add lab6 using express-prom-bundle

Author: csantanapr

README.md

@@ -26,4 +26,6 @@ Combined all examples [lab5](./lab5/README.md)
 
 Putting all the examples together, collects all metrics, sends to push gateway and available via scrape endpoint on the Node.js web server
 
+## Lab 6
 
+Using the prom-client express middleware wrapper [express-prom-bundle](https://www.npmjs.com/package/express-prom-bundle)

lab1/README.md

@@ -27,9 +27,14 @@ npm install
 npm start
 ```
 
-Get the metrics via `/metrics`
+Use the app
+```bash
+open http://localhost:8080/
 ```
-curl localhost:8080/metrics
+
+Get the metrics via `/metrics`
+```bash
+curl http://localhost:8080/metrics
 ```
 
 Here is an example of the output:

lab2/README.md

@@ -27,9 +27,14 @@ npm install
 npm start
 ```
 
-Get the metrics via `/metrics`
+Use the app
+```bash
+open http://localhost:8080/
 ```
-curl localhost:8080/metrics
+
+Get the metrics via `/metrics`
+```bash
+curl http://localhost:8080/metrics
 ```
 
 Here is an example of the output:

lab3/README.md

@@ -44,9 +44,14 @@ npm install
 npm start
 ```
 
-Get the metrics via `/metrics`
+Use the app
+```bash
+open http://localhost:8080/
 ```
-curl localhost:8080/metrics
+
+Get the metrics via `/metrics`
+```bash
+curl http://localhost:8080/metrics
 ```
 
 Here is an example of the output:

lab4/README.md

@@ -58,6 +58,11 @@ npm install
 npm start
 ```
 
+Use the app
+```bash
+open http://localhost:8080/
+```
+
 The web server will push the metrics every 5 seconds as configured in the code.
 
 Metrics are not available via scrape endpoint `/metrics` on the Node.js web server.

lab5/README.md

@@ -76,11 +76,16 @@ npm install
 npm start
 ```
 
+Use the app
+```bash
+open http://localhost:8080/
+```
+
 The web server will push the metrics every 5 seconds as configured in the code.
 
 You can access the metrics from the gateway using http://localhost:9091/metrics
 
-Metrics are also available via scrape endpoint http://localhost/metrics on the Node.js web server.
+Metrics are also available via scrape endpoint http://localhost:8080/metrics on the Node.js web server.
 
 Open the UI on Prometheus Metrics http://localhost:9091/
 

lab5/pushgateway.png

@@ -0,0 +1,2 @@
+node_modules
+npm-debug.log

lab6/.dockerignore

@@ -0,0 +1,13 @@
+FROM registry.access.redhat.com/ubi8/nodejs-12
+
+COPY package*.json ./
+
+ENV NODE_ENV=production
+
+RUN npm ci
+
+COPY . .
+
+EXPOSE 8080
+
+CMD [ "npm", "start" ]

lab6/Dockerfile

@@ -0,0 +1,160 @@
+# Using the prom-client express middleware wrapper express-prom-bundle
+
+
+See the content of [./metrics.js](./metrics.js)
+```js
+const promBundle = require("express-prom-bundle");
+
+const metricsMiddleware = promBundle({
+  includeMethod: true,
+  includePath: true,
+  includeUp: false,
+  metricType: 'histogram',
+  buckets: [0.025, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.45, 0.5, 0.55, 0.6, 0.75, 1, 2.5, 10],
+  promClient: {
+    collectDefaultMetrics: {
+      timestamps: false
+    }
+  }
+});
+
+module.exports = (app) => {
+  app.use(metricsMiddleware)
+}
+```
+
+Start the application
+```bash
+npm install
+```
+
+```bash
+npm start
+```
+
+Use the app
+```bash
+open http://localhost:8080/
+```
+
+Get the metrics via `/metrics`
+```bash
+curl http://localhost:8080/metrics
+```
+
+Here is an example of the output:
+```
+# HELP process_cpu_user_seconds_total Total user CPU time spent in seconds.
+# TYPE process_cpu_user_seconds_total counter
+process_cpu_user_seconds_total 0.050724 1580409960992
+
+# HELP process_cpu_system_seconds_total Total system CPU time spent in seconds.
+# TYPE process_cpu_system_seconds_total counter
+process_cpu_system_seconds_total 0.00534 1580409960992
+
+# HELP process_cpu_seconds_total Total user and system CPU time spent in seconds.
+# TYPE process_cpu_seconds_total counter
+process_cpu_seconds_total 0.056064 1580409960992
+
+# HELP process_start_time_seconds Start time of the process since unix epoch in seconds.
+# TYPE process_start_time_seconds gauge
+process_start_time_seconds 1580409821
+
+# HELP process_resident_memory_bytes Resident memory size in bytes.
+# TYPE process_resident_memory_bytes gauge
+process_resident_memory_bytes 27602944 1580409960992
+
+# HELP nodejs_eventloop_lag_seconds Lag of event loop in seconds.
+# TYPE nodejs_eventloop_lag_seconds gauge
+nodejs_eventloop_lag_seconds 0.000334835 1580409960992
+
+# HELP nodejs_active_handles Number of active libuv handles grouped by handle type. Every handle type is C++ class name.
+# TYPE nodejs_active_handles gauge
+nodejs_active_handles{type="WriteStream"} 2
+nodejs_active_handles{type="ReadStream"} 1
+nodejs_active_handles{type="Server"} 1
+nodejs_active_handles{type="Socket"} 2
+
+# HELP nodejs_active_handles_total Total number of active handles.
+# TYPE nodejs_active_handles_total gauge
+nodejs_active_handles_total 6
+
+# HELP nodejs_active_requests Number of active libuv requests grouped by request type. Every request type is C++ class name.
+# TYPE nodejs_active_requests gauge
+
+# HELP nodejs_active_requests_total Total number of active requests.
+# TYPE nodejs_active_requests_total gauge
+nodejs_active_requests_total 0 1580409960992
+
+# HELP nodejs_heap_size_total_bytes Process heap size from node.js in bytes.
+# TYPE nodejs_heap_size_total_bytes gauge
+nodejs_heap_size_total_bytes 7970816
+
+# HELP nodejs_heap_size_used_bytes Process heap size used from node.js in bytes.
+# TYPE nodejs_heap_size_used_bytes gauge
+nodejs_heap_size_used_bytes 6371536
+
+# HELP nodejs_external_memory_bytes Nodejs external memory size in bytes.
+# TYPE nodejs_external_memory_bytes gauge
+nodejs_external_memory_bytes 1346123
+
+# HELP nodejs_heap_space_size_total_bytes Process heap space size total from node.js in bytes.
+# TYPE nodejs_heap_space_size_total_bytes gauge
+nodejs_heap_space_size_total_bytes{space="read_only"} 262144 1580409960992
+nodejs_heap_space_size_total_bytes{space="new"} 1048576 1580409960992
+nodejs_heap_space_size_total_bytes{space="old"} 4857856 1580409960992
+nodejs_heap_space_size_total_bytes{space="code"} 430080 1580409960992
+nodejs_heap_space_size_total_bytes{space="map"} 790528 1580409960992
+nodejs_heap_space_size_total_bytes{space="large_object"} 532480 1580409960992
+nodejs_heap_space_size_total_bytes{space="code_large_object"} 49152 1580409960992
+nodejs_heap_space_size_total_bytes{space="new_large_object"} 0 1580409960992
+
+# HELP nodejs_heap_space_size_used_bytes Process heap space size used from node.js in bytes.
+# TYPE nodejs_heap_space_size_used_bytes gauge
+nodejs_heap_space_size_used_bytes{space="read_only"} 33040 1580409960992
+nodejs_heap_space_size_used_bytes{space="new"} 1005984 1580409960992
+nodejs_heap_space_size_used_bytes{space="old"} 4272040 1580409960992
+nodejs_heap_space_size_used_bytes{space="code"} 181120 1580409960992
+nodejs_heap_space_size_used_bytes{space="map"} 354240 1580409960992
+nodejs_heap_space_size_used_bytes{space="large_object"} 524344 1580409960992
+nodejs_heap_space_size_used_bytes{space="code_large_object"} 2784 1580409960992
+nodejs_heap_space_size_used_bytes{space="new_large_object"} 0 1580409960992
+
+# HELP nodejs_heap_space_size_available_bytes Process heap space size available from node.js in bytes.
+# TYPE nodejs_heap_space_size_available_bytes gauge
+nodejs_heap_space_size_available_bytes{space="read_only"} 0 1580409960992
+nodejs_heap_space_size_available_bytes{space="new"} 41440 1580409960992
+nodejs_heap_space_size_available_bytes{space="old"} 570664 1580409960992
+nodejs_heap_space_size_available_bytes{space="code"} 12000 1580409960992
+nodejs_heap_space_size_available_bytes{space="map"} 434640 1580409960992
+nodejs_heap_space_size_available_bytes{space="large_object"} 0 1580409960992
+nodejs_heap_space_size_available_bytes{space="code_large_object"} 0 1580409960992
+nodejs_heap_space_size_available_bytes{space="new_large_object"} 1047424 1580409960992
+
+# HELP nodejs_version_info Node.js version info.
+# TYPE nodejs_version_info gauge
+nodejs_version_info{version="v13.7.0",major="13",minor="7",patch="0"} 1
+
+# HELP http_request_duration_seconds duration histogram of http responses labeled with: status_code, method, path
+# TYPE http_request_duration_seconds histogram
+http_request_duration_seconds_bucket{le="0.025",status_code="200",method="GET",path="/"} 12
+http_request_duration_seconds_bucket{le="0.05",status_code="200",method="GET",path="/"} 12
+http_request_duration_seconds_bucket{le="0.1",status_code="200",method="GET",path="/"} 12
+http_request_duration_seconds_bucket{le="0.15",status_code="200",method="GET",path="/"} 17
+http_request_duration_seconds_bucket{le="0.2",status_code="200",method="GET",path="/"} 17
+http_request_duration_seconds_bucket{le="0.25",status_code="200",method="GET",path="/"} 17
+http_request_duration_seconds_bucket{le="0.3",status_code="200",method="GET",path="/"} 17
+http_request_duration_seconds_bucket{le="0.35",status_code="200",method="GET",path="/"} 17
+http_request_duration_seconds_bucket{le="0.45",status_code="200",method="GET",path="/"} 17
+http_request_duration_seconds_bucket{le="0.5",status_code="200",method="GET",path="/"} 17
+http_request_duration_seconds_bucket{le="0.55",status_code="200",method="GET",path="/"} 17
+http_request_duration_seconds_bucket{le="0.6",status_code="200",method="GET",path="/"} 17
+http_request_duration_seconds_bucket{le="0.75",status_code="200",method="GET",path="/"} 17
+http_request_duration_seconds_bucket{le="1",status_code="200",method="GET",path="/"} 17
+http_request_duration_seconds_bucket{le="2.5",status_code="200",method="GET",path="/"} 17
+http_request_duration_seconds_bucket{le="10",status_code="200",method="GET",path="/"} 17
+http_request_duration_seconds_bucket{le="+Inf",status_code="200",method="GET",path="/"} 17
+http_request_duration_seconds_sum{status_code="200",method="GET",path="/"} 0.5371957699999999
+http_request_duration_seconds_count{status_code="200",method="GET",path="/"} 17
+```
+

lab6/README.md

@@ -0,0 +1,18 @@
+const express = require('express')
+const app = express()
+const port = process.env.PORT | 8080
+
+// Add /metrics endpoint
+require('./metrics.js')(app)
+
+let counter = 1
+app.get('/', async (req, res) => {
+  // simulate a slow request every 3 requests
+  setTimeout(async () => {
+    res.send('Hello World')
+  }, counter++ % 3 === 0 ? 100 : 0)
+})
+app.disable('etag')
+app.listen(port, () => console.log(`Service listening on port ${port}!`))
+
+module.exports = app

lab6/app.js

@@ -0,0 +1,18 @@
+const promBundle = require("express-prom-bundle");
+
+const metricsMiddleware = promBundle({
+  includeMethod: true,
+  includePath: true,
+  includeUp: false,
+  metricType: 'histogram',
+  buckets: [0.025, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.45, 0.5, 0.55, 0.6, 0.75, 1, 2.5, 10],
+  promClient: {
+    collectDefaultMetrics: {
+      timestamps: false
+    }
+  }
+});
+
+module.exports = (app) => {
+  app.use(metricsMiddleware)
+}