Build automation

Build automation is the practice of building software systems in a relatively unattended fashion. The build is configured to run with minimized or no software developer interaction and without using a developer's personal computer. Build automation encompasses the act of configuring the build system as well the resulting system itself.

Build automation encompasses both sequencing build operations via non-interactive interface tools and running builds on a shared server.^[1]

Tools

Build automation tools allow for sequencing the tasks of building software via a non-interactive interface. A build system or build automation tool^[2] is a tool or set of tools that automate the compilation and linking of source code into an executable program or library. They streamline the software development process by managing dependencies, resolving conflicts, and ensuring consistent builds across different environments.

When software projects grow complex, their build steps may involve multiple programming languages or compilation units, making manual build processes increasingly cumbersome. Dependencies between code components necessitate careful ordering and potentially different tools for each piece. Managing these dependencies manually can quickly lead to version conflicts, stale binaries, and difficulty tracking updates, making solutions such as shell scripts too difficult to maintain.^[3]

While individual developers might compile code directly, a robust build system is foundational to efficient software development in large organizations and teams, where automated builds become commonplace and most builds are triggered automatically rather than manually.^[4] Given the essential role of build systems, it is said that they act as "repositories of essential build knowledge".^[5] They effectively eliminate roadblocks and accelerates development velocity by enabling engineers to share resources and results.^[6]

Key features

Most build systems include features that make building large projects easier:

• Dependency management: Resolving and tracking dependencies between components.
• Incremental builds: Only rebuilding what has changed.
• Cross-platform support: Building for multiple environments (e.g., Windows, Linux, macOS).
• Parallel builds: Speeding up builds by running tasks concurrently.
• Extensibility: Supporting plugins or custom scripts.

Example tools

Tools such as Make can be used via custom configuration file or using the command-line. Custom tools such as shell scripts can also be used, although they become increasingly cumbersome as the codebase grows more complex.^[7]

Some tools, such as shell scripts, are task-oriented declarative programming. They encode sequences of commands to perform with usually minimal conditional logic.

Some tools, such as Make are product-oriented. They build a product, a.k.a. target, based on configured dependencies.^[8]

Servers

A build server is a server setup to run builds. As opposed to a personal computer, a server allows for a more consistent and available build environment.

Traditionally, a build server was a local computer dedicated as a shared resource instead of used as a personal computer. Today, there are many cloud computing, software as a service (SaaS) websites for building.

Without a build server, developers typically rely on their personal computers for building, leading to several drawbacks, such as (but not limited to):

• Developers who know how to build might be unavailable (e.g., on vacation).
• Issues with a developer's machine could prevent building.
• Conflicting software on a developer's machine may hinder proper building.

A continuous integration server is a build server that is setup to build in a relatively frequent way – often on each code commit. A build server may also be incorporated into an ARA tool or ALM tool.

Typical build triggering options include:

• On-demand: requested by a user.
• Scheduled: such as a nightly build.
• On-commit: building on every commit to a version control system.

Continuous integration and continuous delivery

Automating the build process is a required step for implementing continuous integration and continuous delivery (CI/CD) – all of which considered best practice for software development.^[9][how?]

Advantages

Pluses of build automation include:^[10]

• Can save time and money in the long run
• Enables continuous integration, delivery and testing
• More consistent build process
• Can optimize the build process; reducing time and redundant tasks
• Reduces dependency on key personnel and their personal computers
• Can automate collection of build history

See also

• Application-release automation – Process of packaging and deployment

• Continuous configuration automation
• Continuous integration – Software development practice of building and testing frequently
• Continuous delivery – Software engineering approach of short cycles
• Continuous testing
• DevOps – Integration of software development and operations
• Incremental compiler
• List of build automation software
• Product family engineering
• Release engineering – Sub-discipline in software engineering
• Software configuration management – Tracking and controlling software changes
• Unit testing – Validating the behavior of isolated source code