Make client init take a config struct not a path

* Rename the function to `New`.
* Lift config file unmarshaling out of the package and into the
  consumer.

Author: Andrew Farries

components/usage/cmd/run.go

@@ -5,15 +5,17 @@
 package cmd
 
 import (
+	"encoding/json"
+	"net"
+	"os"
+	"time"
+
 	"github.com/gitpod-io/gitpod/common-go/baseserver"
 	"github.com/gitpod-io/gitpod/common-go/log"
 	"github.com/gitpod-io/gitpod/usage/pkg/controller"
 	"github.com/gitpod-io/gitpod/usage/pkg/db"
 	"github.com/gitpod-io/gitpod/usage/pkg/stripe"
 	"github.com/spf13/cobra"
-	"net"
-	"os"
-	"time"
 )
 
 func init() {
@@ -47,9 +49,20 @@ func run() *cobra.Command {
 			var billingController controller.BillingController = &controller.NoOpBillingController{}
 
 			if apiKeyFile != "" {
-				c, err := stripe.Authenticate(apiKeyFile)
+				bytes, err := os.ReadFile(apiKeyFile)
+				if err != nil {
+					log.WithError(err).Fatal("Failed to read Stripe API keys.")
+				}
+
+				var config stripe.ClientConfig
+				err = json.Unmarshal(bytes, &config)
+				if err != nil {
+					log.WithError(err).Fatal("Failed to unmarshal Stripe API keys.")
+				}
+
+				c, err := stripe.New(config)
 				if err != nil {
-					log.WithError(err).Fatal("Failed to initialize stripe client.")
+					log.WithError(err).Fatal("Failed to initialize Stripe client.")
 				}
 				billingController = controller.NewStripeBillingController(c)
 			}

components/usage/pkg/stripe/stripe.go

@@ -5,10 +5,8 @@
 package stripe
 
 import (
-	"encoding/json"
 	"fmt"
 	"math"
-	"os"
 	"strings"
 
 	"github.com/gitpod-io/gitpod/common-go/log"
@@ -20,27 +18,14 @@ type Client struct {
 	sc *client.API
 }
 
-type stripeKeys struct {
+type ClientConfig struct {
 	PublishableKey string `json:"publishableKey"`
 	SecretKey      string `json:"secretKey"`
 }
 
-// Authenticate authenticates the Stripe client using a provided file containing a Stripe secret key.
-func Authenticate(apiKeyFile string) (*Client, error) {
-	bytes, err := os.ReadFile(apiKeyFile)
-	if err != nil {
-		return nil, err
-	}
-
-	var stripeKeys stripeKeys
-	err = json.Unmarshal(bytes, &stripeKeys)
-	if err != nil {
-		return nil, err
-	}
-
-	sc := &client.API{}
-	sc.Init(stripeKeys.SecretKey, nil)
-	return &Client{sc: sc}, nil
+// New authenticates a Stripe client using the provided config
+func New(config ClientConfig) (*Client, error) {
+	return &Client{sc: client.New(config.SecretKey, nil)}, nil
 }
 
 // UpdateUsage updates teams' Stripe subscriptions with usage data