Code migrations

Code migrations can be of a few flavors - upgrading a library (e.g. SQLAlchemy 1.4 to 2.0 in python), upgrading a language framework (Java 8 to Java 17) or migrating to a completely new framework (Ember to React).

Typically large migrations can require multiple teams collaboration and may be spread over a huge amount of codebase. Using Runbooks these migrations can be planned out with all teams involved and executed step by step while ensuring compatibility.

Remote Agents framework also comes pre-bundled with a library of Runbook templates that can be used as a starting point while adding more context of the nuances associated with your own codebase.

When to use

Ideal scenarios

Framework upgrades: Moving to newer versions of React, Angular, Vue, or other frameworks
Language migrations: Converting from one programming language to another
Architecture evolution: Moving from monolith to microservices or updating patterns
Technology stack modernization: Updating to modern tools and best practices
Platform migrations: Moving between cloud platforms or infrastructure patterns

Perfect for teams that

Need to upgrade legacy applications to modern frameworks
Want to adopt new technologies without rewriting everything from scratch
Have tight deadlines for technology updates
Need to maintain functionality during migration
Want to minimize migration risks and ensure consistency

Pre-built migration templates

Frontend framework migrations examples

React Migration Templates

React 16 to 18: Updates React APIs, lifecycle methods, and new features
Class components to hooks: Converts class-based components to functional components
Enzyme to react testing library: Updating the rendering and quering method
PropTypes to TypeScript: Adds static type checking with TypeScript

Angular Migration Templates

Angular 12 to 15: Handles breaking changes and new API adoptions
AngularJS to Angular: Complete framework migration with modern patterns
Angular Forms migration: Updates to reactive forms and validation patterns
Angular Router updates: Migrates routing configurations and guards

Vue Migration Templates

Vue 2 to Vue 3: Comprehensive migration including Composition API
Options API to Composition API: Modernizes component structure
Vuex to Pinia: State management migration to modern patterns
Vue Router updates: Updates routing for Vue 3 compatibility

Backend and language migrations

Java migration templates

Java 8 to 11: Updates language features and deprecated APIs
Java 11 to 17: Adopts new language features and performance improvements
Java 17 to 21: Latest language features and virtual threads
Spring Boot 2.x to 3.x: Framework upgrade with configuration updates

Node.js migration templates

Node.js 14 to 18: Runtime updates and new API adoption
Node.js 16 to 20: Performance improvements and feature updates
Express.js upgrades: Framework version migrations with middleware updates
CommonJS to ES modules: Module system modernization

Python migration templates

Python 2.7 to 3.x: Complete language migration with syntax updates
Django upgrades: Framework version migrations with ORM updates
Flask modernization: Updates to modern Flask patterns and features
Async/Await migration: Converts callback patterns to modern async syntax

Infrastructure and platform migrations

Cloud platform migrations

File storage migration: Migration to AWS, Azure, or Google Cloud
Docker Optimization: Container best practices and multi-stage builds
CI/CD Platform Migration: Jenkins to GitHub Actions, Travis to GitLab CI

Database migration templates

MySQL 5.7 to 8.0: Database version upgrades with compatibility fixes
PostgreSQL Upgrades: Version migrations with feature adoption
MongoDB Updates: NoSQL database version and API migrations

Migration without a template

1. Migration assessment and planning

Start by describing your migration goals:

"We need to migrate our React 16 application to React 18. The application includes:
- 150+ components using class-based patterns
- Legacy Context API implementation
- Deprecated lifecycle methods
- PropTypes for type checking
- We want to adopt React 18 features while maintaining all functionality"

What Runbooks does:

Analyzes your entire codebase to understand current patterns
Identifies all components that need migration
Maps dependencies and potential breaking changes
Creates a comprehensive migration plan with risk assessment

2. Compatibility analysis

Runbooks performs deep compatibility analysis:

Breaking changes: Identifies APIs that have changed or been removed
Dependency updates: Analyzes third-party library compatibility
Feature adoption: Recommends new features to adopt during migration
Risk assessment: Evaluates potential issues and mitigation strategies

3. Incremental migration strategy

The AI creates a step-by-step migration plan:

Infrastructure Updates: Update build tools, dependencies, and configuration
Core API Migration: Update fundamental framework APIs and patterns
Component Migration: Convert components in dependency order
Feature Enhancement: Adopt new framework features and improvements
Testing and Validation: Comprehensive testing at each stage

4. Automated implementation

Runbooks executes migration systematically:

Updates one component or module at a time
Maintains functionality throughout the process
Runs tests after each change to ensure stability
Creates detailed pull requests explaining each migration step

Real-world migration examples

Example 1: React Class to Hooks Migration

Before Migration:

class UserProfile extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      user: null,
      loading: true,
      error: null
    };
  }

  async componentDidMount() {
    try {
      const user = await api.getUser(this.props.userId);
      this.setState({ user, loading: false });
    } catch (error) {
      this.setState({ error, loading: false });
    }
  }

  componentDidUpdate(prevProps) {
    if (prevProps.userId !== this.props.userId) {
      this.fetchUser();
    }
  }

  fetchUser = async () => {
    this.setState({ loading: true });
    try {
      const user = await api.getUser(this.props.userId);
      this.setState({ user, loading: false });
    } catch (error) {
      this.setState({ error, loading: false });
    }
  }

  render() {
    const { user, loading, error } = this.state;
    if (loading) return <LoadingSpinner />;
    if (error) return <ErrorMessage error={error} />;
    return <UserDetails user={user} />;
  }
}

After Runbooks Migration:

import { useState, useEffect, useCallback } from 'react';

const UserProfile = ({ userId }) => {
  const [user, setUser] = useState(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState(null);

  const fetchUser = useCallback(async () => {
    setLoading(true);
    setError(null);
    try {
      const userData = await api.getUser(userId);
      setUser(userData);
    } catch (err) {
      setError(err);
    } finally {
      setLoading(false);
    }
  }, [userId]);

  useEffect(() => {
    fetchUser();
  }, [fetchUser]);

  if (loading) return <LoadingSpinner />;
  if (error) return <ErrorMessage error={error} />;
  return <UserDetails user={user} />;
};

export default UserProfile;

Example 2: Python 2 to Python 3 Migration

Before Migration:

# Python 2 syntax and patterns
import urllib2
import ConfigParser

class DataProcessor:
    def __init__(self, config_file):
        self.config = ConfigParser.ConfigParser()
        self.config.read(config_file)

    def fetch_data(self, url):
        response = urllib2.urlopen(url)
        data = response.read()
        return unicode(data, 'utf-8')

    def process_items(self, items):
        for item in items:
            print "Processing:", item
            yield item.upper()

    def get_keys(self, data_dict):
        return data_dict.keys()

After Runbooks Migration:

# Python 3 syntax and patterns
import urllib.request
import configparser

class DataProcessor:
    def __init__(self, config_file):
        self.config = configparser.ConfigParser()
        self.config.read(config_file)

    def fetch_data(self, url):
        with urllib.request.urlopen(url) as response:
            data = response.read()
            return data.decode('utf-8')

    def process_items(self, items):
        for item in items:
            print("Processing:", item)
            yield item.upper()

    def get_keys(self, data_dict):
        return list(data_dict.keys())

Example 3: Angular 12 to 15 Migration

Before Migration:

// Angular 12 patterns
import { Component, OnInit } from '@angular/core';
import { FormBuilder, FormGroup, Validators } from '@angular/forms';

@Component({
  selector: 'app-user-form',
  template: `
    <form [formGroup]="userForm" (ngSubmit)="onSubmit()">
      <input formControlName="name" placeholder="Name">
      <input formControlName="email" placeholder="Email">
      <button type="submit">Submit</button>
    </form>
  `
})
export class UserFormComponent implements OnInit {
  userForm: FormGroup;

  constructor(private fb: FormBuilder) {}

  ngOnInit() {
    this.userForm = this.fb.group({
      name: ['', Validators.required],
      email: ['', [Validators.required, Validators.email]]
    });
  }

  onSubmit() {
    if (this.userForm.valid) {
      console.log(this.userForm.value);
    }
  }
}

After Runbooks Migration:

// Angular 15 with modern patterns
import { Component, inject } from '@angular/core';
import { FormBuilder, Validators, ReactiveFormsModule } from '@angular/forms';
import { CommonModule } from '@angular/common';

@Component({
  selector: 'app-user-form',
  standalone: true,
  imports: [CommonModule, ReactiveFormsModule],
  template: `
    <form [formGroup]="userForm" (ngSubmit)="onSubmit()">
      <input formControlName="name" placeholder="Name">
      <input formControlName="email" placeholder="Email">
      <button type="submit" [disabled]="userForm.invalid">Submit</button>
    </form>
  `
})
export class UserFormComponent {
  private fb = inject(FormBuilder);

  userForm = this.fb.nonNullable.group({
    name: ['', Validators.required],
    email: ['', [Validators.required, Validators.email]]
  });

  onSubmit() {
    if (this.userForm.valid) {
      const formValue = this.userForm.getRawValue();
      console.log(formValue);
    }
  }
}

Advanced migration scenarios

Monolith to microservices migration

Large-scale architecture migration:

"Migrate our monolithic application to microservices architecture:
- Extract user management into a separate service
- Create API gateways for service communication
- Implement distributed tracing and monitoring
- Maintain data consistency across services"

Migration strategy:

Service boundary analysis: Identify logical service boundaries
API design: Create clean interfaces between services
Data migration: Handle database splitting and consistency
Infrastructure setup: Container orchestration and service discovery
Gradual cutover: Incremental migration with feature flags

Cross-platform migration

Technology stack migration:

"Migrate our .NET Framework application to .NET Core for cloud deployment:
- Update framework-specific APIs to .NET Core equivalents
- Migrate Entity Framework to EF Core
- Update deployment configuration for containerization
- Maintain Windows compatibility while adding Linux support"

Comprehensive approach:

Compatibility assessment: Identify .NET Core compatibility issues
API migration: Update framework-specific code
Configuration updates: Modernize configuration patterns
Testing strategy: Ensure cross-platform compatibility
Deployment modernization: Container and cloud-ready deployment

Legacy system modernization

Complete technology refresh:

"Modernize our legacy jQuery application to React:
- Convert jQuery DOM manipulation to React components
- Replace Ajax calls with modern fetch API and state management
- Implement modern routing and navigation
- Add TypeScript for type safety"

Modernization steps:

Component identification: Map jQuery code to React components
State management: Implement modern state patterns
API integration: Replace jQuery Ajax with modern patterns
UI modernization: Update styling and user experience
Testing implementation: Add comprehensive test coverage

When to use

Ideal scenarios

Perfect for teams that

Pre-built migration templates

Frontend framework migrations examples

Backend and language migrations

Infrastructure and platform migrations

Migration without a template

1. Migration assessment and planning

2. Compatibility analysis

3. Incremental migration strategy

4. Automated implementation

Real-world migration examples

Example 1: React Class to Hooks Migration

Example 2: Python 2 to Python 3 Migration

Example 3: Angular 12 to 15 Migration

Advanced migration scenarios

Monolith to microservices migration

Cross-platform migration

Legacy system modernization

See also