Add user_map setting to docker backend

internal/backends/backends.go

@@ -22,8 +22,6 @@
 package backends
 
 import (
-	"strings"
-
 	"github.com/zclconf/go-cty/cty"
 	"go.elara.ws/seashell/internal/config"
 	"go.elara.ws/seashell/internal/router"
@@ -84,17 +82,6 @@ func ctyObjToStringMap(o *cty.Value) map[string]string {
 	return out
 }
 
-// sshGetenv gets an environment variable from the SSH session
-func sshGetenv(env []string, key string) string {
-	for _, kv := range env {
-		before, after, ok := strings.Cut(kv, "=")
-		if ok && before == key {
-			return after
-		}
-	}
-	return ""
-}
-
 // valueOr returns the value that v points to
 // or a default value if v is nil.
 func valueOr[T any](v *T, or T) T {

internal/backends/docker.go

@@ -41,6 +41,7 @@ type dockerSettings struct {
 	Command    *cty.Value `cty:"command"`
 	Privileged *bool      `cty:"privileged"`
 	User       *string    `cty:"user"`
+	UserMap    *cty.Value `cty:"user_map"`
 }
 
 // Docker is the docker backend. It returns a handler that connects
@@ -62,6 +63,17 @@ func Docker(route config.Route) router.Handler {
 		if !ok {
 			return errors.New("this route only accepts pty sessions (try adding the -t flag)")
 		}
+		
+		if opts.User == nil {
+			userMap := ctyObjToStringMap(opts.UserMap)
+			user, _ := sshctx.GetUser(sess.Context())
+
+			if muser, ok := userMap[user.Name]; ok {
+				opts.User = &muser
+			} else {
+				opts.User = &user.Name
+			}
+		}
 
 		c, err := client.NewClientWithOpts(
 			client.WithHostFromEnv(),
@@ -72,11 +84,6 @@ func Docker(route config.Route) router.Handler {
 			return err
 		}
 
-		if opts.User == nil {
-			envUser := sshGetenv(sess.Environ(), "DOCKER_USER")
-			opts.User = &envUser
-		}
-
 		cmd := sess.Command()
 		if len(cmd) == 0 {
 			cmd = ctyTupleToStrings(opts.Command)