ihatemodels 24e8161262 Add initial project structure

- add base structure
 - unify the proto metrics creation and propagation
 - implement arp and openvpn
 - refactor to meet the prom exporter standart
 - add instance label to the metrics
 - refactor the call chain
 - add gateway, unbound_dns and openvpn implementations
 - add gateway stuff
 - structure refactor; mod clean; cron implementation
 - implement cron in the collector; refactor utils in the opnsense package

refactor names and implement option functions to disable collectorInstances

add GH action workflows

Create codeql.yml

- clean

fix stuff

2023-11-26 16:06:03 +02:00

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Backoff

A simple exponential backoff counter in Go (Golang)

Install

$ go get -v github.com/jpillora/backoff

Usage

Backoff is a time.Duration counter. It starts at Min. After every call to Duration() it is multiplied by Factor. It is capped at Max. It returns to Min on every call to Reset(). Jitter adds randomness (see below). Used in conjunction with the time package.

Simple example


b := &backoff.Backoff{
	//These are the defaults
	Min:    100 * time.Millisecond,
	Max:    10 * time.Second,
	Factor: 2,
	Jitter: false,
}

fmt.Printf("%s\n", b.Duration())
fmt.Printf("%s\n", b.Duration())
fmt.Printf("%s\n", b.Duration())

fmt.Printf("Reset!\n")
b.Reset()

fmt.Printf("%s\n", b.Duration())

100ms
200ms
400ms
Reset!
100ms

Example using `net` package

b := &backoff.Backoff{
    Max:    5 * time.Minute,
}

for {
	conn, err := net.Dial("tcp", "example.com:5309")
	if err != nil {
		d := b.Duration()
		fmt.Printf("%s, reconnecting in %s", err, d)
		time.Sleep(d)
		continue
	}
	//connected
	b.Reset()
	conn.Write([]byte("hello world!"))
	// ... Read ... Write ... etc
	conn.Close()
	//disconnected
}

Example using `Jitter`

Enabling Jitter adds some randomization to the backoff durations. See Amazon's writeup of performance gains using jitter. Seeding is not necessary but doing so gives repeatable results.

import "math/rand"

b := &backoff.Backoff{
	Jitter: true,
}

rand.Seed(42)

fmt.Printf("%s\n", b.Duration())
fmt.Printf("%s\n", b.Duration())
fmt.Printf("%s\n", b.Duration())

fmt.Printf("Reset!\n")
b.Reset()

fmt.Printf("%s\n", b.Duration())
fmt.Printf("%s\n", b.Duration())
fmt.Printf("%s\n", b.Duration())

100ms
106.600049ms
281.228155ms
Reset!
100ms
104.381845ms
214.957989ms

Documentation

https://godoc.org/github.com/jpillora/backoff

Credits

Forked from some JavaScript written by @tj

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