The singularity package was renamed to apptainer

[afbjorklund]

In fedora, singularity-3.8.7 was replaced with apptainer-1.0.3

https://singularity.hpcng.org/

https://apptainer.org/news/community-announcement-20211130

So the example should be renamed too, to reflect the reality.

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SingularityCE has not been packaged as dnf, only from sylabs.io

https://sylabs.io/singularity/

https://docs.sylabs.io/guides/3.10/admin-guide/

If requested, it could be resurrected as an example (like e.g. centos stream)

[afbjorklund]

Once the fedora package has been updated to 1.1.0, this PR replaces the experimental/apptainer.yaml example.

I believe that using Fedora is a better match than using Rocky, because of 1) download size 2) uses EPEL anyway

[afbjorklund]

Currently there are problems with using tmpfs as /tmp, but a simple workaround is TMPDIR=/var/tmp

I will do a separate PR for this, once renamed... https://fedoraproject.org/wiki/Features/tmp-on-tmpfs

• For apptainer, move TMPDIR away from tmpfs #1085

[AkihiroSuda]

Once the fedora package has been updated to 1.1.0, this PR replaces the experimental/apptainer.yaml example.

How long will it take?
Shall we wait until that happens or shall we merge this PR now?

[afbjorklund]

Shall we wait until that happens or shall we merge this PR now?

I think the only difference was that apptainer-suid was split into a separate package:

-    dnf install --enablerepo=epel-testing -y apptainer apptainer-suid
+    dnf install -y apptainer

I tried enabling the updates-testing, but seems like the package only made it to fc38 ?

https://src.fedoraproject.org/rpms/apptainer

---

But you could merge it now, and we could tweak it later perhaps. It doesn't change anything.

The previous example has the same end result, with a symlink /usr/bin/singularity -> apptainer

$ limactl shell singularity singularity --version
apptainer version 1.0.3-2.fc36

So the change is more cosmetic and documentation, as it also has a new icon and home page.

[afbjorklund]

@AkihiroSuda note that this also a new feature, in the new release: i.e. rootless by default

https://apptainer.org/news/apptainer-1-1-0-20220927

It is still possible to use rootless, by using flags or by changing the apptainer.conf configuration:

allow setuid = no

[AkihiroSuda]

If we are going to merge this now, shall we remove experimental/apptainer.yaml?

[afbjorklund]

@AkihiroSuda apptainer 1.1.0 has now been accepted in both Fedora and EPEL

https://src.fedoraproject.org/rpms/apptainer

Release	Stable version	Version in testing
Fedora 36	apptainer-1.1.0-1.fc36
Fedora 35	apptainer-1.1.0-1.fc35
Fedora EPEL 9	apptainer-1.1.0-1.el9
Fedora EPEL 8	apptainer-1.1.0-1.el8

I moved the suid binary into a separate example, like with the other engines

I also deleted the Rocky-based example, since it is replaced with the Fedora-based

[afbjorklund]

The rootless example doesn't need squashfs anymore, since it uses squashfuse instead.

It does need fuse, but that seems to be loaded by default in the fedora operating system.

[AkihiroSuda]

Added follow-up commits

[AkihiroSuda]

Thanks