feat(update): add support for automatically rolling back failed updates

Author: vikaspotluri123

lib/commands/update.js

@@ -114,7 +114,12 @@ class UpdateCommand extends Command {
                     return;
                 }
 
-                return this.ui.listr(tasks, context);
+                return this.ui.listr(tasks, context).catch(error =>
+                    this.rollbackFromFail(error, {
+                        argv,
+                        version: context.vesion
+                    })
+                );
             });
         });
     }
@@ -196,6 +201,24 @@ class UpdateCommand extends Command {
         });
     }
 
+    rollbackFromFail(error, ctx) {
+        const oldVer = this.system.getInstance().cliConfig.get('previous-version');
+        const newVer = ctx.version;
+        this.ui.error(error);
+        const question = `Unable to upgrade Ghost from v${oldVer} to v${newVer} - Would you like to revert back to v${oldVer}?`;
+        const promise = ctx.argv['auto-rollback'] ? Promise.resolve(true) : this.ui.confirm(question, true);
+
+        return promise.then(answer => {
+            if (!answer) {
+                return Promise.resolve();
+            }
+
+            return this.run({
+                rollback: true
+            });
+        });
+    }
+
     link(context) {
         const symlinkSync = require('symlink-or-copy').sync;
 
@@ -233,6 +256,11 @@ UpdateCommand.options = {
         describe: 'Limit update to Ghost 1.x releases',
         type: 'boolean',
         default: false
+    },
+    'auto-rollback': {
+        description: '[--no-auto-rollback] Enable/Disable automatically rolling back Ghost if updating fails',
+        type: 'boolean',
+        default: false
     }
 };
 UpdateCommand.checkVersion = true;