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opentelemetry

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#

NameTypeRequiredDefaultValid ValuesDescription
samplerobjectFalse--Sampling configuration.
sampler.namestringFalsealways_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.optionsobjectFalse--Parameters for sampling strategy.
sampler.options.fractionnumberFalse0[0, 1]Sampling ratio when the sampling strategy is trace_id_ratio.
sampler.options.rootobjectFalse--Root sampler when the sampling strategy is parent_base strategy.
sampler.options.root.namestringFalse-["always_on", "always_off", "trace_id_ratio"]Root sampling strategy.
sampler.options.root.optionsobjectFalse--Root sampling strategy parameters.
sampler.options.root.options.fractionnumberFalse0[0, 1]Root sampling ratio when the sampling strategy is trace_id_ratio.
additional_attributesarray[string]False--Additional attributes appended to the trace span. Support built-in variables in values.
additional_header_prefix_attributesarray[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:

config.yaml
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

Update the configuration file as below. You should customize the access log format to use the opentelemetry Plugin variables, and set opentelemetry variables in the set_ngx_var field.

conf/config.yaml
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
plugin_attr:
opentelemetry:
set_ngx_var: true

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"}