Add generic bitcoin-cli commands

This commit adds a special `external_subcommand` that can call any valid
bitcoin-cli rpc call on the node. Even if we don't have it covered in our
node command lists.

src/commands.rs

@@ -156,6 +156,9 @@ pub enum NodeSubCommand {
     GetBalance,
     /// Send to an external wallet address
     SendToAddress { address: String, amount: u64 },
+    /// Execute any bitcoin-cli commands
+    #[structopt(external_subcommand)]
+    BitcoinCli(Vec<String>),
 }
 
 #[derive(Debug, StructOpt, Clone, PartialEq)]

src/handlers.rs

@@ -617,7 +617,10 @@ pub(crate) fn handle_command(cli_opts: CliOpts) -> Result<String, Error> {
                             #[cfg(feature = "regtest-node")]
                             ReplSubCommand::Node { subcommand } => {
                                 let backend = new_backend(&home_dir)?;
-                                backend.exec_cmd(subcommand)
+                                match backend.exec_cmd(subcommand) {
+                                    Ok(result) => Ok(result),
+                                    Err(e) => Ok(serde_json::Value::String(e.to_string())),
+                                }
                             }
                             #[cfg(any(
                                 feature = "electrum",

src/nodes.rs

@@ -22,6 +22,7 @@ use {
         Error,
     },
     electrsd::bitcoind::bitcoincore_rpc::{Client, RpcApi},
+    serde_json::Value,
     std::str::FromStr,
 };
 
@@ -95,6 +96,17 @@ impl Nodes {
                     .map_err(|e| Error::Generic(e.to_string()))?;
                 Ok(serde_json::to_value(&txid)?)
             }
+
+            NodeSubCommand::BitcoinCli(args) => {
+                let cmd = &args[0];
+                let args = args[1..]
+                    .iter()
+                    .map(|arg| serde_json::Value::from_str(arg))
+                    .collect::<Result<Vec<Value>, _>>()?;
+                client
+                    .call::<Value>(cmd, &args)
+                    .map_err(|e| Error::Generic(e.to_string()))
+            }
         }
     }