feat: Ability to pass in ssh2 client to transport

lib/Connection.js

@@ -58,6 +58,8 @@ const availableTransports = {
  * @property {string} [password] - The user's password.
  * @property {string} [privateKey] - The user's privateKey.
  * @property {string} [passphrase] - The user's passphrase to decrypt the private key.
+ * @property {object} [sshClient] - An ssh2 Client instance that is already connected and
+ * ready to exec a command.
  */
 
 /**

lib/transports/sshTransport.js

@@ -17,23 +17,110 @@
 
 const { Client } = require('ssh2');
 
-function sshCall(config, xmlIn, done) {
+/**
+ * Function to call xmlservice regardless if an existing connection was passed
+ * @param {Object} parameters - Arguments to call xmlservice-cli
+ * @private
+ */
+function callXmlService(parameters) {
   const {
-    verbose = false,
-  } = config;
+    client, xmlIn, done, verbose, shouldEndClient,
+  } = parameters;
 
   let xmlOut = '';
   const xmlBuffer = Buffer.from(xmlIn);
 
-  const client = new Client();
+  client.exec('/QOpenSys/pkgs/bin/xmlservice-cli', (error, stream) => {
+    if (error) {
+      if (verbose) {
+        console.log('Exec error: ', error);
+      }
+      client.emit('error', error);
+      return;
+    }
+    stream.on('exit', (code, signal, didCoreDump, description) => {
+      if (verbose) {
+        console.log(`Stream exit code: ${code}`);
+        if (signal) {
+          console.log(`Signal: ${signal}, Description: ${description}`);
+        }
+      }
+
+      if (signal) {
+        client.emit('error', new Error(`xmlservice-cli was signaled with: ${signal}`));
+        return;
+      }
 
-  // subscribe for events
+      if (code !== 0) {
+        client.emit('error', new Error(`xmlservice-cli exited abnormally with code: ${code}`));
+        return;
+      }
+      if (shouldEndClient) {
+        client.end();
+        client.destroy();
+      }
+      done(null, xmlOut);
+    });
+
+    stream.stdin.on('end', () => {
+      if (verbose) {
+        console.log('stdin has ended');
+      }
+    });
+
+    stream.stdout.on('end', () => {
+      if (verbose) {
+        console.log('stdout has ended');
+      }
+    });
+
+    stream.stdout.on('data', (data) => {
+      xmlOut += data.toString();
+      if (verbose) {
+        console.log(`STDOUT:\n${data}`);
+      }
+    });
+
+    stream.stderr.on('data', (data) => {
+      if (verbose) {
+        console.log(`STDERR:\n${data}`);
+      }
+    });
+
+    stream.stdin.write(xmlBuffer);
+    stream.stdin.end();
+  });
+}
+
+/**
+ * @private
+ * @param {object} config - Configuration options for ssh transport
+ * @param {string} xmlIn - The xml input to run with xml service
+ * @param {function} done - User defined callback to invoke when completed
+ */
+function sshCall(config, xmlIn, done) {
+  const {
+    sshClient, verbose = false,
+  } = config;
+
+  const client = sshClient || new Client();
+  const shouldEndClient = !sshClient; // Should not end and destroy passed in client
+
+  // Ensure passed in client really is an instance of ssh2.Client
+  if (!(client instanceof Client)) {
+    done('The existing connection is not an ssh2 Client instance', null);
+    return;
+  }
+
+  // setup event listeners
   client.on('error', (error) => {
     if (verbose) {
       console.log('SSH CLIENT ERROR: ', error);
     }
-    client.end();
-    client.destroy();
+    if (shouldEndClient) {
+      client.end();
+      client.destroy();
+    }
     done(error, null);
   });
 
@@ -49,71 +136,26 @@ function sshCall(config, xmlIn, done) {
     }
   });
 
-  client.on('ready', () => {
-    if (verbose) {
-      console.log('SSH Client is ready');
-    }
-    client.exec('/QOpenSys/pkgs/bin/xmlservice-cli', (error, stream) => {
-      if (error) {
-        if (verbose) {
-          console.log('Exec error: ', error);
-        }
-        client.emit('error', error);
-        return;
+  const parameters = {
+    client, xmlIn, done, verbose, shouldEndClient,
+  };
+
+  if (!sshClient) {
+    // ssh2 client is event driven
+    // the ready event emits once authtenticatation was succefully
+    // we can only call xmlservice after the ready event has fired
+    client.on('ready', () => {
+      if (verbose) {
+        console.log('SSH Client is ready');
       }
-      stream.on('exit', (code, signal, didCoreDump, description) => {
-        if (verbose) {
-          console.log(`Stream exit code: ${code}`);
-          if (signal) {
-            console.log(`Signal: ${signal}, Description: ${description}`);
-          }
-        }
-
-        if (signal) {
-          client.emit('error', new Error(`xmlservice-cli was signaled with: ${signal}`));
-          return;
-        }
-
-        if (code !== 0) {
-          client.emit('error', new Error(`xmlservice-cli exited abnormally with code: ${code}`));
-          return;
-        }
-        client.end();
-        client.destroy();
-        done(null, xmlOut);
-      });
-
-      stream.stdin.on('end', () => {
-        if (verbose) {
-          console.log('stdin has ended');
-        }
-      });
-
-      stream.stdout.on('end', () => {
-        if (verbose) {
-          console.log('stdout has ended');
-        }
-      });
-
-      stream.stdout.on('data', (data) => {
-        xmlOut += data.toString();
-        if (verbose) {
-          console.log(`STDOUT:\n${data}`);
-        }
-      });
-
-      stream.stderr.on('data', (data) => {
-        if (verbose) {
-          console.log(`STDERR:\n${data}`);
-        }
-      });
-
-      stream.stdin.write(xmlBuffer);
-      stream.stdin.end();
+      callXmlService(parameters);
     });
-  });
 
-  client.connect(config);
+    client.connect(config);
+  } else {
+    // client should already be connected and ready to call xml service
+    callXmlService(parameters);
+  }
 }
 
 exports.sshCall = sshCall;