@opentelemetry/propagator-instana/build/esm/InstanaPropagator.js

The OpenTelemetry Instana Propagator implements the propagation format used by IBM Observability by Instana

/*
 * Copyright The OpenTelemetry Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import { trace, isSpanContextValid, isValidSpanId, isValidTraceId, TraceFlags, INVALID_TRACEID, INVALID_SPANID, } from '@opentelemetry/api';
/** Instana header names */
export const INSTANA_TRACE_ID_HEADER = 'X-INSTANA-T';
export const INSTANA_SPAN_ID_HEADER = 'X-INSTANA-S';
export const INSTANA_LEVEL_HEADER = 'X-INSTANA-L';
const FIELDS = [
    INSTANA_TRACE_ID_HEADER,
    INSTANA_SPAN_ID_HEADER,
    INSTANA_LEVEL_HEADER,
];
function readHeader(carrier, getter, key) {
    // By convention, X-INSTANA-* headers are sent all-upper-case. For http and http/2, Node.js normalizes all headers to
    // all-lower-case, that's why we first read via the lower case variant of the header name. For other protocols, no
    // such normalization happens, so we also need to read via the original all-upper-case variant.
    let header = getter.get(carrier, key.toLowerCase()) || getter.get(carrier, key);
    if (Array.isArray(header))
        [header] = header;
    return header || '';
}
/**
 * Propagator for the Instana HTTP headers.
 */
export class InstanaPropagator {
    /**
     * Injects the current span context into Instana's vendor specific trace correlation headers (X-INSTANA-T, X-INSTANA-S
     * and X-INSTANA-L).
     */
    inject(context, carrier, setter) {
        const spanContext = trace.getSpan(context)?.spanContext();
        if (!spanContext || !isSpanContextValid(spanContext)) {
            return;
        }
        setter.set(carrier, INSTANA_TRACE_ID_HEADER, spanContext.traceId);
        setter.set(carrier, INSTANA_SPAN_ID_HEADER, spanContext.spanId);
        const sampled = (spanContext.traceFlags & TraceFlags.SAMPLED) === TraceFlags.SAMPLED;
        setter.set(carrier, INSTANA_LEVEL_HEADER, sampled ? '1' : '0');
    }
    /**
     * Extracts the span context from Instana's vendor specific trace correlation headers (X-INSTANA-T, X-INSTANA-S
     * and X-INSTANA-L).
     */
    extract(context, carrier, getter) {
        let traceId = readHeader(carrier, getter, INSTANA_TRACE_ID_HEADER);
        if (traceId && traceId.length < 32) {
            traceId = traceId.padStart(32, '0');
        }
        let spanId = readHeader(carrier, getter, INSTANA_SPAN_ID_HEADER);
        if (spanId && spanId.length < 16) {
            spanId = spanId.padStart(16, '0');
        }
        const level = readHeader(carrier, getter, INSTANA_LEVEL_HEADER) || '1';
        const sampled = level !== '0';
        const traceFlags = sampled ? TraceFlags.SAMPLED : TraceFlags.NONE;
        if (isValidTraceId(traceId) && isValidSpanId(spanId)) {
            context = trace.setSpan(context, trace.wrapSpanContext({
                traceId,
                spanId,
                isRemote: true,
                traceFlags,
            }));
        }
        else if (!sampled) {
            // Even if we do not receive a trace ID/span ID via X-INSTANA-T/X-INSTANA-S, if there is an explicit incoming
            // X-INSTANA-L=0, we want to capture that via trace flags. For Instana tracers, it is perfectly valid to send
            // X-INSTANA-L=0 without X-INSTANA-T/-S.
            context = trace.setSpan(context, trace.wrapSpanContext({
                traceId: INVALID_TRACEID,
                spanId: INVALID_SPANID,
                isRemote: true,
                traceFlags,
            }));
        }
        return context;
    }
    fields() {
        return FIELDS.slice();
    }
}
//# sourceMappingURL=InstanaPropagator.js.map