CI tests: enforce TMPDIR on tmpfs

First, setup a custom TMPDIR to ensure we have no special assumptions
about hard coded paths. Second, make sure it is actually on a tmpfs so
we can catch regressions in the VM setup immediately.

Signed-off-by: Paul Holzinger <[email protected]>

.cirrus.yml

@@ -111,8 +111,6 @@ build_task:
  CI_DESIRED_RUNTIME: crun
  CI_DESIRED_DATABASE: boltdb
  CI_DESIRED_STORAGE: vfs
- # Catch invalid "TMPDIR == /tmp" assumptions; PR #19281
- TMPDIR: /var/tmp
  - env:
  <<: *stdenvars
  DISTRO_NV: ${RAWHIDE_NAME}

contrib/cirrus/runner.sh

@@ -144,6 +144,7 @@ exec_container() {
  # shellcheck disable=SC2154
  exec bin/podman run --rm --privileged --net=host --cgroupns=host \
  -v `mktemp -d -p /var/tmp`:/var/tmp:Z \
+ --tmpfs /tmp:mode=1777 \
  -v /dev/fuse:/dev/fuse \
  -v "$GOPATH:$GOPATH:Z" \
  --workdir "$GOSRC" \
@@ -407,8 +408,21 @@ dotest() {
  die "Found fallback podman '$fallback_podman' in \$PATH; tests require none, as a guarantee that we're testing the right binary."
  fi
 
+ # Catch invalid "TMPDIR == /tmp" assumptions; PR #19281
+ TMPDIR=$(mktemp --tmpdir -d CI_XXXX)
+ # tmp dir is commonly 1777 to allow all user to read/write
+ chmod 1777 $TMPDIR
+ export TMPDIR
+ fstype=$(findmnt -n -o FSTYPE --target $TMPDIR)
+ if [[ "$fstype" != "tmpfs" ]]; then
+ die "The CI test TMPDIR is not on a tmpfs mount, we need tmpfs to make the tests faster"
+ fi
+
  showrun make ${localremote}${testsuite} PODMAN_SERVER_LOG=$PODMAN_SERVER_LOG \
  |& logformatter
+
+ rm -rf $TMPDIR
+ unset TMPDIR
 }
 
 _run_machine-linux() {