Re: [PATCH] selftests: txtimestamp: tear down setup() 'tc' and 'ip' env on EXIT

On Tue, Jul 21, 2020 at 10:52 AM Paolo Pisati paolo.pisati@canonical.com wrote:

Add a cleanup() path upon exit, making it possible to run the test twice in a row:

$ sudo bash -x ./txtimestamp.sh

• set -e

++ ip netns identify

• [[ '' == \r\o\o\t ]]
• main
• [[ 0 -eq 0 ]]
• run_test_all
• setup
• tc qdisc add dev lo root netem delay 1ms

Error: Exclusivity flag on, cannot modify.

Signed-off-by: Paolo Pisati paolo.pisati@canonical.com

The test should already clean up after itself, by being run inside a network namespace. That is a more robust method to ensure that all state is reset.

The issue here is that the else branch is taken in

if [[ "$(ip netns identify)" == "root" ]]; then ./in_netns.sh $0 $@ else main $@ fi

because the ip netns identify usually returns an empty string, not "root". If we fix that, no need to add additional cleanup.