Implement the snapshot commands

[afbjorklund]

For making qcow2 snapshots of the running virtual machine.

It is possible to make multiple snapshots, in the diffdisk.

Closes #1051

---

limactl start

limactl snapshot create default --tag snap

limactl snapshot list default

limactl snapshot apply default --tag snap

limactl stop

limactl snapshot delete default --tag snap

[afbjorklund]

This has similar problems to the pause commands, in that the ssh mux is not too happy about the restore ?

• Implement the suspend and resume commands #642

[AkihiroSuda]

Perhaps add a comment to clarify that the result is not machine-parsable

[afbjorklund]

Good idea, I think the original API just promises a list of strings (lines).

    printf("Snapshot list:\n");
    bdrv_snapshot_dump(NULL);
    printf("\n");
    for(i = 0; i < nb_sns; i++) {
        sn = &sn_tab[i];
        bdrv_snapshot_dump(sn);
        printf("\n");
    }

[afbjorklund]

I removed the initial heading, so now it at least looks similar to limactl ls

$ limactl snapshot create --tag snap alpine
$ limactl snapshot list alpine
ID        TAG                     VM SIZE                DATE       VM CLOCK
1         snap                        0 B 2022-10-16 11:37:23   00:00:00.000

[AkihiroSuda]

Thanks, the CLI design looks good, could you update the docs and integration tests?

[afbjorklund]

Left to do is adding integration tests, for the limactl snapshot sub-commands.

[afbjorklund]

Some help with the integration tests for snapshots would be appreciated. 🙏

[AkihiroSuda]

Integration tests can be added like this

lima/hack/test-example.sh

Line 24 in 4a4cc62

["restart"]="1"

lima/hack/test-example.sh

Lines 240 to 267 in 4a4cc62

	if [[ -n ${CHECKS["restart"]} ]]; then
	INFO "Create file in the guest home directory and verify that it still exists after a restart"
	# shellcheck disable=SC2016
	limactl shell "$NAME" sh -c 'touch $HOME/sweet-home'
	INFO "Stopping \"$NAME\""
	limactl stop "$NAME"
	sleep 3
	export ftp_proxy=my.proxy:8021
	INFO "Restarting \"$NAME\""
	limactl start "$NAME"
	INFO "Make sure proxy setting is updated"
	got=$(limactl shell "$NAME" env | grep FTP_PROXY)
	expected="FTP_PROXY=my.proxy:8021"
	INFO "FTP_PROXY: expected=${expected} got=${got}"
	if [ "$got" != "$expected" ]; then
	ERROR "proxy environment variable not set to correct value"
	exit 1
	fi
	# shellcheck disable=SC2016
	if ! limactl shell "$NAME" sh -c 'test -f $HOME/sweet-home'; then
	ERROR "Guest home directory does not persist across restarts"
	exit 1
	fi
	fi

[afbjorklund]

Snapshot worked on default (and alpine, but failed on experimental/9p ?

TEST| [INFO] Testing online snapshots
time="2022-11-16T20:21:20Z" level=info msg="Sending HMP savevm command"
TEST| [INFO] snapshot list: expected=snap1 got=
Error: ERROR] snapshot list did not return expected value

Need to see if there is a better way to return errors, after running HMP/QMP...

[afbjorklund]

Now it is at least logging the real problem:
"output: Error: Migration is disabled when VirtFS export path '/tmp/lima' is mounted in the guest using mount_tag 'mount1'\r\n"

So this means that snapshots won't work with 9p mounts, while the instance is still running.

EDIT: Disabled the online tests for 9p, still running offline tests.

Trimmed off the extra whitespace, from the output.

[AkihiroSuda]

Thanks

[AkihiroSuda]

Could you rebase to rerun the CI?

[afbjorklund]

It would be nice, if the generated command help stayed out of the README....

[AkihiroSuda]

Sorry needs rebase again

[AkihiroSuda]

Thanks

[AkihiroSuda]

CI failing

+ set +x
TEST| [INFO] Testing online snapshots
time="2023-05-09T05:21:18Z" level=info msg="Sending HMP savevm command"
time="2023-05-09T05:21:26Z" level=info msg="Sending HMP info command"
TEST| [INFO] snapshot list: expected=snap1 got=snap1
time="2023-05-09T05:21:26Z" level=info msg="Sending HMP loadvm command"

Timed out!

[balajiv113]

LGTM :)

[AkihiroSuda]

CI for experimental/net-user-v2.yaml seems consistenly failing

[afbjorklund]

CI for experimental/net-user-v2.yaml seems consistenly failing

Looks like the net-user-v2 does not survive an "online" VM restore.

So it needs to be excluded.

"net-user-v2")
        CHECKS["port-forwards"]=""
        CHECKS["user-v2"]=1
        ;;

It already was, for 9p.

"9p")
        CHECKS["snapshot-online"]=""
        ;;

[AkihiroSuda]

thanks