Re: master 55eabe96c9: ; Improve manual for Tramp kubernetes method

[Filipp Gunbin]

Hi Michael,

Generally it works, thank you very much!

Test case:

1) kubectl config set-context --current --namespace=main
2) dired /kubernetes:myapp-67cd597654-wxdjn:/
3) tramp-cleanup-this-connection
4) kubectl config set-context --current --namespace=
5) again dired /kubernetes:myapp-67cd597654-wxdjn:/ - I get an error and
  cache is cleared

However, now auto-completing /kubernetes: shows this, why 2?

--8<---------------cut here---------------start------------->8---
In this buffer, type RET to select the completion near point.

2 possible completions:
kubernetes:
--8<---------------cut here---------------end--------------->8---

Another issue: if at step 5 I instead use existing dired window and
type, say, "i" on a subdirectory, then I get the same-looking error, but
the Tramp cache is not cleared (perhaps this is not
Kubernetes-specific).

Also please see comments below.

On 24/10/2022 20:54 +0200, Michael Albinus wrote:

> Michael Albinus <michael.albinus@gmx.de> writes:
>
> Hi Filipp,
>
>>> Yep, but I would recommend "kubectl config view --context=$(kubectl
>>> config current-context) -o json". We don't need the information about
>>> other context.
>>
>> Oops. The better way is "kubectl config view -o json --minify".
>
> Patch is appended, could you pls test?
>
> Best regards, Michael.
>
> diff --git a/lisp/tramp-container.el b/lisp/tramp-container.el
> index e104babe..5603fa0f 100644
> --- a/lisp/tramp-container.el
> +++ b/lisp/tramp-container.el
> @@ -130,6 +130,15 @@ see its function help for a description of the format."
>                (list nil name))
>              names)))
>
> +(defun tramp-kubernetes--current-context-data (vec)
> +  "Return current context data as JSON string."
> +  (with-temp-buffer
> +    (when (zerop
> +        (tramp-call-process
> +         vec tramp-kubernetes-program nil t nil
> +         "config" "view" "--minify" "-o" "json"))
> +      (buffer-string))))
> +

Let's remove --minify.

Also, maybe save the checksum (simple md5 would do it), not the full
listing?  The listing may contain sensitive data (for example, mine
shows my OAuth id token).

>  ;;;###tramp-autoload
>  (defvar tramp-default-remote-shell) ;; Silence byte compiler.
>
> @@ -165,6 +174,7 @@ see its function help for a description of the format."
>                                     ("-it")
>                                     ("--")
>                                  ("%l")))
> +             (tramp-config-check tramp-kubernetes--current-context-data)
>                  (tramp-remote-shell ,tramp-default-remote-shell)
>                  (tramp-remote-shell-login ("-l"))
>                  (tramp-remote-shell-args ("-i" "-c"))))
> diff --git a/lisp/tramp-sh.el b/lisp/tramp-sh.el
> index d74afc84..39043482 100644
> --- a/lisp/tramp-sh.el
> +++ b/lisp/tramp-sh.el
> @@ -4472,7 +4472,8 @@ process to set up.  VEC specifies the connection."
>    ;; Check whether the output of "uname -sr" has been changed.  If
>    ;; yes, this is a strong indication that we must expire all
>    ;; connection properties.  We start again with
> -  ;; `tramp-maybe-open-connection', it will be caught there.
> +  ;; `tramp-maybe-open-connection', it will be caught there.  The same
> +  ;; check will be applied with the function kept in`tramp-config-check'.
>    (tramp-message vec 5 "Checking system information")
>    (let* ((old-uname (tramp-get-connection-property vec "uname"))
>        (uname
> @@ -4481,8 +4482,23 @@ process to set up.  VEC specifies the connection."
>             old-uname
>           (tramp-set-connection-property
>            vec "uname"
> -          (tramp-send-command-and-read vec "echo \\\"`uname -sr`\\\"")))))
> -    (when (and (stringp old-uname) (not (string-equal old-uname uname)))
> +          (tramp-send-command-and-read vec "echo \\\"`uname -sr`\\\""))))
> +      (config-check-function
> +       (tramp-get-method-parameter vec 'tramp-config-check))
> +      (old-config-check
> +       (and config-check-function
> +            (tramp-get-connection-property vec "config-check-data")))
> +      (config-check
> +       (and config-check-function
> +            ;; If we are in `make-process', we don't need to recompute.
> +            (if (and old-config-check
> +                     (tramp-get-connection-property vec "process-name"))
> +                old-config-check
> +              (tramp-set-connection-property
> +               vec "config-check-data"
> +               (tramp-compat-funcall config-check-function vec))))))
> +    (when (and (stringp old-uname) (stringp uname)
> +            (not (string-equal old-uname uname)))
>        (tramp-message
>         vec 3
>         "Connection reset, because remote host changed from `%s' to `%s'"
> @@ -4490,6 +4506,15 @@ process to set up.  VEC specifies the connection."
>        ;; We want to keep the password.
>        (tramp-cleanup-connection vec t t)
>        (throw 'uname-changed (tramp-maybe-open-connection vec)))
> +    (when (and (stringp old-config-check) (stringp config-check)
> +            (not (string-equal old-config-check config-check)))
> +      (tramp-message
> +       vec 3
> +       "Connection reset, because remote configuration changed from `%s' to 
> `%s'"
> +       old-config-check config-check)

Currently, we'll get huge config listings here (at the level 3)?  If we
change to checksums, that'd be not very useful.  So perhaps don't output
those strings?

> +      ;; We want to keep the password.
> +      (tramp-cleanup-connection vec t t)
> +      (throw 'uname-changed (tramp-maybe-open-connection vec)))
>
>      ;; Try to set up the coding system correctly.
>      ;; CCC this can't be the right way to do it.  Hm.
> diff --git a/lisp/tramp.el b/lisp/tramp.el
> index 57063154..933bac7e 100644
> --- a/lisp/tramp.el
> +++ b/lisp/tramp.el
> @@ -281,6 +281,13 @@ pair of the form (KEY VALUE).  The following KEYs are 
> defined:
>      Until now, just \"ssh\"-based, \"sshfs\"-based and
>      \"adb\"-based methods do.
>
> +  * `tramp-config-check'
> +    A function to be called with one argument, VEC.  It should
> +    return a string which is used to check, whether the

Comma not needed?

> +    configuration of the remote host has been changed (which
> +    would require to flush the cache data).  This string is kept
> +    as connection property \"config-check-data\".
> +
>    * `tramp-copy-program'
>      This specifies the name of the program to use for remotely copying
>      the file; this might be the absolute filename of scp or the name of

Also, my added paragraph in manual can be removed now.

Thanks.
Filipp