services: Add Singularity.

* gnu/packages/linux.scm (singularity)[source](snippet): Change file
name of setuid helpers in libexec/cli/*.exec.
[arguments]: Remove "--disable-suid".
* gnu/services/docker.scm (%singularity-activation): New variable.
(singularity-setuid-programs): New procedure.
(singularity-service-type): New variable.
* gnu/tests/singularity.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.
* doc/guix.texi (Miscellaneous Services): Document it.

1 files changed, 12 insertions, 1 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index bdfe14c724..d37d63066f 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -24090,7 +24090,7 @@ The following is an example @code{dicod-service} configuration.
 @cindex Docker
 @subsubheading Docker Service
 
-The @code{(gnu services docker)} module provides the following service.
+The @code{(gnu services docker)} module provides the following services.
 
 @defvr {Scheme Variable} docker-service-type
 
@@ -24163,6 +24163,17 @@ The audit package to use.
 @end table
 @end deftp
 
+@defvr {Scheme Variable} singularity-service-type
+This is the type of the service that allows you to run
+@url{https://www.sylabs.io/singularity/, Singularity}, a Docker-style tool to
+create and run application bundles (aka. ``containers'').  The value for this
+service is the Singularity package to use.
+
+The service does not install a daemon; instead, it installs helper programs as
+setuid-root (@pxref{Setuid Programs}) such that unprivileged users can invoke
+@command{singularity run} and similar commands.
+@end defvr
+
 @node Setuid Programs
 @section Setuid Programs