
+
+	eval "$(devbox global shellenv)"
+`)
+
 // In the future we will support multiple global profiles
 const currentGlobalProfile = "default"
 
@@ -143,6 +151,20 @@ func GlobalNixProfilePath() (string, error) {
 	return filepath.Join(path, "profile"), nil
 }
 
+func globalBinPath() (string, error) {
+	nixProfilePath, err := GlobalNixProfilePath()
+	if err != nil {
+		return "", err
+	}
+	currentPath := xdg.DataSubpath("devbox/global/current")
+	// For now default is always current. In the future we will support multiple
+	// and allow user to switch.
+	if err := os.Symlink(nixProfilePath, currentPath); err != nil && !os.IsExist(err) {
+		return "", errors.WithStack(err)
+	}
+	return filepath.Join(currentPath, "bin"), nil
+}
+
 // GenerateShellEnv generates shell commands that configure the user's shell
 // environment to work with Devbox packages. Most notably, it adds Devbox
 // packages to the user's PATH. The commands are intended to be evaluated in
@@ -163,25 +185,12 @@ func GenerateShellEnv() string {
 
 // Checks if the global profile is in the path
 func ensureGlobalProfileInPath() error {
-	nixProfilePath, err := GlobalNixProfilePath()
+	binPath, err := globalBinPath()
 	if err != nil {
 		return err
 	}
-	currentPath := xdg.DataSubpath("devbox/global/current")
-	// For now default is always current. In the future we will support multiple
-	// and allow user to switch.
-	if err := os.Symlink(nixProfilePath, currentPath); err != nil && !os.IsExist(err) {
-		return errors.WithStack(err)
-	}
-	binPath := filepath.Join(currentPath, "bin")
 	if !strings.Contains(os.Getenv("PATH"), binPath) {
-		return usererr.NewWarning(`the devbox global profile is not in your $PATH.
-
-Add the following line to your shell's rcfile (e.g., ~/.bashrc or ~/.zshrc)
-and restart your shell to fix this:
-
-	eval "$(devbox global shellenv)"
-`)
+		return warningNotInPath
 	}
 	return nil
 }

internal/impl/util.go

@@ -0,0 +1,59 @@
+package impl
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/pkg/errors"
+	"go.jetpack.io/devbox/internal/nix"
+	"go.jetpack.io/devbox/internal/planner/plansdk"
+	"go.jetpack.io/devbox/internal/xdg"
+)
+
+// addDevboxUtilityPackage adds a package to the devbox utility profile.
+// It's used to install applications devbox might need, like process-compose
+// This is an alternative to a global install which would modify a user's
+// environment.
+func addDevboxUtilityPackage(pkg string) error {
+	profilePath, err := utilityNixProfilePath()
+	if err != nil {
+		return err
+	}
+	return nix.ProfileInstall(profilePath, plansdk.DefaultNixpkgsCommit, pkg)
+}
+
+func utilityLookPath(binName string) (string, error) {
+	binPath, err := utilityBinPath()
+	if err != nil {
+		return "", err
+	}
+	absPath := filepath.Join(binPath, binName)
+	if _, err := os.Stat(absPath); os.IsNotExist(err) {
+		return "", err
+	}
+	return absPath, nil
+}
+
+func utilityDataPath() (string, error) {
+	path := xdg.DataSubpath("devbox/util")
+	if err := os.MkdirAll(path, 0755); err != nil {
+		return "", errors.WithStack(err)
+	}
+	return path, nil
+}
+
+func utilityNixProfilePath() (string, error) {
+	path, err := utilityDataPath()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(path, "profile"), nil
+}
+
+func utilityBinPath() (string, error) {
+	nixProfilePath, err := utilityNixProfilePath()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(nixProfilePath, "bin"), nil
+}

internal/plugin/services.go

@@ -2,13 +2,15 @@ package plugin
 
 import (
 	"encoding/json"
+	"strings"
 
 	"github.com/a8m/envsubst"
 )
 
 type Services map[string]service
 
 type service struct {
+	config  *config
 	Name    string `json:"name"`
 	RawPort string `json:"port"`
 	Start   string `json:"start"`
@@ -22,6 +24,15 @@ func (s *service) Port() (string, error) {
 	return envsubst.String(s.RawPort)
 }
 
+func (s *service) ProcessComposeYaml() (string, bool) {
+	for file := range s.config.CreateFiles {
+		if strings.HasSuffix(file, "process-compose.yaml") || strings.HasSuffix(file, "process-compose.yml") {
+			return file, true
+		}
+	}
+	return "", false
+}
+
 func GetServices(pkgs []string, projectDir string) (Services, error) {
 	services := map[string]service{}
 	for _, pkg := range pkgs {
@@ -34,6 +45,7 @@ func GetServices(pkgs []string, projectDir string) (Services, error) {
 		}
 		for name, svc := range c.Services {
 			svc.Name = name
+			svc.config = c
 			services[name] = svc
 		}
 	}

internal/services/manager.go

@@ -0,0 +1,27 @@
+package services
+
+import (
+	"context"
+	"os"
+	"os/exec"
+
+	"go.jetpack.io/devbox/internal/plugin"
+)
+
+func StartProcessManager(
+	ctx context.Context,
+	processComposePath string,
+	services plugin.Services,
+) error {
+	flags := []string{"-p", "8280"}
+	for _, s := range services {
+		if file, hasComposeYaml := s.ProcessComposeYaml(); hasComposeYaml {
+			flags = append(flags, "-f", file)
+		}
+	}
+	cmd := exec.Command(processComposePath, flags...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	cmd.Stdin = os.Stdin
+	return cmd.Run()
+}

plugins/nginx.json

@@ -9,6 +9,7 @@
   },
   "create_files": {
     "{{ .Virtenv }}/temp": "",
+    "{{ .Virtenv }}/process-compose.yaml": "nginx/process-compose.yaml",
     "{{ .DevboxDir }}/nginx.conf": "nginx/nginx.conf",
     "{{ .DevboxDir }}/fastcgi.conf": "nginx/fastcgi.conf",
     "{{ .DevboxDirRoot }}/web/index.html": "web/index.html"

plugins/nginx/process-compose.yaml

@@ -0,0 +1,15 @@
+version: "0.5"
+
+processes:
+  nginx:
+    command: "nginx -p $NGINX_PATH_PREFIX -c $NGINX_CONFDIR -e error.log -g \"pid nginx.pid;daemon off;\""
+    availability:
+      restart: "always"
+  nginx-error:
+    command: "tail -f $NGINX_PATH_PREFIX/error.log"
+    availability:
+      restart: "always"
+  nginx-access:
+    command: "tail -f $NGINX_PATH_PREFIX/access.log"
+    availability:
+      restart: "always"