1.1 Verify Gateway Configuration

The OpenTelemetry Gateway serves as a central hub for receiving, processing, and exporting telemetry data. It sits between your telemetry sources (such as applications and services) and your observability backends like Splunk Observability Cloud.

By centralizing telemetry traffic, the gateway enables advanced features such as data filtering, enrichment, transformation, and routing to one or more destinations. It helps reduce the burden on individual services by offloading telemetry processing and ensures consistent, standardized data across distributed systems.

This makes your observability pipeline easier to manage, scale, and analyze—especially in complex, multi-service environments.

Exercise

Open or create your second terminal window and name it Gateway. Navigate to the first exercise directory [WORKSHOP]/1-agent-gateway then check the contents of the gateway.yaml file.

This file outlines the core structure of the OpenTelemetry Collector as deployed in Gateway mode.

Understanding the Gateway Configuration

Let’s explore the gateway.yaml file that defines how the OpenTelemetry Collector is configured in Gateway mode during this workshop. This Gateway is responsible for receiving telemetry from the Agent, then processing and exporting it for inspection or forwarding.

OTLP Receiver (Custom Port)
```
receivers:
  otlp:
    protocols:
      http:
        endpoint: "0.0.0.0:5318"
```
The port 5318 matches the otlphttp exporter in the Agent configuration, ensuring that all telemetry data sent by the Agent is accepted by the Gateway.

Note

This separation of ports avoids conflicts and keeps responsibilities clear between agent and gateway roles.

File Exporters

The Gateway uses three file exporters to output telemetry data to local files. These exporters are defined as:

exporters:                        # List of exporters
  debug:                          # Debug exporter
    verbosity: detailed           # Enable detailed debug output
  file/traces:                    # Exporter Type/Name
    path: "./gateway-traces.out"  # Path for OTLP JSON output for traces
    append: false                 # Overwrite the file each time
  file/metrics:                   # Exporter Type/Name
    path: "./gateway-metrics.out" # Path for OTLP JSON output for metrics
    append: false                 # Overwrite the file each time
  file/logs:                      # Exporter Type/Name
    path: "./gateway-logs.out"    # Path for OTLP JSON output for logs
    append: false                 # Overwrite the file each time

Each exporter writes a specific signal type to its corresponding file.

These files are created once the gateway is started and will be populated with real telemetry as the agent sends data. You can monitor these files in real time to observe the flow of telemetry through your pipeline.