cli: Add rpcuser, rpcpassword and rpcconnect to bitcoind

Might help alleviate some of the issues of having to run a full-node
on the same machine as `lightningd`.

Signed-off-by: Christian Decker <decker.christian@gmail.com>

lightningd/bitcoind.c

@@ -42,6 +42,22 @@ static char **gather_args(const struct bitcoind *bitcoind,
 		args[n++] = tal_fmt(args, "-datadir=%s", bitcoind->datadir);
 		tal_resize(&args, n + 1);
 	}
+
+	if (bitcoind->rpcconnect) {
+		args[n++] = tal_fmt(args, "-rpcconnect=%s", bitcoind->rpcconnect);
+		tal_resize(&args, n + 1);
+	}
+
+	if (bitcoind->rpcuser) {
+		args[n++] = tal_fmt(args, "-rpcuser=%s", bitcoind->rpcuser);
+		tal_resize(&args, n + 1);
+	}
+
+	if (bitcoind->rpcpass) {
+		args[n++] = tal_fmt(args, "-rpcpassword=%s", bitcoind->rpcpass);
+		tal_resize(&args, n + 1);
+	}
+
 	args[n++] = cast_const(char *, cmd);
 	tal_resize(&args, n + 1);
 
@@ -716,6 +732,9 @@ struct bitcoind *new_bitcoind(const tal_t *ctx,
 	bitcoind->req_running = false;
 	bitcoind->shutdown = false;
 	bitcoind->error_count = 0;
+	bitcoind->rpcuser = NULL;
+	bitcoind->rpcpass = NULL;
+	bitcoind->rpcconnect = NULL;
 	list_head_init(&bitcoind->pending);
 	tal_add_destructor(bitcoind, destroy_bitcoind);
 

lightningd/bitcoind.h

@@ -49,6 +49,9 @@ struct bitcoind {
 
 	/* Ignore results, we're shutting down. */
 	bool shutdown;
+
+	/* Passthrough parameters for bitcoin-cli */
+	char *rpcuser, *rpcpass, *rpcconnect;
 };
 
 struct bitcoind *new_bitcoind(const tal_t *ctx,

lightningd/options.c

@@ -548,6 +548,16 @@ void register_opts(struct lightningd *ld)
 	opt_register_arg("--alias", opt_set_alias, NULL, ld,
 			 "Up to 32-byte alias for node");
 
+	opt_register_arg("--bitcoin-rpcuser", opt_set_talstr, NULL,
+			 &ld->topology->bitcoind->rpcuser,
+			 "bitcoind RPC username");
+	opt_register_arg("--bitcoin-rpcpassword", opt_set_talstr, NULL,
+			 &ld->topology->bitcoind->rpcpass,
+			 "bitcoind RPC password");
+	opt_register_arg("--bitcoin-rpcconnect", opt_set_talstr, NULL,
+			 &ld->topology->bitcoind->rpcconnect,
+			 "bitcoind RPC host to connect to");
+
 	opt_register_arg(
 	    "--channel-update-interval=<s>", opt_set_u32, opt_show_u32,
 	    &ld->config.channel_update_interval,