Dev containers
A Development Container is an open-source specification for defining containerized development environments which are also called development containers (dev containers).
Dev containers provide developers with increased autonomy and control over their Coder cloud development environments.
By using dev containers, developers can customize their workspaces with tools pre-approved by platform teams in registries like JFrog Artifactory. This simplifies workflows, reduces the need for tickets and approvals, and promotes greater independence for developers.
Prerequisites
An administrator should construct or choose a base image and create a template
that includes a devcontainer_builder image before a developer team configures
dev containers.
Benefits of devcontainers
There are several benefits to adding a dev container-compatible template to Coder:
- Reliability through standardization
- Scalability for growing teams
- Improved security
- Performance efficiency
- Cost Optimization
Reliability through standardization
Use dev containers to empower development teams to personalize their own environments while maintaining consistency and security through an approved and hardened base image.
Standardized environments ensure uniform behavior across machines and team members, eliminating "it works on my machine" issues and creating a stable foundation for development and testing. Containerized setups reduce dependency conflicts and misconfigurations, enhancing build stability.
Scalability for growing teams
Dev containers allow organizations to handle multiple projects and teams efficiently.
You can leverage platforms like Kubernetes to allocate resources on demand, optimizing costs and ensuring fair distribution of quotas. Developer teams can use efficient custom images and independently configure the contents of their version-controlled dev containers.
This approach allows organizations to scale seamlessly, reducing the maintenance burden on the administrators that support diverse projects while allowing development teams to maintain their own images and onboard new users quickly.
Improved security
Since Coder and Envbuilder run on your own infrastructure, you can use firewalls and cluster-level policies to ensure Envbuilder only downloads packages from your secure registry powered by JFrog Artifactory or Sonatype Nexus. Additionally, Envbuilder can be configured to push the full image back to your registry for additional security scanning.
This means that Coder admins can require hardened base images and packages, while still allowing developer self-service.
Envbuilder runs inside a small container image but does not require a Docker daemon in order to build a dev container. This is useful in environments where you may not have access to a Docker socket for security reasons, but still need to work with a container.
Performance efficiency
Create a unique image for each project to reduce the dependency size of any given project.
Envbuilder has various caching modes to ensure workspaces start as fast as possible, such as layer caching and even full image caching and fetching via the Envbuilder Terraform provider.
Cost optimization
By creating unique images per-project, you remove unnecessary dependencies and reduce the workspace size and resource consumption of any given project. Full image caching ensures optimal start and stop times.
When to use a dev container
Dev containers are a good fit for developer teams who are familiar with Docker and are already using containerized development environments. If you have a large number of projects with different toolchains, dependencies, or that depend on a particular Linux distribution, dev containers make it easier to quickly switch between projects.
They may also be a great fit for more restricted environments where you may not have access to a Docker daemon since it doesn't need one to work.
Devcontainer Features
Dev container Features allow owners of a project to specify self-contained units of code and runtime configuration that can be composed together on top of an existing base image. This is a good place to install project-specific tools, such as language-specific runtimes and compilers.
Coder Envbuilder
Envbuilder is an open-source project maintained by Coder that runs dev containers via Coder templates and your underlying infrastructure. Envbuilder can run on Docker or Kubernetes.
It is independently packaged and versioned from the centralized Coder open-source project. This means that Envbuilder can be used with Coder, but it is not required. It also means that dev container builds can scale independently of the Coder control plane and even run within a CI/CD pipeline.