Network Proxies

As covered in the Network sections of the requirements document, Anchore requires three categories of network connectivity.

  • Registry Access Network connectivity, including DNS resolution, to the registries from which Anchore needs to download images.

  • Feed Service Anchore synchronizes feed data such as operating system vulnerabilities (CVEs) from Anchore Cloud Service. See Feeds Overview for the full list of endpoints.

  • Access to Anchore Internal Services Anchore is composed of six smaller services that can be deployed in a single container or scaled out to handle load. Each Anchore service should be able to connect the other services over the network.

In environments were access to the public internet is restricted then a proxy server may be required to allow Anchore to connect to Anchore Cloud Feed Service or to a publicly hosted container registry.

Anchore can be configured to access a proxy server by using environment variables that are read by Anchore at run time.

  • https_proxy: Address of the proxy service to use for HTTPS traffic in the following form: {PROTOCOL}://{IP or HOSTNAME}:{PORT} eg.

  • http_proxy:
    Address of the proxy service to use for HTTP traffic in the following form: {PROTOCOL}://{IP or HOSTNAME}:{PORT}

  • no_proxy:
    Comma delimited list of hostnames or IP address which should be accessed directly without using the proxy service. eg. localhost,,registry,

Environment Variables to Control Proxy Behavior

  • Setting the endpoints to HTTP proxy:
    • Set both HTTP_PROXY and http_proxy environment variables for regular HTTP protocol use.
    • Set both HTTPS_PROXY and https_proxy environment variables for HTTP + TLS (HTTPS) protocol use.
  • Setting endpoints to exclude from proxy use:
    • Set both NO_PROXY and no_proxy environment variables to exclude those domains from proxy use defined in the preceding proxy configurations.

If using Docker Compose these need to be set in each service entry.

If using Helm Chart, set these in the extraEnv entry for each service.


  • Do not use double quotes (") around the proxy variable values.


For proxy servers that require authentication the username and password can be provided as part of the URL:

eg. https_proxy=https://user:[email protected]:8128

If the username or password contains and non-url safe characters then these should be urlencoded.

For example:

The password F@oBar! would be encoded as F%40oBar%21

Setting Environment Variables

Docker Compose:


Deployment Architecture Notes

When setting up a network proxy, keep in mind that you will need to explicitly allow inter-service communication within the anchore engine deployment to bypass the proxy, and potentially other hostnames as well (e.g. internal registries) to ensure that traffic is directed correctly. In general, all anchore engine service endpoints (the URLs for enabled services in the output of an ‘anchorectl system status’ command) as well as any internal registries (the hostnames you may have set up with ‘anchorectl registry add –username …’ or as part of an un-credentialed image add ‘anchorectl image add registry:port/….’), should not be proxied (i.e. added to the no_proxy list, as described above).

If you wish to tune this further, below is a list of each component that makes an external URL fetch for various purposes:

  • Catalog: makes connections to image registries (any host added via ‘anchorectl registry add’ or directly via ‘anchorectl image add’)
  • Analyzer: same as catalog
  • Policy Engine: by default, makes HTTPS connection to for the public GrypeDB data unless a local feed service is deployed.
  • Feeds: connects to public and Anchore-private data sources for downloading vulnerability data. See Feed Drivers for the full list.
Last modified February 16, 2024