paularlott/knot-ubuntu repository overview

⁠knot-ubuntu

Base Ubuntu image used by knot⁠, a tool for managing cloud and local development environments. It is the foundation that the knot-desktop, knot-php and other Ubuntu-based knot images build upon, but it is also useful on its own as a general-purpose, fully-tooled development container.

The image adds the knot entrypoint and startup framework, a runtime user, rsyslog logging, gosu, and a broad set of CLI utilities to every container.

⁠Tags

All tags are multi-arch (linux/amd64, linux/arm64); see Docker Hub⁠ for the current list.

Each release is also tagged <version>-<BUILD_DATE> (e.g. 24.04-20260101).

⁠Usage

⁠As a knot space

When KNOT_SERVER is set the entrypoint downloads the knot agent and connects the container to your knot cluster:

docker run -d \
  -e KNOT_SERVER=https://knot.example.com \
  -e KNOT_SPACEID=... \
  -e KNOT_USER=alice \
  -v knot_home:/home \
  paularlott/knot-ubuntu:26.04

⁠Standalone

With no KNOT_SERVER, the image still sets up the runtime user, home directory, rsyslog and startup hooks, then waits (or runs the command you pass):

# Interactive shell as the runtime user
docker run --rm -it -v knot_home:/home paularlott/knot-ubuntu:26.04 bash

# Run a one-off command
docker run --rm paularlott/knot-ubuntu:26.04 whoami

⁠How it works

The ENTRYPOINT is /usr/local/bin/knot-entrypoint, which:

1. Creates the KNOT_USER (uid 1000) if missing, renames the home directory if the user changed, and fixes ownership. The user is granted passwordless sudo.
2. Optionally starts sshd on KNOT_SSH_PORT when KNOT_SSHD=native.
3. If KNOT_SERVER is set, downloads and starts the knot agent (granted CAP_NET_BIND_SERVICE).
4. Starts rsyslog and forwards all logs to the agent's syslog port (KNOT_SYSLOG_PORT).
5. Runs every script in /etc/knot-startup.d/ alphabetically, then ~/.knot-startup.d/.
6. Waits on the agent (or execs the supplied command as KNOT_USER).

⁠Startup hooks

Drop executable scripts into:

• /etc/knot-startup.d/ — system hooks, run as root.
• ~/.knot-startup.d/ — per-user hooks, run as KNOT_USER via gosu.

See the knot startup-scripts docs⁠ for details.

⁠Environment variables

⁠Volumes

• /home — persistent home directory for KNOT_USER. Mount this to preserve work across restarts.

⁠License

The Ubuntu base image and its packages are licensed under their respective upstream licenses. This image's packaging — the Dockerfile, knot-entrypoint and supporting scripts/configs — is Apache License 2.0⁠.

Source: paularlott/knot-base-images⁠.