Docker Config Examples: Simple Usage and Windows Service

- [`docker config ls`](/reference/cli/docker/config/ls.md) - [`docker config rm`](/reference/cli/docker/config/rm.md) ## Examples This section includes graduated examples which illustrate how to use Docker configs. > [!NOTE] > > These examples use a single-engine swarm and unscaled services for > simplicity. The examples use Linux containers, but Windows containers also > support configs. ### Defining and using configs in compose files The `docker stack` command supports defining configs in a Compose file. However, the `configs` key is not supported for `docker compose`. See [the Compose file reference](/reference/compose-file/legacy-versions.md) for details. ### Simple example: Get started with configs This simple example shows how configs work in just a few commands. For a real-world example, continue to [Advanced example: Use configs with a Nginx service](#advanced-example-use-configs-with-a-nginx-service). 1. Add a config to Docker. The `docker config create` command reads standard input because the last argument, which represents the file to read the config from, is set to `-`. ```console $ echo "This is a config" | docker config create my-config - ``` 2. Create a `redis` service and grant it access to the config. By default, the container can access the config at `/my-config`, but you can customize the file name on the container using the `target` option. ```console $ docker service create --name redis --config my-config redis:alpine ``` 3. Verify that the task is running without issues using `docker service ps`. If everything is working, the output looks similar to this: ```console $ docker service ps redis ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS bkna6bpn8r1a redis.1 redis:alpine ip-172-31-46-109 Running Running 8 seconds ago ``` 4. Get the ID of the `redis` service task container using `docker ps`, so that you can use `docker container exec` to connect to the container and read the contents of the config data file, which defaults to being readable by all and has the same name as the name of the config. The first command below illustrates how to find the container ID, and the second and third commands use shell completion to do this automatically. ```console $ docker ps --filter name=redis -q 5cb1c2348a59 $ docker container exec $(docker ps --filter name=redis -q) ls -l /my-config -r--r--r-- 1 root root 12 Jun 5 20:49 my-config $ docker container exec $(docker ps --filter name=redis -q) cat /my-config This is a config ``` 5. Try removing the config. The removal fails because the `redis` service is running and has access to the config. ```console $ docker config ls ID NAME CREATED UPDATED fzwcfuqjkvo5foqu7ts7ls578 hello 31 minutes ago 31 minutes ago $ docker config rm my-config Error response from daemon: rpc error: code = 3 desc = config 'my-config' is in use by the following service: redis ``` 6. Remove access to the config from the running `redis` service by updating the service. ```console $ docker service update --config-rm my-config redis ``` 7. Repeat steps 3 and 4 again, verifying that the service no longer has access to the config. The container ID is different, because the `service update` command redeploys the service. ```none $ docker container exec -it $(docker ps --filter name=redis -q) cat /my-config cat: can't open '/my-config': No such file or directory ``` 8. Stop and remove the service, and remove the config from Docker. ```console $ docker service rm redis $ docker config rm my-config ``` ### Simple example: Use configs in a Windows service This is a very simple example which shows how to use configs with a Microsoft

This section provides practical examples of Docker configs, including defining them in compose files (supported by `docker stack` but not `docker compose`), a basic example to demonstrate config usage, and a simple example using configs in a Windows service. The basic example walks through adding a config, creating a Redis service with access to it, verifying the service is running, checking the config data within the container, attempting and failing to remove the config while the service is running, removing config access from the service, and finally removing the service and config. It also includes commands for listing configs and removing them, and verifies the service no longer has access to the config after the update.