Make mongodb auth mechanism configurable.

cmd/task/main.go

@@ -63,8 +63,9 @@ func main() {
 	db, err := mongo.Connect(
 		context.Background(),
 		options.Client().ApplyURI(cfg.Mongo.Addr).SetAuth(options.Credential{
-			Username: cfg.Mongo.User,
-			Password: cfg.Mongo.Pass,
+			Username:      cfg.Mongo.User,
+			Password:      cfg.Mongo.Pass,
+			AuthMechanism: cfg.Mongo.AuthMechanism,
 		}),
 	)
 	if err != nil {

internal/config/config.go

@@ -31,9 +31,10 @@ type authConfig struct {
 }
 
 type mongoConfig struct {
-	Addr string `envconfig:"MONGO_ADDR" required:"true"`
-	User string `envconfig:"MONGO_USER" required:"true"`
-	Pass string `envconfig:"MONGO_PASS" required:"true"`
+	Addr          string `envconfig:"MONGO_ADDR" required:"true"`
+	User          string `envconfig:"MONGO_USER" required:"true"`
+	Pass          string `envconfig:"MONGO_PASS" required:"true"`
+	AuthMechanism string `envconfig:"MONGO_AUTH_MECHANISM" default:"SCRAM-SHA-1"`
 }
 
 type policyConfig struct {