Add CI test shards with the data directory on SMB and NFS shares

Adds 'smb' and 'nfs' entries to the test matrix that run the DB and
file test suites with the test data directory on a loopback CIFS or
NFS mount, covering the network-filesystem database handling from
bba85a3939. The test harness places the data directory under TMPDIR,
so connection initialization itself runs against the share, which is
where network-filesystem failures (startup crashes and hangs) occur.
The step timeout turns a startup hang into a failure.

(cherry picked from commit 18f6fa50d5)

.github/workflows/ci.yml

@@ -5,7 +5,7 @@ concurrency:
   cancel-in-progress: true
 jobs:
   test:
-    name: Test (shard ${{ matrix.shard }})
+    name: Test (${{ matrix.shard }})
     runs-on: ubuntu-latest
     # Same-repo PRs are covered by the push run, so run pull_request jobs only for forks
     if: >
@@ -13,7 +13,11 @@ jobs:
       || github.event.pull_request.head.repo.full_name != github.repository
     strategy:
       matrix:
-        shard: [1, 2, 3, 4]
+        # Numbered shards split the full suite. 'smb' and 'nfs' run the db and file tests
+        # with the test data directory on a loopback CIFS or NFS mount, so that connection
+        # initialization itself runs against a network filesystem, which is where
+        # network-filesystem failures (startup crashes and hangs) occur.
+        shard: ['1', '2', '3', '4', 'smb', 'nfs']
     steps:
       - uses: actions/checkout@v4
         with:
@@ -81,8 +85,41 @@ jobs:
           cd build
           unzip ../build.zip
 
+      - name: Set up SMB share
+        if: matrix.shard == 'smb'
+        run: |
+          sudo apt install -y --no-install-recommends samba cifs-utils
+          sudo mkdir -p /srv/zotero-smb /mnt/zotero-smb
+          sudo chown $(whoami) /srv/zotero-smb
+          sudo tee -a /etc/samba/smb.conf > /dev/null <<EOF
+          [ztest]
+          path = /srv/zotero-smb
+          read only = no
+          EOF
+          (echo smbtestpass; echo smbtestpass) | sudo smbpasswd -s -a $(whoami)
+          sudo systemctl restart smbd
+          sudo mount -t cifs //127.0.0.1/ztest /mnt/zotero-smb \
+            -o user=$(whoami),pass=smbtestpass,vers=3.0,uid=$(id -u),gid=$(id -g)
+
+      - name: Set up NFS share
+        if: matrix.shard == 'nfs'
+        run: |
+          sudo apt install -y --no-install-recommends nfs-kernel-server
+          sudo mkdir -p /srv/zotero-nfs /mnt/zotero-nfs
+          sudo chown $(whoami) /srv/zotero-nfs
+          echo "/srv/zotero-nfs localhost(rw,no_subtree_check,insecure)" | sudo tee -a /etc/exports
+          sudo exportfs -ra
+          sudo mount -t nfs4 localhost:/srv/zotero-nfs /mnt/zotero-nfs
+
       - name: Run tests
-        run: xvfb-run test/runtests.sh -f -r 3 -p ${{ matrix.shard }}/${{ strategy.job-total }}
+        if: matrix.shard != 'smb' && matrix.shard != 'nfs'
+        run: xvfb-run test/runtests.sh -f -r 3 -p ${{ matrix.shard }}/4
+
+      # The step timeout turns a startup hang into a failure
+      - name: Run tests on network share
+        if: matrix.shard == 'smb' || matrix.shard == 'nfs'
+        timeout-minutes: 20
+        run: TMPDIR=/mnt/zotero-${{ matrix.shard }} xvfb-run test/runtests.sh -f -r 3 -b db file
 
   utilities:
     name: Utilities Tests