implemented token/credentials cache

storage/selctl/main.go

@@ -12,9 +12,11 @@ import (
 )
 
 const (
-	envKey       = storage.EnvKey
-	envUser      = storage.EnvUser
-	envContainer = "SELECTEL_CONTAINER"
+	envKey        = storage.EnvKey
+	envUser       = storage.EnvUser
+	cacheFilename = ".~selct.cache"
+	envCache      = "SELCTL_CACHE"
+	envContainer  = "SELECTEL_CONTAINER"
 )
 
 var (
@@ -23,11 +25,13 @@ var (
 	container      string
 	api            storage.API
 	debug          bool
+	cache          bool
 	errorNotEnough = errors.New("Not enought arguments")
 )
 
 func init() {
 	client.DefineBoolFlagVar(&debug, "debug", false, "debug mode")
+	client.DefineBoolFlagVar(&cache, "cache", false, "cache credentials")
 	client.DefineStringFlag("key", "", fmt.Sprintf("selectel storage key (%s)", envKey))
 	client.AliasFlag('k', "key")
 	client.DefineStringFlag("user", "", fmt.Sprintf("selectel storage user (%s)", envUser))
@@ -70,27 +74,48 @@ func blank(s string) bool {
 
 // connect reads credentials and performs auth
 func connect(c cli.Command) {
+	var err error
+
 	key = readFlag(c, "key", envKey)
 	user = readFlag(c, "user", envUser)
 	container = readFlag(c, "container", envContainer)
 
+	if cache {
+		api, err = storage.NewFromCache(cacheFilename)
+		if err != nil && err != os.ErrNotExist {
+			log.Println("unable to load from cache:", err)
+		} else {
+			return
+		}
+	} else {
+		os.Remove(cacheFilename)
+	}
+
 	// checking for blank credentials
-	if blank(key) || blank(user) {
+	if blank(key) || blank(user) && api != nil {
 		log.Fatal(storage.ErrorBadCredentials)
 	}
 
 	// connencting to api
-	var err error
-	api, err = storage.New(user, key)
-	if err != nil {
+	api = storage.NewAsync(user, key)
+	api.Debug(debug)
+	if err = api.Auth(user, key); err != nil {
 		log.Fatal(err)
 	}
-	api.Debug(debug)
 }
 
 func wrap(callback func(cli.Command)) func(cli.Command) {
 	return func(c cli.Command) {
 		connect(c.Parent())
+		defer func() {
+			if cache {
+				if err := api.SaveToCache(cacheFilename); err != nil {
+					log.Println("unable to save to cache:", err)
+				} else {
+					log.Println("saved to cache")
+				}
+			}
+		}()
 		callback(c)
 	}
 }

storage/storage.go

@@ -1,6 +1,7 @@
 package storage
 
 import (
+	"encoding/gob"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -61,6 +62,65 @@ type Client struct {
 	debug       bool
 }
 
+type ClientCredentials struct {
+	Token      string
+	Key        string
+	User       string
+	Debug      bool
+	Expire     int
+	ExpireFrom *time.Time
+	URL        string
+}
+
+func NewFromCache(filename string) (API, error) {
+	var cache = new(ClientCredentials)
+	f, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	decorer := gob.NewDecoder(f)
+	if err := decorer.Decode(cache); err != nil {
+		return nil, err
+	}
+	c := newClient(new(http.Client))
+	if blank(cache.User) || blank(cache.Key) {
+		return nil, ErrorBadCredentials
+	}
+	c.user = cache.User
+	c.key = cache.Key
+	c.token = cache.Token
+	c.tokenExpire = cache.Expire
+	c.debug = cache.Debug
+	c.expireFrom = cache.ExpireFrom
+	c.storageURL, err = url.Parse(cache.URL)
+	if err != nil {
+		return nil, ErrorBadCredentials
+	}
+	return c, nil
+}
+
+func (c *Client) Credentials() (cache ClientCredentials) {
+	cache.User = c.user
+	cache.Key = c.key
+	cache.URL = c.storageURL.String()
+	cache.Expire = c.tokenExpire
+	cache.ExpireFrom = c.expireFrom
+	cache.Token = c.token
+	cache.Debug = c.debug
+
+	return cache
+}
+
+func (c *Client) SaveToCache(filename string) error {
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	encoder := gob.NewEncoder(f)
+	return encoder.Encode(c.Credentials())
+}
+
 // StorageInformation contains some usefull metrics about storage for current user
 type StorageInformation struct {
 	ObjectCount     uint64
@@ -91,6 +151,8 @@ type API interface {
 	ContainerInfo(name string) (info ContainerInfo, err error)
 	ContainersInfo() ([]ContainerInfo, error)
 	Containers() ([]ContainerAPI, error)
+	Credentials() (cache ClientCredentials)
+	SaveToCache(filename string) error
 }
 
 // DoClient is mock of http.Client