lkl: timeout dhcp request ealier if not available

[thehajime]

Signed-off-by: Hajime Tazaki thehajime@gmail.com

---

This change is 

[thehajime]

This should fix #285.
it sets hard-coded 5-second timeout which I'm not sure this is sufficient or not, but at least circleci looks like fine.

Cc: @liuyuan10

[liuyuan10]

I don't know how it works. If killall doesn't find net-test, it still return 1 which is considered a failure by the script?

[thehajime]

if kilall doesn't find, it return 0, keep quiet (-q) and goto next
if killall finds, return 1 and report via echo ..., but no error.

hmm, there is no chance to report an error with dhcp test now..
if there were a way to predict that dhcp works, this check can be expanded but dunno how.

[tavip]

Maybe we should use an env variable to specificy if DHCP test should run? Then we can set it in those environments where we know it runs.

[thehajime]

ah, that's a good idea.
maybe we can introduce LKL_TEST_DHCP for circleci environment, then timeout should not be needed.

will resubmit a patch.

[liuyuan10]

Just curious, killall -q xxx || echo $? prints 1 instead of 0 on my desktop. So killall -q xxx && echo "hello" won't print but is an error. What am I missing here?

[thehajime]

All your results make sense to me.

Just curious, killall -q xxx || echo $?

This is an OR condition. The 2nd statement is not evaluated if the 1st one is true.

killall -q xxx && echo "hello"

This is an AND condition. The 2nd statement is not evaluated if the 1st one is false.

in those case, (return value = 0) is true while (return value !=0) is false (this is a bit complicated part to me).

• killall(1)

killall returns a zero return code if at least one process has been killed for each listed command, or no commands were listed and at least one process matched the -u and -Z search criteria.  killall returns non-zero otherwise.

[liuyuan10]

You explanation is correct. That's why I'm wondering how the "sudo killall -q net-test && (echo "killed, skipped")" can work. It seems to me just work in the opposite way. If net-test is not there, killall returns 1 and the test will fail.

…

On Tue, Feb 14, 2017 at 3:26 PM, Hajime Tazaki ***@***.***> wrote: All your results make sense to me. Just curious, killall -q xxx || echo $? This is an OR condition. The 2nd statement is not evaluated if the 1st one is true. killall -q xxx && echo "hello" This is an AND condition. The 2nd statement is not evaluated if the 1st one is false. in those case, (return value = 0) is true while (return value !=0) is false (this is a bit complicated part to me). - killall(1) killall returns a zero return code if at least one process has been killed for each listed command, or no commands were listed and at least one process matched the -u and -Z search criteria. killall returns non-zero otherwise. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#324 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AEVfUvpoBiScbH3xfOQOYKmXPJrStLaeks5rcjgcgaJpZM4MACpY> .

[thehajime]

@liuyuan10 your curious is right.

in short, there was an error.

my intention of the original patch (now diminished) was

• ignore net-test result with text report if there is not DHCP server (the test should be PASS)
• pass if DHCP server is available (the test should be PASS)

so I didn't intended to report an error after this test.

OTOH, the circleci test passed my patch with the above 2nd case with the Exit code 0 (no error) so I was thinking that the above cases were working fine.
https://circleci.com/gh/libos-nuse/lkl-linux/501

the statement sudo killall -q net-test && (echo "killed, skipped") in above 501 test surely returns 1 (error), but the script (net.sh) didn't exit and keep going to next steps.

it looks like there was something odd.

if I changed my patch like below, it will report an error.

diff --git a/tools/lkl/tests/net.sh b/tools/lkl/tests/net.sh
index 896f9c0..bc7497d 100755
--- a/tools/lkl/tests/net.sh
+++ b/tools/lkl/tests/net.sh
@@ -45,7 +45,7 @@ if ! [ -z $DST ]; then
     sudo ip link set dev ${IFNAME} promisc on
     sudo ./net-test raw ${IFNAME} ${DST} dhcp &
     sleep 5
-    sudo killall -q net-test && (echo "killed, skipped")
+    (sudo killall -q net-test && (echo "killed, skipped"))
     sudo ip link set dev ${IFNAME} promisc off
 
     echo "== macvtap (LKL net) tests =="

so, again, you caught a good point.