Ping & Latency Dashboard — Step‑by‑Step Guide

Jump to:

1) Prerequisites 2) Get the code 3) Run the stack 4) Configure endpoints 5) Verify metrics & dashboards 6) Trigger & see alerts 7) Real notifications (Slack) 8) Monitor your own local services 9) Troubleshooting 10) Stop / restart How it works

1) Prerequisites

Required Docker Desktop running ( docker --version, docker compose version)
Optional Git ( git --version)

Windows users: run Docker with WSL2. If you see Hyper‑V/WSL prompts, enable WSL in “Turn Windows features on or off” and reboot.

2) Get the code

Download or clone the repository that contains this guide and the docker-compose.yml.

git clone https://github.com/shri-124/ping-latency-dashboard.git
cd ping-latency-dashboard

If you don’t use git, just create the folder structure and copy the files from the project (see README).

3) Run the stack

From the project root (same folder as docker-compose.yml):

docker compose up -d --build

Open the UIs

Pinger metrics: http://localhost:8000/metrics
Prometheus: http://localhost:9090
Alertmanager: http://localhost:9093
Grafana: http://localhost:3000

Check containers

docker compose ps

4) Configure endpoints

Edit config/targets.yml. Supports HTTP/HTTPS (full request latency) and TCP (connect latency):

interval_seconds: 15
request_timeout_seconds: 5

targets:
  - name: google
    url: https://www.google.com
    threshold_seconds: 0.35
  - name: cloudflare-dns-tcp
    url: tcp://1.1.1.1:53
    threshold_seconds: 0.05
  - name: github
    url: https://github.com
    threshold_seconds: 0.40

The pinger auto‑reloads this file every cycle. To apply immediately:

docker compose restart pinger

Tip: This app measures HTTP/TCP latency (no raw ICMP ping), which works without extra privileges and matches SRE‑style checks.

5) Verify metrics & dashboards

Quick via metrics endpoint

curl -s http://localhost:8000/metrics | grep -E '^ping_(latency_seconds|up){'

Look for labels like target="https://www.google.com" and name="google".

Prometheus queries

List targets: label_values(ping_latency_seconds, target)
Up/Down: sum by (name, target) (ping_up)
Latency series: ping_latency_seconds

Grafana dashboard

Open Grafana → folder Ping → dashboard Ping & Latency.

6) Trigger & see alerts

Prometheus alerts are defined in prometheus/alerts.yml:

HighLatency: fires when ping_latency_seconds > ping_latency_threshold_seconds for 1m
TargetDown: fires when ping_up == 0 for 2m

Fastest way to test

Set one target threshold_seconds: 0.001 and save.
Wait 15–30s (or restart pinger).
Open Alertmanager: / → you should see HighLatency.
Tail webhook payloads from pinger:

docker logs -f pinger

7) Real notifications (Slack)

Edit alertmanager/alertmanager.yml to add Slack (or email). Example Slack config:

route:
  receiver: slack
  group_by: ["alertname","name","target"]
  group_wait: 10s
  group_interval: 1m
  repeat_interval: 2h

receivers:
  - name: slack
    slack_configs:
      - api_url: https://hooks.slack.com/services/YOUR/WEBHOOK/URL
        channel: "#alerts"
        send_resolved: true

Apply the change:

docker compose restart alertmanager

In this starter, a local webhook receiver posts to http://pinger:8000/alert so you can see alert payloads end‑to‑end. Swap the route.receiver to slack to notify Slack.

8) Monitor your own local services

Add your app or DB as a target in config/targets.yml:

targets:
  - name: my-api
    url: http://host.docker.internal:8080
    threshold_seconds: 0.25
  - name: postgres
    url: tcp://host.docker.internal:5432
    threshold_seconds: 0.05

Linux note: Add this under pinger: in docker-compose.yml to map host.docker.internal:

extra_hosts:
  - "host.docker.internal:host-gateway"

9) Troubleshooting

No data in Prometheus

Open /metrics (should show text metrics)
Prometheus → Status → Targets → pinger:8000 must be UP
Check logs: docker logs pinger

Alerts never fire

Lower the threshold to below observed latency
Prometheus → Status → Rules shows HighLatency loaded
No silences in Alertmanager

Port already in use

Change the left side of the port in docker-compose.yml (e.g., 3001:3000) and restart.

10) Stop / start / reset

Pause (keep containers)

docker compose stop
# later
docker compose start

Shutdown (remove containers)

docker compose down
# start again
docker compose up -d

Clean slate (also volumes/images)

docker compose down --volumes --rmi local --remove-orphans

How it works

Pinger
probes endpoints; exposes /metrics → Prometheus
scrapes & stores; evaluates alerts → Alertmanager
routes notifications ↘ Slack/Email/Webhook
↘ Grafana
dashboards via Prometheus