Scrape Lightrun dynamic logs using Datadog¶

You can use Datadog to scrape the Lightrun log file and send the log data directly to you Datadog account.

Configure the Lightrun agent to output logs in JSON format - JVM¶

By default, the Lightrun logs are written in XML format. The Datadog agent does not know how to parse XML logs without pre-processing, but it does know how to parse JSON Logs automatically.

You can configure the aggent to output logs in JSON format in the Lightrun agent's config file, located in <PATH_TO_AGENT>/agent.config:

com.lightrun.DynamicLog.FileHandler.formatter=json

tail -f /tmp/lightrun_file_handler_logs*.log

Configure the Lightrun agent to output logs in JSON format - Node.js & Python¶

The Lightrun Node.js & python agents write logs out to the console/stdout by default.

There are 2 approaches you can take in order to make sure the datadog agent collects these logs:

1. Pipe the program's output directly to a file, and add it as a file source in conf.yaml below. This can be done on unix-like systems by node app.js >> /tmp/lightrun_nodejs_logs.log or python app.py >> /tmp/lightrun_python_logs.log respectively.
2. You can use an application-level logger to write logs to a file - i.e. by using winston in a node application or the common logging facility for Python.

Configure Datadog to scrape the log files¶

First you need to enable log collection in /etc/datadog-agent/datadog.yaml by uncommenting the following property:

logs_enabled: true

Now you need to configure the Datadog agent to scrape the Lightrun log file. Create the configuration folder:

mkdir /etc/datadog-agent/conf.d/lightrun.d/

logs:
  - type: file
    path: "/tmp/lightrun_file_handler_logs*.log"
    service: "<YOUR_APPLICATION/SERVICE_NAME>"
    source: "Lightrun"

Restart your Datadog service

sudo service datadog-agent restart

View Lightrun logs in your Datadog account¶

• Login to your Datadog account
• Go to Live Tail

Your logs should now appear in Datadog's live tail console

Troubleshooting¶

• Make sure the Lightrun logs are continuously printed to the log files and are in JSON format

  tail -f /tmp/lightrun_file_handler_logs*.log
  

• Make sure Datadog agent is running

  service datadog-agent status
  

• Make sure Datadog agent successfully found the log file

  datadog-agent status
  

  Example output

  ==========
  Logs Agent
  ==========
  
      Sending compressed logs in HTTPS to agent-http-intake.logs.datadoghq.com on port 443
      BytesSent: 2.5242779e+07
      EncodedBytesSent: 738819
      LogsProcessed: 66557
      LogsSent: 66493
  
    lightrun
    --------
      - Type: file
        Path: /tmp/lightrun_file_handler_logs*.log
        Status: OK
          2 files tailed out of 2 files matching
        Inputs:
          /tmp/lightrun_file_handler_logs1.log
          /tmp/lightrun_file_handler_logs0.log
        BytesRead: 1.1758002e+07
        Average Latency (ms): 49
        24h Average Latency (ms): 49
        Peak Latency (ms): 1256
        24h Peak Latency (ms): 1256
  

• Make sure Datadog's API key is configured and that the API key is valid

  cat /etc/datadog-agent/datadog.yaml | grep api_key:
  

  Example output

  $ cat /etc/datadog-agent/datadog.yaml | grep api_key:
  api_key: ****************************ac11