Wait for service(s) to be available before executing a command.
Wait for service(s) to be available before executing a command.
wait-for-it
is a script that will wait on the availability of one or more TCP services (i.e. host:port
) before executing a user-defined command.
It is useful for synchronizing the spin-up of interdependent services, such as linked docker containers.
Since v2.0.0,
wait-for-it
will return the exit code of the executed command(s).
Check out the wait-for-it docs
$ pip install wait-for-it
Usage: wait-for-it [OPTIONS] [COMMANDS]...
Wait for service(s) to be available before executing a command.
Options:
-h, --help Show this message and exit.
-v, --version Show the version and exit.
-q, --quiet Do not output any status messages
-p, --parallel Test services in parallel rather than in serial
-t, --timeout seconds Timeout in seconds, 0 for no timeout [default: 15]
-s, --service host:port Services to test, in one of the formats: ':port',
'hostname:port', 'v4addr:port', '[v6addr]:port' or
'https://...'
Test to see if we can access port 80 on www.google.com, and if it is available, echo the message google is up:
$ wait-for-it \
--service www.google.com:80 \
-- echo "google is up"
[*] Waiting 15 seconds for www.google.com:80
[+] www.google.com:80 is available after 0 seconds
google is up
You can set your own timeout with the -t
or --timeout
option. Setting the timeout value to 0 will disable the timeout:
$ wait-for-it \
--service www.google.com:80 \
--timeout 0 \
-- echo "google is up"
[*] Waiting for www.google.com:80 without a timeout
[+] www.google.com:80 is available after 0 seconds
google is up
Multiple services can be tested by adding additional -s
or --service
options:
$ wait-for-it \
--service www.google.com:80 \
--service www.bing.com:80 \
--service www.duckduckgo.com:80 \
-- echo "google, bing, and duckduckgo are up"
[*] Waiting 15 seconds for www.google.com:80
[+] www.google.com:80 is available after 0 seconds
[*] Waiting 15 seconds for www.bing.com:80
[+] www.bing.com:80 is available after 0 seconds
[*] Waiting 15 seconds for www.duckduckgo.com:80
[+] www.duckduckgo.com:80 is available after 0 seconds
google, bing, and duckduckgo are up
By adding the -p
or --parallel
option, wait-for-it
can do the same in parallel rather than serial:
$ wait-for-it \
--parallel \
--service www.google.com:80 \
--service www.bing.com:80 \
--service www.duckduckgo.com:80 \
-- echo "google, bing, and duckduckgo are up"
[*] Waiting 15 seconds for www.bing.com:80
[*] Waiting 15 seconds for www.duckduckgo.com:80
[*] Waiting 15 seconds for www.google.com:80
[+] www.bing.com:80 is available after 0 seconds
[+] www.duckduckgo.com:80 is available after 0 seconds
[+] www.google.com:80 is available after 0 seconds
google, bing, and duckduckgo are up
Status message output can be suppressed with the -q
or --quiet
option:
$ wait-for-it \
--quiet \
--service www.google.com:80 \
-- echo "google is up"
google is up
MIT © Travis Clarke, Sebastian Pipping