✔️ Interval based checking of predefined Resources
✔️ Posts monitor lag to cachet graphs
✔️ Creates & Resolves Incidents
✔️ Updates Component to Partial Outage
✔️ Updates Component to Major Outage if already in Partial Outage (works with distributed monitors)
✔️ Can be run on multiple servers and geo regions
✔️ HTTP Checks (body/status code)
✔️ DNS Checks
✔️ TCP Checks
✔️ ICMP Checks

Quick Start

Configuration can be done in either yaml or json format. An example JSON-File would look something like this:

{
  "api": {
    "url": "https://demo.cachethq.io/api/v1",
    "token": "9yMHsdioQosnyVK4iCVR",
    "insecure": false
  },
  "date_format": "02/01/2006 15:04:05 MST",
  "monitors": [
    {
      "active": false,
      "name": "google",
      "target": "https://google.com",
      "strict": true,
      "method": "POST",
      "component_id": 1,
      "metric_id": 4,
      "template": {
        "investigating": {
          "subject": "{{ .Monitor.Name }} - {{ .SystemName }}",
          "message": "{{ .Monitor.Name }} check **failed** (server time: {{ .now }})\n\n{{ .FailReason }}"
        },
        "fixed": {
          "subject": "I HAVE BEEN FIXED"
        }
      },
      "interval": 1,
      "timeout": 1,
      "threshold": 80,
      "headers": {
        "Authorization": "Basic <hash>"
      },
      "expected_status_code": 200,
      "expected_body": "P.*NG"
    }
  ]
}

Installation

Download binary from release page
Add the binary to an executable path (/usr/bin, etc.)
Create a configuration following provided examples
cachet-monitor -c /etc/cachet-monitor.json

pro tip: run in background using nohup cachet-monitor 2>&1 > /var/log/cachet-monitor.log &, or use a tmux/screen session

Usage:
  cachet-monitor (-c PATH | --config PATH) [--log=LOGPATH] [--name=NAME] [--immediate]
  cachet-monitor -h | --help | --version

Arguments:
  PATH     path to config.json
  LOGPATH  path to log output (defaults to STDOUT)
  NAME     name of this logger

Examples:
  cachet-monitor -c /root/cachet-monitor.json
  cachet-monitor -c /root/cachet-monitor.json --log=/var/log/cachet-monitor.log --name="development machine"

Options:
  -c PATH.json --config PATH     Path to configuration file
  -h --help                      Show this screen.
  --version                      Show version
  --immediate                    Tick immediately (by default waits for first defined interval)
  --restarted                    Get open incidents before start monitoring (if monitor died or restarted)

Environment varaibles:
  CACHET_API      override API url from configuration
  CACHET_TOKEN    override API token from configuration
  CACHET_DEV      set to enable dev logging

Init script

If your system is running systemd (like Debian, Ubuntu 16.04, Fedora, RHEL7, or Archlinux) you can use the provided example file: example.cachet-monitor.service.

Simply put it in the right place with cp example.cachet-monitor.service /etc/systemd/system/cachet-monitor.service
Then do a systemctl daemon-reload in your terminal to update Systemd configuration
Finally you can start cachet-monitor on every startup with systemctl enable cachet-monitor.service! 👍

Templates

This package makes use of text/template. Default HTTP template

The following variables are available:

Root objects	Description
`.SystemName`	system name
`.API`	`api` object from configuration
`.Monitor`	`monitor` object from configuration
`.now`	formatted date string

Monitor variables
`.Name`
`.Target`
`.Type`
`.Strict`
`.MetricID`
...

All monitor variables are available from monitor.go

Monitor Types

We support a variety of monitor-types. Here are the configuration parameters for each of them

Also, the following parameters are shared for all monitors.

Key	Description
name	a friendly name for the monitor
target	target for the check (e.g. a domain or IP)
active	a boolean wether or not this test is currently active
type	type type of the check, see supported types above or below
interval	the interval in seconds in which to check the monitor
timeout	the timeout for each check. Needs to be smaller than the interval
metric_id	the ID of the metric. Metrics are used for graphing values
component_id	the ID of the component inside of Cachet. Used for creating incidents
templates.investigating	template to use as a message for when the check enters the investigating stage
templates.fixed	template to use as a message for when the check enters the fixed stage
threshold	If % of downtime is over this threshold, open an incident
threshold_count	the number of checks that count into the threshold (defaults to 10)

HTTP

Either expected_body or expected_status_code needs to be set.

Key	Description
method	the HTTP Request method to use (Defaults to GET)
headers	a key-value array of additional headers to use for the request
expected_status_code	the expected status-code returned from the request
expected_body	a regex or normal string that will be used to test against the returned body of the request
expected_md5sum	a md5 checksum of the body, which will be checked against
expected_length	the length of the string of the response body
data	body-data for a post request

DNS

Key	Description
dns	set a custom DNS-Resolver (IP:Port format)
question	the type of DNS-Request to execute (e.g. A, MX, CNAME...). Can also be a List (['A', 'MX', 'CNAME'])
answers	an array of response objects. see below

Answer Object

Key	Description
regex	if you want to use a regexp, use this key and the regexp as the value
exact	exact match for the response value

TCP

Key	Description
port	the port to do a tcp connection to

ICMP

No special variables needed

Vision and goals

We made this tool because we felt the need to have our own monitoring software (leveraging on Cachet). The idea is a stateless program which collects data and pushes it to a central cachet instance.

This gives us power to have an army of geographically distributed loggers and reveal issues in both latency & downtime on client websites.

Package usage

When using cachet-monitor as a package in another program, you should follow what cli/main.go does. It is important to call Validate on CachetMonitor and all the monitors inside.

API Documentation

Contributions welcome

We'll happily accept contributions for anything usefull.

Build on Linux/MacOS

Read and install with https://ahmadawais.com/install-go-lang-on-macos-with-homebrew/
Test in console with go get -u and go build cli/main.go
Run ./go-executable-build.sh cli/main.go
This will create a build/cli/main.go-linux-amd64-file, which is the executable binary
mv build/cli/main.go-linux-amd64 /usr/bin/cachet-monitor