Make "kubernetes" multi-hop completion capable in Tramp

* lisp/net/tramp-container.el (tramp-skeleton-completion-function):
New defmacro.
(tramp-container--completion-function): Use it.
(tramp-kubernetes--completion-function): Use METHOD as argument.
Use `tramp-skeleton-completion-function'.
(tramp-skeleton-kubernetes-vector): New defmacro.
(tramp-kubernetes--current-context)
(tramp-kubernetes--current-context-data): Use it.
(tramp-completion-multi-hop-methods): Add "kubernetes".

1 files changed, 102 insertions, 68 deletions

diff --git a/lisp/net/tramp-container.el b/lisp/net/tramp-container.el
index 2e9ddc64bd3..bef3b04b371 100644
--- a/lisp/net/tramp-container.el
+++ b/lisp/net/tramp-container.el
@@ -158,6 +158,26 @@ If it is nil, the default context will be used."
   "Tramp method name to use to connect to Flatpak sandboxes.")
 
 ;;;###tramp-autoload
+(defmacro tramp-skeleton-completion-function (method &rest body)
+  "Skeleton for `tramp-*-completion-function' with multi-hop support.
+BODY is the backend specific code."
+  (declare (indent 1) (debug t))
+  `(let* ((default-directory
+           (or (and (member ,method tramp-completion-multi-hop-methods)
+                    tramp--last-hop-directory)
+               tramp-compat-temporary-file-directory))
+          (program (tramp-get-method-parameter
+                    (make-tramp-file-name :method ,method) 'tramp-login-program))
+          (vec (when (tramp-tramp-file-p default-directory)
+                 (tramp-dissect-file-name default-directory)))
+          non-essential)
+     ;; We don't use connection properties, because this information
+     ;; shouldn't be kept persistently.
+     (with-tramp-file-property
+         vec (concat "/" ,method ":") "user-host-completions"
+       ,@body)))
+
+;;;###tramp-autoload
 (defun tramp-container--completion-function (method)
   "List running containers available for connection.
 METHOD is the Tramp method to be used for \"ps\", either
@@ -165,62 +185,51 @@ METHOD is the Tramp method to be used for \"ps\", either
 
 This function is used by `tramp-set-completion-function', please
 see its function help for a description of the format."
-  (let ((default-directory
-         (or (and (member method tramp-completion-multi-hop-methods)
-                  tramp--last-hop-directory)
-             tramp-compat-temporary-file-directory))
-        (program (tramp-get-method-parameter
-                  (make-tramp-file-name :method method) 'tramp-login-program))
-        non-essential)
-    ;; We don't use connection properties, because this information
-    ;; shouldn't be kept persistently.
-    (with-tramp-file-property
-        (when (tramp-tramp-file-p default-directory)
-          (tramp-dissect-file-name default-directory))
-        (concat "/" method ":") "user-host-completions"
-      (when-let ((raw-list
-                  (shell-command-to-string
-                   (concat program " ps --format '{{.ID}}\t{{.Names}}'")))
-                 (lines (split-string raw-list "\n" 'omit))
-                 (names
-                  (mapcar
-                   (lambda (line)
-                     (when (string-match
-                            (rx bol (group (1+ nonl))
-                                "\t" (? (group (1+ nonl))) eol)
-                            line)
-                       (or (match-string 2 line) (match-string 1 line))))
-                   lines)))
-        (mapcar (lambda (name) (list nil name)) (delq nil names))))))
+  (tramp-skeleton-completion-function method
+    (when-let ((raw-list
+                (shell-command-to-string
+                 (concat program " ps --format '{{.ID}}\t{{.Names}}'")))
+               (lines (split-string raw-list "\n" 'omit))
+               (names
+                (mapcar
+                 (lambda (line)
+                   (when (string-match
+                          (rx bol (group (1+ nonl))
+                              "\t" (? (group (1+ nonl))) eol)
+                          line)
+                     (or (match-string 2 line) (match-string 1 line))))
+                 lines)))
+      (mapcar (lambda (name) (list nil name)) (delq nil names)))))
 
 ;;;###tramp-autoload
-(defun tramp-kubernetes--completion-function (&rest _args)
+(defun tramp-kubernetes--completion-function (method)
   "List Kubernetes pods available for connection.
 
 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)
-             (raw-list (shell-command-to-string
-                        (concat
-                         tramp-kubernetes-program " "
-                         (tramp-kubernetes--context-namespace nil)
-                         " get pods --no-headers"
-                         ;; We separate pods by "|".  Inside a pod,
-                         ;; its name is separated from the containers
-                         ;; by ":".  Containers are separated by ",".
-                         " -o jsonpath='{range .items[*]}{\"|\"}{.metadata.name}"
-                         "{\":\"}{range .spec.containers[*]}{.name}{\",\"}"
-                         "{end}{end}'")))
-             (lines (split-string raw-list "|" 'omit)))
-    (let (names)
-      (dolist (line lines)
-        (setq line (split-string line ":" 'omit))
-        ;; Pod name.
-        (push (car line) names)
-        ;; Container names.
-        (dolist (elt (split-string (cadr line) "," 'omit))
-          (push (concat elt "." (car line)) names)))
-      (mapcar (lambda (name) (list nil name)) (delq nil names)))))
+  (tramp-skeleton-completion-function method
+    (when-let ((raw-list
+                (shell-command-to-string
+                 (concat
+                  program " "
+                  (tramp-kubernetes--context-namespace vec)
+                  " get pods --no-headers"
+                  ;; We separate pods by "|".  Inside a pod, its name
+                  ;; is separated from the containers by ":".
+                  ;; Containers are separated by ",".
+                  " -o jsonpath='{range .items[*]}{\"|\"}{.metadata.name}"
+                  "{\":\"}{range .spec.containers[*]}{.name}{\",\"}"
+                  "{end}{end}'")))
+               (lines (split-string raw-list "|" 'omit)))
+      (let (names)
+        (dolist (line lines)
+          (setq line (split-string line ":" 'omit))
+          ;; Pod name.
+          (push (car line) names)
+          ;; Container names.
+          (dolist (elt (split-string (cadr line) "," 'omit))
+            (push (concat elt "." (car line)) names)))
+        (mapcar (lambda (name) (list nil name)) (delq nil names))))))
 
 (defconst tramp-kubernetes--host-name-regexp
   (rx (? (group (regexp tramp-host-regexp)) ".")
@@ -243,30 +252,53 @@ see its function help for a description of the format."
              (match-string 2 host)))
       ""))
 
+;; We must change `vec' and `default-directory' to the previous hop,
+;; in order to run `process-file' in a proper environment.
+(defmacro tramp-skeleton-kubernetes-vector (vec &rest body)
+  "Skeleton for `tramp-kubernetes--current-context*' with multi-hop support.
+BODY is the backend specific code."
+  (declare (indent 1) (debug t))
+  `(let* ((vec
+           (cond
+            ((null ,vec) tramp-null-hop)
+            ((equal (tramp-file-name-method ,vec) tramp-kubernetes-method)
+             (if (tramp-file-name-hop ,vec)
+                 (tramp-dissect-hop-name (tramp-file-name-hop ,vec))
+               tramp-null-hop))
+            (t ,vec)))
+          (default-directory
+           (if (equal vec tramp-null-hop)
+               tramp-compat-temporary-file-directory
+             (tramp-make-tramp-file-name vec "/"))))
+     ,@body))
+
 (defun tramp-kubernetes--current-context (vec)
   "Return Kubernetes current context.
 Obey `tramp-kubernetes-context'"
   (or tramp-kubernetes-context
-      (with-tramp-connection-property nil "current-context"
-        (with-temp-buffer
-          (when (zerop
-                 (tramp-call-process
-                  vec tramp-kubernetes-program nil t nil
-                  "config" "current-context"))
-            (goto-char (point-min))
-            (buffer-substring (point) (line-end-position)))))))
+      (tramp-skeleton-kubernetes-vector vec
+        (with-tramp-file-property
+            vec (concat "/" tramp-kubernetes-method ":") "current-context"
+          (with-temp-buffer
+            (when (zerop
+                   (process-file
+                    tramp-kubernetes-program nil t nil
+                    "config" "current-context"))
+              (goto-char (point-min))
+              (buffer-substring (point) (line-end-position))))))))
 
 (defun tramp-kubernetes--current-context-data (vec)
   "Return Kubernetes current context data as JSON string."
   (when-let ((current-context (tramp-kubernetes--current-context vec)))
-    (with-temp-buffer
-      (when (zerop
-             (tramp-call-process
-              vec tramp-kubernetes-program nil t nil
-              "config" "view" "-o"
-              (format
-               "jsonpath='{.contexts[?(@.name == \"%s\")]}'" current-context)))
-        (buffer-string)))))
+    (tramp-skeleton-kubernetes-vector vec
+      (with-temp-buffer
+        (when (zerop
+               (process-file
+                tramp-kubernetes-program nil t nil
+                "config" "view" "-o"
+                (format
+                 "jsonpath='{.contexts[?(@.name == \"%s\")]}'" current-context)))
+          (buffer-string))))))
 
 ;;;###tramp-autoload
 (defun tramp-kubernetes--context-namespace (vec)
@@ -404,7 +436,7 @@ see its function help for a description of the format."
 
  (tramp-set-completion-function
   tramp-kubernetes-method
-  '((tramp-kubernetes--completion-function "")))
+  `((tramp-kubernetes--completion-function ,tramp-kubernetes-method)))
 
  (tramp-set-completion-function
   tramp-toolbox-method
@@ -416,6 +448,7 @@ see its function help for a description of the format."
 
  (add-to-list 'tramp-completion-multi-hop-methods tramp-docker-method)
  (add-to-list 'tramp-completion-multi-hop-methods tramp-podman-method)
+ (add-to-list 'tramp-completion-multi-hop-methods tramp-kubernetes-method)
 
  ;; Default connection-local variables for Tramp.
 
@@ -425,7 +458,8 @@ see its function help for a description of the format."
      (tramp-extra-expand-args
       . (?a (tramp-kubernetes--container (car tramp-current-connection))
          ?h (tramp-kubernetes--pod (car tramp-current-connection))
-         ?x (tramp-kubernetes--context-namespace (car tramp-current-connection)))))
+         ?x (tramp-kubernetes--context-namespace
+             (car tramp-current-connection)))))
    "Default connection-local variables for remote kubernetes connections.")
 
  (connection-local-set-profile-variables