Merge pull request #1 from nvtkaszpir/fix-dependencies

Fix issues with standalone run (dependencies), update readme.

.gitignore

+.venv/
+*.pyc

README.md

 # clean_registry
 Clean the Docker Registry by removing untagged repositories and running the garbage collector in Docker Registry >= 2.4.0
 
-The optional `-x` flag may be used to remove the specified repositories or tagged images.
+The optional ``-x`` flag may be used to remove the specified repositories or tagged images.
 
-NOTES:
-  - This script stops the Registry container during cleanup to prevent corruption, making it temporarily unavailable to clients.
-  - This script assumes the [filesystem](https://github.com/docker/distribution/blob/master/docs/configuration.md#storage) storage driver.
-  - This script may run stand-alone (on local setups) or dockerized (which supports both local and remote Docker setups). To run stand-alone, you must install **docker-py** and **pyyaml** with:
-  
-  `pip3 install docker pyyaml`
-  
-## Usage:
+# WARNING:
+
+Make backups of target docker-registry/containers/tags to avoid loosing data.
+
+This script stops the Registry container during cleanup to prevent corruption, making it temporarily unavailable to clients.
+
+This script assumes the [filesystem](https://github.com/docker/distribution/blob/master/docs/configuration.md#storage) storage driver.
+
+## Running standalone
+
+This script may be run as stand-alone (on local setups) or dockerized (which supports both local and remote Docker setups). To run stand-alone, the best is to run in virtualenv and install required packages via pip:
+
+```bash
+virtualenv --python=python3 .venv
+. .venv/bin/activate
+pip3 install --upgrade pip
+pip3 install -r requirements.txt
+```
+
+You may need to execute above commands as privileged user to access docker service (sudo + activate virtualenv).
+
+## Usage
 
 ```
 clean_registry.py [OPTIONS] CONTAINER [REPOSITORY[:TAG]]...
 Options:
         -x, --remove    Remove the specified images or repositories.
-        -q, --quiet     Supress non-error messages.
+        -q, --quiet     Suppress non-error messages.
         -V, --version   Show version and exit.
 ```
 
 ## Docker usage with local Docker setup
 
-`docker run --rm --volumes-from CONTAINER -v /var/run/docker.sock:/var/run/docker.sock ricardobranco/clean_registry [OPTIONS] CONTAINER [REPOSITORY[:TAG]]...`
+```bash
+docker run --rm --volumes-from CONTAINER -v /var/run/docker.sock:/var/run/docker.sock ricardobranco/clean_registry [OPTIONS] CONTAINER [REPOSITORY[:TAG]] ...
+```
+
+## Docker usage with remote Docker setup
+
+Make sure to read about [remote Docker setup](https://docs.docker.com/engine/security/https/#secure-by-default).
 
-## Docker usage with [remote Docker setup](https://docs.docker.com/engine/security/https/#secure-by-default)
+```bash
+docker run --rm --volumes-from CONTAINER -e DOCKER_HOST -e DOCKER_TLS_VERIFY=1 -v /root/.docker:/root/.docker ricardobranco/clean_registry [OPTIONS] CONTAINER [REPOSITORY[:TAG]]...
+```
 
-`docker run --rm --volumes-from CONTAINER -e DOCKER_HOST -e DOCKER_TLS_VERIFY=1 -v /root/.docker:/root/.docker ricardobranco/clean_registry [OPTIONS] CONTAINER [REPOSITORY[:TAG]]...`
+Note:
 
-Note: Paths other than `/root/.docker` path may be specified with the **DOCKER_CERT_PATH** environment variable.  In any case, your `~/.docker/*.pem` files should be in the server to be able to run as a client against itself.
+Paths other than ``/root/.docker`` path may be specified with the ``**DOCKER_CERT_PATH**`` environment variable.  In any case, your ``~/.docker/*.pem`` files should be in the server to be able to run as a client against itself.

clean_registry.py

   - This script may run stand-alone (on local setups) or dockerized (which supports remote Docker setups).
   - This script is Python 3 only.
 
-v1.2.1 by Ricardo Branco
+v1.2.2 by Ricardo Branco
 
 MIT License
 """
 
 import yaml
 
-VERSION = "1.2.1"
+VERSION = "1.2.2"
 REGISTRY_DIR = "REGISTRY_STORAGE_FILESYSTEM_ROOTREGISTRY_DIR"
 
 
     def get_image_version(self):
         '''Gets the Docker distribution version running on the container'''
         if self.info['State']['Running']:
-            data = self.docker.containers.get(self.container).exec_run("/bin/registry --version")[0]
+            data = self.docker.containers.get(self.container).exec_run("/bin/registry --version").output
         else:
             data = self.docker.containers.run(self.info["Image"], command="--version", remove=True)
         return data.decode('utf-8').split()[2]

requirements.txt

+backports.ssl-match-hostname==3.5.0.1
+backports.weakref==1.0.post1
+certifi==2018.1.18
+chardet==3.0.4
+docker==3.1.0
+docker-pycreds==0.2.2
+idna==2.6
+pkg-resources==0.0.0
+PyYAML==3.12
+requests==2.18.4
+six==1.11.0
+urllib3==1.22
+websocket-client==0.47.0