move dcgoss into its own directory and add a readme

Signed-off-by: Felix Bartels <[email protected]>

extras/dcgoss/README.md

@@ -0,0 +1,66 @@
+# dcgoss
+
+dcgoss is a convenience wrapper around goss that aims to bring the simplicity of goss to docker-compose managed containers. It is based on `dgoss`.
+
+## Usage
+
+`dgoss [run|edit] <docker_run_params>`
+
+
+### Run
+
+Run is used to validate a docker container defined in `docker-compose.yml`. It expects both a `docker-compose.yml` and `goss.yaml` file to exist in the directory it was invoked from. Container configuration is used from the compose file, for example:
+
+**run:**
+
+`docker-compose up db`
+
+**test:**
+
+`dcgoss run db`
+
+`dcgoss run` will do the following:
+* Start the container as defined in `docker-compose.yml`
+* Stream the containers log output into the container as `/goss/docker_output.log`
+  * This allows writing tests or waits against the docker output
+* (optional) Run `goss` with `$GOSS_WAIT_OPTS` if `./goss_wait.yaml` file exists in the current dir
+* Run `goss` with `$GOSS_OPTS` using `./goss.yaml`
+
+
+### Edit
+
+Edit will launch a docker container, install goss, and drop the user into an interactive shell. Once the user quits the interactive shell, any `goss.yaml` or `goss_wait.yaml` are copied out into the current directory. This allows the user to leverage the `goss add|autoadd` commands to write tests as they would on a regular machine.
+
+**Example:**
+
+`dcgoss db`
+
+### Environment vars and defaults
+The following environment variables can be set to change the behavior of dgoss.
+
+##### GOSS_PATH
+Location of the goss binary to use. (Default: `$(which goss)`)
+
+##### GOSS_OPTS
+Options to use for the goss test run. (Default: `--color --format documentation`)
+
+##### GOSS_WAIT_OPTS
+Options to use for the goss wait run, when `./goss_wait.yaml` exists. (Default: `-r 30s -s 1s > /dev/null`)
+
+##### GOSS_SLEEP
+Time to sleep after running container (and optionally `goss_wait.yaml`) and before running tests. (Default: `0.2`)
+
+##### GOSS_FILES_PATH
+Location of the goss yaml files. (Default: `.`)
+
+##### GOSS_VARS
+The name of the variables file relative to `GOSS_FILES_PATH` to copy into the
+docker container and use for valiation (i.e. `dgoss run`) and copy out of the
+docker container when writing tests (i.e. `dgoss edit`). If set, the
+`--vars` flag is passed to `goss validate` commands inside the container.
+If unset (or empty), the `--vars` flag is omitted, which is the normal behavior.
+(Default: `''`).
+
+##### GOSS_FILES_STRATEGY
+Strategy used for copying goss files into the docker container. If set to `'mount'` a volume with goss files is mounted and log output is streamed into the container as `/goss/docker_output.log` file. Other strategy is `'cp'` which uses `'docker cp'` command to copy goss files into docker container. With the `'cp'` strategy you lose the ability to write tests or waits against the docker output. The `'cp'` strategy is required especially when docker daemon is not on the local machine. 
+(Default `'mount'`)