Adapt tramp-docker integration

* doc/misc/tramp.texi (Inline methods): Add docker.
(Customizing Methods): Remove docker-tramp.  Adapt references to this.

* etc/NEWS: Mention new Tramp method "docker".  Fix typos.

* lisp/net/tramp-compat.el (docker-tramp): Warn, if that package is used.

* lisp/net/tramp-docker.el: Format header lines.
(tramp-docker): Remove custom group.
(tramp-docker-program, tramp-docker-method): Add
;;;###tramp-autoload cookie.
(tramp-docker-program): Change group to `tramp'.  Add version.
(tramp-docker--completion-function): Fix docstring.
(tramp-docker--add-method, tramp-docker--remove-method)
(tramp-docker-unload-function, tramp-docker-setup): Remove functions.
(tramp-methods, tramp-set-completion-function): Initialize via
`tramp--with-startup'.
(tramp-unload-hook):  Unload `tramp-docker'.

4 files changed, 70 insertions, 87 deletions

diff --git a/doc/misc/tramp.texi b/doc/misc/tramp.texi
index 0e55b6c1d2a..455e145a818 100644
--- a/doc/misc/tramp.texi
+++ b/doc/misc/tramp.texi
@@ -903,6 +903,15 @@ supports changing the remote login shell @command{/bin/sh}.
 Check the @samp{Share SSH connections if possible} control for that
 session.
 
+@item @option{docker}
+@cindex method @option{docker}
+@cindex @option{docker} method
+
+Integration for Docker containers.  A container is accessed via
+@file{@trampfn{docker,user@@container,/path/to/file}}, where
+@samp{user} is the (optional) user that you want to use, and
+@samp{container} is the id or name of the container.
+
 @end table
 
 
@@ -1763,36 +1772,30 @@ They can be installed with Emacs's Package Manager.  This includes
 @c @item ibuffer-tramp.el
 @c Contact Svend Sorensen <svend@@ciffer.net>
 
-@item docker-tramp
-@cindex method @option{docker}
-@cindex @option{docker} method
-Integration for Docker containers.  A container is accessed via
-@file{@trampfn{docker,user@@container,/path/to/file}}, where
-@samp{user} is the (optional) user that you want to use, and
-@samp{container} is the id or name of the container.
-
 @item kubernetes-tramp
 @cindex method @option{kubectl}
 @cindex @option{kubectl} method
-Integration for Docker containers deployed in a Kubernetes cluster.
-It is derived from @samp{docker-tramp}.  A container is accessed via
+Integration for Docker containers deployed in a Kubernetes cluster.  A
+container is accessed via
 @file{@trampfn{kubectl,user@@container,/path/to/file}}, @samp{user}
-and @samp{container} have the same meaning as in @samp{docker-tramp}.
+and @samp{container} have the same meaning as with the @option{docker}
+method.
 
 @item lxc-tramp
 @cindex method @option{lxc}
 @cindex @option{lxc} method
 Integration for LXC containers.  A container is accessed via
 @file{@trampfn{lxc,container,/path/to/file}}, @samp{container} has the
-same meaning as in @samp{docker-tramp}.  A @samp{user} specification
-is ignored.
+same meaning as with the @option{docker} method.  A @samp{user}
+specification is ignored.
 
 @item lxd-tramp
 @cindex method @option{lxd}
 @cindex @option{lxd} method
 Integration for LXD containers.  A container is accessed via
 @file{@trampfn{lxd,user@@container,/path/to/file}}, @samp{user} and
-@samp{container} have the same meaning as in @samp{docker-tramp}.
+@samp{container} have the same meaning as with the @option{docker}
+method.
 
 @item magit-tramp
 @cindex method @option{git}
diff --git a/etc/NEWS b/etc/NEWS
index 037368d1ec8..5b15e9dcb60 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -400,7 +400,7 @@ performance, but the latter is closer to a drop-in replacement.
 
 ---
 ** The thumbs.el library is now obsolete.
-We recommend using `M-x image-dired' instead.
+We recommend using 'M-x image-dired' instead.
 
 ---
 ** The autoarg.el library is now marked obsolete.
@@ -1371,7 +1371,7 @@ This controls how statements like the following are indented:
     foo &&
         bar
 
-*** New Flymake backend using the ShellCheck program
+*** New Flymake backend using the ShellCheck program.
 It is enabled by default, but requires that the external "shellcheck"
 command is installed.
 
@@ -2311,6 +2311,10 @@ and friends.
 
 ** Tramp
 
++++
+*** New connection method "docker".
+It allows accessing environments provided by Docker.
+
 ---
 *** Tramp supports abbreviating remote home directories now.
 When calling 'abbreviate-file-name' on a Tramp file name, the result
@@ -2640,7 +2644,7 @@ didn't work well in most files in the past, either, but it will now
 signal an error in any file.)
 
 In addition, files are scanned in a slightly different way.
-Previously ';;;###' specs inside a top-level form (i.e., something
+Previously, ';;;###' specs inside a top-level form (i.e., something
 like '(when ... ;;;### ...)' would be ignored.  They are now parsed as
 normal.
 
@@ -2919,7 +2923,7 @@ functions.
 
 ---
 ** '?\' at the end of a line now signals an error.
-Previously it produced a nonsense value, -1, that was never intended.
+Previously, it produced a nonsense value, -1, that was never intended.
 
 ---
 ** Some libraries obsolete since Emacs 24.1 and 24.3 have been removed:
diff --git a/lisp/net/tramp-compat.el b/lisp/net/tramp-compat.el
index a7dd9c03f32..f6cc1034ca5 100644
--- a/lisp/net/tramp-compat.el
+++ b/lisp/net/tramp-compat.el
@@ -50,6 +50,10 @@
   (warn "Tramp has been compiled with Emacs %s, this is Emacs %s"
 	tramp-compat-emacs-compiled-version emacs-version))
 
+(with-eval-after-load 'docker-tramp
+  (warn (concat "Package `docker-tramp' has been obsoleted, "
+		"please use integrated package `tramp-docker'")))
+
 ;; For not existing functions, obsolete functions, or functions with a
 ;; changed argument list, there are compiler warnings.  We want to
 ;; avoid them in cases we know what we do.
diff --git a/lisp/net/tramp-docker.el b/lisp/net/tramp-docker.el
index 3953e4d2721..40257a4a12c 100644
--- a/lisp/net/tramp-docker.el
+++ b/lisp/net/tramp-docker.el
@@ -3,39 +3,31 @@
 ;; Copyright © 2022 Free Software Foundation, Inc.
 
 ;; Author: Brian Cully <bjc@kublai.com>
-;; Maintainer: Brian Cully <bjc@kublai.com>
-;; URL: https://git.spork.org/tramp-docker
-;; Keywords: tramp, docker
-;; Version: 0.99.1
-;; Package-Requires: ((emacs "23"))
+;; Keywords: comm, processes
+;; Package: tramp
 
-;;; License:
+;; This file is part of GNU Emacs.
 
-;; This program is free software; you can redistribute it and/or
-;; modify it under the terms of the GNU General Public License as
-;; published by the Free Software Foundation, either version 3 of the
-;; License, or (at your option) any later version.
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
 
-;; This program is distributed in the hope that it will be useful, but
-;; WITHOUT ANY WARRANTY; without even the implied warranty of
-;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-;; General Public License for more details.
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
 
 ;; You should have received a copy of the GNU General Public License
-;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
 
 ;;; Commentary:
 
-;;
 ;; ‘tramp-docker’ allows Tramp access to environments provided by
 ;; Docker.
 ;;
 ;; ## Usage
 ;;
-;; Call ‘tramp-docker-setup’ in your Emacs initialization.
-;;
-;;     (add-hook 'after-init-hook 'tramp-docker-setup)
-;;
 ;; Open a file on a running systemd-docker container:
 ;;
 ;;     C-x C-f /docker:USER@CONTAINER:/path/to/file
@@ -43,33 +35,28 @@
 ;; Where:
 ;;     USER          is the user on the container to connect as (optional)
 ;;     CONTAINER     is the container to connect to
-;;
 
 ;;; Code:
-
-(require 'tramp)
 
-(defgroup tramp-docker nil
-  "Tramp integration for Docker containers."
-  :prefix "tramp-docker-"
-  :group 'applications
-  :link '(url-link :tag "repo" "https://git.spork.org/tramp-docker.git")
-  :link '(emacs-commentary-link :tag "Commentary" "tramp-docker"))
+(require 'tramp)
 
+;;;###tramp-autoload
 (defcustom tramp-docker-program "docker"
   "Name of the Docker client program."
+  :group 'tramp
+  :version "29.1"
   :type '(choice (const "docker")
                  (const "podman")
-                 (string))
-  :group 'tramp-docker)
+                 (string)))
 
+;;;###tramp-autoload
 (defconst tramp-docker-method "docker"
   "Tramp method name to use to connect to Docker containers.")
 
 (defun tramp-docker--completion-function (&rest _args)
   "List Docker containers available for connection.
 
-This function is used by ‘tramp-set-completion-function’, please
+This function is used by `tramp-set-completion-function', please
 see its function help for a description of the format."
   (let* ((raw-list (shell-command-to-string
                     (concat tramp-docker-program
@@ -83,43 +70,28 @@ see its function help for a description of the format."
     (mapcar (lambda (m) (list nil m)) machines)))
 
 ;; todo: check tramp-async-args and tramp-direct-async
-(defun tramp-docker--add-method ()
-  "Add Tramp method handler for Docker containers."
-  (push `(,tramp-docker-method
-          (tramp-login-program ,tramp-docker-program)
-          (tramp-login-args (("exec")
-                             ("-it")
-                             ("-u" "%u")
-                             ("%h")
-			     ("/bin/sh")))
-          (tramp-remote-shell "/bin/sh")
-          (tramp-remote-shell-login ("-l"))
-          (tramp-remote-shell-args ("-i" "-c")))
-        tramp-methods))
-
-(defun tramp-docker--remove-method ()
-  "Remove Tramp method handler for docker containers."
-  (setf (alist-get tramp-docker-method tramp-methods nil t 'string=) nil))
-
-(defun tramp-docker-unload-function ()
-  "Remove Tramp method handler and completion functions."
-  (tramp-set-completion-function tramp-docker-method nil)
-  (tramp-docker--remove-method)
-  nil)
-
-(when nil
-  (load-file (buffer-file-name))
-  (setq tramp-docker-program "doas podman")
-  (setq tramp-verbose 7) ;; default 3
-  (tramp-docker-setup)
-  (tramp-docker-unload-function))
-
-;;;###autoload
-(defun tramp-docker-setup ()
-  "Initialize Docker support for Tramp."
-  (tramp-docker--add-method)
-  (tramp-set-completion-function tramp-docker-method
-                                 '((tramp-docker--completion-function ""))))
+;;;###tramp-autoload
+(tramp--with-startup
+ (push `(,tramp-docker-method
+         (tramp-login-program ,tramp-docker-program)
+         (tramp-login-args (("exec")
+                            ("-it")
+                            ("-u" "%u")
+                            ("%h")
+			    ("/bin/sh")))
+         (tramp-remote-shell "/bin/sh")
+         (tramp-remote-shell-login ("-l"))
+         (tramp-remote-shell-args ("-i" "-c")))
+       tramp-methods)
+
+ (tramp-set-completion-function
+  tramp-docker-method
+  '((tramp-docker--completion-function ""))))
+
+(add-hook 'tramp-unload-hook
+	  (lambda ()
+	    (unload-feature 'tramp-docker 'force)))
 
 (provide 'tramp-docker)
+
 ;;; tramp-docker.el ends here