docs/en/latest/plugins/opentelemetry.md

title: opentelemetry keywords:

Apache APISIX
API Gateway
Plugin
OpenTelemetry description: The opentelemetry Plugin instruments APISIX and sends traces to OpenTelemetry collector based on the OpenTelemetry specification, in binary-encoded OLTP over HTTP.

Description

The opentelemetry Plugin can be used to report tracing data according to the OpenTelemetry Specification.

The Plugin only supports binary-encoded OLTP over HTTP.

Configurations

By default, configurations of the Service name, tenant ID, collector, and batch span processor are pre-configured in default configuration.

You can change this configuration of the Plugin through the endpoint apisix/admin/plugin_metadata/opentelemetry For example:

:::note You can fetch the admin_key from config.yaml and save to an environment variable with the following command:

admin_key=$(yq '.deployment.admin.admin_key[0].key' conf/config.yaml | sed 's/"//g')

:::

curl http://127.0.0.1:9180/apisix/admin/plugin_metadata/opentelemetry -H "X-API-KEY: $admin_key" -X PUT -d '
{
    "trace_id_source": "x-request-id",
    "resource": {
      "service.name": "APISIX"
    },
    "collector": {
      "address": "127.0.0.1:4318",
      "request_timeout": 3,
      "request_headers": {
        "Authorization": "token"
      }
    },
    "batch_span_processor": {
      "drop_on_queue_full": false,
      "max_queue_size": 1024,
      "batch_timeout": 2,
      "inactive_timeout": 1,
      "max_export_batch_size": 16
    },
    "set_ngx_var": false
}'

Attributes

Name	Type	Required	Default	Valid Values	Description
sampler	object	False	-	-	Sampling configuration.
sampler.name	string	False	`always_off`	[“always_on”, “always_off”, “trace_id_ratio”, “parent_base”]	Sampling strategy. To always sample, use `always_on`. To never sample, use `always_off`. To randomly sample based on a given ratio, use `trace_id_ratio`. To use the sampling decision of the span's parent, use `parent_base`. If there is no parent, use the root sampler.
sampler.options	object	False	-	-	Parameters for sampling strategy.
sampler.options.fraction	number	False	0	[0, 1]	Sampling ratio when the sampling strategy is `trace_id_ratio`.
sampler.options.root	object	False	-	-	Root sampler when the sampling strategy is `parent_base` strategy.
sampler.options.root.name	string	False	-	[“always_on”, “always_off”, “trace_id_ratio”]	Root sampling strategy.
sampler.options.root.options	object	False	-	-	Root sampling strategy parameters.
sampler.options.root.options.fraction	number	False	0	[0, 1]	Root sampling ratio when the sampling strategy is `trace_id_ratio`.
additional_attributes	array[string]	False	-	-	Additional attributes appended to the trace span. Support built-in variables in values.
additional_header_prefix_attributes	array[string]	False	-	-	Headers or header prefixes appended to the trace span's attributes. For example, use `x-my-header"` or `x-my-headers-*` to include all headers with the prefix `x-my-headers-`.

Examples

The examples below demonstrate how you can work with the opentelemetry Plugin for different scenarios.

Enable `opentelemetry` Plugin

By default, the opentelemetry Plugin is disabled in APISIX. To enable, add the Plugin to your configuration file as such:

plugins:
  - ...
  - opentelemetry

Reload APISIX for changes to take effect.

See static configurations for other available options you can configure in config.yaml.

Send Traces to OpenTelemetry

The following example demonstrates how to trace requests to a Route and send traces to OpenTelemetry.

Start an OpenTelemetry collector instance in Docker:

docker run -d --name otel-collector -p 4318:4318 otel/opentelemetry-collector-contrib

Create a Route with opentelemetry Plugin:

curl "http://127.0.0.1:9180/apisix/admin/routes" -X PUT \
  -H "X-API-KEY: ${admin_key}" \
  -d '{
    "id": "otel-tracing-route",
    "uri": "/anything",
    "plugins": {
      "opentelemetry": {
        "sampler": {
          "name": "always_on"
        }
      }
    },
    "upstream": {
      "type": "roundrobin",
      "nodes": {
        "httpbin.org": 1
      }
    }
  }'

Send a request to the Route:

curl "http://127.0.0.1:9080/anything"

You should receive an HTTP/1.1 200 OK response.

In OpenTelemetry collector's log, you should see information similar to the following:

2024-02-18T17:14:03.825Z info ResourceSpans #0
Resource SchemaURL:
Resource attributes:
     -> telemetry.sdk.language: Str(lua)
     -> telemetry.sdk.name: Str(opentelemetry-lua)
     -> telemetry.sdk.version: Str(0.1.1)
     -> hostname: Str(e34673e24631)
     -> service.name: Str(APISIX)
ScopeSpans #0
ScopeSpans SchemaURL:
InstrumentationScope opentelemetry-lua
Span #0
    Trace ID       : fbd0a38d4ea4a128ff1a688197bc58b0
    Parent ID      :
    ID             : af3dc7642104748a
    Name           : GET /anything
    Kind           : Server
    Start time     : 2024-02-18 17:14:03.763244032 +0000 UTC
    End time       : 2024-02-18 17:14:03.920229888 +0000 UTC
    Status code    : Unset
    Status message :
Attributes:
     -> net.host.name: Str(127.0.0.1)
     -> http.method: Str(GET)
     -> http.scheme: Str(http)
     -> http.target: Str(/anything)
     -> http.user_agent: Str(curl/7.64.1)
     -> apisix.route_id: Str(otel-tracing-route)
     -> apisix.route_name: Empty()
     -> http.route: Str(/anything)
     -> http.status_code: Int(200)
{"kind": "exporter", "data_type": "traces", "name": "debug"}

To visualize these traces, you can export your telemetry to backend Services, such as Zipkin and Prometheus. See exporters for more details.

Using Trace Variables in Logging

The following example demonstrates how to configure the opentelemetry Plugin to set the following built-in variables, which can be used in logger Plugins or access logs:

opentelemetry_context_traceparent: trace parent ID
opentelemetry_trace_id: trace ID of the current span
opentelemetry_span_id: span ID of the current span

Configure the plugin metadata to set set_ngx_var as true:

curl http://127.0.0.1:9180/apisix/admin/plugin_metadata/opentelemetry -H "X-API-KEY: $admin_key" -X PUT -d '
{
    "set_ngx_var": true
}'

Update the configuration file as below. You should customize the access log format to use the opentelemetry Plugin variables.

nginx_config:
  http:
    enable_access_log: true
    access_log_format: '{"time": "$time_iso8601","opentelemetry_context_traceparent": "$opentelemetry_context_traceparent","opentelemetry_trace_id": "$opentelemetry_trace_id","opentelemetry_span_id": "$opentelemetry_span_id","remote_addr": "$remote_addr"}'
    access_log_format_escape: json

Reload APISIX for configuration changes to take effect.

You should see access log entries similar to the following when you generate requests:

{"time": "18/Feb/2024:15:09:00 +0000","opentelemetry_context_traceparent": "00-fbd0a38d4ea4a128ff1a688197bc58b0-8f4b9d9970a02629-01","opentelemetry_trace_id": "fbd0a38d4ea4a128ff1a688197bc58b0","opentelemetry_span_id": "af3dc7642104748a","remote_addr": "172.10.0.1"}