Run Elastic Agent in a container

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You can run Elastic Agent inside a container — either with Fleet Server or standalone. Docker images for all versions of Elastic Agent are available from the Elastic Docker registry. If you are running in Kubernetes, refer to run Elastic Agent on ECK.

Considerations:

  • When Elastic Agent runs inside a container, it cannot be upgraded through Fleet as it expects that the container itself is upgraded.
  • Enrolling and running an Elastic Agent is usually a two-step process. However, this doesn’t work in a container, so a special subcommand, container, is called. This command allows environment variables to configure all properties, and runs the enroll and run commands as a single command.
What you need
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Step 1: Pull the image
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There are two images for Elastic Agent, elastic-agent and elastic-agent-complete. The elastic-agent image contains all the binaries for running Beats, while the elastic-agent-complete image contains these binaries plus additional dependencies to run browser monitors through Elastic Synthetics. Refer to Synthetic monitoring via Elastic Agent and Fleet for more information.

Run the docker pull command against the Elastic Docker registry:

docker pull docker.elastic.co/beats/elastic-agent:8.6.2

If you want to run Synthetics tests, run the docker pull command to fetch the elastic-agent-complete image:

docker pull docker.elastic.co/beats/elastic-agent-complete:8.6.2
Step 2: Get aware of the Elastic Agent container command
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The Elastic Agent container command offers a wide variety of options. To see the full list, run:

docker run --rm docker.elastic.co/beats/elastic-agent:8.6.2 elastic-agent container -h
Step 3: Run the Elastic Agent image
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docker run \
  --env FLEET_ENROLL=1 \ 
  --env FLEET_URL=<fleet-server-host-url> \ 
  --env FLEET_ENROLLMENT_TOKEN=<enrollment-token> \ 
  --rm docker.elastic.co/beats/elastic-agent:8.6.2 

Set to 1 to enroll the Elastic Agent into Fleet Server.

URL to enroll the Fleet Server into. You can find it in Kibana. Select Management → Fleet → Fleet Settings, and copy the Fleet Server host URL.

The token to use for enrollment. Close the flyout panel and select Enrollment tokens. Find the Agent policy you want to enroll Elastic Agent into, and display and copy the secret token. To learn how to create a policy, refer to Create an agent policy without using the UI.

If you want to run elastic-agent-complete image, replace elastic-agent to elastic-agent-complete. Use the elastic-agent user instead of root to run Synthetics Browser tests. Synthetic tests cannot run under the root user. Refer to Synthetics Fleet Quickstart for more information.

Refer to Environment variables for all available options.

Step 4: View your data in Kibana
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  1. Launch Kibana:

    1. Log in to your Elastic Cloud account.
    2. Navigate to the Kibana endpoint in your deployment.
  2. To check if your Elastic Agent is enrolled in Fleet, go to Management → Fleet → Agents.

    Elastic Agents Fleet page
  3. To view data flowing in, go to Analytics → Discover and select the index metrics-*, or even more specific, metrics-kubernetes.*. If you can’t see these indexes, create a data view for them.
  4. To view predefined dashboards, either select Analytics→Dashboard or install assets through an integration.
Docker compose
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You can run Elastic Agent in docker-compose. The example below shows how to enroll an Elastic Agent:

version: "3"
services:
  elastic-agent:
    image: docker.elastic.co/beats/elastic-agent:8.6.2 
    container_name: elastic-agent
    restart: always
    user: root # note, synthetic browser monitors require this set to `elastic-agent`
    environment:
      - FLEET_ENROLLMENT_TOKEN=<enrollment-token>
      - FLEET_ENROLL=1
      - FLEET_URL=<fleet-server-url>

Switch elastic-agent to elastic-agent-complete if you intend to use the complete version. Use the elastic-agent user instead of root to run Synthetics Browser tests. Synthetic tests cannot run under the root user. Refer to Synthetics Fleet Quickstart for more information.

If you need to run Fleet Server as well, adjust the docker-compose file above by adding these environment variables:

      - FLEET_SERVER_ENABLE=true
      - FLEET_SERVER_ELASTICSEARCH_HOST=<elasticsearch-host>
      - FLEET_SERVER_SERVICE_TOKEN=<service-token>

Refer to Environment variables for all available options.

Logs
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Since a container supports only a single version of Elastic Agent, logs and state are stored a bit differently than when running an Elastic Agent outside of a container. The logs can be found under: /usr/share/elastic-agent/state/data/logs/*.

It’s important to note that only the logs from the Elastic Agent process itself are logged to stdout. Subprocess logs are not. Each subprocess writes its own logs to the default directory inside the logs directory:

/usr/share/elastic-agent/state/data/logs/default/*

Running into errors with Fleet Server? Check the fleet-server subprocess logs for more information.

Debugging
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A monitoring endpoint can be enabled to expose resource usage and event processing data. The endpoint is compatible with Elastic Agents running in both Fleet mode and Standalone mode.

Enable the monitoring endpoint in elastic-agent.yml on the host where the Elastic Agent is installed. A sample configuration looks like this:

agent.monitoring:
  enabled: true 
  logs: true 
  metrics: true 
  http:
      enabled: true 
      host: localhost 
      port: 6791 

Enable monitoring of running processes.

Enable log monitoring.

Enable metrics monitoring.

Expose Elastic Agent metrics over HTTP. By default, sockets and named pipes are used.

The hostname, IP address, Unix socket, or named pipe that the HTTP endpoint will bind to. When using IP addresses, we recommend only using localhost.

The port that the HTTP endpoint will bind to.

The above configuration exposes a monitoring endpoint at http://localhost:6791/processes.

http://localhost:6791/processes output
{
   "processes":[
      {
         "id":"metricbeat-default",
         "pid":"36923",
         "binary":"metricbeat",
         "source":{
            "kind":"configured",
            "outputs":[
               "default"
            ]
         }
      },
      {
         "id":"filebeat-default-monitoring",
         "pid":"36924",
         "binary":"filebeat",
         "source":{
            "kind":"internal",
            "outputs":[
               "default"
            ]
         }
      },
      {
         "id":"metricbeat-default-monitoring",
         "pid":"36925",
         "binary":"metricbeat",
         "source":{
            "kind":"internal",
            "outputs":[
               "default"
            ]
         }
      }
   ]
}

Each process ID in the /processes output can be accessed for more details.

http://localhost:6791/processes/{process-name} output
{
   "beat":{
      "cpu":{
         "system":{
            "ticks":537,
            "time":{
               "ms":537
            }
         },
         "total":{
            "ticks":795,
            "time":{
               "ms":796
            },
            "value":795
         },
         "user":{
            "ticks":258,
            "time":{
               "ms":259
            }
         }
      },
      "info":{
         "ephemeral_id":"eb7e8025-7496-403f-9f9a-42b20439c737",
         "uptime":{
            "ms":75332
         },
         "version":"7.14.0"
      },
      "memstats":{
         "gc_next":23920624,
         "memory_alloc":20046048,
         "memory_sys":76104712,
         "memory_total":60823368,
         "rss":83165184
      },
      "runtime":{
         "goroutines":58
      }
   },
   "libbeat":{
      "config":{
         "module":{
            "running":4,
            "starts":4,
            "stops":0
         },
         "reloads":1,
         "scans":1
      },
      "output":{
         "events":{
            "acked":0,
            "active":0,
            "batches":0,
            "dropped":0,
            "duplicates":0,
            "failed":0,
            "toomany":0,
            "total":0
         },
         "read":{
            "bytes":0,
            "errors":0
         },
         "type":"elasticsearch",
         "write":{
            "bytes":0,
            "errors":0
         }
      },
      "pipeline":{
         "clients":4,
         "events":{
            "active":231,
            "dropped":0,
            "failed":0,
            "filtered":0,
            "published":231,
            "retry":112,
            "total":231
         },
         "queue":{
            "acked":0,
            "max_events":4096
         }
      }
   },
   "metricbeat":{
      "system":{
         "cpu":{
            "events":8,
            "failures":0,
            "success":8
         },
         "filesystem":{
            "events":80,
            "failures":0,
            "success":80
         },
         "memory":{
            "events":8,
            "failures":0,
            "success":8
         },
         "network":{
            "events":135,
            "failures":0,
            "success":135
         }
      }
   },
   "system":{
      "cpu":{
         "cores":8
      },
      "load":{
         "1":2.5957,
         "15":5.415,
         "5":3.5815,
         "norm":{
            "1":0.3245,
            "15":0.6769,
            "5":0.4477
         }
      }
   }
}