shell

go-shell

Library to write "shelling out" Go code more shell-like, while remaining idiomatic to Go.

Features

• Function-wrapper factories for shell commands
• Panic on non-zero exits for set -e behavior
• Result of Run() is a Stringer for STDOUT, has Error for STDERR
• Heavily variadic function API Cmd("rm", "-r", "foo") == Cmd("rm -r", "foo")
• Go-native piping Cmd(...).Pipe(...) or inline piping Cmd("... | ...")
• Template compatible "last arg" piping Cmd(..., Cmd(..., Cmd(...)))
• Optional trace output mode like set +x
• Similar variadic functions for paths and path templates
• CommandBuilder for creating command using SSH, Docker or Docker over SSH

Docker support (commandbuilder)

Running commands inside docker containers can be used by the CommandBuilder (see examples below). The variable connection.Docker has to set to the docker container id or the following schema has to be used:

CONTAINER is the name of the docker-compose container.

Examples shell

import (
  "fmt"
  "github.com/webdevops/go-shell"
)

var (
  sh = shell.Run
)

shell.Trace = true // like set +x
shell.Shell = []string{"/bin/bash", "-c"} // defaults to /bin/sh

func main() {
  defer shell.ErrExit()
  sh("echo Foobar > /foobar")
  sh("rm /fobar") // typo raises error
  sh("echo Done!") // never run, program exited
}

import (
  "fmt"
  "github.com/webdevops/go-shell"
)

func main() {
  cmd := shell.Cmd("echo", "foobar").Pipe("wc", "-c").Pipe("awk", "'{print $1}'")
  
  // -> wc -c | awk '{print $1}'
  fmt.Println(cmd.ToString())
  
  // -> 7 
  fmt.Println(cmd.Run())
}

import "github.com/webdevops/go-shell"

var (
  echo = shell.Cmd("echo").OutputFn()
  copy = shell.Cmd("cp").ErrFn()
  rm = shell.Cmd("rm").ErrFn()
)

func main() {
  err := copy("/foo", "/bar")
  // handle err
  err = rm("/bar")
  // handle err
  out, _ := echo("Done!")
}

Error recovery

package main

import (
	"os"
	"fmt"
	"github.com/webdevops/go-shell"
)

func main() {
	defer func() {
		if r := recover(); r != nil {
			message := fmt.Sprintf("%v", r)

			if obj, ok := r.(*shell.Process); ok {
				message = obj.Debug()
			}
			fmt.Println(message)
			os.Exit(255)
		}
	}()

	shell.Cmd("exit", "2").Run()
}

Examples commandbuilder

package main

import (
	"fmt"
	"github.com/webdevops/go-shell"
	"github.com/webdevops/go-shell/commandbuilder"
)

func main() {
	var cmd *shell.Command
	var connection commandbuilder.Connection

	// ------------------------------------------
	// local execution
	connection = commandbuilder.Connection{}
		
	cmd = shell.Cmd(connection.CommandBuilder("date")...)
	cmd.Run()

	// ------------------------------------------
	// SSH access
	connection = commandbuilder.Connection{}
	connection.Ssh.Set("foobar@example.com")
	
	cmd = shell.Cmd(connection.CommandBuilder("date")...)
	fmt.Println("LOCAL: " + cmd.Run().Stdout.String())
	
	
	// ------------------------------------------
	// Docker execution
	connection = commandbuilder.Connection{}
	connection.Docker.Set("32ceb49d2958")
	
	cmd = shell.Cmd(connection.CommandBuilder("date")...)
	fmt.Println("DOCKER: " + cmd.Run().Stdout.String())

	// ------------------------------------------
	// Docker (lookup via docker-compose) execution
	connection = commandbuilder.Connection{}
	connection.Docker.Set("compose:mysql;path=/path/to/project;file=custom-compose-yml")

	cmd = shell.Cmd(connection.CommandBuilder("date")...)
	fmt.Println("DOCKER with COMPOSE: " + cmd.Run().Stdout.String())

	// ------------------------------------------
	// Docker on remote host via SSH execution
	connection = commandbuilder.Connection{}
	connection.Ssh.Set("foobar@example.com")
	connection.Docker.Set("32ceb49d2958")
	
	cmd = shell.Cmd(connection.CommandBuilder("date")...)
	fmt.Println("DOCKER via SSH: " + cmd.Run().Stdout.String())
}

License

MIT