How to create a loop in bash that is waiting for a webserver to respond?
The poster asks a specific question about printing .
, but I think most people coming here are looking for the solution below, as it is a single command that supports finite retries.
curl --head -X GET --retry 5 --retry-connrefused --retry-delay 1 http://myhost:myport
httping is nice for this. simple, clean, quiet.
while ! httping -qc1 http://myhost:myport ; do sleep 1 ; done
while/until etc is a personal pref.
I wanted to limit the maximum number of attempts. Based on Thomas's accepted answer I made this:
attempt_counter=0
max_attempts=5
until $(curl --output /dev/null --silent --head --fail http://myhost:myport); do
if [ ${attempt_counter} -eq ${max_attempts} ];then
echo "Max attempts reached"
exit 1
fi
printf '.'
attempt_counter=$(($attempt_counter+1))
sleep 5
done
Combining the question with chepner's answer, this worked for me:
until $(curl --output /dev/null --silent --head --fail http://myhost:myport); do
printf '.'
sleep 5
done