Hello,
Ludovic Courtès <l...@gnu.org> writes:
> Could you write it in functional style using a vhash (info "(guile)
> VHashes")? You’ll probably need two list traversals: one to build the
> user/key mapping, and one to compute the list of users.
I thought that as the vhash data structure inherited the drawbacks of
vlist, it would not be worth using in place of a hash table, but you’re
saying that it’s still a better (more functional) data structure, noted.
Here is the new patch (and I also forgot that appending short lists to
long lists was not great, so I do all the appending at the end of the
function now).
>From a2c4d7cefbc71fd3d35b0b7cc2f61118bd3a29b2 Mon Sep 17 00:00:00 2001
From: Vivien Kraus <viv...@planete-kraus.eu>
Date: Fri, 29 Oct 2021 18:25:24 +0200
Subject: [PATCH] gnu: openssh-service: Collect all keys for all users.
* gnu/services/ssh.scm (extend-openssh-authorized-keys): ensure that no key is forgotten.
---
gnu/services/ssh.scm | 29 +++++++++++++++++++++++++----
1 file changed, 25 insertions(+), 4 deletions(-)
diff --git a/gnu/services/ssh.scm b/gnu/services/ssh.scm
index a018052eeb..6ddaf55eeb 100644
--- a/gnu/services/ssh.scm
+++ b/gnu/services/ssh.scm
@@ -39,6 +39,7 @@ (define-module (gnu services ssh)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-26)
#:use-module (ice-9 match)
+ #:use-module (ice-9 vlist)
#:export (lsh-configuration
lsh-configuration?
lsh-service
@@ -532,10 +533,30 @@ (define (openssh-pam-services config)
(define (extend-openssh-authorized-keys config keys)
"Extend CONFIG with the extra authorized keys listed in KEYS."
- (openssh-configuration
- (inherit config)
- (authorized-keys
- (append (openssh-authorized-keys config) keys))))
+ (let generate-keys
+ ((user-keys
+ (append (openssh-authorized-keys config) keys))
+ ;; The by-user vhash indexes a list of list of keys for each user, the
+ ;; list of list is not concatenated eagerly to avoid quadratic
+ ;; complexity.
+ (by-user (alist->vhash '())))
+ (match user-keys
+ (()
+ (openssh-configuration
+ (inherit config)
+ (authorized-keys
+ (vhash-fold
+ (lambda (user keys other-users)
+ `((,user ,@(apply append (reverse keys))) ,@other-users))
+ '() by-user))))
+ (((user keys ...) other-user-keys ...)
+ (let ((existing
+ (match (vhash-assoc user by-user)
+ ((_ . keys) keys)
+ (#f '()))))
+ (generate-keys
+ other-user-keys
+ (vhash-cons user `(,keys ,@existing) by-user)))))))
(define openssh-service-type
(service-type (name 'openssh)
--
2.33.1
Vivien
