ssh tunnel - reuse SSH connection + local port for multiple DB connections

packages/api/src/utility/sshTunnel.js

@@ -0,0 +1,61 @@
+const { SSHConnection } = require('node-ssh-forward');
+const portfinder = require('portfinder');
+const stableStringify = require('json-stable-stringify');
+const _ = require('lodash');
+
+const sshConnectionCache = {};
+const sshTunnelCache = {};
+
+const CONNECTION_FIELDS = ['sshHost', 'sshPort', 'sshLogin', 'sshPassword'];
+const TUNNEL_FIELDS = [...CONNECTION_FIELDS, 'server', 'port'];
+
+async function getSshConnection(connection) {
+  const connectionCacheKey = stableStringify(_.pick(connection, CONNECTION_FIELDS));
+  if (sshConnectionCache[connectionCacheKey]) return sshConnectionCache[connectionCacheKey];
+
+  const sshConfig = {
+    endHost: connection.sshHost || '',
+    endPort: connection.sshPort || 22,
+    bastionHost: '',
+    agentForward: false,
+    passphrase: undefined,
+    username: connection.sshLogin,
+    password: connection.sshPassword,
+    skipAutoPrivateKey: true,
+    noReadline: true,
+  };
+
+  const sshConn = new SSHConnection(sshConfig);
+  sshConnectionCache[connectionCacheKey] = sshConn;
+  return sshConn;
+}
+
+async function getSshTunnel(connection) {
+  const sshConn = await getSshConnection(connection);
+  const tunnelCacheKey = stableStringify(_.pick(connection, TUNNEL_FIELDS));
+  if (sshTunnelCache[tunnelCacheKey]) return sshTunnelCache[tunnelCacheKey].localPort;
+
+  const localPort = await portfinder.getPortPromise({ port: 10000, stopPort: 60000 });
+  // workaround for `getPortPromise` not releasing the port quickly enough
+  await new Promise(resolve => setTimeout(resolve, 500));
+  const tunnelConfig = {
+    fromPort: localPort,
+    toPort: connection.port,
+    toHost: connection.server,
+  };
+  const tunnel = await sshConn.forward(tunnelConfig);
+  console.log(
+    `Created SSH tunnel to ${connection.sshHost}-${connection.server}:${connection.port}, using local port ${localPort}`
+  );
+
+  sshTunnelCache[tunnelCacheKey] = {
+    tunnel,
+    localPort,
+  };
+
+  return localPort;
+}
+
+module.exports = {
+  getSshTunnel,
+};