diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
new file mode 100644
index 0000000..fc38784
--- /dev/null
+++ b/.pre-commit-config.yaml
@@ -0,0 +1,30 @@
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v5.0.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml
+      - id: check-merge-conflict
+      - id: mixed-line-ending
+        args: [--fix=lf]
+
+  - repo: https://github.com/AleksaC/hadolint-py
+    rev: v2.15.1
+    hooks:
+      - id: hadolint
+
+  - repo: https://github.com/shellcheck-py/shellcheck-py
+    rev: v0.11.0.1
+    hooks:
+      - id: shellcheck
+
+  # No upstream equivalent: a distro added under distros/ but left out of a
+  # Woodpecker matrix silently never gets built.
+  - repo: local
+    hooks:
+      - id: check-distros
+        name: distros match the woodpecker matrices
+        entry: ci/check-distros.sh
+        language: system
+        pass_filenames: false
diff --git a/.woodpecker/build.yaml b/.woodpecker/build.yaml
new file mode 100644
index 0000000..9910e1a
--- /dev/null
+++ b/.woodpecker/build.yaml
@@ -0,0 +1,33 @@
+when:
+  - event: pull_request
+
+matrix:
+  include:
+    # One entry per distro. Adding a distro: add distros/<name>/ and one entry here.
+    - DISTRO: alma9
+      IMAGE: almalinux9
+      BASE_IMAGE: "docker.io/almalinux:9"
+
+steps:
+  - name: build
+    image: "artifactapi.k8s.syd1.au.unkin.net/docker-internal/plugin-docker-buildx:latest"
+    settings:
+      repo: "artifactapi.k8s.syd1.au.unkin.net/docker-internal/${IMAGE}"
+      target: image
+      dry_run: true
+      build_args:
+        BASE_IMAGE: "${BASE_IMAGE}"
+        DISTRO: "${DISTRO}"
+      buildkit_config: |
+        [registry."artifactapi.k8s.syd1.au.unkin.net"]
+          ca = ["/etc/docker/certs.d/artifactapi.k8s.syd1.au.unkin.net/ca.crt"]
+    backend_options:
+      kubernetes:
+        serviceAccountName: default
+        resources:
+          requests:
+            memory: 1Gi
+            cpu: 1
+          limits:
+            memory: 4Gi
+            cpu: 2
diff --git a/.woodpecker/docker.yaml b/.woodpecker/docker.yaml
new file mode 100644
index 0000000..78d8274
--- /dev/null
+++ b/.woodpecker/docker.yaml
@@ -0,0 +1,37 @@
+when:
+  - event: tag
+    ref: refs/tags/v*
+
+matrix:
+  include:
+    # One entry per distro. Adding a distro: add distros/<name>/ and one entry here.
+    - DISTRO: alma9
+      IMAGE: almalinux9
+      BASE_IMAGE: "docker.io/almalinux:9"
+
+steps:
+  - name: docker
+    image: "artifactapi.k8s.syd1.au.unkin.net/docker-internal/plugin-docker-buildx:latest"
+    settings:
+      registry: artifactapi.k8s.syd1.au.unkin.net
+      repo: "artifactapi.k8s.syd1.au.unkin.net/docker-internal/${IMAGE}"
+      target: image
+      build_args:
+        BASE_IMAGE: "${BASE_IMAGE}"
+        DISTRO: "${DISTRO}"
+      buildkit_config: |
+        [registry."artifactapi.k8s.syd1.au.unkin.net"]
+          ca = ["/etc/docker/certs.d/artifactapi.k8s.syd1.au.unkin.net/ca.crt"]
+      tags:
+        - "${CI_COMMIT_TAG##v}"
+        - latest
+    backend_options:
+      kubernetes:
+        serviceAccountName: default
+        resources:
+          requests:
+            memory: 1Gi
+            cpu: 1
+          limits:
+            memory: 4Gi
+            cpu: 2
diff --git a/.woodpecker/pre-commit.yaml b/.woodpecker/pre-commit.yaml
new file mode 100644
index 0000000..e4446ad
--- /dev/null
+++ b/.woodpecker/pre-commit.yaml
@@ -0,0 +1,18 @@
+when:
+  - event: pull_request
+
+steps:
+  - name: pre-commit
+    image: "git.unkin.net/unkin/almalinux9-gobuilder:20260606"
+    commands:
+      - uvx pre-commit run --all-files
+    backend_options:
+      kubernetes:
+        serviceAccountName: default
+        resources:
+          requests:
+            memory: 512Mi
+            cpu: 1
+          limits:
+            memory: 2Gi
+            cpu: 2
diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..65bf7de
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,22 @@
+ARG BASE_IMAGE=artifactapi.k8s.syd1.au.unkin.net/dockerhub/library/almalinux:9
+
+FROM ${BASE_IMAGE} AS image
+ARG DISTRO=alma9
+COPY distros/${DISTRO}/ /tmp/distro/
+# DL3041: versions are pinned by the estate dnf repos, not here. SC2086: $PACKAGES is a
+# word list on purpose. DL4006: the only pipe ends in sha256sum, whose status is the
+# pipeline's, and set -e catches it.
+# hadolint ignore=DL3041,DL4006,SC2086
+RUN set -eux; \
+    . /tmp/distro/distro.env; \
+    rm -f /etc/yum.repos.d/*.repo; \
+    curl -fsSL -o /tmp/ca.rpm "$CA_RPM_URL"; \
+    echo "$CA_RPM_SHA256  /tmp/ca.rpm" | sha256sum -c -; \
+    rpm -i /tmp/ca.rpm; \
+    cp /tmp/distro/yum.repos.d/*.repo /etc/yum.repos.d/; \
+    dnf makecache; \
+    dnf update -y; \
+    dnf install -y $PACKAGES; \
+    dnf clean all; \
+    rm -rf /var/cache/dnf /tmp/ca.rpm /tmp/distro
+CMD ["/bin/bash"]
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..e5f1c65
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,39 @@
+REGISTRY := artifactapi.k8s.syd1.au.unkin.net/docker-internal
+DISTROS  := $(notdir $(wildcard distros/*))
+VERSION  ?= $(patsubst v%,%,$(or $(shell git describe --tags --exact-match 2>/dev/null),0.1.0-dev))
+
+.PHONY: build clean pre-commit patch minor major
+build: $(addprefix build-,$(DISTROS))
+clean: $(addprefix clean-,$(DISTROS))
+
+pre-commit:
+	@uvx pre-commit run --all-files
+
+# Not .PHONY: GNU make skips implicit-rule search for phony targets.
+
+build-%:
+	@set -eu; . ./distros/$*/distro.env; \
+	docker build --build-arg "BASE_IMAGE=$$BASE_IMAGE" --build-arg "DISTRO=$*" \
+	  -t "$(REGISTRY)/$$IMAGE:$(VERSION)" .
+
+clean-%:
+	@set -eu; . ./distros/$*/distro.env; \
+	docker rmi "$(REGISTRY)/$$IMAGE:$(VERSION)" 2>/dev/null || true
+
+_LATEST := $(shell git tag --sort=-v:refname | grep -E '^v[0-9]+\.[0-9]+\.[0-9]+$$' | head -1)
+_BASE   := $(if $(_LATEST),$(_LATEST),v0.0.0)
+_MAJ    := $(shell echo $(_BASE) | sed 's/^v//' | cut -d. -f1)
+_MIN    := $(shell echo $(_BASE) | sed 's/^v//' | cut -d. -f2)
+_PAT    := $(shell echo $(_BASE) | sed 's/^v//' | cut -d. -f3)
+
+patch:
+	@NEW=v$(_MAJ).$(_MIN).$(shell expr $(_PAT) + 1); \
+	git tag $$NEW && echo "Tagged $$NEW" && git push origin $$NEW
+
+minor:
+	@NEW=v$(_MAJ).$(shell expr $(_MIN) + 1).0; \
+	git tag $$NEW && echo "Tagged $$NEW" && git push origin $$NEW
+
+major:
+	@NEW=v$(shell expr $(_MAJ) + 1).0.0; \
+	git tag $$NEW && echo "Tagged $$NEW" && git push origin $$NEW
diff --git a/README.md b/README.md
index dfa88a8..1ba8650 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,35 @@
 # container-base
 
-Base container images for the estate, carrying internal CA trust and dnf/repo configuration, built as a matrix across the supported distros.
\ No newline at end of file
+The estate's base container images, one per distro, replacing what `packer-images`
+built. Published as `artifactapi.k8s.syd1.au.unkin.net/docker-internal/<image>:<version>`
+— the image name is the distro (`almalinux9`), the repo's single semver is the tag.
+
+| distro | image | from |
+| --- | --- | --- |
+| `alma9` | `almalinux9` | `dockerhub/library/almalinux:9` |
+
+Each image bootstraps the internal CA, installs the estate dnf repository
+configuration pointed at artifactapi, and installs the base package set.
+
+## Adding a distro
+
+1. `distros/<name>/distro.env` — `BASE_IMAGE`, `IMAGE`, `CA_RPM_URL`, `CA_RPM_SHA256`, `PACKAGES`.
+2. `distros/<name>/yum.repos.d/*.repo` — repository configuration for that distro.
+3. One `include` entry in each of `.woodpecker/{build,docker}.yaml`.
+
+The `check-distros` pre-commit hook fails if step 1 or 3 is incomplete.
+
+## CA bootstrap
+
+`unkin-ca-certificates` lives in artifactapi, but the image cannot trust artifactapi
+over HTTPS until it is installed. The package is therefore fetched over plain HTTP and
+checked against `CA_RPM_SHA256` before `rpm -i`; everything after that uses HTTPS. The
+pinned hash is the `pkgid` checksum recorded for the file in the repo's own repodata
+(`repodata/repomd.xml` → `*-primary.xml.gz`).
+
+## Make
+
+    make build          # build every distro
+    make pre-commit     # uvx pre-commit run --all-files
+    make build-alma9    # one distro
+    make patch|minor|major
diff --git a/ci/check-distros.sh b/ci/check-distros.sh
new file mode 100755
index 0000000..8ac5ccd
--- /dev/null
+++ b/ci/check-distros.sh
@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+# Every distros/<name>/ needs a complete distro.env and an entry in every Woodpecker
+# matrix, or a newly added distro silently never gets built.
+set -uo pipefail
+
+KEYS="BASE_IMAGE IMAGE CA_RPM_URL CA_RPM_SHA256 ESTATE_REPO PACKAGES"
+WORKFLOWS=(.woodpecker/build.yaml .woodpecker/docker.yaml)
+
+fail=0
+for d in distros/*/; do
+  n=$(basename "$d")
+  for k in $KEYS; do
+    grep -q "^${k}=" "${d}distro.env" || { echo "${d}distro.env: missing ${k}"; fail=1; }
+  done
+  for wf in "${WORKFLOWS[@]}"; do
+    grep -q "DISTRO: ${n}\$" "$wf" || { echo "${wf}: distro ${n} missing from matrix"; fail=1; }
+  done
+done
+
+exit "$fail"
diff --git a/distros/alma9/distro.env b/distros/alma9/distro.env
new file mode 100644
index 0000000..ffe5b18
--- /dev/null
+++ b/distros/alma9/distro.env
@@ -0,0 +1,18 @@
+# alma9 — AlmaLinux 9
+# Pulled through the artifactapi dockerhub remote: a buildkit FROM does its own pull
+# and ignores the nodes' containerd mirror. The library/ prefix is required — the
+# remote allowlists ^library/almalinux, so dockerhub/almalinux:9 returns 403.
+BASE_IMAGE="artifactapi.k8s.syd1.au.unkin.net/dockerhub/library/almalinux:9"
+IMAGE="almalinux9"
+
+# Bootstrap of the internal CA. The image cannot trust artifactapi over HTTPS until
+# this package is installed, so it is fetched over plain HTTP and verified against a
+# pinned sha256 before rpm -i. The hash is the pkgid checksum recorded for this file
+# in the rpm-vendor-el9 repodata (repodata/repomd.xml -> *-primary.xml.gz).
+CA_RPM_URL="http://artifactapi.k8s.syd1.au.unkin.net/api/v1/local/rpm-vendor-el9/Packages/unkin-ca-certificates-2025.7.13-1.el9.x86_64.rpm"
+CA_RPM_SHA256="c12fb81ea639a92d19506e07e88df290635b15e175b1f8c063d4e8a2d86bab6e"
+
+# Estate local repo used to prove HTTPS trust and dnf reachability.
+ESTATE_REPO="rpm-vendor-el9"
+
+PACKAGES="git jq make python3.11 python3.11-pip python3.12 python3.12-pip uv wget"
diff --git a/distros/alma9/yum.repos.d/almalinux.repo b/distros/alma9/yum.repos.d/almalinux.repo
new file mode 100644
index 0000000..d25e3e1
--- /dev/null
+++ b/distros/alma9/yum.repos.d/almalinux.repo
@@ -0,0 +1,27 @@
+[baseos]
+name=baseos repository
+baseurl=https://artifactapi.k8s.syd1.au.unkin.net/api/v1/remote/almalinux/$releasever/BaseOS/$basearch/os/
+gpgkey=https://artifactapi.k8s.syd1.au.unkin.net/api/v1/remote/almalinux/$releasever/BaseOS/$basearch/os/RPM-GPG-KEY-AlmaLinux-9
+enabled=1
+gpgcheck=1
+
+[appstream]
+name=appstream repository
+baseurl=https://artifactapi.k8s.syd1.au.unkin.net/api/v1/remote/almalinux/$releasever/AppStream/$basearch/os/
+gpgkey=https://artifactapi.k8s.syd1.au.unkin.net/api/v1/remote/almalinux/$releasever/AppStream/$basearch/os/RPM-GPG-KEY-AlmaLinux-9
+enabled=1
+gpgcheck=1
+
+[extras]
+name=extras repository
+baseurl=https://artifactapi.k8s.syd1.au.unkin.net/api/v1/remote/almalinux/$releasever/extras/$basearch/os/
+gpgkey=https://artifactapi.k8s.syd1.au.unkin.net/api/v1/remote/almalinux/$releasever/extras/$basearch/os/RPM-GPG-KEY-AlmaLinux-9
+enabled=1
+gpgcheck=1
+
+[crb]
+name=crb repository
+baseurl=https://artifactapi.k8s.syd1.au.unkin.net/api/v1/remote/almalinux/$releasever/CRB/$basearch/os/
+gpgkey=https://artifactapi.k8s.syd1.au.unkin.net/api/v1/remote/almalinux/$releasever/CRB/$basearch/os/RPM-GPG-KEY-AlmaLinux-9
+enabled=1
+gpgcheck=1
diff --git a/distros/alma9/yum.repos.d/epel.repo b/distros/alma9/yum.repos.d/epel.repo
new file mode 100644
index 0000000..7a49c70
--- /dev/null
+++ b/distros/alma9/yum.repos.d/epel.repo
@@ -0,0 +1,6 @@
+[epel]
+name=epel repository
+baseurl=https://artifactapi.k8s.syd1.au.unkin.net/api/v1/remote/epel/$releasever/Everything/$basearch
+gpgkey=https://artifactapi.k8s.syd1.au.unkin.net/api/v1/remote/epel/RPM-GPG-KEY-EPEL-$releasever
+enabled=1
+gpgcheck=1
diff --git a/distros/alma9/yum.repos.d/unkin.repo b/distros/alma9/yum.repos.d/unkin.repo
new file mode 100644
index 0000000..337159e
--- /dev/null
+++ b/distros/alma9/yum.repos.d/unkin.repo
@@ -0,0 +1,27 @@
+[rpm-internal-el9]
+name=rpm-internal-el9 repository
+baseurl=https://artifactapi.k8s.syd1.au.unkin.net/api/v1/local/rpm-internal-el9/
+enabled=1
+gpgcheck=0
+metadata_expire=60
+
+[rpm-vendor-el9]
+name=rpm-vendor-el9 repository
+baseurl=https://artifactapi.k8s.syd1.au.unkin.net/api/v1/local/rpm-vendor-el9/
+enabled=1
+gpgcheck=0
+metadata_expire=60
+
+[rpm-internal]
+name=rpm-internal repository
+baseurl=https://artifactapi.k8s.syd1.au.unkin.net/api/v1/local/rpm-internal/
+enabled=1
+gpgcheck=0
+metadata_expire=60
+
+[rpm-vendor]
+name=rpm-vendor repository
+baseurl=https://artifactapi.k8s.syd1.au.unkin.net/api/v1/local/rpm-vendor/
+enabled=1
+gpgcheck=0
+metadata_expire=60