Help Center/ Cloud Container Instance (CCI)/ User Guide/ Using CCI Through the Console/ Images/ Image Overview
Updated on 2026-04-28 GMT+08:00
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Image Overview

A container image contains all file systems and configurations required for running a container. A container image is a lightweight and executable software package that contains applications and all components required by the applications, such as the environment, libraries, and configuration files.

CCI allows containers to pull SWR images and third-party images. For details about how images are pulled from SWR, see Pulling an Image.

Third-Party Images

Third-party images are container images provided by organizations or individuals other than the official image registries and SWR. These images typically contain custom applications, tools, or specific versions of OSs to meet particular service requirements. If third-party images are used, the network where pods are running must be able to access the network where the third-party image repository is deployed. There are three types of network access:

  • Private network access: The third-party image repository can be accessed over a private network.
    • If the third-party image repository is in the same VPC as the pods, the pods can directly pull images over the private network without additional configurations.
    • If the third-party image repository and the pod are in different VPCs in the same region, you can use a VPC peering connection to enable network connectivity between the two VPCs. Then pods can pull images over a private network. For details about VPC peering connections, see VPC Peering Connections.
  • Public network access: If the third-party image repository is accessible over a public network, pods can pull images over the public network. In this case, you must ensure that pods can access the public network. There are two ways to enable pods access the public network.

    Ensure there is sufficient bandwidth for pulling images over the public network. Insufficient bandwidth may cause slow or failed image pull.

    • Configure an SNAT rule: After an SNAT rule is configured, the VPC where pods are running can access the public network, and pods can pull images directly over the public network when you create a workload. For details, see Accessing the Public Network from a Container.
    • Configure an EIP for each pod when creating a workload: Only pods with EIPs bound can access the public network. This method can be used when you create a workload. For more information, see Configuring an EIP for a Pod.
  • Access over Direct Connect or VPN: To use images from an on-premises image repository, use Direct Connect or VPN to connect the on-premises network to the VPC where the pods are running. Once the on-premises network is connected to the VPC, no additional configuration is needed.

Image Snapshots

When you are creating a workload, CCI needs to pull the specified container images. The image download speed affects the workload creation efficiency. To speed up image creation, CCI provides image snapshots to accelerate image download. This not only shortens the image pull time, but also reduces bandwidth consumption and avoids workload creation failures caused by network problems, thereby significantly improving the efficiency and reliability of workload creation.

The following are common application scenarios of image snapshots:

  • Large images: When the image size exceeds 1 GiB, image snapshots can significantly speed up workload creation.
  • Auto scaling: When workloads need to be quickly scaled out during peak hours, image snapshots can effectively improve the scaling efficiency.

For more information, see Image Snapshots.

Parent Topic: Images