cmd: rpc url env added to ingest cmd (#48)

What
Adds a new RPC_URL environment variable to the ingest command.

Why
It was previously not being read from the envs.

cmd/ingest.go

@@ -25,6 +25,7 @@ func (c *ingestCmd) Command() *cobra.Command {
 		utils.NetworkPassphraseOption(&cfg.NetworkPassphrase),
 		utils.SentryDSNOption(&sentryDSN),
 		utils.StellarEnvironmentOption(&stellarEnvironment),
+		utils.RPCClientURLOption(&cfg.RPCURL),
 		{
 			Name:           "captive-core-bin-path",
 			Usage:          "Path to Captive Core's binary file.",

cmd/utils/global_options.go

@@ -67,6 +67,16 @@ func HorizonClientURLOption(configKey *string) *config.ConfigOption {
 	}
 }
 
+func RPCClientURLOption(configKey *string) *config.ConfigOption {
+	return &config.ConfigOption{
+		Name:      "rpc-url",
+		Usage:     "The URL of the Stellar RPC server which this application will communicate with.",
+		OptType:   types.String,
+		ConfigKey: configKey,
+		Required:  true,
+	}
+}
+
 func ChannelAccountEncryptionPassphraseOption(configKey *string) *config.ConfigOption {
 	return &config.ConfigOption{
 		Name:      "channel-account-encryption-passphrase",