In OpenTelemetry configuration files, connectors have their own dedicated section, similar to receivers and processors.

Add the routing connector: In the Gateway terminal window edit gateway.yaml and add the following below the receivers: section and above the processors: section:

connectors:
  routing:
    default_pipelines: [traces/standard] # Default pipeline if no rule matches
    error_mode: ignore                   # Ignore errors in routing
    table:                               # Define routing rules
      # Routes spans to a target pipeline if the resourceSpan attribute matches the rule
      - statement: route() where attributes["deployment.environment"] == "security_applications"
        pipelines: [traces/security]     # Target pipeline 

The rules above apply to traces, but this approach also applies to metrics and logs, allowing them to be routed based on attributes in resourceMetrics or resourceLogs.

Configure file: exporters: The routing connector requires separate targets for routing. Add two file exporters, file/traces/security and file/traces/standard, to ensure data is directed correctly.

  file/traces/standard:                    # Exporter for regular traces
    path: "./gateway-traces-standard.out"  # Path for saving trace data
    append: false                          # Overwrite the file each time
  file/traces/security:                    # Exporter for security traces
    path: "./gateway-traces-security.out"  # Path for saving trace data
    append: false                          # Overwrite the file each time 

Add both the standard and security traces pipelines:

1. Add the Standard pipeline: This pipeline processes all spans that do not match the routing rule.
   This pipeline is using routing as its receiver. Place it below the existing traces: pipeline, keeping its configuration unchanged for now:

       traces/standard:                # Default pipeline for unmatched spans
         receivers: 
         - routing                     # Receive data from the routing connector
         processors:
         - memory_limiter              # Limits memory usage
         - resource/add_mode           # Adds collector mode metadata
         exporters:
         - debug                       # Debug exporter
         - file/traces/standard        # File exporter for unmatched spans

2. Configure the Security pipeline: This pipeline will handle all spans that match the routing rule.
   This also uses routing as its receiver. Add this below the Standard one:

       traces/security:                # New Security Traces/Spans Pipeline       
         receivers: 
         - routing                     # Routing Connector, Only receives data from Connector
         processors:
         - memory_limiter              # Memory Limiter Processor
         - resource/add_mode           # Adds collector mode metadata
         exporters:
         - debug                       # Debug Exporter 
         - file/traces/security        # File Exporter for spans matching rule

Update the traces pipeline to use routing:

1. To enable routing, update the original traces: pipeline by using routing as the only exporter.
   This ensures all span data is sent through the routing connector for evaluation.

2. Remove all processors and replace it with an empty array []. These are now defined in the traces/standard and traces/security pipelines.

     pipelines:
       traces:                           # Original traces pipeline
         receivers: 
         - otlp                          # OTLP Receiver
         processors: []
         exporters: 
         - routing                       # Routing Connector

Start the Gateway: In the Gateway terminal window navigate to the [WORKSHOP]/8-routing directory and run:

../otelcol --config=gateway.yaml

Start the Agent: In the Agent terminal window navigate to the [WORKSHOP]/8-routing directory and run:

../otelcol --config=agent.yaml

Create new security trace: In the Tests terminal window navigate to the [WORKSHOP]/8-routing directory.

The following JSON contains attributes which will trigger the routing rule. Copy the content from the tab below and save into a file named security.json.

{"resourceSpans":[{"resource":{"attributes":[{"key":"service.name","value":{"stringValue":"password_check"}},{"key":"deployment.environment","value":{"stringValue":"security_applications"}}]},"scopeSpans":[{"scope":{"name":"my.library","version":"1.0.0","attributes":[{"key":"my.scope.attribute","value":{"stringValue":"some scope attribute"}}]},"spans":[{"traceId":"5B8EFFF798038103D269B633813FC60C","spanId":"EEE19B7EC3C1B174","parentSpanId":"EEE19B7EC3C1B173","name":"I'm a server span","startTimeUnixNano":"1544712660000000000","endTimeUnixNano":"1544712661000000000","kind":2,"attributes":[{"keytest":"my.span.attr","value":{"stringValue":"some value"}}]}]}]}]}

Send a Regular Span:

1. Locate the Test terminal and navigate to the [WORKSHOP]/8-routing directory.
2. Send a regular span using the trace.json file to confirm proper communication.

Both the Agent and Gateway should display debug information, including the span you just sent. The gateway will also generate a new gateway-traces-standard.out file, as this is now the designated destination for regular spans.

Send a Security Span:

1. Ensure both the Agent and Gateway are running.
2. Send a security span using the security.json file to test the gateway’s routing rule.

Again, both the Agent and Gateway should display debug information, including the span you just sent. This time, the Gateway will write a line to the gateway-traces-security.out file, which is designated for spans where the deployment.environment resource attribute matches "security_applications". The gateway-traces-standard.out should be unchanged.

You can repeat this scenario multiple times, and each trace will be written to its corresponding output file.