Following up on
https://lists.gnu.org/archive/html/tramp-devel/2023-08/msg00001.html, I have
prepared a patch to add remote container completion support to TRAMP.
A couple of questions/things I'm uncertain of in this patch:
1. I am removing the check for executable-find for the docker and podman
programs since they need to be run on the remote system (and executable-find
will fail as it only checks the local machine while multi-hopping). I'm not
sure if there is a better way to handle this.
2. In tramp-set-completion-function I am short-circuiting the cond check for a
valid "file or registry key" since again, file-exists-p will fail when checking
for the docker or podman program on a remote system when checking a multi-hop
path. I'm open to a better ideas here since my change effectively no-ops the
whole cond.
3. (style question) I've added my required variable tramp-last-hop-directory as
an autoload in tramp.el but if there's a better place for it I'd be happy to
move it.
>From b4cb455cae55eef48c14dae8fc69f50cd434afb4 Mon Sep 17 00:00:00 2001
From: Gene Goykhman <g...@indigo1.com>
Date: Tue, 22 Aug 2023 12:10:44 -0400
Subject: [PATCH] Provide completion candidates for remote containers over a
TRAMP connection
* lisp/net/tramp.el (tramp-last-hop-directory): Add new variable.
(tramp-set-completion-function): Don't use executable-find for
container program since it might not be running locally.
(container-host-directory): Determine default directory for container
host.
(tramp-completion-handle-file-name-all-completions): Use container
host directory to execute container program on remote.
* lisp/net/tramp-container.el (tramp-last-hop-directory): Declare variable.
(tramp-container--completion-function): Set default directory to last hop.
---
lisp/net/tramp-container.el | 9 ++++++---
lisp/net/tramp.el | 20 ++++++++++++++++++--
2 files changed, 24 insertions(+), 5 deletions(-)
diff --git a/lisp/net/tramp-container.el b/lisp/net/tramp-container.el
index 7f8d4473ad7..5ad8a09fd51 100644
--- a/lisp/net/tramp-container.el
+++ b/lisp/net/tramp-container.el
@@ -157,6 +157,8 @@ If it is nil, the default context will be used."
(defconst tramp-flatpak-method "flatpak"
"Tramp method name to use to connect to Flatpak sandboxes.")
+(defvar tramp-last-hop-directory)
+
;;;###tramp-autoload
(defun tramp-container--completion-function (program)
"List running containers available for connection.
@@ -165,7 +167,8 @@ PROGRAM is the program to be run for \"ps\", either
This function is used by `tramp-set-completion-function', please
see its function help for a description of the format."
- (when-let ((default-directory tramp-compat-temporary-file-directory)
+ (when-let ((default-directory (or tramp-last-hop-directory
+ tramp-compat-temporary-file-directory))
(raw-list (shell-command-to-string
(concat program " ps --format '{{.ID}}\t{{.Names}}'")))
(lines (split-string raw-list "\n" 'omit))
@@ -383,12 +386,12 @@ see its function help for a description of the format."
(tramp-set-completion-function
tramp-docker-method
`((tramp-container--completion-function
- ,(executable-find tramp-docker-program))))
+ ,tramp-docker-program)))
(tramp-set-completion-function
tramp-podman-method
`((tramp-container--completion-function
- ,(executable-find tramp-podman-program))))
+ ,tramp-podman-program)))
(tramp-set-completion-function
tramp-kubernetes-method
diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index a0092a2d706..427c0871310 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -82,6 +82,9 @@
(defvar tramp-completion-method-regexp)
(defvar tramp-completion-file-name-regexp)
+;;;###tramp-autoload
+(defvar tramp-last-hop-directory nil)
+
;; Reload `tramp-compat' when we reload `tramp-autoloads' of the GNU
;; ELPA package.
;;;###autoload (when (featurep 'tramp-compat)
@@ -2133,8 +2136,8 @@ Example:
;; DNS-SD service type.
((string-match-p
tramp-dns-sd-service-regexp (nth 1 (car v))))
- ;; Configuration file or empty string.
- (t (file-exists-p (nth 1 (car v))))))
+ ;; Allow arbitrary executable name (for remote systems) too.
+ (t t)))
(setq r (delete (car v) r)))
(setq v (cdr v)))
@@ -2689,12 +2692,25 @@ not in completion mode."
(tramp-run-real-handler #'file-exists-p (list filename))))
+(defun container-host-directory (orig)
+ "Strips off the `tramp-docker-program' or `tramp-podman-program' suffix from ORIG."
+ "Returned path can be used to start programs on the container host."
+ (let ((regexp (format "\\(.*\\)|\\(\\(%s\\)\\|\\(%s\\)\\)" tramp-docker-program tramp-podman-program)))
+ (if (string-match regexp orig)
+ (concat (match-string 1 orig) ":/")
+ orig)))
+
;; Method, host name and user name completion.
;; `tramp-completion-dissect-file-name' returns a list of
;; `tramp-file-name' structures. For all of them we return possible
;; completions.
(defun tramp-completion-handle-file-name-all-completions (filename directory)
"Like `file-name-all-completions' for partial Tramp files."
+ (let ((use-container-host-directory (container-host-directory directory)))
+ (when (tramp-tramp-file-p use-container-host-directory)
+ (let ((minibuffer-completing-file-name nil))
+ (setq tramp-last-hop-directory (tramp-make-tramp-file-name
+ (tramp-dissect-file-name use-container-host-directory))))))
(let ((fullname
(tramp-drop-volume-letter (expand-file-name filename directory)))
;; When `tramp-syntax' is `simplified', we need a default method.
--
2.39.2 (Apple Git-143)
