add docker documentation

Dockerfile

@@ -22,7 +22,7 @@ RUN apt update && \
     rm -rf /var/lib/apt/lists/*
 ENV ORGANIZE_CONFIG=/config/config.yml \
     ORGANIZE_EXIFTOOL_PATH=exiftool
-RUN mkdir /config && touch ./README.md
+RUN mkdir /config && mkdir /data
 COPY --from=pydeps ${VIRTUAL_ENV} ${VIRTUAL_ENV}
 COPY ./organize ./organize
 

docker-conf.yml

@@ -0,0 +1,4 @@
+rules:
+  - locations: /data
+    actions:
+      - echo: "Found file: {path}"

docs/docker.md

@@ -0,0 +1,52 @@
+# Using the organize docker image
+
+The organize docker image comes preinstalled with `exiftool` and `pdftotext` as well as
+all the python dependencies set up and ready to go.
+
+!!! note
+
+    As organize is mainly used for moving files around you have to be careful about your
+    volume mounts and paths. If you move a file to a folder which is not persisted
+    it is gone as soon as the container is stopped!
+
+## Building the image
+
+`cd` into the organize folder (containing `Dockerfile`) and build the image:
+
+```sh
+docker build -t organize .
+```
+
+The image is now tagged as `organize`. Now you can test the image by running
+
+```sh
+docker run --rm organize
+```
+
+This will show the organize usage help text.
+
+## Running
+
+Let's create a basic config file `docker-conf.yml`:
+
+```yml
+rules:
+  - locations: /data
+    actions:
+      - echo: "Found file: {path}"
+```
+
+We can now run mount the config file to the container path `/config/config.yml`. The current directory is mounted to `/data` so we have some files present.
+We can now start the container:
+
+```sh
+docker run --rm -v ./docker-conf.yml:/config/config.yml -v .:/data organize run
+```
+
+### Passing the config file from stdin
+
+Instead of mounting the config file into the container you can also pass it from stdin:
+
+```sh
+docker run -i --rm organize check --stdin < ./docker-conf.yml
+```

mkdocs.yml

@@ -9,6 +9,7 @@ nav:
   - Locations: locations.md
   - Filters: filters.md
   - Actions: actions.md
+  - Docker: docker.md
   - Changelog: changelog.md
   - Migrating from older versions: migrating.md
 plugins:

organize/config.py

@@ -64,6 +64,8 @@ def from_string(cls, config: str, config_path: Optional[Path] = None) -> Config:
         dedented = textwrap.dedent(normalized)
         as_dict = yaml.load(dedented, Loader=yaml.SafeLoader)
         try:
+            if not as_dict:
+                raise ValueError("Config is empty")
             inst = cls(**as_dict)
             inst._config_path = config_path
             return inst