docker stack config
Description | Outputs the final config file, after doing merges and interpolations |
---|---|
Usage | docker stack config [OPTIONS] |
Swarm This command works with the Swarm orchestrator.
Description
Outputs the final Compose file, after doing the merges and interpolations of the input Compose files.
Options
Option | Default | Description |
---|---|---|
-c, --compose-file | Path to a Compose file, or - to read from stdin | |
--skip-interpolation | Skip interpolation and output only merged config |
Examples
The following command outputs the result of the merge and interpolation of two Compose files.
$ docker stack config --compose-file docker-compose.yml --compose-file docker-compose.prod.yml
The Compose file can also be provided as standard input with --compose-file -
:
$ cat docker-compose.yml | docker stack config --compose-file -
Skipping interpolation
In some cases, it might be useful to skip interpolation of environment variables.
For example, when you want to pipe the output of this command back to stack deploy
.
If you have a regex for a redirect route in an environment variable for your webserver you would use two $
signs to prevent stack deploy
from interpolating ${1}
.
service: webserver
environment:
REDIRECT_REGEX=http://host/redirect/$${1}
With interpolation, the stack config
command will replace the environment variable in the Compose file
with REDIRECT_REGEX=http://host/redirect/${1}
, but then when piping it back to the stack deploy
command it will be interpolated again and result in undefined behavior.
That is why, when piping the output back to stack deploy
one should always prefer the --skip-interpolation
option.
$ docker stack config --compose-file web.yml --compose-file web.prod.yml --skip-interpolation | docker stack deploy --compose-file -