README
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mon - A simple local services monitor
mon is a simple command-line tool to monitor services. Services are specified in a simple JSON file, containing service name, a URL to check, and optional HTTP headers to send in any requests (for things like specifying Accepts or Authorization headers).
All services are assumed to be HTTP services, and mon simply checks that the provided URL for a service returns a 200 (OK) response.
monis MacOS-centric currently, and assumes presence ofosascriptfor delivering desktop notifications.
Installation
mon is a regular Go program with no third-party dependencies. It can be installed into $GOBIN with:
go install github.com/chriswalker/mon
Configuration
Services to monitor are defined in a simple JSON file, by default located at ~/Library/Application Support/mon/services.json under MacOS. This can be overridden with the --services-file or -s flags.
The file is an array of objects, each of which must minimally define a name and url. HTTP headers can be optionally specified in the headers property.
A sample services file might look like:
[
{ "name": "godocs", "url": "http://localhost:6060" },
{ "name": "rss - miniflux", "url": "http://localhost:8050" },
{
"name": "gokrazy",
"url": "http://gokrazy.local/",
"headers": {
"Accepts": "application/json",
"Authorization": "Basic <bas64 encoded username/pwd here>"
}
}
]
If a headers map is provided for a service, the specified headers are provided as-is to the request made to the service. Use this for services that might require some kind of authorisation, or where requests must specify what they accept.
Command-line Flags
| Flag | Description |
|---|---|
-s, --services-file |
Path to the services configuration file (defaults to ~/Library/Application Support/mon/services.json on MacOS) |
-j, --json |
Output status information as JSON (if omitted, defaults to tubular status output) |
--notify |
Display a desktop notification for each service that does not return a success (200 OK) status |
Automation
A sample launchd plist file is provided as a starting point for using mon on MacOS.
Documentation
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Overview ¶
mon is a simple service monitor.
It pings HTTP services specified in a JSON configuration file. Services returning a 200 (OK) status code are deemed to be up. Non-200 status codes result in an error status.
By default, mon reads its configuration file from:
[config_dir]/mon/services.json
where [config_dir] is whatever os.UserConfigDir() returns. This can be overriden with the -s/-services-file flags.
mon can output status results in tabular format (the default), as JSON or as a MacOS notification for 'failing' services.
Usage:
mon [flags]
The flags are:
-s,-services-file
Full path including filename to the configuration file
-j,-json
Output results in JSON format
-notify
Display a MacOS notification for failing services via osascript
Source Files