Datadog Agent Debugging Checklist for Docker Containers

📌 Datadog Agent Debugging Checklist for Docker Containers

If your Datadog Agent is running as a Docker container but your metrics or logs are missing from the Datadog UI, follow this guide to diagnose and resolve the issue efficiently.

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1️⃣ Verify Datadog Agent Container is Running

Run the following command to check if the Datadog Agent container is active:

docker ps | grep datadog-agent

✅ Expected Output:

CONTAINER ID   IMAGE                            COMMAND                  STATUS              NAMES
abcdef123456   gcr.io/datadoghq/agent:7         '/bin/entrypoint.sh'                  Up X minutes        datadog-agent

🚨 If the container is not running, restart it:

docker-compose -f /opt/datadog/docker-compose.yml up -d

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2️⃣ Check Datadog Agent Logs

To review logs for potential issues:

docker logs --tail 50 datadog-agent

✅ Look for messages related to:

• API key authentication failures
• Connection refused errors
• Failure to reach Datadog servers

🚨 If errors appear, check environment variables in your docker-compose.yml.

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3️⃣ Verify API Key & Connectivity

Ensure the API key is correctly set inside the container:

docker exec -it datadog-agent env | grep DD_API_KEY

Then, test connectivity manually:

docker exec -it datadog-agent sh -c 'curl -v "https://api.datadoghq.com/api/v1/validate?api_key=$DD_API_KEY"'

✅ Expected Response (200 OK):

{"valid":true}

🚨 If response is 403 Forbidden or 401 Unauthorized, the API key is incorrect. Verify and update it in your docker-compose.yml.

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4️⃣ Ensure Datadog Agent Can Reach Datadog Servers

docker exec -it datadog-agent curl -v https://app.datadoghq.com

✅ Expected Output: No Connection refused or Timeout errors.

🚨 If blocked, allow outbound traffic:

sudo ufw allow out to api.datadoghq.com

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5️⃣ Verify Datadog Agent is Sending Data

docker exec -it datadog-agent agent status | grep -A10 "Forwarder"

✅ Look for:

Transactions flushed: successfully: X, errors: 0

🚨 If errors: X appears, the agent is not sending data. Restart it:

docker-compose -f /opt/datadog/docker-compose.yml restart datadog-agent

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6️⃣ Manually Send a Test Metric

If the agent is running but not visible, manually send a test metric:

docker exec -it datadog-agent agent telemetry send test.metric 1

✅ Check in Datadog UI → Metrics Explorer and search for test.metric.

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📌 Summary of Debugging Steps

Check	Command	Expected Result
Container is running	`docker ps	grep datadog-agent`	Container is running
Check logs for errors	docker logs --tail 50 datadog-agent	No connection/auth errors
Verify API key	`docker exec -it datadog-agent env	grep DD_API_KEY`	Correct API key is set
Test Datadog connectivity	docker exec -it datadog-agent sh -c 'curl -v "https://api.datadoghq.com/api/v1/validate?api_key=$DD_API_KEY"'	No network errors
Check agent network reachability	docker exec -it datadog-agent curl -v https://app.datadoghq.com	Successful connection
Ensure metrics are sent	`docker exec -it datadog-agent agent status	grep -A10 "Forwarder"`	No errors in transactions
Manually send a test metric	docker exec -it datadog-agent agent telemetry send test.metric 1	Appears in Datadog UI

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🚀 Follow these steps to ensure your Docker-based Datadog Agent is properly configured! Need more help? Drop a comment or reach out! 🚀