Remote image

The remote images allow to extend the

• Capella base image (capella/base)
• T4C base image (t4c/client/base)
• Pure::variants image (t4c/client/pure-variants)

with a RDP or XPRA server and a metrics endpoint to measure the container activity.

It is a basic Linux server with a Openbox installation.

Build it yourself

Preparation

Optional: Customize Openbox

Openbox is only used for the connection method RDP.

Feel free to adjust the configurations remote/rc.xml and remote/menu.xml to satisfy custom Openbox configuration needs.

Build it manually with Docker

docker build -t $BASE_IMAGE/remote remote --build-arg BASE_IMAGE=$BASE_IMAGE

where $BASE_IMAGE is capella/base, t4c/client/base or t4c/client/pure-variants (depends on the image you'd like to extend with remote functionality)

Run the container

Replace the followings variables:

• $BASE_IMAGE with capella/base, t4c/client/base or t4c/client/pure-variants. Please check the individual section In a remote container (RDP) of the individual base image documentation pages for additional configuration options.

Connect via RDPConnect via XPRA

The container image contains a xrdp server. To use RDP to connect to the container, run the container with the following command:

docker run -d \
    -p $RDP_EXTERNAL_PORT:3389 \
    -e CONNECTION_METHOD=xrdp \
    -e RMT_PASSWORD=$RMT_PASSWORD \
    $BASE_IMAGE/remote

Replace $RDP_EXTERNAL_PORT with the external port that the RDP server should listen on (usually 3389).

Also replace $RMT_PASSWORD with the password for remote connections (for the login via RDP). The value has to be at least 8 characters long.

After starting the container, you should be able to connect to localhost:$RDP_EXTERNAL_PORT with your preferred RDP Client.

For the login use the followings credentials:

• Username: techuser
• Password: $RMT_PASSWORD

The screen size is set every time the connection is established. Depending on your RDP client, you will also be able to set the preferred screen size in the settings.

By default, Remmina (RDP client for Linux) starts in a tiny window. To fix that, you can set "Use client resolution" instead of "Use initial window size" in the remote connection profile.

The container image contains a xpra-html5 server. To use XPRA via HTML5 to connect to the container, run the container with the following command:

docker run -d \
    -p $XPRA_PORT:10000 \
    -e CONNECTION_METHOD=xpra \
    -e XPRA_SUBPATH="/" \
    $BASE_IMAGE/remote

Authentication

Since version v1.19.0, xpra based containers are exposed without authentication. If used with the Capella Collaboration Manager >= v3.1.0, authentication is handled via session pre-authentication automatically. In other cases, you have to implement your own authentication mechanism.

Embedding in iframes

To embed the XPRA session in an iframe, you have to set a custom Content Security Policy. You can pass the environment variable XPRA_CSP_ORIGIN_HOST to the hostname of the website you'd like to embed the XPRA session in. If you want to embed the XPRA session in an iframe on example.com, set XPRA_CSP_ORIGIN_HOST to https://example.com.

Set the XPRA_SUBPATH to the subpath that xpra should serve on. If you want to have it running on /xpra, set XPRA_SUBPATH to /xpra.

Then, open a browser and connect to:

http://localhost:${XPRA_PORT}${XPRA_SUBPATH}/?floating_menu=0

More configuration options can be passed as query parameters. See the xpra-html5 documentation for more information.