Monitor multi-container applications in a single pod

In a sidecar scenario, a single pod can run multiple containers with applications written in various programming languages. This topic explains how to use the ack-onepilot component to instrument these polyglot applications.

Prerequisites

The ack-onepilot version is 4.2.0 or later.

Procedure

Install ack-onepilot and grant it the required resource access permissions as described in one of the following topics:
- Install the Java agent by using the ack-onepilot component in Container Service for Kubernetes (ACK) and Container Compute Service (ACS)
- Automatically install an agent in a generic Kubernetes environment

Add the required labels to the workload.

Example application YAML

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: multicontainer          
  name: multicontainer
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: multicontainer
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: multicontainer
        apsara.apm/container.test-java.app-language: java
        apsara.apm/container.test-java.armsPilotAutoEnable: 'on'
        apsara.apm/container.test-java.armsPilotCreateAppName: multilanguage-java
        apsara.apm/container.test-go.app-language: golang
        apsara.apm/container.test-go.armsPilotAutoEnable: 'on'
        apsara.apm/container.test-go.armsPilotCreateAppName: multilanguage-go
        apsara.apm/container.test-python.app-language: python
        apsara.apm/container.test-python.armsPilotAutoEnable: 'on'
        apsara.apm/container.test-python.armsPilotCreateAppName: multilanguage-python
    spec:
      containers:
        - command:
            - sleep
            - '360000'
          image: alibaba-cloud-linux-3-registry.cn-hangzhou.cr.aliyuncs.com/alinux3/alinux3:latest
            # Replace with your actual Java application image.
          imagePullPolicy: Always
          name: test-java
          resources:
            requests:
              cpu: 250m
              memory: 512Mi
        - command:
            - sleep
            - '3600000'
          image: alibaba-cloud-linux-3-registry.cn-hangzhou.cr.aliyuncs.com/alinux3/alinux3:latest
            # Replace with your actual Go application image.
          imagePullPolicy: Always
          name: test-go
          resources:
            requests:
              cpu: 500m
              memory: 512Mi
        - command:
            - sleep
            - '3600000'
          image: alibaba-cloud-linux-3-registry.cn-hangzhou.cr.aliyuncs.com/alinux3/alinux3:latest
            # Replace with your actual Python application image.
          imagePullPolicy: Always
          name: test-python
          resources:
            requests:
              cpu: 500m
              memory: 512Mi

The preceding YAML defines an application that uses Java, Go, and Python in three separate containers: test-java, test-go, and test-python.

To isolate monitoring data, instrument each container to report data to a separate ARMS application. Follow these steps:

Log on to the ACK console. In the left navigation pane, click Clusters.
On the Clusters page, click the name of your cluster. In the left navigation pane, click Workloads > Deployments.
On the Stateless page, find your target application, and then choose > Edit YAML in the Actions column.

To create a new application, click Create From YAML.

In the YAML file, add the following labels under the spec.template.metadata section, and then click Update.

labels:
  # Replace ${containerName} with the actual container name.
  apsara.apm/container.${containerName}.app-language: java # Replace with the container's actual programming language.
  apsara.apm/container.${containerName}.armsPilotAutoEnable: 'on'
  apsara.apm/container.${containerName}.armsPilotCreateAppName: "<your-deployment-name>"    # Replace <your-deployment-name> with your application name.

The instrumentation is successful if your applications appear on the Application Monitoring > Application List page in the ARMS console and are reporting data.

In the search box, enter multilanguage- to filter for the three applications: multilanguage-go, multilanguage-java, and multilanguage-python.