RNX UPDU Checkmk Extension

A CheckMK extension for monitoring RNX UPDU (Universal Power Distribution Unit) devices.

Development Environment

Using Development Container (Recommended)

This project includes a pre-configured development container with CheckMK 2.3.0.

Prerequisites

• Docker or Podman
• Visual Studio Code with Dev Containers extension

Getting Started

1. Open the project in VS Code
2. When prompted, click "Reopen in Container" or use Ctrl+Shift+P → "Dev Containers: Reopen in Container"
3. The container will automatically:
   • Set up CheckMK environment
   • Install required Python dependencies
   • Create symbolic links for the plugin
   • Apply necessary Nagios fixes for compatibility

Development Workflow

Once the dev container is running, you need to set up the CheckMK environment:

# Set password for cmkadmin user
cmk-passwd cmkadmin

# Start CheckMK services
omd start

# Build the extension within the container
.devcontainer/build.sh

# Test the extension
mkp inspect ./build/rnx_updu-0.0.3.mkp

The CheckMK web interface is available at http://localhost:8080/cmk (user: cmkadmin, password: set above).

Alternative: Manual Docker Setup

If you prefer to run CheckMK manually in Docker:

REV="2.3.0-latest"

docker run --rm -it -v /tmp/.X11-unix:/tmp/.X11-unix \
    --name checkmk \
    -p 8080:5000 \
    -p 8000:8000 \
    --tmpfs /opt/omd/sites/cmk/tmp:uid=1000,gid=1000 \
    -v /etc/localtime:/etc/localtime:ro \
    --volume=".:/project:rw" \
    checkmk/check-mk-raw:$REV /bin/bash

Access CheckMK shell: omd su cmk

Then set up the environment:

# Set password for cmkadmin user
cmk-passwd cmkadmin

# Start CheckMK services
omd start

Build

Using Development Container

.devcontainer/build.sh

Manual Build

Run the provided .devcontainer/build.sh script to compile the extension:

./.devcontainer/build.sh

The built package will be created in the build/ directory as rnx_updu-<version>.mkp.

Installation

Install the built plugin in your CheckMK instance:

mkp add rnx_updu-0.0.3.mkp
mkp enable rnx_updu

After installation, you can add and configure RNX UPDU hosts through the CheckMK web interface.

Testing

Local Testing with Development Container

1. Follow the development workflow above to set up the environment
2. Build and install the extension:

   .devcontainer/build.sh
   mkp add build/rnx_updu-*.mkp
   mkp enable rnx_updu

3. Access the CheckMK web interface at http://localhost:8080/cmk/
4. Add a new host and configure it to use the RNX UPDU special agent

Manual Testing

You can also test the plugin components individually:

# Validate plugin syntax
python3 -m py_compile src/rnx_updu/agent_based/*.py

# Check package contents
mkp inspect ./build/rnx_updu-*.mkp

# List installed packages
mkp list

Troubleshooting

Common Issues

• CheckMK services not starting: Make sure you've run omd start after setting up the container
• Web interface not accessible: Check that port 5000 is properly forwarded (to 8080 by default) and not blocked by firewall
• Plugin not loading: Verify the plugin is properly installed with mkp list and enabled with mkp enable rnx_updu

Logs

Check CheckMK logs for debugging:

# View general CheckMK logs
tail -f ~/var/log/web.log

# View agent output
cmk -v --debug <hostname>

# Check for plugin errors
tail -f ~/var/log/cmc.log

Project Structure

├── .devcontainer/          # Development container configuration
│   └── build.sh           # Build script for the extension
├── src/                    # Source code
│   ├── info               # Package metadata
│   └── rnx_updu/          # Plugin package
│       └── agent_based/   # CheckMK agent-based plugins
├── build/                 # Built packages (generated)
├── doc/                   # Documentation
├── VERSION                # Current version
├── RELEASE-NOTES.md       # Release notes and changelog
└── README.md             # This file

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Test thoroughly using the development container
5. Submit a pull request

License

This project is licensed under the terms specified in the CheckMK licensing.