Re: [RFC 4/7] selftests: openvswitch: delete previously allocated netns

[Paolo Abeni <pabeni@redhat.com>]

On Fri, 2024-02-16 at 10:28 -0500, Aaron Conole wrote:
> Many openvswitch test cases reused netns and interface names.  This works
> fine as long as the test case cleans up gracefully.  However, if there is
> some kind of ungraceful termination (such as an external signal) the netns
> or interfaces can be left lingering.  

It looks the openvswitch.sh test script is already trying quite hard to
delete the allocated resources on ungraceful termination via "trap...".

That is usually enough for other self-tests, could you please detail
when it fails here?

> This happens when the selftest
> timeout gets exceeded, while running under very slow debugging conditions.

'timeout' should send SIG_TERM, and the script already handle that
gracefully?

> The solution here is to cleanup the netns on executing the next test.

I suggest avoiding this, it could end up killing innocent alias netns.

You could consider using the 'setup_ns' helper from the
tools/testing/selftests/net/lib.sh library to always generate unique
netns names.

> Signed-off-by: Aaron Conole <aconole@redhat.com>
> ---
>  tools/testing/selftests/net/openvswitch/openvswitch.sh | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/tools/testing/selftests/net/openvswitch/openvswitch.sh b/tools/testing/selftests/net/openvswitch/openvswitch.sh
> index 678a72ad47c1..8dc315585710 100755
> --- a/tools/testing/selftests/net/openvswitch/openvswitch.sh
> +++ b/tools/testing/selftests/net/openvswitch/openvswitch.sh
> @@ -115,6 +115,10 @@ ovs_netns_spawn_daemon() {
>  
>  ovs_add_netns_and_veths () {
>  	info "Adding netns attached: sbx:$1 dp:$2 {$3, $4, $5}"
> +	ntns_e=`ip netns list | grep $3`
> +	[ "$ntns_e" != "" ] && ip netns del "$3"
> +	if4_e=`ip link show $4 2>/dev/null`

Minor unrelated note: $() is preferable to `` for sub-shells, as it's
more friendly to nesting, string expansing, quotes, etc.


Cheers,

Paolo