System tests: new checkpoint tests

Includes a test for the stdout-goes-away bug (crun #756).

Skip on Ubuntu due to a many-months-old kernel bug that
keeps getting fixed and then un-fixed.

Signed-off-by: Ed Santiago <[email protected]>

test/system/520-checkpoint.bats

@@ -0,0 +1,175 @@
+#!/usr/bin/env bats   -*- bats -*-
+#
+# test podman checkpoint. Similar in many ways to our pause tests.
+#
+
+load helpers
+
+CHECKED_ROOTLESS=
+function setup() {
+    # FIXME: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1857257
+    # TL;DR they keep fixing it then breaking it again. There's a test we
+    # could run to see if it's fixed, but it's way too complicated. Since
+    # integration tests also skip checkpoint tests on Ubuntu, do the same here.
+    if grep -qiw ubuntu /etc/os-release; then
+        skip "FIXME: checkpointing broken in Ubuntu 2004, 2104, 2110, ..."
+    fi
+
+    # None of these tests work rootless....
+    if is_rootless; then
+        # ...however, is that a genuine cast-in-stone limitation, or one
+        # that can some day be fixed? If one day some PR removes that
+        # restriction, fail loudly here, so the developer can enable tests.
+        if [[ -n "$CHECKED_ROOTLESS" ]]; then
+            run_podman '?' container checkpoint -l
+            is "$output" "Error: checkpointing a container requires root" \
+               "Confirming that rootless checkpoint doesn't work. If that changed, please reexamine this test file!"
+            CHECKED_ROOTLESS=y
+        fi
+        skip "checkpoint does not work rootless"
+    fi
+
+    basic_setup
+}
+
+function teardown() {
+    run_podman '?' volume rm myvol
+
+    basic_teardown
+}
+
+@test "podman checkpoint - basic test" {
+    run_podman run -d $IMAGE sh -c 'while :;do cat /proc/uptime; sleep 0.1;done'
+    local cid="$output"
+
+    # Wait for container to start emitting output
+    wait_for_output '[1-9]\+' $cid
+
+    # Checkpoint, and confirm via inspect
+    run_podman container checkpoint $cid
+    is "$output" "$cid" "podman container checkpoint"
+
+    run_podman container inspect \
+               --format '{{.State.Status}}:{{.State.Running}}:{{.State.Paused}}:{{.State.Checkpointed}}' $cid
+    is "$output" "exited:false:false:true" "State. Status:Running:Pause:Checkpointed"
+
+    # Plan A was to do something similar to 080-pause.bats: sleep for long
+    # enough to cause a gap in the timestamps in the log. But checkpoint
+    # doesn't seem to work like that: upon restore, even if we sleep a long
+    # time, the newly-started container seems to pick back up close to
+    # where it left off. (Maybe it's something about /proc/uptime?)
+    # Anyway, scratch Plan A. Plan B is simply to make sure that the
+    # restarted container spits something out.
+    run_podman logs $cid
+    local nlines_before="${#lines[*]}"
+
+    # Restart immediately and confirm state
+    run_podman container restore $cid
+    is "$output" "$cid" "podman container restore"
+
+    # Note that upon restore, .Checkpointed reverts to false (#12117)
+    run_podman container inspect \
+               --format '{{.State.Status}}:{{.State.Running}}:{{.State.Paused}}:{{.State.Checkpointed}}' $cid
+    is "$output" "running:true:false:false" \
+       "State. Status:Running:Pause:Checkpointed"
+
+    # Pause briefly to let restarted container emit some output
+    sleep 0.3
+
+    # Get full logs, and make sure something changed
+    run_podman logs $cid
+    local nlines_after="${#lines[*]}"
+    if [[ $nlines_after -eq $nlines_before ]]; then
+        die "Container failed to output new lines after first restore"
+    fi
+
+    # Same thing again: test for https://github.com/containers/crun/issues/756
+    # in which, after second checkpoint/restore, we lose logs
+    run_podman container checkpoint $cid
+    run_podman container logs $cid
+    nlines_before="${#lines[*]}"
+    run_podman container restore $cid
+
+    # Give container time to write new output; then confirm that something
+    # was emitted
+    sleep 0.3
+    run_podman container logs $cid
+    nlines_after="${#lines[*]}"
+    if [[ $nlines_after -eq $nlines_before ]]; then
+        die "stdout went away after second restore (crun issue 756)"
+    fi
+
+    run_podman rm -t 0 -f $cid
+}
+
+
+@test "podman checkpoint --export, with volumes" {
+    skip_if_remote "Test uses --root/--runroot, which are N/A over remote"
+
+    # Create a root in tempdir. We will run a container here.
+    local p_root=${PODMAN_TMPDIR}/testroot/root
+    local p_runroot=${PODMAN_TMPDIR}/testroot/runroot
+    mkdir -p $p_root $p_runroot
+
+    # To avoid network pull, copy $IMAGE straight to temp root
+    local p_opts="--root $p_root --runroot $p_runroot --events-backend file"
+    run_podman         save -o $PODMAN_TMPDIR/image.tar $IMAGE
+    run_podman $p_opts load -i $PODMAN_TMPDIR/image.tar
+
+    # Create a volume, find unused network port, and create a webserv container
+    run_podman $p_opts volume create myvol
+    local cname=c_$(random_string 10)
+    local host_port=$(random_free_port)
+    local server=http://127.0.0.1:$host_port
+
+    run_podman $p_opts run -d --name $cname --volume myvol:/myvol \
+               -p $host_port:80 \
+               -w /myvol \
+               $IMAGE sh -c "/bin/busybox-extras httpd -p 80;echo $cname >cname;echo READY;while :;do cat /proc/uptime >mydate.tmp;mv -f mydate.tmp mydate;sleep 0.1;done"
+    local cid="$output"
+    _PODMAN_TEST_OPTS="$p_opts" wait_for_ready $cid
+
+    # Confirm that container responds
+    run curl --max-time 3 -s $server/cname
+    is "$output" "$cname" "curl $server/cname"
+    run curl --max-time 3 -s $server/mydate
+    local date_oldroot="$output"
+
+    # Checkpoint...
+    run_podman $p_opts container checkpoint \
+               --ignore-rootfs \
+               --export=$PODMAN_TMPDIR/$cname.tar.gz \
+               $cname
+
+    # ...confirm that port is now closed
+    run curl --max-time 1 -s $server/mydate
+    is "$status" "7" "cannot connect to port $host_port while container is down"
+
+    # ...now restore it to our regular root
+    run_podman container restore --import=$PODMAN_TMPDIR/$cname.tar.gz
+    is "$output" "$cid"
+
+    # Inspect (on regular root). Note that, unlike the basic test above,
+    # .State.Checkpointed here is *false*.
+    run_podman container inspect \
+               --format '{{.State.Status}}:{{.State.Running}}:{{.State.Paused}}:{{.State.Checkpointed}}' $cname
+    is "$output" "running:true:false:false" "State. Status:Running:Pause:Checkpointed"
+
+    # Pause a moment to let the restarted container update the timestamp file
+    sleep .3
+    run curl --max-time 3 -s $server/mydate
+    local date_newroot="$output"
+    if [[ $date_newroot = $date_oldroot ]]; then
+        die "Restored container did not update the timestamp file"
+    fi
+
+    run_podman exec $cid cat /myvol/cname
+    is "$output" "$cname" "volume transferred fine"
+
+    run_podman rm -t 0 -f $cid
+    run_podman volume rm -f myvol
+}
+
+# FIXME: test --leave-running
+
+# vim: filetype=sh