Bash default backend with configuration

README.md

@@ -569,11 +569,11 @@ The following discovery order is used: `compose.yml, compose.yaml, process-compo
 
 ##### ✅ Linux
 
-The default backend is `bash`. You can define a different backend with a `SHELL` environment variable.
+The default backend is `bash`. You can define a different backend with a `COMPOSE_SHELL` environment variable.
 
 ##### ✅ Windows
 
-The default backend is `cmd`. You can define a different backend with a `SHELL` environment variable.
+The default backend is `cmd`. You can define a different backend with a `COMPOSE_SHELL` environment variable.
 
 ```yaml
 process1:
@@ -590,7 +590,23 @@ process2:
 
 ##### ✅ macOS
 
+The default backend is `bash`. You can define a different backend with a `COMPOSE_SHELL` environment variable.
 
+##### ✅ Configurable Backend
+
+For cases where you process compose requires a non default or transferable backend definition, setting an environment variable won't do. For that you  can configure it directly in the `process-compose.yaml` file:
+
+```yaml
+version: "0.5"
+shell:
+  shell_command: "python3"
+  shell_argument: "-m"
+processes:
+	http:
+		command: "server.py"
+```
+
+**Note**: please make sure that the `shell.shell_command` value is in your `$PATH`
 
 ## How to Contribute
 

process-compose.yaml

@@ -128,3 +128,6 @@ processes:
 environment:
   - 'ABC=222'
 log_location: ./pc.log
+shell:
+  shell_command: "zsh"
+  shell_argument: "-c"

src/app/config.go

@@ -1,19 +1,21 @@
 package app
 
 import (
+	"github.com/f1bonacc1/process-compose/src/command"
 	"sync"
 
 	"github.com/f1bonacc1/process-compose/src/health"
 	"github.com/f1bonacc1/process-compose/src/pclog"
 )
 
 type Project struct {
-	Version     string    `yaml:"version"`
-	LogLocation string    `yaml:"log_location,omitempty"`
-	LogLevel    string    `yaml:"log_level,omitempty"`
-	LogLength   int       `yaml:"log_length,omitempty"`
-	Processes   Processes `yaml:"processes"`
-	Environment []string  `yaml:"environment,omitempty"`
+	Version     string               `yaml:"version"`
+	LogLocation string               `yaml:"log_location,omitempty"`
+	LogLevel    string               `yaml:"log_level,omitempty"`
+	LogLength   int                  `yaml:"log_length,omitempty"`
+	Processes   Processes            `yaml:"processes"`
+	Environment []string             `yaml:"environment,omitempty"`
+	ShellConfig *command.ShellConfig `yaml:"shell,omitempty"`
 
 	runningProcesses map[string]*Process
 	processStates    map[string]*ProcessState

src/app/process.go

@@ -49,6 +49,7 @@ type Process struct {
 	startTime     time.Time
 	liveProber    *health.Prober
 	readyProber   *health.Prober
+	shellConfig   command.ShellConfig
 }
 
 func NewProcess(
@@ -57,7 +58,8 @@ func NewProcess(
 	procConf ProcessConfig,
 	procState *ProcessState,
 	procLog *pclog.ProcessLogBuffer,
-	replica int) *Process {
+	replica int,
+	shellConfig command.ShellConfig) *Process {
 	colNumeric := rand.Intn(int(color.FgHiWhite)-int(color.FgHiBlack)) + int(color.FgHiBlack)
 
 	proc := &Process{
@@ -71,6 +73,7 @@ func NewProcess(
 		done:          false,
 		replica:       replica,
 		logBuffer:     procLog,
+		shellConfig:   shellConfig,
 		procStateChan: make(chan string, 1),
 		procReadyChan: make(chan string, 1),
 	}
@@ -138,7 +141,7 @@ func (p *Process) run() int {
 
 func (p *Process) getProcessStarter() func() error {
 	return func() error {
-		p.command = command.BuildCommand(p.getCommand())
+		p.command = command.BuildCommandShellArg(p.shellConfig, p.getCommand())
 		p.command.Env = p.getProcessEnvironment()
 		p.command.Dir = p.procConf.WorkingDir
 		p.setProcArgs()
@@ -254,7 +257,7 @@ func (p *Process) doConfiguredStop(params ShutDownParams) error {
 	defer cancel()
 	defer p.notifyDaemonStopped()
 
-	cmd := command.BuildCommandContext(ctx, params.ShutDownCommand)
+	cmd := command.BuildCommandShellArgContext(ctx, p.shellConfig, params.ShutDownCommand)
 	cmd.Env = p.getProcessEnvironment()
 
 	if err := cmd.Run(); err != nil {

src/app/project.go

@@ -3,6 +3,7 @@ package app
 import (
 	"errors"
 	"fmt"
+	"github.com/f1bonacc1/process-compose/src/command"
 	"github.com/f1bonacc1/process-compose/src/pclog"
 	"os"
 	"path/filepath"
@@ -23,6 +24,7 @@ const (
 var PROJ *Project
 
 func (p *Project) init() {
+	p.setConfigDefaults()
 	p.initProcessStates()
 	p.initProcessLogs()
 	p.deprecationCheck()
@@ -65,7 +67,7 @@ func (p *Project) runProcess(proc ProcessConfig) {
 		log.Error().Msgf("Error: Can't get log: %s using empty buffer", err.Error())
 		procLog = pclog.NewLogBuffer(0)
 	}
-	process := NewProcess(p.Environment, procLogger, proc, p.GetProcessState(proc.Name), procLog, 1)
+	process := NewProcess(p.Environment, procLogger, proc, p.GetProcessState(proc.Name), procLog, 1, *p.ShellConfig)
 	p.addRunningProcess(process)
 	p.wg.Add(1)
 	go func() {
@@ -149,6 +151,15 @@ func (p *Project) deprecationCheck() {
 	}
 }
 
+func (p *Project) setConfigDefaults() {
+	if p.ShellConfig == nil {
+		p.ShellConfig = command.DefaultShellConfig()
+	}
+	log.Info().Msgf("Global shell command: %s %s", p.ShellConfig.ShellCommand, p.ShellConfig.ShellArgument)
+	command.ValidateShellConfig(*p.ShellConfig)
+
+}
+
 func (p *Project) GetProcessState(name string) *ProcessState {
 	if procState, ok := p.processStates[name]; ok {
 		proc := p.getRunningProcess(name)

src/command/command.go

@@ -2,6 +2,7 @@ package command
 
 import (
 	"context"
+	"github.com/rs/zerolog/log"
 	"os"
 	"os/exec"
 	"runtime"
@@ -11,12 +12,20 @@ func BuildCommand(shellCmd string) *exec.Cmd {
 	return exec.Command(getRunnerShell(), getRunnerArg(), shellCmd)
 }
 
+func BuildCommandShellArg(shell ShellConfig, cmd string) *exec.Cmd {
+	return exec.Command(shell.ShellCommand, shell.ShellArgument, cmd)
+}
+
 func BuildCommandContext(ctx context.Context, shellCmd string) *exec.Cmd {
 	return exec.CommandContext(ctx, getRunnerShell(), getRunnerArg(), shellCmd)
 }
 
+func BuildCommandShellArgContext(ctx context.Context, shell ShellConfig, cmd string) *exec.Cmd {
+	return exec.CommandContext(ctx, shell.ShellCommand, shell.ShellArgument, cmd)
+}
+
 func getRunnerShell() string {
-	shell, ok := os.LookupEnv("SHELL")
+	shell, ok := os.LookupEnv("COMPOSE_SHELL")
 	if !ok {
 		if runtime.GOOS == "windows" {
 			shell = "cmd"
@@ -28,9 +37,23 @@ func getRunnerShell() string {
 }
 
 func getRunnerArg() string {
+	arg := "-c"
 	if runtime.GOOS == "windows" {
-		return "/C"
-	} else {
-		return "-c"
+		arg = "/C"
+	}
+	return arg
+}
+
+func DefaultShellConfig() *ShellConfig {
+	return &ShellConfig{
+		ShellCommand:  getRunnerShell(),
+		ShellArgument: getRunnerArg(),
+	}
+}
+
+func ValidateShellConfig(shell ShellConfig) {
+	_, err := exec.LookPath(shell.ShellCommand)
+	if err != nil {
+		log.Fatal().Msgf("Couldn't find %s", shell.ShellCommand)
 	}
 }

src/command/config.go

@@ -0,0 +1,6 @@
+package command
+
+type ShellConfig struct {
+	ShellCommand  string `yaml:"shell_command"`
+	ShellArgument string `yaml:"shell_argument"`
+}