Support both bearer + consumer tokens for Twitter modules

* Add support to both the twitter and twitterstats modules for authenticating using both bearer tokens as well as consumer key + secret.
  * A bearer token is defaulted to if it's supplied
  * Add this support to both the twitterstats module as well as to the existing twitter module, modifying its functionality to re-use the same HTTP client and handle authentication upfront via oauth2

modules/twitter/client.go

@@ -1,9 +1,14 @@
 package twitter
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
+	"net/http"
 	"strconv"
+
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/clientcredentials"
 )
 
 /* NOTE: Currently single application ONLY
@@ -13,18 +18,36 @@ import (
 // Client represents the data required to connect to the Twitter API
 type Client struct {
 	apiBase    string
-	bearerToken string
 	count      int
 	screenName string
+	httpClient *http.Client
 }
 
 // NewClient creates and returns a new Twitter client
 func NewClient(settings *Settings) *Client {
+	var httpClient *http.Client
+	// If a bearer token is supplied, use that directly.  Otherwise, let the Oauth client fetch a token
+	// using the consumer key and secret.
+	if settings.bearerToken == "" {
+		conf := &clientcredentials.Config{
+			ClientID:     settings.consumerKey,
+			ClientSecret: settings.consumerSecret,
+			TokenURL:     "https://api.twitter.com/oauth2/token",
+		}
+		httpClient = conf.Client(oauth2.NoContext)
+	} else {
+		ctx := context.Background()
+		httpClient = oauth2.NewClient(ctx, oauth2.StaticTokenSource(&oauth2.Token{
+			AccessToken: settings.bearerToken,
+			TokenType:   "Bearer",
+		}))
+	}
+
 	client := Client{
 		apiBase:    "https://api.twitter.com/1.1/",
 		count:      settings.count,
 		screenName: "",
-		bearerToken: settings.bearerToken,
+		httpClient: httpClient,
 	}
 
 	return &client
@@ -53,7 +76,7 @@ func (client *Client) tweets() (tweets []Tweet, err error) {
 		strconv.Itoa(client.count),
 	)
 
-	data, err := Request(client.bearerToken, apiURL)
+	data, err := Request(client.httpClient, apiURL)
 	if err != nil {
 		return tweets, err
 	}

modules/twitter/request.go

@@ -2,21 +2,11 @@ package twitter
 
 import (
 	"bytes"
-	"fmt"
 	"net/http"
 )
 
-func Request(bearerToken string, apiURL string) ([]byte, error) {
-	req, err := http.NewRequest("GET", apiURL, nil)
-	if err != nil {
-		return nil, err
-	}
-
-	// Expected authorization format for single-application twitter dev accounts
-	req.Header.Add("Authorization", fmt.Sprintf("Bearer %s", bearerToken))
-
-	client := &http.Client{}
-	resp, err := client.Do(req)
+func Request(httpClient *http.Client, apiURL string) ([]byte, error) {
+	resp, err := httpClient.Get(apiURL)
 	if err != nil {
 		return nil, err
 	}

modules/twitter/settings.go

@@ -16,6 +16,8 @@ type Settings struct {
 	common *cfg.Common
 
 	bearerToken    string
+	consumerKey    string
+	consumerSecret string
 	count          int
 	screenNames    []interface{}
 }
@@ -25,6 +27,8 @@ func NewSettingsFromYAML(name string, ymlConfig *config.Config, globalConfig *co
 		common: cfg.NewCommonSettingsFromModule(name, defaultTitle, defaultFocusable, ymlConfig, globalConfig),
 
 		bearerToken:    ymlConfig.UString("bearerToken", os.Getenv("WTF_TWITTER_BEARER_TOKEN")),
+		consumerKey:    ymlConfig.UString("consumerKey", os.Getenv("WTF_TWITTER_CONSUMER_KEY")),
+		consumerSecret: ymlConfig.UString("consumerSecret", os.Getenv("WTF_TWITTER_CONSUMER_SECRET")),
 		count:          ymlConfig.UInt("count", 5),
 		screenNames:    ymlConfig.UList("screenName"),
 	}

modules/twitterstats/client.go

@@ -1,6 +1,7 @@
 package twitterstats
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
@@ -15,6 +16,7 @@ import (
 type Client struct {
 	httpClient  *http.Client
 	screenNames []string
+	bearerToken string
 }
 
 // TwitterStats Represents a stats snapshot for a single Twitter user at a point in time
@@ -37,12 +39,23 @@ func NewClient(settings *Settings) *Client {
 		}
 	}
 
+	var httpClient *http.Client
+	// If a bearer token is supplied, use that directly.  Otherwise, let the Oauth client fetch a token
+	// using the consumer key and secret.
+	if settings.bearerToken == "" {
 		conf := &clientcredentials.Config{
 			ClientID:     settings.consumerKey,
 			ClientSecret: settings.consumerSecret,
 			TokenURL:     "https://api.twitter.com/oauth2/token",
 		}
-	httpClient := conf.Client(oauth2.NoContext)
+		httpClient = conf.Client(oauth2.NoContext)
+	} else {
+		ctx := context.Background()
+		httpClient = oauth2.NewClient(ctx, oauth2.StaticTokenSource(&oauth2.Token{
+			AccessToken: settings.bearerToken,
+			TokenType:   "Bearer",
+		}))
+	}
 
 	client := Client{
 		httpClient:  httpClient,

modules/twitterstats/settings.go

@@ -15,6 +15,7 @@ const (
 type Settings struct {
 	common *cfg.Common
 
+	bearerToken    string
 	consumerKey    string
 	consumerSecret string
 	screenNames    []interface{}
@@ -24,6 +25,7 @@ func NewSettingsFromYAML(name string, ymlConfig *config.Config, globalConfig *co
 	settings := Settings{
 		common: cfg.NewCommonSettingsFromModule(name, defaultTitle, defaultFocusable, ymlConfig, globalConfig),
 
+		bearerToken:    ymlConfig.UString("bearerToken", os.Getenv("WTF_TWITTER_BEARER_TOKEN")),
 		consumerKey:    ymlConfig.UString("consumerKey", os.Getenv("WTF_TWITTER_CONSUMER_KEY")),
 		consumerSecret: ymlConfig.UString("consumerSecret", os.Getenv("WTF_TWITTER_CONSUMER_SECRET")),