wait-for-it

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

Installation

$ pip install wait-for-it

Demo

Usage

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:
                           'hostname:port', 'v4addr:port', '[v6addr]:port' or
                           'https://...'

Examples

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

Related

• vishnubob/wait-for-it

License

MIT © Travis Clarke, Sebastian Pipping