readystack/flannelcniplugin repository overview

⁠flannel CNI plugin

readystack/flannelcniplugin:v1.9.1-flannel3-CE-ubuntu24.04-r1

Source, recipe and records

• Source and build recipe: https://readystack.dev/products/flannelcniplugin/recipe⁠
• Upstream source at this release's pinned commit (v1.9.1-flannel3): https://github.com/flannel-io/cni-plugin/tree/b380f201008e9bed159703846cf10d3c50b4f9ce⁠
• Product page: https://readystack.dev/products/flannelcniplugin⁠
• Hermetic Build Kit for this release (free with an account): https://readystack.dev/products/flannelcniplugin⁠
• Release history (JSON): https://readystack.dev/api/releases/flannelcniplugin⁠
• Defect record: https://readystack.dev/defects.html?product=flannelcniplugin⁠
• Today's scan: https://readystack.dev/products/flannelcniplugin#pp-grade⁠
• Report an issue: https://github.com/ReadyStackFree/readystack/issues/new?template=bug.yml&product=flannelcniplugin⁠
• Signing key (cosign): https://readystack.dev/keys/cosign.pub⁠
• Part of the Kubernetes VM Stack: https://readystack.dev/stacks/kubernetes-vm-stack⁠

A cosign-signed build of https://github.com/flannel-io/cni-plugin⁠ v1.9.1-flannel3 (Apache-2.0), commit b380f201008e9bed159703846cf10d3c50b4f9ce, built clean-room from official upstream source by ReadyStack⁠.

⁠Who uses it and why

Who: Kubernetes cluster operators who use flannel for pod networking.

Why: The flannel CNI plugin connects each new pod to the flannel network: it reads the subnet flannel leased to the host and configures a standard CNI plugin, such as bridge, with it.

Use case: When the container runtime starts a pod on a node running flannel, it calls the flannel CNI plugin. The plugin reads the node's flannel subnet settings and delegates to the bridge plugin, which gives the pod an address from that subnet, so new pods join the cluster network with no manual setup.

About the upstream project, written from its own description: https://github.com/flannel-io/cni-plugin⁠

⁠What you get

Signature, user and attestations below were measured on the published digest sha256:5f2cca0ce5ed6c50076994d41712ab4c9321451785bc7cc17fef475000dbb560 on 2026-10-29.

• Scan scores — we scan every image we publish every day (an SBOM made with syft, vulnerabilities matched with grype, scored with cerodeo-v1, the rubric ce.rodeo published until 2026-10-26) and record each scan with how its score was derived. This release's first and latest scan: https://readystack.dev/products/flannelcniplugin⁠
• ReadyStack release check — passed at release on 2026-10-29: no fixable critical or high vulnerability (Docker Scout and OSV), a non-root user, SBOM and provenance attached. This is ReadyStack's own test, not a Docker grade; vulnerabilities published since then are in today's result at https://readystack.dev/queue⁠.
• Signed — cosign signature by the ReadyStack release key (fingerprint 04daa92344a52dbc) on this release's index digest sha256:5f2cca0ce5ed6c50076994d41712ab4c9321451785bc7cc17fef475000dbb560; verify with cosign verify --key https://readystack.dev/keys/cosign.pub readystack/flannelcniplugin:v1.9.1-flannel3-CE-ubuntu24.04-r1.
• Attestations — An SPDX SBOM and SLSA v1 build provenance are attached to this digest.
• Runs as a non-root user (flannelcniplugin).
• Built from source by ReadyStack.

⁠Which tag should I pull?

This image follows the ReadyStack release-tag convention:

• The current release is v1.9.1-flannel3-CE-ubuntu24.04-r1 — the release listed at readystack.dev. Release tags use the pattern <upstream-version>-CE-<base-os>-r<N>; the current one is signed, attested (SBOM + provenance), and is provided under the ReadyStack Agreement⁠.

• Earlier release tags (an older version or revision in the same pattern) are superseded. They stay pullable so existing deployments can pin them, but they are no longer re-graded, and fixes appear only in newer releases: move to the current release. For a superseded release's build kit, ask support.

• Release tags never move, so pulling the same tag again never changes the image. To be offered each new release automatically (a new revision r<N+1>, or a new upstream version), use the ReadyStack Renovate preset: https://readystack.dev/updates.html⁠

• Any tag beginning with internal- is an engineering-pipeline artifact published for build observability. It is unsupported, may change or disappear without notice, and must not be used in production.

# ✓ current release
docker pull readystack/flannelcniplugin:v1.9.1-flannel3-CE-ubuntu24.04-r1

# ✗ unsupported (do not pull)
docker pull readystack/flannelcniplugin:internal-...

This release is signed; verify it with cosign verify --key https://readystack.dev/keys/cosign.pub readystack/flannelcniplugin:v1.9.1-flannel3-CE-ubuntu24.04-r1 (the signature is recorded in the public Sigstore transparency log). Support: [email protected]⁠, as set out in the ReadyStack Agreement⁠.

⁠Deployment

Used as the install-cni-plugin init container of the kube-flannel DaemonSet (product-kits/kubevirt-stack/install/network/kube-flannel.yml): cp -f /flannel /opt/cni/bin/flannel with the host's /opt/cni/bin mounted. The image's default user is the unprivileged flannelcniplugin (uid 999); the init container sets runAsUser: 0, because /opt/cni/bin on the host belongs to root.

docker run --rm readystack/flannelcniplugin:v1.9.1-flannel3-CE-ubuntu24.04-r1

Prints CNI Plugin flannel version v1.9.1 (linux/amd64) commit b380f201 and the CNI versions it supports. The binary reports v1.9.1: upstream stamps the first six characters of its tag (scripts/version.sh).

⁠The full ReadyStack Hermetic Build Kit

The complete --network=none build kit for this image — plus admin/DB/API handbooks, the build's validation records, and its build provenance records — is a free download for any registered account at readystack.dev/products/flannelcniplugin⁠. A clean-room rebuild from this release's archive on an egress-blocked host reproduced its linux/amd64 digest sha256:4511acd7413d1e6fd78d3d712921d794cb820a3b62973512532d7b64f2cc4e8a on 2026-10-29.

— ReadyStack · readystack.dev