Per exporter reporting period

[dhontecillas]

⚠️ we need to bump krakend-otel to v0.10.0

krakend/krakend-otel#50

With this PR, we add a custom_metric_reporting_period to the OTEL exporters config (docs about it here: https://www.krakend.io/docs/telemetry/opentelemetry/#exporters-otlp )

custom_metric_reporting_period : unsigned integer specifying the seconds to wait between sending report, 0 will not override the metric_reporting_period set for all metric exporters (https://www.krakend.io/docs/telemetry/opentelemetry/#metric_reporting_period)

In order to easily check the reporting periods, I've created two otel exporters with addresses pointing to non-existing services, so we can see an error in the log, each time it tries to report the metrics:

• one at localhost:5005 that should be reporting each 5 seconds (global configuration)
• one at localhost:5011 that should be reporting each 11 seconds (overriden configuration)

{
  "$schema": "https://www.krakend.io/schema/v3.json",
  "version": 3,
  "name": "My first API Gateway - KrakenD",
  "port": 8081,
  "host": ["http://my_service:8080"],
  "debug_endpoint": true,
  "extra_config": { 
    "telemetry/opentelemetry": {
      "service_name": "krakend_prometheus_service",
      "metric_reporting_period": 5,
      "trace_sample_rate": 1,
      "exporters": {
        "otlp": [
          {
            "disable_metrics": false,
            "disable_traces": true,
            "host": "localhost",
            "name": "five_seconds",
            "port": 5005,
            "use_http": true
          },
          {
            "disable_metrics": false,
            "disable_traces": true,
            "host": "localhost",
            "name": "eleven_seconds",
            "port": 5011,
            "use_http": true,
            "custom_metric_reporting_period": 11,
            "custom_reporting_period": 11
          }
        ]
      },
      "layers": {
        "global": {
          "disable_metrics": false,
          "disable_propagation": false,
          "disable_traces": false,
          "report_headers": true
        },
        "proxy": {
          "disable_metrics": false,
          "disable_traces": true,
          "report_headers": true
        },
        "backend": {
          "metrics": {
            "detailed_connection": true,
            "disable_stage": false,
            "read_payload": false,
            "round_trip": false
          },
          "traces": {
            "detailed_connection": false,
            "disable_stage": false,
            "read_payload": false,
            "report_headers": false,
            "round_trip": false
          }
        }
      }
    }
  },
  "endpoints": [
    {
      "endpoint": "/dashboard",
      "backend": [
        {
          "url_pattern": "/customer.json"
        },
        {
          "url_pattern": "/sales.json"
        }
      ]
    }
  ]
}

2025/03/03 09:58:56 KRAKEND ERROR: [SERVICE: OpenTelemetry] failed to upload metrics: Post "https://localhost:5005/v1/metrics": dial tcp 127.0.0.1:5005: connect: connection refused
2025/03/03 09:59:01 KRAKEND ERROR: [SERVICE: OpenTelemetry] failed to upload metrics: Post "https://localhost:5005/v1/metrics": dial tcp 127.0.0.1:5005: connect: connection refused
2025/03/03 09:59:02 KRAKEND ERROR: [SERVICE: OpenTelemetry] failed to upload metrics: Post "https://localhost:5011/v1/metrics": dial tcp 127.0.0.1:5011: connect: connection refused
2025/03/03 09:59:06 KRAKEND ERROR: [SERVICE: OpenTelemetry] failed to upload metrics: Post "https://localhost:5005/v1/metrics": dial tcp 127.0.0.1:5005: connect: connection refused
2025/03/03 09:59:11 KRAKEND ERROR: [SERVICE: OpenTelemetry] failed to upload metrics: Post "https://localhost:5005/v1/metrics": dial tcp 127.0.0.1:5005: connect: connection refused
2025/03/03 09:59:13 KRAKEND ERROR: [SERVICE: OpenTelemetry] failed to upload metrics: Post "https://localhost:5011/v1/metrics": dial tcp 127.0.0.1:5011: connect: connection refused
2025/03/03 09:59:16 KRAKEND ERROR: [SERVICE: OpenTelemetry] failed to upload metrics: Post "https://localhost:5005/v1/metrics": dial tcp 127.0.0.1:5005: connect: connection refused
2025/03/03 09:59:21 KRAKEND ERROR: [SERVICE: OpenTelemetry] failed to upload metrics: Post "https://localhost:5005/v1/metrics": dial tcp 127.0.0.1:5005: connect: connection refused
2025/03/03 09:59:24 KRAKEND ERROR: [SERVICE: OpenTelemetry] failed to upload metrics: Post "https://localhost:5011/v1/metrics": dial tcp 127.0.0.1:5011: connect: connection refused
2025/03/03 09:59:26 KRAKEND ERROR: [SERVICE: OpenTelemetry] failed to upload metrics: Post "https://localhost:5005/v1/metrics": dial tcp 127.0.0.1:5005: connect: connection refused
2025/03/03 09:59:31 KRAKEND ERROR: [SERVICE: OpenTelemetry] failed to upload metrics: Post "https://localhost:5005/v1/metrics": dial tcp 127.0.0.1:5005: connect: connection refused
2025/03/03 09:59:35 KRAKEND ERROR: [SERVICE: OpenTelemetry] failed to upload metrics: Post "https://localhost:5011/v1/metrics": dial tcp 127.0.0.1:5011: connect: connection refused
2025/03/03 09:59:36 KRAKEND ERROR: [SERVICE: OpenTelemetry] failed to upload metrics: Post "https://localhost:5005/v1/metrics": dial tcp 127.0.0.1:5005: connect: connection refused