userdata

README

Go User Data

The library for cloud-init User Data

Getting Started

Use go get to install the library

go get github.com/Aton-Kish/gouserdata

Import in your application

import (
	userdata "github.com/Aton-Kish/gouserdata"
)

Usage

This example shows how to make mime multipart user data.

package main

import (
	"bytes"
	"fmt"
	"log"
	"os"

	userdata "github.com/Aton-Kish/gouserdata"
)

func main() {
	d := userdata.NewMultipart()

	cfg, err := os.ReadFile("cloud-config.yaml")
	if err != nil {
			log.Fatal(err)
	}
	d.AddPart(userdata.MediaTypeCloudConfig, cfg)

	j2, err := os.ReadFile("script.j2")
	if err != nil {
		log.Fatal(err)
	}
	d.AddPart(userdata.MediaTypeJinja2, j2)

	hook, err := os.ReadFile("boothook.sh")
	if err != nil {
		log.Fatal(err)
	}
	d.AddPart(userdata.MediaTypeCloudBoothook, hook)

	buf := new(bytes.Buffer)
	d.Render(buf)

	fmt.Println(buf.String())
}

License

This library is licensed under the MIT License, see LICENSE.

Documentation

Overview

The library for cloud-init User Data. This is licensed under the MIT License.

Index

• type Header
  • func NewHeader() *Header
  • func (h *Header) Render(w io.Writer) error
• type MediaType
• type Multipart
  • func NewMultipart() *Multipart
  • func (m *Multipart) AddPart(mediaType MediaType, body []byte)
  • func (m *Multipart) Boundary() string
  • func (m *Multipart) Render(w io.Writer) error
  • func (m *Multipart) SetBoundary(boundary string) error
• type Part
  • func NewPart() *Part
  • func (p *Part) MediaType() MediaType
  • func (p *Part) Render(w io.Writer) error
  • func (p *Part) SetBody(mediaType MediaType, body []byte)

Examples

• Multipart.Render
• Multipart.Render (IncludesUtf8)
• Multipart.SetBoundary

Types

type Header

type Header struct {
	textproto.MIMEHeader
}

func NewHeader

func NewHeader() *Header

func (*Header) Render

func (h *Header) Render(w io.Writer) error

type MediaType

type MediaType string

const (
	MediaTypeCloudBoothook           MediaType = "text/cloud-boothook"
	MediaTypeCloudConfig             MediaType = "text/cloud-config"
	MediaTypeCloudConfigArchive      MediaType = "text/cloud-config-archive"
	MediaTypeCloudConfigJsonp        MediaType = "text/cloud-config-jsonp"
	MediaTypeJinja2                  MediaType = "text/jinja2"
	MediaTypePartHandler             MediaType = "text/part-handler"
	MediaTypeXIncludeOnceUrl         MediaType = "text/x-include-once-url"
	MediaTypeXIncludeUrl             MediaType = "text/x-include-url"
	MediaTypeXShellscript            MediaType = "text/x-shellscript"
	MediaTypeXShellscriptPerBoot     MediaType = "text/x-shellscript-per-boot"
	MediaTypeXShellscriptPerInstance MediaType = "text/x-shellscript-per-instance"
	MediaTypeXShellscriptPerOnce     MediaType = "text/x-shellscript-per-once"
)

type Multipart

type Multipart struct {
	Header Header
	Parts  []Part
	// contains filtered or unexported fields
}

func NewMultipart

func NewMultipart() *Multipart

func (*Multipart) AddPart

func (m *Multipart) AddPart(mediaType MediaType, body []byte)

func (*Multipart) Boundary

func (m *Multipart) Boundary() string

func (*Multipart) Render

func (m *Multipart) Render(w io.Writer) error

Example

package main

import (
	"bytes"
	"fmt"
	"strings"

	userdata "github.com/Aton-Kish/gouserdata"
)

func main() {
	d := userdata.NewMultipart()

	cfg := []byte(`#cloud-config
timezone: Europe/London`)
	d.AddPart(userdata.MediaTypeCloudConfig, cfg)

	scr := []byte(`#!/bin/bash
echo 'Hello World'`)
	d.AddPart(userdata.MediaTypeXShellscript, scr)

	buf := new(bytes.Buffer)
	d.Render(buf)

	output := buf.String()
	output = strings.ReplaceAll(output, "\r\n", "\n") // for testing
	fmt.Println(output)
}

Output:

Content-Type: multipart/mixed; boundary="+Go+User+Data+Boundary=="
Mime-Version: 1.0

--+Go+User+Data+Boundary==
Content-Transfer-Encoding: 7bit
Content-Type: text/cloud-config; charset=us-ascii

#cloud-config
timezone: Europe/London

--+Go+User+Data+Boundary==
Content-Transfer-Encoding: 7bit
Content-Type: text/x-shellscript; charset=us-ascii

#!/bin/bash
echo 'Hello World'

--+Go+User+Data+Boundary==--

Example (IncludesUtf8)

package main

import (
	"bytes"
	"fmt"
	"strings"

	userdata "github.com/Aton-Kish/gouserdata"
)

func main() {
	d := userdata.NewMultipart()

	cfg := []byte(`#cloud-config
timezone: Asia/Tokyo`)
	d.AddPart(userdata.MediaTypeCloudConfig, cfg)

	scr := []byte(`#!/bin/bash
echo 'こんにちは世界'`)
	d.AddPart(userdata.MediaTypeXShellscript, scr)

	buf := new(bytes.Buffer)
	d.Render(buf)

	output := buf.String()
	output = strings.ReplaceAll(output, "\r\n", "\n") // for testing
	fmt.Println(output)
}

Output:

Content-Type: multipart/mixed; boundary="+Go+User+Data+Boundary=="
Mime-Version: 1.0

--+Go+User+Data+Boundary==
Content-Transfer-Encoding: 7bit
Content-Type: text/cloud-config; charset=us-ascii

#cloud-config
timezone: Asia/Tokyo

--+Go+User+Data+Boundary==
Content-Transfer-Encoding: base64
Content-Type: text/x-shellscript; charset=utf-8

IyEvYmluL2Jhc2gKZWNobyAn44GT44KT44Gr44Gh44Gv5LiW55WMJw==

--+Go+User+Data+Boundary==--

func (*Multipart) SetBoundary

func (m *Multipart) SetBoundary(boundary string) error

Example

package main

import (
	"bytes"
	"fmt"
	"log"
	"strings"

	userdata "github.com/Aton-Kish/gouserdata"
)

func main() {
	d := userdata.NewMultipart()

	if err := d.SetBoundary("+Custom+User+Data+Boundary+"); err != nil {
		log.Fatal(err)
	}

	scr := []byte(`#!/bin/bash
echo 'Hello World'`)
	d.AddPart(userdata.MediaTypeXShellscript, scr)

	buf := new(bytes.Buffer)
	d.Render(buf)

	output := buf.String()
	output = strings.ReplaceAll(output, "\r\n", "\n") // for testing
	fmt.Println(output)
}

Output:

Content-Type: multipart/mixed; boundary=+Custom+User+Data+Boundary+
Mime-Version: 1.0

--+Custom+User+Data+Boundary+
Content-Transfer-Encoding: 7bit
Content-Type: text/x-shellscript; charset=us-ascii

#!/bin/bash
echo 'Hello World'

--+Custom+User+Data+Boundary+--

type Part

type Part struct {
	Header Header
	Body   []byte
	// contains filtered or unexported fields
}

func NewPart

func NewPart() *Part

func (*Part) MediaType

func (p *Part) MediaType() MediaType

func (*Part) Render

func (p *Part) Render(w io.Writer) error

func (*Part) SetBody

func (p *Part) SetBody(mediaType MediaType, body []byte)