[PATCH consfigurator] add user:group-exists

[David Bremner]

This is essentially a copy of has-account, with the equivalent of
USER-EXISTS inlined.

Signed-off-by: David Bremner <david at tethera.net>
---
 src/package.lisp       |  1 +
 src/property/user.lisp | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/src/package.lisp b/src/package.lisp
index a8b298e..c65b04b 100644
--- a/src/package.lisp
+++ b/src/package.lisp
@@ -558,6 +558,7 @@
                              (#:os    #:consfigurator.property.os))
            (:export #:has-account
                     #:has-account-with-uid
+                    #:group-exists
                     #:has-groups
                     #:has-desktop-groups
 	            #:has-login-shell
diff --git a/src/property/user.lisp b/src/property/user.lisp
index 1dd9f1d..67190df 100644
--- a/src/property/user.lisp
+++ b/src/property/user.lisp
@@ -52,6 +52,16 @@ that group, and ~USERNAME and its contents are owned by UID:GID."
   (has-account username)
   (%has-uid-gid username uid gid))
 
+(defprop group-exists :posix (groupname)
+  "Ensure there is a group GROUPNAME.
+Note that this uses getent(1) and so is not strictly POSIX-compatible."
+  (:desc #?"Group ${groupname} exists")
+  (:check
+   (zerop (mrun :for-exit "getent" "group" groupname)))
+  (:apply
+   (assert-remote-euid-root)
+   (mrun "groupadd" groupname)))
+
 (defprop has-groups :posix
     (username &rest groups &aux (groups* (format nil "~{~A~^,~}" groups)))
   "Ensure that USERNAME is a member of secondary groups GROUPS."
-- 
2.35.2