hosts

README

= A library to interact with etc/hosts file

**Work in Progress**

This go library provides methods to interact with `etc/hosts` file.
One can parse the `etc/hosts` file to a go struct.
One can parse a go struct to a valid well-formed `etc/hosts` file.

== Some examples

_For more examples check the tests._

=== Parse from io.Reader

[source,go]
----
package main

import (
    "fmt"
    "github.com/bitofcode/hosts/parser"
    "os"
)
import "bytes"

func main() {

	reader := bytes.NewBufferString(
		`127.0.0.1  localhost localhost.local
# a comment
192.168.10.10 example.com
192.168.10.10 example.io # another comment
192.168.15.15 hello.world# a dummy host`)

	entrySet, err := parser.Read(reader)

    if err != nil {
    	fmt.Fprintf(os.Stderr, "unexpected error %v\n", err)
    }

    fmt.Println(entrySet)

}
----

=== Parse to a io.Writer

[source,go]
----
package main

import (
    "bytes"
    "fmt"
    "github.com/bitofcode/hosts"
    "github.com/bitofcode/hosts/parser"
    "os"
)


func main() {
    entrySet := hosts.NewEntrySet()
    entrySet.AddEntry(hosts.NewEntry("127.0.0.1", []string{"localhost", "localhost.local"}))
    entrySet.AddEntry(hosts.NewEntry("10.0.0.10", []string{"example.com", "example.io"}))
    entrySet.AddEntry(hosts.NewEntry("127.0.0.1", []string{"docker.host.local"}))

    buffer := bytes.NewBuffer(make([]byte, 0))

    err := parser.Write(entrySet, buffer)

    if err != nil {
        fmt.Fprintf(os.Stderr,"unexpected error '%v'\n", err)
    }
}
----

Documentation

Overview

Package hosts provides an implementation to model an /etc/hosts file.

Index

• Variables
• type Entry
  • func CloneEntry(entry Entry) (Entry, error)
  • func NewEntry(ip net.IP, hostNames []string) (Entry, error)
  • func NewEntryIp(ip net.IP) (Entry, error)
  • func NewEntryUnsafe(ip net.IP, hosts []string) Entry
• type EntrySet
  • func NewEntrySet() EntrySet

Variables

var ErrorInvalidHostName = errors.New("invalid host-name")

var ErrorInvalidIp = errors.New("invalid ip")

var ErrorNilEntry = errors.New("entry is nil")

Types

type Entry

type Entry interface {
	Ip() net.IP
	IpString() string
	HostNames() []string
	AddHostName(hostName string) error
	String() string
	Contains(hostName string) bool
}

An Entry represent a line in /etc/hosts with multiple hosts associate to one ip.

func CloneEntry

func CloneEntry(entry Entry) (Entry, error)

func NewEntry

func NewEntry(ip net.IP, hostNames []string) (Entry, error)

NewEntry returns an Entry which contains the given ip and the host names.

func NewEntryIp

func NewEntryIp(ip net.IP) (Entry, error)

NewEntryIp returns an Entry which contains the given ip.

func NewEntryUnsafe

func NewEntryUnsafe(ip net.IP, hosts []string) Entry

type EntrySet

type EntrySet interface {
	AddEntry(entry Entry, entries ...Entry)
	Contains(entry Entry) bool
	EntriesOfIP(ip net.IP) (hosts []string, ok bool)
	AllEntries() []Entry
}

func NewEntrySet

func NewEntrySet() EntrySet