formating

.env

@@ -0,0 +1,5 @@
+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

Dockerfile

@@ -14,10 +14,10 @@ COPY custom_snmp_script.py /usr/local/bin/custom_snmp_script.py
 RUN chmod +x /usr/local/bin/custom_snmp_script.py
 
 # Configure snmpd to use the custom script
-RUN echo "extend .1.3.6.1.4.1.38446.1.2.4.1.9.1 /usr/local/bin/custom_snmp_script.py" >> /etc/snmp/snmpd.conf
+RUN echo "extend customOID /usr/local/bin/custom_snmp_script.py" >> /etc/snmp/snmpd.conf
 
-# Expose the SNMP port
+# Expose the SNMP port using an environment variable
 EXPOSE 161/udp
 
-# Start snmpd
+# Start snmpd with environment variables
-CMD ["snmpd", "-f"]
+CMD ["sh", "-c", "snmpd -f -c /etc/snmp/snmpd.conf -Lf /dev/null -p /var/run/snmpd.pid -a -x $SNMP_COMMUNITY -p $SNMP_PORT"]

README.md

@@ -1,12 +1,13 @@
 # SNMPD Custom OID Docker Container
 
-This Docker container runs `snmpd` with a custom script that provides a specific OID (`.1.3.6.1.4.1.38446.1.2.4.1.9.1`). The value of this OID increases randomly by a small amount every 4 minutes.
+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
 
@@ -16,12 +17,24 @@ This Docker container runs `snmpd` with a custom script that provides a specific
 ## Dependencies
 
 - `snmpd`: The SNMP daemon.
-- Python 3: Used to write the custom script.
+- `Python 3`: Used to write the custom script.
-- `random`: Python library for generating random numbers.
+- `random`: Python library for generating random numbers (included in Python's standard library).
 
 ## How to Use
 
-### Step 1: Build the Docker Image
+### 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:
 
@@ -29,15 +42,17 @@ Navigate to the directory containing the `Dockerfile` and `custom_snmp_script.py
 docker build -t snmpd-custom .
 ```
 
-### Step 2: Run the Docker Container
+### Step 3: Run the Docker Container
 
-Start the Docker container with the following command:
+Start the Docker container with the following command, using the `--env-file` option to pass the environment variables:
 
 ```bash
-docker run -d -p 161:161/udp --name snmpd-custom-container snmpd-custom
+docker run -d -p ${SNMP_PORT}:${SNMP_PORT}/udp --name snmpd-custom-container --env-file .env snmpd-custom
 ```
 
-### Step 3: Verify the Setup
+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:
 
@@ -50,15 +65,21 @@ 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 in the script to change how much the value increments.
+- **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 (`public` in the example) matches your configuration.
+- Ensure that the SNMP community string and port in the `.env` file match your configuration.
-- The container exposes port 161 for SNMP communication.
+- The container exposes the specified SNMP port for communication.
 
 ## License
 
 This project is licensed under the MIT License.
 
+---
+
+Feel free to contribute or modify the setup to fit your specific needs!
+

custom_snmp_script.py

@@ -1,16 +1,22 @@
 #!/usr/bin/env python3
+import os
 import random
 import time
 
+# Read the OID and range from environment variables
+oid = os.getenv('CUSTOM_OID', '.1.3.6.1.4.1.38446.1.2.4.1.9.1')
+range_min = int(os.getenv('RANGE_MIN', 0))
+range_max = int(os.getenv('RANGE_MAX', 6))
+
 # Initial value
 value = 1385062
 
 while True:
-    # Increment the value by a random amount between 0 and 6
+    # Increment the value by a random amount within the specified range
-    value += random.randint(0, 6)
+    value += random.randint(range_min, range_max)
 
     # Output the value in the required format
-    print(f"INTEGER: {value}")
+    print(f"{oid} = INTEGER: {value}")
 
     # Wait for 4 minutes
     time.sleep(240)