mtlott/clutch repository overview

⁠Docker container for Clutch

This is a Docker container for Clutch.

Clutch provides a bridge between a DVR which outputs EDL files such as Channels-DVR⁠ and an automated version of HandBrake⁠.

At this time the GUI provides only status information through a web-based VNC session.

The fully automated functionality provides watch folders: drop files into a watch folder and let Clutch process them without any user interaction. Or have an upstream processing stage write to the watch folder.

Clutch is an EDL (Edit Decision List) splicer tool which utilizes ffmpeg to cut segments from a video file without reencoding.

Clutch is based on the amazing work of jlesage on docker-handbrake⁠

⁠Table of Content

• Docker container for Clutch⁠
  • Table of Content⁠
  • Quick Start⁠
  • Usage⁠
    • Environment Variables⁠
    • Data Volumes⁠
    • Ports⁠
    • Changing Parameters of a Running Container⁠
  • Docker Compose File⁠
  • Docker Image Update⁠
  • User/Group IDs⁠
  • Accessing the GUI⁠
  • Security⁠
    • SSVNC⁠
    • Certificates⁠
    • VNC Password⁠
  • Reverse Proxy⁠
    • Routing Based on Hostname⁠
    • Routing Based on URL Path⁠
  • Shell Access⁠
  • Automatic Video Conversion⁠
    • Multiple Watch Folders⁠
    • Hooks⁠
    • Temporary Conversion Directory⁠
  • Nightly Builds⁠
  • Debug Builds⁠
  • Support or Contact⁠

⁠Quick Start

NOTE: The Docker command provided in this quick start is given as an example and parameters should be adjusted to your need.

Launch the Clutch docker container with the following command:

docker run -d \
    --name=clutch \
    -p 5800:5800 \
    -v /docker/appdata/clutch:/config:rw \
    -v $HOME:/storage:ro \
    -v $HOME/Clutch/watch:/watch:rw \
    -v $HOME/Clutch/output:/output:rw \
    mtlott/clutch

Where:

• /docker/appdata/clutch: This is where the application stores its configuration, log and any files needing persistency.
• $HOME: This location contains files from your host that need to be accessible by the application.
• $HOME/Clutch/watch: This is where videos to be automatically converted are located.
• $HOME/Clutch/output: This is where automatically converted video files are written.

Browse to http://your-host-ip:5800 to access the Clutch GUI. Files from the host appear under the /storage folder in the container.

⁠Usage

docker run [-d] \
    --name=clutch \
    [-e <VARIABLE_NAME>=<VALUE>]... \
    [-v <HOST_DIR>:<CONTAINER_DIR>[:PERMISSIONS]]... \
    [-p <HOST_PORT>:<CONTAINER_PORT>]... \
    jlesage/clutch

⁠Environment Variables

To customize some properties of the container, the following environment variables can be passed via the -e parameter (one for each variable). Value of this parameter has the format <VARIABLE_NAME>=<VALUE>.

⁠Data Volumes

The following table describes data volumes used by the container. The mappings are set via the -v parameter. Each mapping is specified with the following format: <HOST_DIR>:<CONTAINER_DIR>[:PERMISSIONS].

⁠Ports

Here is the list of ports used by the container. They can be mapped to the host via the -p parameter (one per port mapping). Each mapping is defined in the following format: <HOST_PORT>:<CONTAINER_PORT>. The port number inside the container cannot be changed, but you are free to use any port on the host side.

⁠Changing Parameters of a Running Container

As seen, environment variables, volume mappings and port mappings are specified while creating the container.

The following steps describe the method used to add, remove or update parameter(s) of an existing container. The generic idea is to destroy and re-create the container:

1. Stop the container (if it is running):

docker stop clutch

1. Remove the container:

docker rm clutch

1. Create/start the container using the docker run command, by adjusting parameters as needed.

NOTE: Since all application's data is saved under the /config container folder, destroying and re-creating a container is not a problem: nothing is lost and the application comes back with the same state (as long as the mapping of the /config folder remains the same).

⁠Docker Compose File

Here is an example of a docker-compose.yml file that can be used with Docker Compose⁠.

Make sure to adjust according to your needs. Note that only mandatory network ports are part of the example.

version: '3'
services:
  clutch:
    image: mtlott/clutch
    build: .
    ports:
      - "5800:5800"
    volumes:
      - "/docker/appdata/clutch:/config:rw"
      - "$HOME:/storage:ro"
      - "$HOME/Clutch/watch:/watch:rw"
      - "$HOME/Clutch/output:/output:rw"

⁠Docker Image Update

If the system on which the container runs doesn't provide a way to easily update the Docker image, the following steps can be followed:

1. Fetch the latest image:

docker pull mtlott/clutch

1. Stop the container:

docker stop clutch

1. Remove the container:

docker rm clutch

1. Start the container using the docker run command.

⁠Synology

For owners of a Synology NAS, the following steps can be used to update a container image.

1. Open the Docker application.
2. Click on Registry in the left pane.
3. In the search bar, type the name of the container (mtlott/clutch).
4. Select the image, click Download and then choose the latest tag.
5. Wait for the download to complete. A notification will appear once done.
6. Click on Container in the left pane.
7. Select your Clutch container.
8. Stop it by clicking Action->Stop.
9. Clear the container by clicking Action->Clear. This removes the container while keeping its configuration.
10. Start the container again by clicking Action->Start. NOTE: The container may temporarily disappear from the list while it is re-created.

⁠unRAID

For unRAID, a container image can be updated by following these steps:

1. Select the Docker tab.
2. Click the Check for Updates button at the bottom of the page.
3. Click the update ready link of the container to be updated.

⁠User/Group IDs

When using data volumes (-v flags), permissions issues can occur between the host and the container. For example, the user within the container may not exists on the host. This could prevent the host from properly accessing files and folders on the shared volume.

To avoid any problem, you can specify the user the application should run as.

This is done by passing the user ID and group ID to the container via the USER_ID and GROUP_ID environment variables.

To find the right IDs to use, issue the following command on the host, with the user owning the data volume on the host:

id <username>

Which gives an output like this one:

uid=1000(myuser) gid=1000(myuser) groups=1000(myuser),4(adm),24(cdrom),27(sudo),46(plugdev),113(lpadmin)

The value of uid (user ID) and gid (group ID) are the ones that you should be given the container.

⁠Accessing the GUI

Assuming that container's ports are mapped to the same host's ports, the graphical interface of the application can be accessed via:

• A web browser:

http://<HOST IP ADDR>:5800

• Any VNC client:

<HOST IP ADDR>:5900

⁠Security

By default, access to the application's GUI is done over an unencrypted connection (HTTP or VNC).

Secure connection can be enabled via the SECURE_CONNECTION environment variable. See the Environment Variables⁠ section for more details on how to set an environment variable.

When enabled, application's GUI is performed over an HTTPs connection when accessed with a browser. All HTTP accesses are automatically redirected to HTTPs.

When using a VNC client, the VNC connection is performed over SSL. Note that few VNC clients support this method. SSVNC⁠ is one of them.

⁠SSVNC

SSVNC⁠ is a VNC viewer that adds encryption security to VNC connections.

While the Linux version of SSVNC⁠ works well, the Windows version has some issues. At the time of writing, the latest version 1.0.30 is not functional, as a connection fails with the following error:

ReadExact: Socket error while reading

However, for your convenience, an unofficial and working version is provided here:

https://github.com/jlesage/docker-baseimage-gui/raw/master/tools/ssvnc_windows_only-1.0.30-r1.zip⁠

The only difference with the official package is that the bundled version of stunnel has been upgraded to version 5.49, which fixes the connection problems.

⁠Certificates

Here are the certificate files needed by the container. By default, when they are missing, self-signed certificates are generated and used. All files have PEM encoded, x509 certificates.

NOTE: To prevent any certificate validity warnings/errors from the browser or VNC client, make sure to supply your own valid certificates.

NOTE: Certificate files are monitored and relevant daemons are automatically restarted when changes are detected.

⁠VNC Password

To restrict access to your application, a password can be specified. This can be done via two methods:

• By using the VNC_PASSWORD environment variable.
• By creating a .vncpass_clear file at the root of the /config volume. This file should contain the password in clear-text. During the container startup, content of the file is obfuscated and moved to .vncpass.

The level of security provided by the VNC password depends on two things:

• The type of communication channel (encrypted/unencrypted).
• How secure the access to the host is.

When using a VNC password, it is highly desirable to enable the secure connection to prevent sending the password in clear over an unencrypted channel.

ATTENTION: Password is limited to 8 characters. This limitation comes from the Remote Framebuffer Protocol RFC⁠ (see section 7.2.2⁠). Any characters beyond the limit are ignored.

⁠Reverse Proxy

The following sections contain NGINX configurations that need to be added in order to reverse proxy to this container.

A reverse proxy server can route HTTP requests based on the hostname or the URL path.

⁠Routing Based on Hostname

In this scenario, each hostname is routed to a different application/container.

For example, let's say the reverse proxy server is running on the same machine as this container. The server would proxy all HTTP requests sent to clutch.domain.tld to the container at 127.0.0.1:5800.

Here are the relevant configuration elements that would be added to the NGINX configuration:

map $http_upgrade $connection_upgrade {
	default upgrade;
	''      close;
}

upstream docker-clutch {
	# If the reverse proxy server is not running on the same machine as the
	# Docker container, use the IP of the Docker host here.
	# Make sure to adjust the port according to how port 5800 of the
	# container has been mapped on the host.
	server 127.0.0.1:5800;
}

server {
	[...]

	server_name clutch.domain.tld;

	location / {
	        proxy_pass http://docker-clutch;
	}

	location /websockify {
		proxy_pass http://docker-clutch;
		proxy_http_version 1.1;
		proxy_set_header Upgrade $http_upgrade;
		proxy_set_header Connection $connection_upgrade;
		proxy_read_timeout 86400;
	}
}

⁠Routing Based on URL Path

In this scenario, the hostname is the same, but different URL paths are used to route to different applications/containers.

For example, let's say the reverse proxy server is running on the same machine as this container. The server would proxy all HTTP requests for server.domain.tld/clutch to the container at 127.0.0.1:5800.

Here are the relevant configuration elements that would be added to the NGINX configuration:

map $http_upgrade $connection_upgrade {
	default upgrade;
	''      close;
}

upstream docker-clutch {
	# If the reverse proxy server is not running on the same machine as the
	# Docker container, use the IP of the Docker host here.
	# Make sure to adjust the port according to how port 5800 of the
	# container has been mapped on the host.
	server 127.0.0.1:5800;
}

server {
	[...]

	location = /clutch {return 301 $scheme://$http_host/clutch/;}
	location /clutch/ {
		proxy_pass http://docker-clutch/;
		location /clutch/websockify {
			proxy_pass http://docker-clutch/websockify/;
			proxy_http_version 1.1;
			proxy_set_header Upgrade $http_upgrade;
			proxy_set_header Connection $connection_upgrade;
			proxy_read_timeout 86400;
		}
	}
}

⁠Shell Access

To get shell access to a the running container, execute the following command:

docker exec -ti CONTAINER sh

Where CONTAINER is the ID or the name of the container used during its creation (e.g. crashplan-pro).

⁠Automatic Video Conversion***

This container has an automatic video converter built-in. This is useful to batch-convert videos without user interaction.

Basically, files copied to the /watch container folder are automatically edited by Clutch based on the supplied EDL file.

See the Environment Variables⁠ section for details about setting environment variables.

NOTE: Converted videos are stored, by default, to the /output folder of the container.

NOTE: The status and progression of conversions performed by the automatic video converter can be seen from both the GUI and the container's log. Container's log can be obtained by executing the command docker logs clutch, where clutch is the name of the container. Also, full details about the conversion are stored in /config/log/hb/conversion.log (container path).

⁠Multiple Watch Folders

If needed, up to 4 additionnal watch folders can be used:

• /watch2
• /watch3
• /watch4
• /watch5

This is useful in scenarios where videos need to be converted by different later stages of the video processing pipeline. For example, one could use a watch folder for movies and another watch folder for TV shows, both having different output directories which are monitored by different downstream post processors.

By default, additional watch folders inherits the same settings has the main one (/watch). A setting for a particular watch folder can be overrided by adding its index to the corresponding environment variable name.

For example, to set the Clutch output directory in /watch2, the environment variable AUTOMATED_CONVERSION_OUTPUT_DIR_2 is used. AUTOMATED_CONVERSION_OUTPUT_DIR_3 is used for /watch3, and so on.

All settings related to the automatic video converter can be overrided for each additional watch folder:

• AUTOMATED_CONVERSION_SOURCE_STABLE_TIME
• AUTOMATED_CONVERSION_SOURCE_MIN_DURATION
• AUTOMATED_CONVERSION_OUTPUT_DIR
• AUTOMATED_CONVERSION_OUTPUT_SUBDIR
• AUTOMATED_CONVERSION_KEEP_SOURCE
• AUTOMATED_CONVERSION_NON_VIDEO_FILE_ACTION
• AUTOMATED_CONVERSION_OVERWRITE_OUTPUT

⁠Hooks

Custom actions can be performed using hooks. Hooks are shell scripts executed by the automatic video converter.

NOTE: Hooks are always invoked via /bin/sh, ignoring any shebang the script may have.

Hooks are optional and by default, no one is defined. A hook is defined and executed when the script is found at a specific location.

The following table describe available hooks: