Overview

When using a custom-built docker image, you may notice higher costs associated with pulling the image. Inn this support article outline some ways to reduce the costs incurred by using a custom-built docker image.

Reducing costs using CircleCI cloud: 

One common reason that you may see additional costs when using a custom-built docker image is that you are using a non-AWS registry and/or hosting your image outside of `us-east-1`. To reduce costs, we recommend hosting your image on Amazon Elastic Cloud Registry in the `us-east-1` region. According to Amazon:
“Data transfer into the Amazon ECR private registry incurs no charge from Amazon ECR. Data transferred between Amazon ECR and other services within the same Region is free.“. You can find more information in their documentation here.

Additionally, in-network data transfers tend to be speedier than those out-of-network, which can improve the performance of your image pulls.

Reducing costs using CircleCI Container runner: 

When using CircleCI container-runner we recommend configuring your K8s cluster to be in the same region as your Docker Container Registry. This approach will not only save on image pull costs, but the images will also be cached on the host after runs. This caching can make subsequent job runs significantly faster.

Additional Resources: 

• CircleCI custom-built docker image
• Amazon Elastic Container Registry Pricing
• CircleCI container-runner