Network Egress Cost - CI/CD Glossary Definition
Network egress cost is the per-gigabyte fee cloud providers charge for data leaving their network to the internet or another region. Inbound (ingress) is typically free, but egress (downloads, cross-region traffic, pushing images to an external registry) is metered.
Why CI hits it
Self-hosted runners that pull large container images, download dependencies from external mirrors, or push build artifacts to a registry in another region accumulate egress. AWS, GCP, and Azure all charge egress in the range of roughly $0.05 to $0.12 per GB after a small free tier.
Reducing it
Keep runners, registries, and caches in the same region and cloud, use a pull-through cache or local mirror for images and packages, and prefer private endpoints (VPC, Private Service Connect) which often have lower or zero egress rates.