Add beginnings of plugin install command

Author: jacobwgillespie

.gitignore

@@ -1,4 +1,5 @@
 mc
+server.yml
 *.exe
 *.*~
 *.swp

command.go

@@ -9,8 +9,9 @@ import (
 )
 
 type Command struct {
-	Run  func(cmd *Command, args []string)
-	Flag flag.FlagSet
+	Run         func(cmd *Command, args []string)
+	Flag        flag.FlagSet
+	NeedsServer bool
 
 	Usage    string // first word must be command name
 	Category string

config.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+	"io/ioutil"
+	"os"
+
+	"github.com/the-obsidian/mc/plugin"
+
+	"gopkg.in/yaml.v2"
+)
+
+type Config struct {
+	Plugins []*plugin.Plugin
+
+	unknownKeys []string
+}
+
+func NewConfigFromString(data string) (*Config, error) {
+	c := Config{}
+
+	err := yaml.Unmarshal([]byte(data), &c)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, plugin := range c.Plugins {
+		err = plugin.Init()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return &c, nil
+}
+
+func NewConfigFromFile(path string) (*Config, error) {
+	data, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	return NewConfigFromString(string(data))
+}
+
+func (c *Config) InstallPlugins() error {
+	err := os.MkdirAll("plugins", 0755)
+	if err != nil {
+		return err
+	}
+
+	for _, plugin := range c.Plugins {
+		err = plugin.Install()
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

install.go

@@ -0,0 +1,38 @@
+package main
+
+import "os"
+
+var cmdInstall = &Command{
+	NeedsServer: true,
+	Usage:       "install",
+	Category:    "app",
+	Short:       "install dependencies",
+	Long: `
+Install installs any required dependencies.
+
+Examples:
+
+	$ mc install
+`,
+}
+
+func init() {
+	cmdInstall.Run = runInstall
+}
+
+func runInstall(cmd *Command, args []string) {
+	if len(args) != 0 {
+		printUsageTo(os.Stderr)
+		os.Exit(2)
+	}
+
+	config, err := NewConfigFromFile("server.yml")
+	if err != nil {
+		printFatal("Error reading config file: %v", err)
+	}
+
+	err = config.InstallPlugins()
+	if err != nil {
+		printFatal("failed to install plugins: %v", err)
+	}
+}

main.go

@@ -13,7 +13,7 @@ import (
 )
 
 var commands = []*Command{
-	//cmdInstall,
+	cmdInstall,
 	//cmdVersion,
 	cmdHelp,
 
@@ -56,6 +56,13 @@ func main() {
 		cmd.Flag.Usage = func() {
 			cmd.PrintUsage()
 		}
+
+		if cmd.NeedsServer {
+			if exists, err := fileExists("server.yml"); err != nil || !exists {
+				printFatal("server.yml not found - is this a server directory?")
+			}
+		}
+
 		if err := cmd.Flag.Parse(args[1:]); err == flag.ErrHelp {
 			cmdHelp.Run(cmdHelp, args[:1])
 		} else if err != nil {

plugin/plugin.go

@@ -0,0 +1,101 @@
+package plugin
+
+import (
+	"crypto/sha1"
+	"fmt"
+	"os"
+	"path"
+
+	"github.com/hashicorp/go-getter"
+	"github.com/the-obsidian/mc/util"
+)
+
+type Plugin struct {
+	Name       string
+	URI        string
+	Sha        string
+	Processors []Processor `yaml:"-"`
+
+	originalProcessors []map[string]interface{} `yaml:"processors"`
+}
+
+func (p *Plugin) Init() error {
+	for _, pr := range p.originalProcessors {
+		processor, err := NewProcessorFromConfig(p, pr)
+		if err != nil {
+			return err
+		}
+		p.Processors = append(p.Processors, processor)
+	}
+
+	return nil
+}
+
+func (p *Plugin) Install() error {
+	dest := path.Join(".", "plugins", p.Name+".jar")
+	tmpDir := path.Join(".", ".tmp", "plugins", p.Name)
+	tmpDownload := path.Join(tmpDir, "download")
+	hash := sha1.New()
+
+	checksumValue, err := decodeChecksum(p.Sha)
+	if err != nil {
+		return err
+	}
+
+	if exists, err := util.FileExists(dest); err != nil {
+		return err
+	} else if exists {
+		err = checksum(dest, hash, checksumValue)
+		if err == nil {
+			return nil
+		}
+	}
+
+	err = os.MkdirAll(tmpDir, 0755)
+	if err != nil {
+		return err
+	}
+
+	err = getter.GetFile(tmpDownload, p.URI)
+	if err != nil {
+		return err
+	}
+
+	err = checksum(tmpDownload, hash, checksumValue)
+	if err != nil {
+		return fmt.Errorf("failed to checksum download: %v", err)
+	}
+
+	err = os.Rename(tmpDownload, dest)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+type Processor interface {
+	Process()
+}
+
+func NewProcessorFromConfig(p *Plugin, config map[string]interface{}) (Processor, error) {
+	switch config["type"] {
+	case "unzip":
+		pr := &UnzipProcessor{
+			Type:  "unzip",
+			Files: config["files"].([]string),
+		}
+		return pr, nil
+	default:
+		return nil, fmt.Errorf("invalid processor type: %v", config["type"])
+	}
+
+	return nil, nil
+}
+
+type UnzipProcessor struct {
+	Type  string
+	Files []string
+}
+
+func (pr *UnzipProcessor) Process() {}

plugin/util.go

@@ -0,0 +1,40 @@
+package plugin
+
+import (
+	"bytes"
+	"encoding/hex"
+	"fmt"
+	"hash"
+	"io"
+	"os"
+)
+
+func decodeChecksum(data string) ([]byte, error) {
+	b, err := hex.DecodeString(data)
+	if err != nil {
+		return nil, fmt.Errorf("invalid checksum: %s", err)
+	}
+	return b, nil
+}
+
+func checksum(source string, h hash.Hash, v []byte) error {
+	f, err := os.Open(source)
+	if err != nil {
+		return fmt.Errorf("Failed to open file for checksum: %s", err)
+	}
+	defer f.Close()
+
+	if _, err := io.Copy(h, f); err != nil {
+		return fmt.Errorf("Failed to hash: %s", err)
+	}
+
+	if actual := h.Sum(nil); !bytes.Equal(actual, v) {
+		return fmt.Errorf(
+			"Checksums did not match.\nExpected: %s\nGot: %s",
+			hex.EncodeToString(v),
+			hex.EncodeToString(actual),
+		)
+	}
+
+	return nil
+}

util.go

@@ -3,10 +3,23 @@ package main
 import (
 	"fmt"
 	"log"
+	"os"
 
 	"github.com/mgutz/ansi"
 )
 
+// exists returns whether the given file or directory exists or not
+func fileExists(path string) (bool, error) {
+	_, err := os.Stat(path)
+	if err == nil {
+		return true, nil
+	}
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return false, err
+}
+
 func printError(message string, args ...interface{}) {
 	log.Println(colorizeMessage("red", "error:", message, args...))
 }

util/util.go

@@ -0,0 +1,14 @@
+package util
+
+import "os"
+
+func FileExists(path string) (bool, error) {
+	_, err := os.Stat(path)
+	if err == nil {
+		return true, nil
+	}
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return false, err
+}