Software Build Tools
Software build tools are used to automate the creation of executable applications from source code. They script or automate a variety of tasks, such as downloading dependencies, compiling and packaging code, running tests, and deployment. They can be triggered through the command line, inside an IDE, or by continuous integration tools after checking the code out of a repository and onto a build machine. Different build systems exist for different languages. Usually, build systems use either a domain-specific language or XML to specify a build.
There are three types of build processes that enable developers to get their software builds done:
1. Continuous Integration (CI) builds: In this practice, developers merge their code to a centralized mainline several times a day. This prevents integration problems with incompatible or buggy code when all of the developers attempt to check in at the last minute prior to a release. While deployments involve simply preparing the code so it can be run, CI builds involve running the code against a test suite.
2. Gated check-in builds: Also known as gated commits, this is a software integration pattern where developers must request a gated commit from the CI server before committing the changes to the shared mainline. That way, they can observe whether the changes break the build before actually committing them.
3. Nightly builds: Also referred to as scheduled builds, the name pretty much describes the process. Builds are done at a scheduled time on a daily basis. This process usually occurs at night so that the code can be compiled by the build computer during off hours, then tested by developers the following morning.
In this section, we will generally be referring to CI builds and, to a lesser extent, gated check-in builds.
What are Software Build Tools?
Modern build automation tools don’t just compile code; they enable workflows by obtaining source code, deploying executables to be tested, and optimizing complex build processes. There are numerous build tools with all sorts of trade-offs between them, but usually they are based on a specific language. For an example, Maven and Ant are XML-based tools, Grunt is JSON-based, and sbt is Scala-based.
Build tool features might include: running ad-hoc commands, ordering the execution of commands based on dependencies, parallelizing different commands, overseeing file changes and running commands based on those changes, using external processes such as compilers, allowing configuration and re-configuration, and downloading dependencies.
Benefits of Software Build Tools
Build automation tools are crucial for moving towards a continuous delivery (CD) model. They allow you to build your project with the click of a button, which reduces errors from manually running steps, and also increases the consistency of the process. Automated builds make sure that the whole team knows almost immediately when something goes wrong, and who is responsible for the error. They are especially important in environments with multiple interdependent projects, helping to ensure that people don’t break anything when working concurrently on different projects. In addition, outside groups (such as marketing and beta customer sites) can pick a stable build and use it while the product or feature is still in progress.
When combined with a solid source control system, build tools allow developers to maintain an archive of builds so that they can backtrack and identify when a bug first appeared in the system. This improves communication and transparency in an organization. Some build tools can even capture metrics for code coverage, code complexity, and features complete that help developers to control code quality and track efficiency.
Add testing to the equation, and you’ll gain the ability to always know the state of your software. That way, you can safely decide whether or not to deploy to production without worrying about unforeseen bugs.
Software Build Tools
Apache Ant is one of the more venerable Java-based build automation tools, originating from the Apache Tomcat project in 2000. Its strengths are portability, flexibility, and simplicity. It does not impose coding conventions or project structures, and its build files can easily be transferred to other platforms because they inherit the Java platform’s independence. By the same token, Ant files can be difficult to understand and grasp immediately.
Ant does not have built-in support for dependency management; rather, Ant’s dependency management is handled by Apache Ivy, a sub-project that integrates with Ant.
Docker is a software container platform. Originally released in 2013 as an open source Docker Engine, it has grown enormously in popularity and now has an integral place in most DevOps toolchains. It enables developers to easily pack, ship, and run any application as a lightweight, portable, self-sufficient container, which can run almost anywhere. This eliminates “works on my machine” problems when collaborating on code, ensuring that applications work seamlessly in any environment.
Docker containers are the preferred replacement for Virtual Machines (VMs), given that they boot faster, perform better, and consume less memory resources. Docker Containers are also able to share a single kernel and share application libraries.
Gradle Build Tool is an open source build automation system designed for multi-project builds. It supports Maven and Ivy repositories for retrieving dependencies so that you can reuse artifacts of existing build systems.
Essentially, Gradle was built to combine the best parts of established tools like Ant and Maven, but with a Groovy-based Domain Specific Language (DSL) instead of XML for declaring project configuration. DSL tends to be easier to read, more succinct, and also more powerful.
Gradle is the official build tool for Android Studio.
Leiningen is a build tool for Clojure. It serves as an adapter between the command line and Clojure, making it easier for you to run Clojure functions.
Apache Maven is a dependency management and build automation tool from the Apache Software Foundation. Based on the concept of a project object model (POM), Maven can manage a project’s build, reporting and documentation from a central piece of information. It uses XML to configure projects and Java to write extensions.
Maven emerged as a result of various frustrations with Ant. Like Ant, it uses XML for project configuration, but with more conventions and predefined commands that provide a framework in which to work. It also has built-in dependency management, which Ant lacks.
NAnt is a free and open source build automation tool similar to Apache Ant, but targeted at the .NET environment instead of Java. It can perform tasks such as compiling source code and resource files into assemblies, running unit tests, configuring build-specific settings, and more.
HashiCorp Packer is a free and open source tool for creating identical machine images for multiple platforms from a single source configuration. Its advantages include: faster infrastructure deployment, multi-provider portability, improved stability, and greater testability.