app-metrics-nozzle

App Metrics Nozzle

This is a nozzle for the Cloud Foundry firehose component. It will ingest router events for every application it can detect and use the timestamps on those events to compute usage metrics. The first usage for this nozzle will be to determine if an application is unused by tracking the last time a request was routed to it. It will also make REST api calls to Cloud Controller and cache application, and user data for the interval specified in configuration.

REST API

This application exposes a RESTful API that allows consumers to query application usage statistics. This API is described in the following table:

JSON Payloads

This is a sample of what the JSON response looks like for the app /api/apps:

{
  "johannes-org/development/app-metrics-nozzle": {
    "buildpack": "https://github.com/cloudfoundry/go-buildpack.git",
    "diego": true,
    "environment": {
      "API_ENDPOINT": "https://api.run.pivotal.io",
      "CF_PULL_TIME": "300s",
      "DOPPLER_ENDPOINT": "wss://doppler.run.pivotal.io:443",
      "FIREHOSE_PASSWORD": "[[PRIVATE]]",
      "FIREHOSE_USER": "[[PRIVATE]]",
      "GOPACKAGENAME": "app-metrics-nozzle",
      "PASSWORD": "[[PRIVATE]]",
      "SKIP_SSL_VALIDATION": "false",
      "USERNAME": "[[PRIVATE]]"
    },
    "environment_summary": {
      "total_cpu": 1.2153818869424569,
      "total_disk_configured": 268435456,
      "total_disk_provisioned": 268435456,
      "total_disk_usage": 51855360,
      "total_memory_configured": 268435456,
      "total_memory_provisioned": 268435456,
      "total_memory_usage": 51267356
    },
    "guid": "dcfbab8d-46cb-475d-a95b-da2e67ee3312",
    "instance_count": {
      "configured": 1,
      "running": 1
    },
    "instances": Array[1][
      {
        "cell_ip": "10.10.148.165",
        "cpu_usage": 1.2153818869424569,
        "disk_usage": 51855360,
        "gc_stats": "",
        "index": 0,
        "memory_usage": 51267356,
        "uptime": 45049,
        "since": 1539962977,
        "state": "RUNNING",
        "last_event": "2018-10-20 04:01:24.970336982 +0000 UTC"
      }
    ],
    "name": "app-metrics-nozzle",
    "organization": {
      "id": "[[PRIVATE]]",
      "name": "[[PRIVATE]]"
    },
    "event_count": 1,
    "last_event_time": 1540008031613128991,
    "requests_per_second": 0.000022214817283127847,
    "elapsed_since_last_event": 0,
    "routes": Array[1][
      "app-metrics-nozzle.cfapps.io"
    ],
    "space": {
      "id": "[[PRIVATE]]5",
      "name": "[[PRIVATE]]"
    },
    "state": "STARTED",
    "fetch_time": "2018-10-20 04:00:27.673069672 +0000 UTC"
  },
  [...]

If the last_event_time field is 0 that indicates that no router events for that application have been discovered since the nozzle was started.

Installation

Run glide install to pull dependencies into vendor directory. To install this application, it should be run as an app within Cloud Foundry. So, the first thing you'll need to do is push the app. There is a manifest.yml already included in the project. After you changed the environment variables in the manifest.yml, you can just run the following command:

cf push app-metrics-nozzle

DOPPLER_ENDPOINT can be obtained by running

cat ~/.cf/config.json | grep Doppler