[bug#47136] [PATCH 3/3] services: certbot: Add dry-run? certificate option.

[Pierre Langlois]

* gnu/services/certbot.scm (certificate-configuration): Add dry-run? field.
(certbot-command): Use it to pass --dry-run to certbot.
* doc/guix.texi (Certificate Services): Document dry-run? option.
---
 doc/guix.texi            | 35 +++++++++++++++++++++++++++++++++++
 gnu/services/certbot.scm | 10 +++++++---
 2 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index ec449b1772..322c717941 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -25665,6 +25665,41 @@ certificates and keys; the shell variable 
@code{$RENEWED_DOMAINS} will
 contain a space-delimited list of renewed certificate domains (for
 example, @samp{"example.com www.example.com"}.

+@item @code{dry-run?} (default: @code{#f})
+Communitcate with the ACME server but do not update certificates nor
+trigger @code{deploy-hook}.  This is useful as a temporary setting to
+test the challenge procedure, especially the @code{authentication-hook}
+and @code{cleanup-hook} while working on them.  It's also a good idea to
+use Let's Encrypt's staging server at
+@url{https://acme-staging-v02.api.letsencrypt.org/directory} while
+testing, which allows for higher rate limits, but with which
+@code{certbot} will helpfully refuse to update certificates and
+recommend the @code{dry-run?} option.  For example:
+
+@lisp
+(define %authentication-hook
+  (program-file "authentication-hook"
+    #~(let ((domain (getenv "CERTBOT_DOMAIN"))
+            (token (getenv "CERTBOT_TOKEN")))
+        (format #t "Hey, can you authenticate ~a with ~a for me?"
+                domain token))))
+
+(define %cleanup-hook
+  (program-file "authentication-hook"
+    #~(display "Bye")
+
+(service certbot-service-type
+         (certbot-configuration
+          (server "https://acme-staging-v02.api.letsencrypt.org/directory";)
+          (certificates
+           (list
+            (certificate-configuration
+              (dry-run? #t)
+              (authentication-hook %authentication-hook)
+              (cleanup-hook %cleanup-hook)
+              (domains '("example.net" "www.example.net")))))))
+@end lisp
+
 @end table
 @end deftp

diff --git a/gnu/services/certbot.scm b/gnu/services/certbot.scm
index 1cea68fc2a..15274cf0ed 100644
--- a/gnu/services/certbot.scm
+++ b/gnu/services/certbot.scm
@@ -61,6 +61,8 @@
   (cleanup-hook        certificate-cleanup-hook
                        (default #f))
   (deploy-hook         certificate-configuration-deploy-hook
+                       (default #f))
+  (dry-run?            certbot-configuration-dry-run?
                        (default #f)))

 (define-record-type* <certbot-configuration>
@@ -96,7 +98,7 @@
               (match-lambda
                 (($ <certificate-configuration> custom-name domains challenge
                                                 authentication-hook 
cleanup-hook
-                                                deploy-hook)
+                                                deploy-hook dry-run?)
                  (let ((name (or custom-name (car domains))))
                    (if challenge
                      (append
@@ -114,7 +116,8 @@
                           `("--manual-auth-hook" ,authentication-hook)
                           '())
                       (if cleanup-hook `("--manual-cleanup-hook" 
,cleanup-hook) '())
-                      (if deploy-hook `("--deploy-hook" ,deploy-hook) '()))
+                      (if deploy-hook `("--deploy-hook" ,deploy-hook) '())
+                      (if dry-run? '("--dry-run")))
                      (append
                       (list name certbot "certonly" "-n" "--agree-tos"
                             "--webroot" "-w" webroot
@@ -125,7 +128,8 @@
                           '("--register-unsafely-without-email"))
                       (if server `("--server" ,server) '())
                       (if rsa-key-size `("--rsa-key-size" ,rsa-key-size) '())
-                      (if deploy-hook `("--deploy-hook" ,deploy-hook) '()))))))
+                      (if deploy-hook `("--deploy-hook" ,deploy-hook) '())
+                      (if dry-run? '("--dry-run") '()))))))
               certificates)))
        (program-file
         "certbot-command"
--
2.30.2