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:

1. Service boundary analysis: Identify logical service boundaries

2. API design: Create clean interfaces between services

3. Data migration: Handle database splitting and consistency

4. Infrastructure setup: Container orchestration and service discovery

5. 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:

1. Compatibility assessment: Identify .NET Core compatibility issues

2. API migration: Update framework-specific code

3. Configuration updates: Modernize configuration patterns

4. Testing strategy: Ensure cross-platform compatibility

5. 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:

1. Component identification: Map jQuery code to React components

2. State management: Implement modern state patterns

3. API integration: Replace jQuery Ajax with modern patterns

4. UI modernization: Update styling and user experience

5. Testing implementation: Add comprehensive test coverage

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See also

• Code refactoring

• Product backlog