A tool to wait for services and execute command. Useful for Docker containers that depend on slow to start services (like almost everything).
- Free software: BSD 2-Clause License
Currently holdup is only published to PyPI and hub.docker.com.
To install from PyPI:
pip install holdup
It has no dependencies except the optional PostgreSQL check support, which you'd install with:
pip install 'holdup[pg]'
You can also install the in-development version with:
pip install https://github.com/ionelmc/python-holdup/archive/master.zip
Alternate installation (Docker image)
docker run --rm ionelmc/holdup tcp://foobar:1234
Note that this will have some limitations:
- executing the
commandis pretty pointless because holdup will run in its own container
- you'll probably need extra network configuration to be able to access services
- you won't be able to use docker run inside a container without exposing a docker daemon in said container
usage: holdup [-h] [-t SECONDS] [-T SECONDS] [-i SECONDS] [-n] service [service ...] [-- command [arg [arg ...]]]
Wait for services to be ready and optionally exec command.
- positional arguments:
- A service to wait for. Supported protocols: "tcp://host:port/", "path:///path/to/something", "unix:///path/to/domain.sock", "eval://expr", "pg://user:password@host:port/dbname" ("postgres" and "postgresql" also allowed), "http://urn", "https://urn", "https+insecure://urn" (status 200 expected for http*). Join protocols with a comma to make holdup exit at the first passing one, eg: "tcp://host:1,host:2" or "tcp://host:1,tcp://host:2" are equivalent and mean any that pass.
- An optional command to exec.
- optional arguments:
-h, --help show this help message and exit -t SECONDS, --timeout SECONDS Time to wait for services to be ready. Default: 60.0 -T SECONDS, --check-timeout SECONDS Time to wait for a single check. Default: 1.0 -i SECONDS, --interval SECONDS How often to check. Default: 0.2 -v, --verbose Verbose mode. --verbose-passwords Disable PostgreSQL/HTTP password masking. -n, --no-abort Ignore failed services. This makes holdup return 0 exit code regardless of services actually responding. --insecure Disable SSL Certificate verification for HTTPS services. --version display the version of the holdup package and its location, then exit.
holdup tcp://foobar:1234 -- django-admin ...
To run all the tests run:
Note, to combine the coverage data from all the tox environments run:
set PYTEST_ADDOPTS=--cov-append tox