@azure/eventgrid
Version:
An isomorphic client library for the Azure Event Grid service.
57 lines • 3.23 kB
JavaScript
;
// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.
Object.defineProperty(exports, "__esModule", { value: true });
exports.cloudEventDistributedTracingEnricherPolicyName = exports.ContentTypeHeaderName = exports.TraceStateHeaderName = exports.TraceParentHeaderName = exports.CloudEventBatchContentType = void 0;
exports.cloudEventDistributedTracingEnricherPolicy = cloudEventDistributedTracingEnricherPolicy;
exports.CloudEventBatchContentType = "application/cloudevents-batch+json; charset=utf-8";
exports.TraceParentHeaderName = "traceparent";
exports.TraceStateHeaderName = "tracestate";
exports.ContentTypeHeaderName = "Content-Type";
/**
* The programmatic identifier of the cloudEventDistributedTracingEnricherPolicy.
*/
exports.cloudEventDistributedTracingEnricherPolicyName = "cloudEventDistributedTracingEnricherPolicy";
/**
* cloudEventDistributedTracingEnricherPolicy is a policy which adds distributed tracing information
* to a batch of cloud events. It does so by copying the `traceparent` and `tracestate` properties
* from the HTTP request into the individual events as extension properties.
*
* This will only happen in the case where an event does not have a `traceparent` defined already. This
* allows events to explicitly set a traceparent and tracestate which would be respected during "multi-hop
* transmition".
*
* See https://github.com/cloudevents/spec/blob/master/extensions/distributed-tracing.md
* for more information on distributed tracing and cloud events.
*/
function cloudEventDistributedTracingEnricherPolicy() {
return {
name: exports.cloudEventDistributedTracingEnricherPolicyName,
async sendRequest(request, next) {
const traceparent = request.headers.get(exports.TraceParentHeaderName);
const tracestate = request.headers.get(exports.TraceStateHeaderName);
if (request.headers.get(exports.ContentTypeHeaderName) === exports.CloudEventBatchContentType &&
typeof request.body === "string" &&
traceparent) {
// per the cloud event batched content type we know the body is an array encoded in JSON.
const parsedBody = JSON.parse(request.body);
for (const item of parsedBody) {
// When using the distributed tracing extension, the "traceparent" is a required property
// and "tracestate" is optional. This means if an item already has a "traceparent" property
// we should not stomp over it. Well formed events will not have a "tracestate" without
// also having a "traceparent" so there's no need to guard against that case.
if (typeof item !== "object" || item.traceparent) {
continue;
}
item.traceparent = traceparent;
if (tracestate) {
item.tracestate = tracestate;
}
}
request.body = JSON.stringify(parsedBody);
}
return next(request);
},
};
}
//# sourceMappingURL=cloudEventDistrubtedTracingEnricherPolicy.js.map