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Scenario: Monitor a Java service with OpenTelemetry in ECS Fargate πŸ”—

Note

To learn how to deploy the Collector in an AWS ECS Fargate environment, see Deploy the Collector with Amazon ECS Fargate.

To instrument a Java service running in ECS Fargate with OpenTelemetry, make the splunk-otel-javaagent.jar file available on the application container in one of these ways:

  1. Update the Dockerfile for the application container to explicitly download the splunk-otel-javaagent.jar file so that it’s baked into that container image. See Option 1: Bake splunk-otel-javaagent.jar into the application image.

  2. Build a separate container image that downloads the splunk-otel-javaagent.jar file, and makes it available as a sidecar ECS container to the application container. See Option 2: Build a separate container image.

Option 1: Bake splunk-otel-javaagent.jar into the application image πŸ”—

Follow these steps to bake splunk-otel-javaagent.jar into the application image:

1. Update the application’s Dockerfile πŸ”—

With this option, the first step is to update the Dockerfile used to build the application container and download the splunk-otel-javaagent.jar file so it’s available on the host. This example assumes the application container is based on Tomcat 9 running on Alpine Linux.

To update the Dockerfile, run:

FROM tomcat:9.0-jre8-alpine

RUN apk add curl

# Create a work directory to copy the agent artifacts
RUN mkdir -p /opt/splunk

# Download and extract agent artifacts to the work directory
RUN curl -L0 https://github.com/signalfx/splunk-otel-java/releases/latest/download/splunk-otel-javaagent.jar \
-o /opt/splunk/splunk-otel-javaagent.jar

WORKDIR /usr/local/tomcat/webapps

EXPOSE 8080

CMD ["/usr/local/tomcat/bin/catalina.sh", "run"]

2. Push the image to your repo πŸ”—

Next, build and push the image to your repo. Replace username with your Docker Hub username:

docker build --platform="linux/amd64" -t tomcat-with-splunk-java-agent:latest --no-cache .

docker tag tomcat-with-splunk-java-agent:latest username/tomcat-with-splunk-java-agent:latest

docker push username/tomcat-with-splunk-java-agent:latest

3. Update the ECS task definition πŸ”—

After updating and pushing your Dockerfile, update the ECS task definition to use the splunk-otel-javaagent.jar file, now part of your application container in the /opt/splunk directory:

{
  "family": "agent-baked-in-example",
  "containerDefinitions": [
      {
          "name": "tomcat",
          "image": "username/tomcat-with-splunk-java-agent:latest",
          "cpu": 0,
          "portMappings": [
              {
                  "name": "tomcat-8080-tcp",
                  "containerPort": 8080,
                  "protocol": "tcp",
                  "appProtocol": "http"
              }
        ],
          "essential": true,
          "environment": [
              {
                  "name": "OTEL_SERVICE_NAME",
                  "value": "myservice"
              },
              {
                  "name": "OTEL_RESOURCE_ATTRIBUTES",
                  "value": "deployment.environment=test,service.version=1.0"
              },
              {
                  "name": "JAVA_TOOL_OPTIONS",
                  "value": "-javaagent:/opt/splunk/splunk-otel-javaagent.jar"
              }
          ],
          "environmentFiles": [],
          "mountPoints": [],
          "volumesFrom": [],
          "dependsOn": [],
          "ulimits": [],
          "logConfiguration": {
              "logDriver": "awslogs",
              "options": {
                  "awslogs-create-group": "true",
                  "awslogs-group": "/ecs/agent-baked-in-example",
                  "awslogs-region": "eu-west-1",
                  "awslogs-stream-prefix": "ecs"
              },
              "secretOptions": []
          }
      },
      {
          "name": "splunk-otel-collector",
          "image": "quay.io/signalfx/splunk-otel-collector:latest",
          "cpu": 0,
          "portMappings": [],
          "essential": true,
          "environment": [
              {
                  "name": "SPLUNK_CONFIG",
                  "value": "/etc/otel/collector/fargate_config.yaml"
              },
              {
                  "name": "SPLUNK_REALM",
                  "value": "<Realm - us0, us1, etc>"
              },
              {
                  "name": "SPLUNK_ACCESS_TOKEN",
                  "value": "<Access Token>"
              },
              {
                  "name": "ECS_METADATA_EXCLUDED_IMAGES",
                  "value": "[\"quay.io/signalfx/splunk-otel-collector:latest\"]"
              }
          ],
          "environmentFiles": [],
          "mountPoints": [],
          "volumesFrom": [],
          "logConfiguration": {
              "logDriver": "awslogs",
              "options": {
                  "awslogs-create-group": "true",
                  "awslogs-group": "/ecs/agent-baked-in-example",
                  "awslogs-region": "eu-west-1",
                  "awslogs-stream-prefix": "ecs"
              },
              "secretOptions": []
          }
      }
  ],
  "executionRoleArn": "arn:aws:iam::539254608140:role/ecsTaskExecutionRole",
  "networkMode": "awsvpc",
  "requiresCompatibilities": [
      "FARGATE"
  ],
  "cpu": "1024",
  "memory": "3072",
  "runtimePlatform": {
      "cpuArchitecture": "X86_64",
      "operatingSystemFamily": "LINUX"
  }
}

Option 2: Build a separate container image πŸ”—

Follow these steps to use a separate container image:

1. Create a Dockerfile for the Splunk Java agent πŸ”—

First, create a Dockerfile to download the splunk-otel-javaagent.jar file and make it available as a volume:

FROM alpine:latest

RUN apk add --no-cache curl

# Create a directory for the agent artifacts
RUN mkdir -p /opt/splunk
WORKDIR /opt/splunk

# Download the Splunk Java agent
RUN curl -L0 https://github.com/signalfx/splunk-otel-java/releases/latest/download/splunk-otel-javaagent.jar \
-o splunk-otel-javaagent.jar

# Expose the /opt/splunk directory as a shared volume
VOLUME ["/opt/splunk"]

CMD tail -f /dev/null

2. Push the image to your repo πŸ”—

Next, build and push the image to your repo. Replace username with your Docker Hub username:

docker build --platform="linux/amd64" -t splunk-java-agent:latest --no-cache .

docker tag splunk-java-agent:latest username/splunk-java-agent:latest

docker push username/splunk-java-agent:latest

3. Update the ECS task definition πŸ”—

Use this container image in your ECS task definition to make the splunk-otel-javaagent.jar file available to your application container, such as Tomcat:

{
 "family": "agent-init-container-example",
 "containerDefinitions": [
     {
         "name": "tomcat",
         "image": "tomcat:9.0",
         "cpu": 0,
         "portMappings": [
             {
                 "name": "tomcat-8080-tcp",
                 "containerPort": 8080,
                 "protocol": "tcp",
                 "appProtocol": "http"
             }
         ],
         "essential": true,
         "environment": [
             {
                 "name": "OTEL_SERVICE_NAME",
                 "value": "myservice"
             },
             {
                 "name": "OTEL_RESOURCE_ATTRIBUTES",
                 "value": "deployment.environment=test,service.version=1.0"
             },
             {
                 "name": "JAVA_TOOL_OPTIONS",
                 "value": "-javaagent:/opt/splunk/splunk-otel-javaagent.jar"
             }
         ],
         "environmentFiles": [],
         "mountPoints": [],
         "volumesFrom": [
             {
                 "sourceContainer": "splunk-java-agent",
                 "readOnly": false
             }
         ],
         "dependsOn": [
             {
                 "containerName": "splunk-java-agent",
                 "condition": "START"
             }
         ],
         "ulimits": [],
         "logConfiguration": {
             "logDriver": "awslogs",
             "options": {
                 "awslogs-create-group": "true",
                 "awslogs-group": "/ecs/agent-init-container-example",
                 "awslogs-region": "eu-west-1",
                 "awslogs-stream-prefix": "ecs"
             },
             "secretOptions": []
         }
     },
     {
         "name": "splunk-otel-collector",
         "image": "quay.io/signalfx/splunk-otel-collector:latest",
         "cpu": 0,
         "portMappings": [],
         "essential": true,
         "environment": [
             {
                 "name": "SPLUNK_CONFIG",
                 "value": "/etc/otel/collector/fargate_config.yaml"
             },
             {
                 "name": "SPLUNK_REALM",
                 "value": "<Realm - us0, us1, etc>"
             },
             {
                 "name": "SPLUNK_ACCESS_TOKEN",
                 "value": "<Access Token>"
             },
             {
                 "name": "ECS_METADATA_EXCLUDED_IMAGES",
                 "value": "[\"quay.io/signalfx/splunk-otel-collector:latest\"]"
             }
         ],
         "environmentFiles": [],
         "mountPoints": [],
         "volumesFrom": [],
         "logConfiguration": {
             "logDriver": "awslogs",
             "options": {
                 "awslogs-create-group": "true",
                 "awslogs-group": "/ecs/agent-init-container-example",
                 "awslogs-region": "eu-west-1",
                 "awslogs-stream-prefix": "ecs"
             },
             "secretOptions": []
         }
     },
     {
         "name": "splunk-java-agent",
         "image": "username/splunk-java-agent:latest",
         "cpu": 0,
         "portMappings": [],
         "essential": false,
         "environment": [],
         "environmentFiles": [],
         "mountPoints": [],
         "volumesFrom": []
     }
 ],
 "executionRoleArn": "arn:aws:iam::539254608140:role/ecsTaskExecutionRole",
 "networkMode": "awsvpc",
 "requiresCompatibilities": [
     "FARGATE"
 ],
 "cpu": "1024",
 "memory": "3072",
 "runtimePlatform": {
     "cpuArchitecture": "X86_64",
     "operatingSystemFamily": "LINUX"
 }
}

Ensure the application container has the required environment variables for Java OpenTelemetry instrumentation:

"environment": [
    {
        "name": "OTEL_SERVICE_NAME",
        "value": "myservice"
    },
    {
        "name": "OTEL_RESOURCE_ATTRIBUTES",
        "value": "deployment.environment=test,service.version=1.0"
    },
    {
        "name": "JAVA_TOOL_OPTIONS",
        "value": "-javaagent:/opt/splunk/splunk-otel-javaagent.jar"
    }
],

Next, tell the application container to get a volume from the splunk-java-agent container. Also, specify that the application container depends on the splunk-java-agent container to ensure the app can access the jar file when it starts:

"volumesFrom": [
  {
    "sourceContainer": "splunk-java-agent",
    "readOnly": false
  }
  ],
"dependsOn": [
  {
    "containerName": "splunk-java-agent",
    "condition": "START"
  }
  ],

This page was last updated on Dec 15, 2023.