CI: convert EL 7 test to an EL 8 test, using Alma

CentOS 7, EPEL 7, CentOS 8 and CentOS Stream 8 are all EOL, so
let's go to Alma 8 for the EL test.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

.github/workflows/ci.yml

@@ -28,7 +28,7 @@ jobs:
         # we want to run this regardless of whether previous lint steps failed
         if: success() || failure()
         run: diff-quality --compare-branch=origin/$GITHUB_BASE_REF --violations=flake8 --fail-under=90
-  unittests-el7:
+  unittests-el8:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout the repo
@@ -38,4 +38,4 @@ jobs:
       - name: Install make
         run: sudo apt-get install make
       - name: Run the tests
-        run: sudo make container-unittests-el7
+        run: sudo make container-unittests-el8

Containerfile.tests.el8

@@ -0,0 +1,18 @@
+# this container definition is intended *only* for running the oz test suite, it is not
+# a general-purpose oz container definition!
+
+FROM quay.io/almalinuxorg/8-base:latest
+RUN set -exo pipefail \
+    && dnf install -y https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm \
+    && dnf install -y --setopt install_weak_deps=false --nodocs \
+    python3-requests python3-cryptography python3-setuptools python3-libvirt python3-lxml python3-libguestfs python3-pytest python3-coverage python3-monotonic \
+    libvirt-daemon libvirt-daemon-kvm libvirt-daemon-driver-qemu libvirt-daemon-config-network systemd \
+    && dnf clean all \
+    && rm -rf /var/cache/* /var/log/dnf*
+
+COPY ./ /oz
+# the XML generation tests are inherently unreliable before Python 3.8,
+# as there was no consistent ordering of XML element attributes. See
+# https://docs.python.org/3/library/xml.etree.elementtree.html#xml.etree.ElementTree.tostring
+RUN printf "#!/bin/sh\n/usr/sbin/libvirtd -d\ncd /oz\npython3 -m pytest -vv -k 'not test_xml_generation and not modify_libvirt_xml_for_serial' tests/" > /usr/local/bin/runtests.sh && chmod ugo+x /usr/local/bin/runtests.sh
+CMD /usr/local/bin/runtests.sh

Makefile

@@ -52,12 +52,12 @@ container-unittests-fedora:
 	docker run --name oz-tests-fedora oz-tests-fedora-image
 	docker cp oz-tests-fedora:/oz/coverage.xml .
 
-container-unittests-el7:
-	docker rm -f oz-tests-el7
-	docker build -f Containerfile.tests.el7 -t oz-tests-el7-image .
-	docker run --name oz-tests-el7 oz-tests-el7-image
+container-unittests-el8:
+	docker rm -f oz-tests-el8
+	docker build -f Containerfile.tests.el8 -t oz-tests-el8-image .
+	docker run --name oz-tests-el8 oz-tests-el8-image
 
-container-unittests: container-unittests-fedora container-unittests-el7
+container-unittests: container-unittests-fedora container-unittests-el8
 
 test-coverage:
 	python-coverage run --source oz /usr/bin/py.test --verbose tests
@@ -72,10 +72,10 @@ flake8:
 
 container-clean:
 	docker rm -f oz-tests-fedora
-	docker rm -f oz-tests-el7
-	docker image rm -f -i oz-tests-fedora-image oz-tests-el7-image
+	docker rm -f oz-tests-el8
+	docker image rm -f -i oz-tests-fedora-image oz-tests-el8-image
 
 clean:
 	rm -rf MANIFEST build dist usr *~ oz.spec *.pyc oz/*~ oz/*.pyc examples/*~ oz/auto/*~ man/*~ docs/*~ man/*.html $(VENV_DIR) tests/tdl/*~ tests/factory/*~ tests/results.xml htmlcov
 
-.PHONY: sdist oz.spec signed-tarball signed-rpm rpm srpm deb release man2html virtualenv unittests container-unittests-fedora container-unittests-el7 container-unittests tests test-coverage pylint clean container-clean
+.PHONY: sdist oz.spec signed-tarball signed-rpm rpm srpm deb release man2html virtualenv unittests container-unittests-fedora container-unittests-el8 container-unittests tests test-coverage pylint clean container-clean