Amazon Web Services has introduced a major improvement to container-based development by enabling teams to use an AWS remote Docker cache stored in Amazon ECR. The new feature allows CodeBuild to reuse Docker layers across multiple runs, which reduces build times and strengthens the speed of CI/CD pipelines. As developers run builds more frequently, this caching model helps eliminate repeated work and shortens feedback loops.
How AWS remote Docker cache speeds up builds
The update relies on Docker BuildKit, which supports the --cache-from and --cache-to flags. With these options, CodeBuild can pull cached layers from an ECR repository before a build starts, then push updated layers back once the build completes. As long as the base layers stay the same, the Docker engine can skip many steps, including rebuilding large dependency layers. This makes the entire process more efficient and reduces unnecessary compute usage.
According to AWS, repeated rebuilding of heavy layers has long been a bottleneck in container-driven pipelines. By offering a remote registry cache, CodeBuild now avoids many redundant operations. In addition, this approach provides a global cache that works across multiple agents and frequent builds, improving consistency compared to local caching alone.
Setting up the AWS remote Docker cache in CodeBuild
The process for enabling the feature is simple. Developers first create an ECR repository to store the cached image. After that, CodeBuild is granted permission to pull and push to the repository. BuildKit must also be turned on within the build environment. Once this is done, CodeBuild pulls cached layers at the start of each build and pushes refreshed layers afterward. Because the cache grows over time, builds become faster as more layers remain unchanged.
A typical configuration includes environment variables and commands defined in buildspec.yml. During the pre-build stage, CodeBuild authenticates with ECR and retrieves the existing cache image, if available. During the build stage, Docker runs with BuildKit enabled and references the ECR cache. The post-build stage pushes new or updated cache layers for future runs.
Real-world performance gains with AWS remote Docker cache
Early adopters have already reported significant improvements. Builds that traditionally required 10–15 minutes now complete in under five minutes when caching is effective. One user noted a drop from six minutes to two after adopting the new approach. These savings are especially strong for projects with large dependency layers or multi-stage Docker builds.
However, AWS also highlights that caching effectiveness depends on how well Dockerfiles are structured. Techniques such as multi-stage builds, consistent layer ordering, and careful dependency handling can boost cache efficiency and reduce the impact of stale layers.
How AWS compares with other cloud providers
AWS is not the only platform introducing remote caching, but its integration feels more native. Google Cloud Build, for example, lets users specify remote cache images with the --cache-image flag and supports registry-based caching for Docker or Buildpacks. Although similar, Google emphasizes Buildpacks more heavily and handles caching slightly differently.
Microsoft Azure Pipelines, in contrast, has a more mixed experience. While self-hosted agents can use --cache-from with a custom registry, Microsoft-hosted agents often struggle with efficient layer reuse. Some developers report that downloading cache layers cancels out the expected time savings, making the workflow less reliable than AWS or Google Cloud.
Why AWS remote Docker cache matters for CI/CD teams
The new ECR-based caching model aligns with a broader shift toward reproducible builds and smarter pipeline optimization. By embedding Docker’s native caching directly into CodeBuild, AWS reduces friction in cloud-native development and helps teams ship updates faster. This improvement also cuts compute costs, since fewer resources are spent rebuilding unchanged layers.
For organizations working with large container workloads, the benefits are immediate. Faster builds, reduced resource consumption, and better consistency across build agents create a more predictable and efficient CI/CD pipeline.
Conclusion
The introduction of AWS remote Docker cache marks a meaningful step forward for CodeBuild users. By storing and reusing Docker layers in ECR, teams can dramatically cut build times and streamline their workflow. The approach is simple to adopt, aligns with industry best practices, and offers clear value for both small teams and large, container-heavy organizations. As caching becomes a standard part of modern CI/CD, AWS’s native solution provides a strong and scalable foundation for faster, more reliable builds.
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