ci: run unit & integration tests in GH Actions

The original CentOS CI infra no longer supports CentOS/RHEL 7, so let's
run the upstream tests in GH Actions in a CentOS 7 container. There are
several workarounds to make this work and some tests can't run there at
all, but it's better than nothing (and we still run the internal test
suite on RHEL 7 builds anyway).

rhel-only
Related: RHEL-61958

Author: mrc0mmand

.github/workflows/ci.yml

@@ -0,0 +1,102 @@
+---
+# vi: ts=2 sw=2 et:
+
+name: Build & test
+on:
+  pull_request:
+    branches:
+      - rhel-7.9
+
+permissions:
+  contents: read
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+  centos7:
+    runs-on: ubuntu-latest
+    container:
+      image: quay.io/centos/centos:7
+      options: "--privileged -v /dev:/dev"
+    concurrency:
+      group: ${{ github.workflow }}-${{ github.ref }}
+      cancel-in-progress: true
+    strategy:
+      fail-fast: false
+    steps:
+      - name: Configure repositories
+        run: |
+          # CentOS 7 is EOL, so we need to grab the repos from the CentOS Vault
+          sed -i 's/^mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-*
+          sed -i 's|#baseurl=http://mirror.centos.org|baseurl=https://vault.centos.org|g' /etc/yum.repos.d/CentOS-*
+          yum clean all
+          yum makecache
+
+      - name: Install build & test dependencies
+        run: |
+          yum-builddep -y systemd
+          yum install -y dhclient e2fsprogs file git kernel kbd net-tools qemu-kvm strace systemd-journal-gateway systemd-resolved xfsprogs
+
+      # We can't use the actions/checkout action, since it's no longer compatible with some _very_ old images,
+      # like CentOS 7. To circumvent this, let's make a poor man's version of the checkout action for our needs.
+      - name: Checkout the repository
+        run: |
+          set -ux
+
+          git clone "https://github.com/$GITHUB_REPOSITORY" "$GITHUB_WORKSPACE"
+          cd "$GITHUB_WORKSPACE"
+          git fetch -fu origin "refs/pull/$GITHUB_REF_NAME:pr"
+          git checkout pr
+          git log -2
+
+      - name: Build
+        run: |
+          set -x
+
+          ./autogen.sh
+          ./configure --with-sysvinit-path=/etc/rc.d/init.d \
+                      --with-rc-local-script-path-start=/etc/rc.d/rc.local \
+                      --disable-timesyncd \
+                      --disable-kdbus \
+                      --disable-terminal \
+                      --enable-gtk-doc \
+                      --enable-compat-libs \
+                      --disable-sysusers \
+                      --disable-ldconfig \
+                      --enable-lz4
+          make -j $(nproc)
+
+      - name: Run unit tests
+        run: |
+          set -ux
+
+          if ! make check; then
+            cat ./test-suite.log
+            exit 1
+          fi
+
+      - name: Run integration tests
+        run: |
+          set -ux
+
+          export QEMU_BIN=/usr/libexec/qemu-kvm
+          export QEMU_TIMEOUT=600
+          export TEST_NO_NSPAWN=1
+          export KERNEL_VER="$(rpm -q --qf '%{VERSION}-%{RELEASE}.%{ARCH}' kernel | head -n1)"
+          export KERNEL_BIN="/boot/vmlinuz-$KERNEL_VER"
+          export KERNEL_APPEND="systemd.default_standard_output=journal+console"
+          export INITRD="$PWD/test.initrd"
+
+          # Note: skip TEST-02-CRYPTSETUP here, since dealing with udev in containers is pain
+          readarray -t TESTS < <(find test/ -maxdepth 1 -name "TEST-*" ! -name "TEST-02-CRYPTSETUP" -type d | sort)
+          [[ "${#TESTS[@]}" -gt 0 ]]
+
+          dracut -v --force --kver "$KERNEL_VER" --no-hostonly "$INITRD"
+
+          for test in "${TESTS[@]}"; do
+            echo "::group::$test"
+            make -C "$test" clean setup run clean
+            echo "::endgroup::"
+          done