readystack/kafka repository overview

⁠Apache Kafka

readystack/kafka:4.4.0-CE-ubuntu24.04-r2

A cosign-signed build of github.com/apache/kafka 4.4.0 (Apache-2.0), built from source (Scala 2.13), built clean-room from official upstream source by ReadyStack⁠.

⁠What you get

Signature, user and attestations below were measured on the published digest sha256:bd758be44fa4d643bd95d0d73230ed52098edcc44d8040c127b109a51db045f7 on 2026-10-27.

• 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.html#kafka⁠
• ReadyStack release check — passed at release on 2026-10-27: 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:bd758be44fa4d643bd95d0d73230ed52098edcc44d8040c127b109a51db045f7; verify with cosign verify --key https://readystack.dev/keys/cosign.pub readystack/kafka:4.4.0-CE-ubuntu24.04-r2.
• Attestations — An SPDX SBOM and SLSA v1 build provenance are attached to this digest.
• Runs as a non-root user (kafka).
• Built from source by ReadyStack.

⁠Which tag should I pull?

This image follows the ReadyStack release-tag convention:

• The current release is 4.4.0-CE-ubuntu24.04-r2 — the release on sale 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• Earlier release tags (an older version or revision in the same pattern) are superseded.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 For a superseded release's build kit, ask support.

• 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/kafka:4.4.0-CE-ubuntu24.04-r2

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

This release is signed; verify it with cosign verify --key https://readystack.dev/keys/cosign.pub readystack/kafka:4.4.0-CE-ubuntu24.04-r2 (the signature is recorded in the public Sigstore transparency log). Support: [email protected]⁠, as set out in the ReadyStack Agreement⁠.

⁠Deployment

A single container running one Kafka node in KRaft combined mode (it is both broker and controller; Kafka 4 has no ZooKeeper) as the non-root kafka user, on the Eclipse Temurin 25 JRE. Topic data is log segments under /var/lib/kafka/data. There is no web UI, no REST API and no SQL database; clients use the Kafka protocol on port 9092, and the Kafka command-line tools are in the image under /opt/kafka/bin (on PATH).

docker run -d --name kafka -p 9092:9092 -v kafka-data:/var/lib/kafka/data readystack/kafka:4.4.0-CE-ubuntu24.04-r2

With no environment variables the node uses the image's default configuration: one PLAINTEXT listener on 9092 advertised as localhost:9092, so clients on the Docker host reach it at localhost:9092. Clients on other hosts or in other containers need KAFKA_ADVERTISED_LISTENERS, and setting it (or any KAFKA_* server property) replaces the whole default configuration (upstream's rule): pass a complete set, e.g. docker run -d --name kafka -p 9092:9092 -v kafka-data:/var/lib/kafka/data -e KAFKA_NODE_ID=1 -e KAFKA_PROCESS_ROLES=broker,controller -e KAFKA_LISTENERS=PLAINTEXT://:9092,CONTROLLER://:9093 -e KAFKA_ADVERTISED_LISTENERS=PLAINTEXT://<host>:9092 -e KAFKA_CONTROLLER_LISTENER_NAMES=CONTROLLER -e KAFKA_LISTENER_SECURITY_PROTOCOL_MAP=CONTROLLER:PLAINTEXT,PLAINTEXT:PLAINTEXT -e KAFKA_CONTROLLER_QUORUM_VOTERS=1@localhost:9093 -e KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR=1 -e KAFKA_TRANSACTION_STATE_LOG_REPLICATION_FACTOR=1 -e KAFKA_TRANSACTION_STATE_LOG_MIN_ISR=1 -e KAFKA_SHARE_COORDINATOR_STATE_TOPIC_REPLICATION_FACTOR=1 -e KAFKA_SHARE_COORDINATOR_STATE_TOPIC_MIN_ISR=1 -e KAFKA_LOG_DIRS=/var/lib/kafka/data readystack/kafka:4.4.0-CE-ubuntu24.04-r2.

⁠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 at readystack.dev/buy.html⁠. A clean-room rebuild from this release's archive on an egress-blocked host reproduced its linux/amd64 digest sha256:d3f92612901df9e1b5427c406b7b4ddf8f46dcc56501ef558e7888fdd585eec4 on 2026-10-27.

— ReadyStack · readystack.dev