Bug 879260

Summary: RFE: add function to to wait till a port is opened
Product: [Fedora] Fedora Reporter: Jan Vcelak <jvcelak>
Component: beakerlibAssignee: Petr Muller <pmuller>
Status: CLOSED DUPLICATE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: rawhideCC: dspurek, ohudlick, pmuller, psplicha, qa-errata-list, tsmetana
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Last Closed: 2013-06-07 11:06:46 UTC Type: Bug
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Description Jan Vcelak 2012-11-22 13:26:39 UTC 
Description of problem:

Beakerlib should provide some function to repeat a given command periodically till executed successfully or till some timeout expires.

For example: we run OpenLDAP server via valgrind on the background and need to wait till the initialization is finished (tcp/389 port is available).

"sleep" is a dummy solution, because it slows down the test on fast machines and can cause the test to fail on slow machines.

Here is a simple proposal, how it could work:

function rlTryRepeat()
{
  command=$1
  retries=${2:-30}

  for (( retry=0; retry < $retries; retry++ )); do
    $command && return 0 || sleep 1
  done
  return 1
}

function rlWaitTcpPort()
{
  port=$1
  host=${2:-localhost}
  retries=$3

  rlTryRepeat "nc -z $host $port" $retries
}

Usage:

rlRun "valgrind ... slapd ... &"
rlWaitTcpPort 389
rlRun "ldapsearch ..."

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Comment 2 Petr Muller 2013-06-07 11:06:46 UTC 

*** This bug has been marked as a duplicate of bug 970143 ***