Wait for HTTP endpoints to return 200 OK with bash, curl and timeout

wait_for_http_200.sh

#!/bin/bash

##############################################################################################
# Wait for URLs until return HTTP 200
#
# - Just pass as many urls as required to the script - the script will wait for each, one by one
#
# Example: ./wait_for_urls.sh "${MY_VARIABLE}" "http://192.168.56.101:8080"
##############################################################################################

wait-for-url() {
    echo "Testing: $1"
    timeout --foreground -s TERM 30s bash -c \
        'while [[ "$(curl -s -o /dev/null -m 3 -L -w ''%{http_code}'' ${0})" != "200" ]];\
        do echo "Waiting for ${0}" && sleep 2;\
        done' ${1}
    local TIMEOUT_RETURN="$?"
    if [[ "${TIMEOUT_RETURN}" == 0 ]]; then
        echo "OK: ${1}"
        return
    elif [[ "${TIMEOUT_RETURN}" == 124 ]]; then
        echo "TIMEOUT: ${1} -> EXIT"
        exit "${TIMEOUT_RETURN}"
    else
        echo "Other error with code ${TIMEOUT_RETURN}: ${1} -> EXIT"
        exit "${TIMEOUT_RETURN}"
    fi
}

echo "Wait for URLs: $@"

for var in "$@"; do
    echo ""
    wait-for-url "$var"
done

echo ""
echo "SUCCESSFUL"

Output is:

For successful run:

Wait for URLs: http://google.de http://google.de

Testing: http://google.de
OK: http://google.de

Testing: http://google.de
OK: http://google.de

SUCCESSFUL

For timeout run:

Wait for URLs: http://google.de http://googleeeeee.de http://google.de

Testing: http://google.de
OK: http://google.de

Testing: http://googleeeeee.de
Waiting for http://googleeeeee.de
Waiting for http://googleeeeee.de
Waiting for http://googleeeeee.de
Waiting for http://googleeeeee.de
Waiting for http://googleeeeee.de
Waiting for http://googleeeeee.de
Waiting for http://googleeeeee.de
Waiting for http://googleeeeee.de
Waiting for http://googleeeeee.de
Waiting for http://googleeeeee.de
Waiting for http://googleeeeee.de
Waiting for http://googleeeeee.de
Waiting for http://googleeeeee.de
Waiting for http://googleeeeee.de
Waiting for http://googleeeeee.de
TIMEOUT: http://googleeeeee.de -> EXIT

Your shebang is wrong ;)
Should be #!/bin/bash or #!/usr/bin/env bash

This script doesn't seem to work properly. If the cURL never succeeds and it times out it still outputs OK!. It should exit 1 if the timeout hits its limit.

@tjcdeveloper I fork this script and just added a timeout check - is error code 124.
https://gist.github.com/p0z/3894d69f90141a463f790db6da8f6547

Your shebang is wrong ;) Should be #!/bin/bash or #!/usr/bin/env bash

Ty, I added it

This script doesn't seem to work properly. If the cURL never succeeds and it times out it still outputs OK!. It should exit 1 if the timeout hits its limit.
Ty, I added a result handling

@tjcdeveloper I fork this script and just added a timeout check - is error code 124. https://gist.github.com/p0z/3894d69f90141a463f790db6da8f6547

Thank you for the idea - just keep in mind that now each return code except of 124 will return OK

Thank you for the idea - just keep in mind that now each return code except of 124 will return OK

Yes, you are right. In fact only interested the response code 0, all other codes is error.

TIMEOUT_RETURN="$?"
if [[ "$TIMEOUT_RETURN" == 0 ]]; then
  echo -e "\n[+] ${1} - 200 OK"
else
  echo -e "\n[-] ${1} - timeout or other error! [$TIMEOUT_RETURN]"
fi