better custom shell support

cmd/configs/config_template.yaml

@@ -79,8 +79,10 @@ sshd:
   # OPTIONAL: if true, the sftp subsystem will be disabled server side
   disable_sftp_subsystem: false
   # OPTIONAL: if empty a shell will be auto inferred. You can
-  # set a custom value here. Example: /usr/bin/python3
-  shell_executable: "your/custom/shell/fullpath"
+  # set a custom value here. 
+  # Example1: /usr/bin/python3
+  # Example2: sh -c your command here
+  shell_executable: "your/custom/shell"
 
 # enables and configures rest endpoints and web ui
 # Be WARNED: the endpoint is not authenticated and through the apis

pkg/sshd/server.go

@@ -6,7 +6,6 @@ import (
 	"net"
 	"net/http"
 	"net/url"
-	"os"
 	"runtime"
 	"strconv"
 	"strings"
@@ -74,12 +73,6 @@ func NewSshServer(conf *SshDConf) *sshServer {
 		panic(err)
 	}
 
-	if conf.ShellExecutable != "" {
-		if _, err := os.Stat(conf.ShellExecutable); err != nil {
-			log.Fatalf("invalid shell executable '%s'", conf.ShellExecutable)
-		}
-	}
-
 	ss := &sshServer{
 		authorizedKeysURI:         conf.AuthorizedKeysURI,
 		password:                  conf.AuthorizedPassword,

pkg/sshd/session_chan_handler.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"os/exec"
 	"os/user"
+	"strings"
 	"sync"
 
 	"github.com/ferama/rospo/pkg/rpty"
@@ -81,7 +82,12 @@ func handleChannelSession(
 			var cmd *exec.Cmd
 
 			if req.Type == "shell" {
-				cmd = exec.Command(shell)
+				if customShell != "" {
+					parts := strings.Split(customShell, " ")
+					cmd = exec.Command(parts[0], parts[1:]...)
+				} else {
+					cmd = exec.Command(shell)
+				}
 			} else {
 				var payload = struct{ Value string }{}
 				ssh.Unmarshal(req.Payload, &payload)