ddTracer.ts

const ddTrace = require('dd-trace');
import { config } from "config"

export const tracer = ddTrace.init({
    enabled: true,
    env: config.env,
    logInjection: true,
    sampleRate: 1,
});

server.ts

const tracer = require("./ddTracer");

import * as Koa from "koa";
import * as Router from "koa-router";
import * as traceView from "./traceView";

const app = new Koa();
const traceRouter = new Router();

// the route we care about
traceRouter.get("/trace/traceTest/:user", traceView.traceTest);

traceDAL.ts

export const functionOne = async () => {
    logger.info('made it in functionOne');
    const childOf = tracer.scope().active();
    const functionOneSpan = tracer.startSpan('functionOne', { childOf })
    
    let result: any = await sleep(10);

      try {
        await functionTwo();
      } catch (error) {
        logger.error(error);
      }
      functionOneSpan.finish();
      
    return result;
};

export const functionTwo = async () => {
    logger.info('made it in functionTwo');
    const childOf = tracer.scope().active();
    const functionTwoSpan = tracer.startSpan('functionTwo', { childOf })
    
    let result: any;

    await sleep(5);

    result = await appdb();

    functionTwoSpan.finish();

    return result;
}

traceView.ts

const tracer = require("dd-trace");
import { trace } from "./traceDAL";

export const traceTest = async (ctx: Context) => {
    logger.info('in the view in traceTest')
    // postgres call
    const fromAppDB = await trace.appdb();
    // redis call
    const fromRedis = await trace.redis();
    // mysql call
    const fromUserDB = await trace.userdb(ctx.params.user);
    
    // internal application function
    const fromInternalFunctions = await trace.functionOne();

    ctx.body = { fromAppDB, fromUserDB, fromRedis, fromInternalFunctions };
};