Re: [RFC PATCH 1/2] Set TOPDIR_PATH and generate its sha256sum at run time

On Thu, Aug 28, 2025 at 04:28:26PM -0400, Chuck Lever wrote:
> From: Chuck Lever <[email protected]>
> 
> Commit 42d27579a9d0 ("guestfs: enhance ssh config choice") added a
> uniquifier to the name of the ssh config to avoid multiple kdevops
> runs clobbering each other's ssh config entries. It uses the TOPDIR
> pathname set in the current .config to benefit from the nice
> convenience of generating an Ansible extra_var using "output yaml".
> 
> However, if the same user generates all her .configs (that will be
> run by other users under automation) while in the same directory
> (say, if they are different branches in the same git repository),
> the TOPDIR pathname and thus the sha256sum of that pathname will be
> exactly the same in all of those .config files, allowing the path
> names of the ephemeral ssh configs to collide.

Both paragraphs above took me quite a bit of time to grasp, I think
it was the parenthesis, as they make me try to switch contexts. So
I think the explanation of the issue can be simplified. I *think*
that the issue your are describing is essentially that we currently
cannot support sharing .config to other users because TOPDIR_PATH
expects the same path to be used. Would that be a summary of the
issue?

> The TOPDIR and its checksum need to be generated not by "make
> menuconfig" but rather by "make" in order that .config files (as
> saved in defconfigs/) can be truly portable.

This is nice.

> Signed-off-by: Chuck Lever <[email protected]>
> ---
>  Kconfig                    | 15 ---------------
>  Makefile                   |  4 ++++
>  scripts/gen-hosts.Makefile |  1 +
>  scripts/ssh.Makefile       |  4 ++--
>  4 files changed, 7 insertions(+), 17 deletions(-)
> 
> diff --git a/Kconfig b/Kconfig
> index 3f2bc8cf019a..948befbce4de 100644
> --- a/Kconfig
> +++ b/Kconfig
> @@ -5,21 +5,6 @@
>  
>  mainmenu "$(PROJECT) $(PROJECTRELEASE)"
>  
> -config TOPDIR_PATH
> -	string
> -	output yaml
> -	default $(shell, echo $TOPDIR_PATH)
> -
> -config TOPDIR_PATH_HAS_SHA256SUM
> -	bool
> -	output yaml
> -	default y
> -
> -config TOPDIR_PATH_SHA256SUM
> -	string
> -	output yaml
> -	default $(shell, ./scripts/compute_sha256sum.sh $(TOPDIR_PATH))
> -
>  config HAVE_KDEVOPS_CUSTOM_DEFAULTS
>  	bool
>  	default n
> diff --git a/Makefile b/Makefile
> index 8755577e4d85..b6fdbe67fc07 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -19,6 +19,8 @@ export KDEVOPS_NODES :=
>  export PYTHONUNBUFFERED=1
>  export TOPDIR=./
>  export TOPDIR_PATH = $(shell readlink -f $(TOPDIR))
> +export TOPDIR_PATH_HAS_SHA256SUM=y

We added this a long time ago, to remain compatible with users who
may git pull to the latest kdevops which didn't yet have the symbol
TOPDIR_PATH_HAS_SHA256SUM.

So I think a prep patch to just remove TOPDIR_PATH_HAS_SHA256SUM now
make sense.

Otherwise this is looking nice.

  Luis