packer

Packer is a command line tool used for creating identical machine images for multiple platforms from a single source configuration. It can automate the process of creating virtual machine images or other machine images such as containers or AMIs. Packer works with various platforms, including Amazon Web Services, Microsoft Azure, and Google Cloud Platform.

By using a simple JSON-based configuration format, Packer allows users to define the contents, configuration, and provisioners needed for building the desired machine image. The configuration file specifies the builders, provisioners, and post-processors that Packer should use during the image creation process.

Builders in Packer are responsible for creating the initial machine image. They can build images in parallel, allowing for faster image creation and multi-platform builds. Provisioners can be used to install software, configure the machine, or execute scripts within the image during the build process. Packer supports a wide range of provisioners, including shell scripts, Ansible, Chef, and Puppet.

Packer also provides post-processors that allow further modification and customization of the created images. For example, post-processors can be used to compress, encrypt, or upload the machine images to a final destination.

Packer has a wide community support with a repository of community-contributed plugins, builders, provisioners, and post-processors, extending its functionality and providing solutions for specific use cases. Packer is open-source and actively maintained by HashiCorp, the same company behind widely-used tools like Vagrant and Terraform.

Overall, Packer simplifies the process of creating machine images by providing a unified, efficient, and repeatable approach, making it a valuable tool in infrastructure-as-code practices and continuous integration/continuous delivery pipelines.