Configured user-simulator to send spans to jaeger-agent.

Author: Uzziah Eyee

docker-compose.dev.yml

@@ -1,15 +1,27 @@
 version: '3'
 
 services:
-  user-simulator: 
+  user-simulator:
     build: user-simulator
     env_file: user-simulator/.env
+    environment:
+      NODE_ENV: development
+      JAEGER_SERVICE_NAME: user-simulator
+      JAEGER_AGENT_HOST: jaeger-agent
+      JAEGER_AGENT_PORT: 6832
+      JAEGER_SAMPLER_TYPE: const
+      JAEGER_SAMPLER_PARAM: 1
     depends_on:
       - api-server
       - log-shipper
+    ports:
+      - "9230:9229" # nodejs debugging port
+    command: wait.sh http://api-server:3000/health 5 20 "nodemon --inspect=0.0.0.0 ."
+    volumes:
+      - ./user-simulator/src:/usr/src/app
     networks:
       - aparnet
-    
+
   api-server:
     build: api-server
     env_file: api-server/.env

user-simulator/.dockerignore

@@ -1,4 +1,4 @@
 .env
-/node_modules
+node_modules
 npm-debug.log
 .DS_Store

user-simulator/.gitignore

@@ -1,4 +1,4 @@
 .env
-/node_modules
+node_modules
 npm-debug.log
 .DS_Store

user-simulator/Dockerfile

@@ -2,12 +2,17 @@ FROM node:10.10.0-alpine
 
 WORKDIR /usr/src/app
 
+RUN apk add --no-cache bash curl \
+	&& npm install -g nodemon
+
+COPY wait.sh /usr/local/bin/
+RUN chmod +x /usr/local/bin/wait.sh
+
 # optimization to only rebuild npm modules iff package[-lock].json changes
 COPY src/package*.json ./
-
 # For production `RUN npm install --only=production`
 RUN npm install
-
 COPY src .
 
-CMD ["npm", "start"]
+
+CMD ["node", "."]

user-simulator/src/package-lock.json

@@ -11,7 +11,7 @@
   "license": "ISC",
   "dependencies": {
     "axios": "^0.18.0",
-    "dotenv": "^6.0.0",
-    "node-cron": "^1.2.1"
+    "node-cron": "^1.2.1",
+    "jaeger-client": "^3.14.4"
   }
 }

user-simulator/src/package.json

@@ -0,0 +1,36 @@
+#!/bin/bash
+
+# Requires a container with Bash and Curl installed.
+
+is_healthy () {
+	retryInterval=${2:-5}
+	maxAttempts=${3:-1000000}
+
+	i=0
+	while [ $i -lt $maxAttempts ]
+	do
+		status=$(curl -s -L -o /dev/null -w %{http_code} $1)
+
+		# stop trying if we get a success response
+		if [ $status -ge 200 ] && [ $status -lt 300 ]
+		then
+			return 0
+		fi
+		
+		((i++))
+		echo "Attempt $i of $maxAttempts: Endpoint $1 returned code $status. Retrying in $retryInterval seconds."
+		sleep $retryInterval
+	done
+
+	return 1
+}
+
+# args: endpoint, retryInterval (secs), maxAttempts, command
+if is_healthy $1 $2 $3
+then
+	echo "Running command: $4"
+	# vulnerable to input-injection attacts (but I don't care :)
+	eval "$4"
+else
+	echo "Exiting: Cannot run command because health-check failed."
+fi