# SNMPD Custom OID Docker Container

This Docker container runs `snmpd` with a custom script that provides a specific OID. The value of this OID increases randomly by a small amount every 4 minutes. The SNMP community string, OID, increment range, and port can be configured using a `.env` file.

## Features

- Lightweight Docker container based on Alpine Linux.
- Custom Python script to generate and update the OID value.
- Configurable SNMP daemon (`snmpd`) to use the custom script.
- Dynamic configuration using a `.env` file with Docker environment variables.

## Requirements

- Docker installed on your system.
- Basic knowledge of Docker commands.

## Dependencies

- `snmpd`: The SNMP daemon.
- Python 3: Used to write the custom script.
- `random`: Python library for generating random numbers (included in Python's standard library).

## How to Use

### Step 1: Create a `.env` File

Create a `.env` file in the same directory as your `Dockerfile` with the following content:

```
SNMP_COMMUNITY=public
CUSTOM_OID=.1.3.6.1.4.1.38446.1.2.4.1.9.1
RANGE_MIN=0
RANGE_MAX=6
SNMP_PORT=161
```

### Step 2: Build the Docker Image

Navigate to the directory containing the `Dockerfile` and `custom_snmp_script.py`, then run:

```bash
docker build -t snmpd-custom .
```

### Step 3: Run the Docker Container

Start the Docker container with the following command, using the `--env-file` option to pass the environment variables:

```bash
docker run -d -p ${SNMP_PORT}:${SNMP_PORT}/udp --name snmpd-custom-container --env-file .env snmpd-custom
```

Replace `${SNMP_PORT}` with the actual port number you want to use, or use the value from your `.env` file.

### Step 4: Verify the Setup

You can verify that the container is running and the SNMP daemon is providing the custom OID by using an SNMP client to query the OID:

```bash
snmpwalk -v 2c -c public localhost .1.3.6.1.4.1.38446.1.2.4.1.9.1
```

You should see the value incrementing randomly every 4 minutes.

## Customization

- **Initial Value**: You can change the initial value in the `custom_snmp_script.py` file.
- **Increment Range**: Modify the `RANGE_MIN` and `RANGE_MAX` in the `.env` file to change how much the value increments.
- **Update Interval**: Adjust the sleep interval in the script to change the frequency of updates.
- **Community String and OID**: Modify the `.env` file to change the SNMP community string and OID.
- **SNMP Port**: Modify the `SNMP_PORT` in the `.env` file to change the port on which `snmpd` listens.

## Notes

- Ensure that the SNMP community string and port in the `.env` file match your configuration.
- The container exposes the specified SNMP port for communication.

## License

This project is licensed under the MIT License.

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Feel free to contribute or modify the setup to fit your specific needs!