Deploying Custom Extension using Machine Agent on Kubernetes

[Abhi.Bajaj]

Currently, InfraViz doesn't let you deploy Custom extensions. If you wish to deploy custom extensions on Kubernetes using machine agents then this article is for you.

This can be done in 2 ways:

1. Creating a new Machine Agent Image
2. Creating a new yaml file for Machine Agent

Creating a new Machine Agent Image

Now if you wish to use this method, which is modifying the Machine Agent image you need to take a step back and ask yourself:

1. Do you need the extension on all nodes?
   If not, then if you deploy InfraViz in default by just updating the Image with extension then on the node where it works, everything will be fine but on others, you will have logs filled with ERROR/WARN messages which can potentially lead to Machine agent collector script timing out.
2. Do you need a Machine Agent on all nodes?
   If not, then we are okay. We can use NodeSelector property of InfraViz and simply deploy this new Image using InfraViz on the specific node.

In any case, the Dockerfile will look like below:

FROM ubuntu:latest

# Install curl and unzip
RUN apt-get update && apt-get install -y curl unzip procps

# Add and unzip the Machine Agent bundle
ADD machineagent-bundle-64bit-linux-23.7.0.3689.zip /tmp/machineagent.zip
RUN unzip /tmp/machineagent.zip -d /opt/appdynamics && rm /tmp/machineagent.zip

# Set environment variable for Machine Agent home
ENV MACHINE_AGENT_HOME /opt/appdynamics

# Add AWS API Gateway Monitor and start-appdynamics script
ADD create-open-file-extension-folder /opt/appdynamics/monitors
ADD start-appdynamics ${MACHINE_AGENT_HOME}

# Make start-appdynamics script executable
RUN chmod 744 ${MACHINE_AGENT_HOME}/start-appdynamics

# Set Java Home environment variable
ENV JAVA_HOME /opt/appdynamics/jre/bin/java

# Run AppDynamics Machine Agent
CMD ["/opt/appdynamics/start-appdynamics"]

NOTE: In the same directory as Dockerfile

1. You need to have the appdynamics zip in your local. In my case, I have machineagent-bundle-64bit-linux-23.7.0.3689.zip in my local
2. create-open-file-extension-folder is the extension folder which I am moving to /opt/appdynamics/monitors, This has my script.sh and monitor.xml file
   
   Remember for extensions, the Machine agent looks for folders and files in monitors directory.
   
   
3. start-appdynamics.sh script. This is the content of start-appdynamics.sh script. You will need to edit it and add your Controller configuration.

MA_PROPERTIES="-Dappdynamics.controller.hostName=xxx.saas.appdynamics.com"
MA_PROPERTIES+=" -Dappdynamics.controller.port=443"
MA_PROPERTIES+=" -Dappdynamics.agent.accountName=xxxx"
MA_PROPERTIES+=" -Dappdynamics.agent.accountAccessKey=xx"
MA_PROPERTIES+=" -Dappdynamics.controller.ssl.enabled=true"
MA_PROPERTIES+=" -Dappdynamics.sim.enabled=true"
MA_PROPERTIES+=" -Dappdynamics.docker.enabled=false"
MA_PROPERTIES+=" -Dappdynamics.docker.container.containerIdAsHostId.enabled=true"
# Start Machine Agent
${MACHINE_AGENT_HOME}/jre/bin/java ${MA_PROPERTIES} -jar ${MACHINE_AGENT_HOME}/machineagent.jar

Great. Now all you need to do is build the Image and push it to your repository. Once done, in the InfraViz section, Update the Image section of InfraViz with this new Image

Creating a new yaml file for Machine Agent

Now the second option is using deployment and InfraViz together.

I have created a infraviz-deployment.yaml file. This is a deployment that I am deploying on a specific node.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: machine-agent-extension
  labels:
    app: machine-agent-extension
spec:
  replicas: 1
  selector:
    matchLabels:
      app: machine-agent-extension
  template:
    metadata:
      labels:
        app: machine-agent-extension
    spec:
      initContainers:
      - name: create-open-file-extension-folder
        image: busybox
        command: ['sh', '-c', 'mkdir -p /opt/appdynamics/monitors/open-file-extension && cp /tmp/config/* /opt/appdynamics/monitors/open-file-extension && chmod +x /opt/appdynamics/monitors/open-file-extension/script.sh']
        volumeMounts:
        - name: config-volume
          mountPath: /tmp/config  # Mount ConfigMap here temporarily
        - name: open-file-extension
          mountPath: /opt/appdynamics/monitors/open-file-extension  # Target directory in emptyDir

      containers:
      - name: machine-agent-extension
        image: appdynamics/machine-agent:latest
        ports:
        - containerPort: 9090
        env:
        - name: APPDYNAMICS_CONTROLLER_HOST_NAME
          value: "xxxx.saas.appdynamics.com"
        - name: APPDYNAMICS_CONTROLLER_PORT
          value: "443"
        - name: APPDYNAMICS_AGENT_ACCOUNT_NAME
          value: "xxx"
        - name: APPDYNAMICS_AGENT_ACCOUNT_ACCESS_KEY
          value: "xxx"
        - name: APPDYNAMICS_SIM_ENABLED
          value: "true"
        - name: APPDYNAMICS_CONTROLLER_SSL_ENABLED
          value: "true"
        volumeMounts:
        - name: open-file-extension
          mountPath: /opt/appdynamics/monitors/open-file-extension

      volumes:
      - name: config-volume
        configMap:
          name: open-file-extension-config  # ConfigMap holding script.sh and monitor.xml
      - name: open-file-extension
        emptyDir: {}  # EmptyDir to allow read/write
      nodeSelector:
        kubernetes.io/hostname: "ip-222-222-222-222.us-west-2.compute.internal"
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: open-file-extension-config
  namespace: default
data:
  script.sh: |
    #!/bin/bash
    # Get the current open files limit for the process
    open_files_limit=$(ulimit -n)

    ##Commentlineforcheck
    # Output the open files limit to stdout
    echo "name=Custom Metrics|OpenFilesLimitMonitor|OpenFilesLimit,value=$open_files_limit"
  monitor.xml: |
    <monitor>
        <name>OpenFile</name>
        <type>managed</type>
        <enabled>true</enabled>
        <enable-override os-type="linux">true</enable-override>
        <description>OpenFile</description>
        <monitor-configuration></monitor-configuration>
        <monitor-run-task>
            <execution-style>periodic</execution-style>
            <name>Run</name>
            <type>executable</type>
            <task-arguments></task-arguments>
            <executable-task>
                <type>file</type>
                <file>script.sh</file>
            </executable-task>
        </monitor-run-task>
    </monitor>

Right now I am only monitoring one node though, so we will use InfraViz to monitor other nodes now.

1. Taint the nodes that I don't want InfraViz to run now which is going to be above one ^
   
   kubectl taint node ip-222-222-222-222.us-west-2.compute.internal machine-agent=false:NoSchedule
2. Now, I can deploy InfraViz.yaml normally and it won't be deployed on ip-222 node.
3. Now you have MA running on all of your nodes, one with extension, and the rest normally

Please reach out to Support if you have any questions.