go-containers

A pre-made Golang module for easily spinning up and managing lxd containers.

• Author: John Connor Sanders
• License: Apache Version 2.0
• Version Release Date: 04/18/2021
• Current Version: 0.0.3
• Developed for Ubuntu 20.x

License

• Copyright 2021 John Connor Sanders

This source code of this package is released under the Apache Version 2.0 license. Please see the LICENSE for the full content of the license.

Installation

$ go get github.com/JECSand/go-containers

Dependencies

Ensure that LXD is installed and running on your environment

• Use the provided lxd installer script if needed:

$ . ./build_lxd.sh

---

Module Main Data Structs

###1. GoCluster

type GoCluster struct {
    Name         string
    Type         string
    ReverseProxy string
    LoadBalancer string
    Controller   string
    Containers   []*GoContainer
    Images       []*GoImage
    Network      *Network
}

• ###GoCluster Methods

  I. Scan()

  func (gc *GoCluster) Scan() ([]*GoContainers, error)
  

  II. CreateContainer()

  func (gc *GoCluster) CreateContainer(auth *Auth, controller bool, name string, cType string, cRelease string, config []byte) error
  

  III. GetContainers()

  func (gc *GoCluster) GetContainers() ([]*GoContainer, error)
  

  IV. GetContainer()

  func (gc *GoCluster) GetContainer(containerName string) (*GoContainer, error)
  

  V. DeleteContainer()

  func (gc *GoCluster) DeleteContainer(containerName string) error
  

  VI. ExportContainer()

  func (gc *GoCluster) ExportContainer(containerName string) (*GoImage, error)
  

  VII. ImportContainer()

  func (gc *GoCluster) ImportContainer(containerName string, image *GoImage) (*GoContainer, error)
  

  VIII. ScanImages()

  func (gc *GoCluster) ScanImages() ([]*GoImage, error)
  

  IX. CreateImage()

  func (gc *GoCluster) CreateImage(containerName string, sName string) error 
  

  X. DeleteImage()

  func (gc *GoCluster) DeleteImage(fingerprint string) error
  

###2. Network

type Network struct {
    PublicIP    string
    PrivateIP   string
    HWAddr      string
    Type        string
    HostName    string
    SSL         bool
    DNS         string
    Connections []*Connection
}

###3. GoContainer

type GoContainer struct {
    Name        string
    Controller  bool
    SSHClient   *SSHClient
    Type        string
    Release     string
    Services    []string
    InitFile    []byte
    Storage     string
    Network     *Network
    Auth        *Auth
    GoSnapshots []*GoSnapshot
    Status      string
}

• ###GoContainer Methods

  I. Create()

  func (c *GoContainer) Create() error
  

  II. Stop()

  func (c *GoContainer) Stop() error
  

  II. Boot()

  func (c *GoContainer) Boot() error
  

  III. Reboot()

  func (c *GoContainer) Reboot() error
  

  IV. Delete()

  func (c *GoContainer) Delete() error
  

  V. CreateSnapshot()

  func (c *GoContainer) CreateSnapshot() (string, error)
  

  VI. GetSnapshots()

  func (c *GoContainer) GetSnapshots() ([]*GoSnapshot, error) 
  

  VII. Restore()

  func (c *GoContainer) Restore(snapshotName string) error
  

  VIII. Image()

  func (c *GoContainer) Image(snapshotName string) (*GoImage, error) 
  

  IX. Export()

  func (c *GoContainer) Export() (*GoImage, error) 
  

  X. Import()

  func (c *GoContainer) Import(image *GoImage) error
  

  XI. CMD()

  func (c *GoContainer) CMD(cmd string, userName string, reErr bool) ([]byte, error)
  

  XII. OpenSSH()

  func (c *GoContainer) OpenSSH() error 
  

###4. GoContainer.Auth

type Auth struct {
    User           string
    Type           string
    Credential     string
    SecurityString string
    Port           string
}

###5. GoContainer.GoSnapshot

type GoSnapshot struct {
    Name       string
    DateTime   string
}

###6. GoContainer.SSHClient

type SSHClient struct {
    SSHConn   *ssh.Client
}

• ###SSHClient Methods

  I. Close()

  func (ssh *SSHClient) Close() error
  

###7. GoImage

type GoImage struct {
    Name        string
    Type        string
    Fingerprint string
    TarMeta     []string
    Contents    [][]byte
    DateTime    string
}

• ###GoImage Methods

  I. Import()

  func (im *GoImage) Import() error
  

  II. Export()

  func (im *GoImage) Export() error
  

---

Usage Examples

package main

import (
	"fmt"
	"github.com/JECSand/go-containers"
	"log"
)

func main() {
	// #1: Declare a Cluster of LXC GoContainers
	goCluster := containers.NewGoCluster("test", "ubuntu", "HA-Proxy", "nginx", "")
	
	// #2: Scan your cluster for existing containers at any time to reload the GoContainer Map
	clusterContains, err := goCluster.Scan()
	if err != nil {
		log.Fatal(err.Error())
	}
	fmt.Println(clusterContains)
	
	// #3: Create a New GoContainer
	//       -Params: Username, AuthType, Pass/Key, SecretKey, SSH Port
	cAuth := containers.NewAuth("envUserName", "password", "envPW", "SecurityString*", "22") // Auth for the GoContainer
	// *Note: SecurityString is for SSH Key Auth, which is coming soon
	isCluterControllerNode := true
	//  Create the new GoContainer
	//       -Params: Auth, isController, ContainerName, ContainerOS, osRelease, CloudInitFile
	err = goCluster.CreateContainer(cAuth, isCluterControllerNode, "testContainer", "ubuntu", "xenial", []byte{})
	if err != nil {
		log.Fatal(err.Error())
	}
	
	// #4: Get a GoContainer from GoCluster
	goCon, err := goCluster.GetContainer("testContainer")
	if err != nil {
		log.Fatal(err.Error())
	}
	goCon.Auth = cAuth
	
	// #5: Open a SSHClient on your GoContainer
	err = goCon.OpenSSH()
	if err != nil {
		log.Fatal(err.Error())
	}
	
	// #6: Execute Shell Commands on your GoContainer via SSH
	cmd := "echo Hello GoContainer ; sudo apt-get -y update"
	sshSession, _ := goCon.SSHClient.SSHConn.NewSession()
	defer sshSession.Close()
	sshSession.Run(cmd) // Execute the SSH Command
	// #7: Close the SSHClient Session
	goCon.SSHClient.close()
	
	// #8: Execute a Shell Command on your GoContainer via lxc exec
	out, _ := goCon.CMD("pwd", "ubuntu", false)
	fmt.Println("Remote Command Output: ", string(out))
	
	// #9: Export GoContainer to GoImage
	reImg, err := goCluster.ExportContainer("testContainer")
	if err != nil {
		log.Fatal("Error Exporting the GoContainer: ", err.Error())
	}
	// Exported GoContainer's contents stored in tar.gz format
	fmt.Println(reImg.TarMeta[0])
	fmt.Println(len(reImg.Contents[0]))

	// #10: Import GoContainer from a GoImage
	imCon, err := goCluster.ImportContainer("ImportedContainer", reImg)
	if err != nil {
		log.Fatal("Error Importing the GoContainer: ", err.Error())
	}
	fmt.Println(imCon.Name)
	
	// #11: Delete GoContainer from GoCluster
	err = goCluster.DeleteContainer("testContainer")
	if err != nil {
		log.Fatal(err.Error())
	}
	
	// #12: Get all GoContainers in GoCluster
	goCons, err := goCluster.GetContainers()
	if err != nil {
		log.Fatal(err.Error())
	}
	fmt.Println(goCons)
}