Last modified October 3, 2025

Domain allowlist

List of the external domains we require access to for our clusters to function.

• alpinelinux.org
  • domains:
    • *.alpinelinux.org
  • Alpine container images may update their package index.
• amazonaws.com
  • domains:
    • *.amazonaws.com
  • AWS services are used for a variety of tasks, such as etcd backup storage.
• azurecr.io
  • domains:
    • giantswarm.azurecr.io
    • giantswarmpublic.azurecr.io
    • gsoci.azurecr.io
    • gsociprivate.azurecr.io
    • .blob.core.windows.net
    • azure.microsoft.com
  • Container images and app catalogs are hosted on Azure container registry.
• cloudfront.net
  • domains:
    • *.cloudfront.net
  • Operators may pull from sites behind Cloudfront.
• docker.com
  • domains:
    • *.docker.com
  • Container images are hosted on Dockerhub.
  • Dockerhub uses Cloudflare as the CDN for serving Docker image layer blobs, manifests, etc.
• docker.io
  • domains:
    • *.docker.io
  • Container images are hosted on Dockerhub.
• flatcar.com
  • domains:
    • *.flatcar-linux.org
  • Flatcar OS images and signing keys.
• ghcr.io
  • domains:
    • ghcr.io
  • Official Falco rules are hosted at ghcr.io/falcosecurity. This domain is optional if official rulesets are disabled or hosted elsewhere.
• github.com
  • domains:
    • *.github.com
  • Various operators need to pull information from GitHub repositories.
• github.io
  • domains:
    • *.github.io
  • Helm chart tarballs are pulled from GitHub Pages.
• githubusercontent.com
  • domains:
    • raw.githubusercontent.com
    • pkg-containers.githubusercontent.com
  • Flux applies some manifests using the raw domain.
  • Falco optionally loads resources from the pkg-containers domain.
• gcr.io
  • domains:
    • k8s.gcr.io
  • (Legacy) k8s container images are hosted on Google Container Registry.
• googleapis.com
  • domains:
    • storage.googleapis.com
  • Google container registry is backed by a Google cloud storage bucket.
• grafana.com
  • domains:
    • grafana.com
  • Grafana may download plugins from the Grafana plugin registry.
• grafana.net
  • domains:
    • *.grafana.net
    • *.grafana.org
  • Some metrics are pushed to our hosted Grafana tenant.
• giantswarm.io
  • domains:
    • vault.operations.giantswarm.io
    • schema.giantswarm.io
  • Our operations Vault is used for unsealing customer Vault servers.
  • Our schema server hosts the schemas for container image validation.
• k8s.io
  • domains:
    • registry.k8s.io
  • Container registry and a global CDN for the k8s project’s container images.
• keybase.io
  • domains:
    • *.keybase.io
  • Vault initialization and unsealing requires access to Keybase.
• letsencrypt.org
  • domains:
    • *.api.letsencrypt.org
  • cert-manager will request certificates from Lets Encrypt.
• microsoft.com
  • domains:
    • graph.microsoft.com
  • Used when logging into the cluster with Microsoft AD.
• microsoftonline.com
  • domains:
    • login.microsoftonline.com
  • Used when logging into the cluster with Microsoft AD.
• opsgenie.com
  • domains:
    • api.opsgenie.com
  • Opsgenie’s API is used to send alerts.
• pagerduty.com
  • domains:
    • api.eu.pagerduty.com
  • PagerDuty’s API is used to send alerts.
• quay.io
  • domains:
    • *.quay.io
  • Container images are hosted on Quay.
• sentry.io
  • domains:
    • o346224.ingest.sentry.io
  • Monitoring and crash reporting for happa.
• sigstore.dev
  • domains:
    • *.sigstore.dev
  • Used for verifying signatures on artifacts signed with the cosign keyless signing method.
• slack.com
  • domains:
    • *.slack.com
  • Used to send alerts on slack channels
• teleport.giantswarm.io
  • domains:
    • teleport.giantswarm.io
  • Used to securely access Kubernetes cluster and SSH access to nodes.
• xpkg.upbound.io
  • domains:
    • xpkg.upbound.io
  • Used to fetch Crossplane packages.

On-premise installations

These domains are only required for on-premise installations.

• cloudflare.com
  • domains:
    • api.cloudflare.com
  • cert-manager may create ACME challenge DNS records.