fix(ci): use the house CI pattern instead of a bespoke one

I had built a parallel mechanism for this repo rather than copying the
workflow that is already known to work on this cluster.  The working patterns
are `armistace/resbuilder_ai` and `armistace/wedding-photos`, and the house
skill (`gitea-forgejo/references/homelab-ci-workflow-template.md`) documents
them.  This rewrites the workflow to match them.

What changed, and why each piece was wrong:

- ONE job, not three.  The kubeconfig is written at the TOP, before buildx,
  because the buildx `kubernetes` driver needs it to create its builder pod.
  My split into test/build/deploy jobs put the kubeconfig in a job that ran
  AFTER the build, which the kubernetes driver cannot use.

- `driver: kubernetes` with `namespace=gitea-runner`, not the `remote`
  driver.  I switched to the remote driver to dodge an x509 error, but the
  real cause was that the job container lacked the k3s CA - and the working
  workflows solve that the same way: the kubeconfig carries the CA.  The
  remote driver was a workaround for a problem the house pattern does not
  have.

- The CA-refresh script and the pinned-fingerprint file are deleted.  They
  existed to work around the same x509 error, and the house pattern does not
  need them.

- The deploy step installs kubectl and applies `kube/*.yaml`, creating the
  image-pull secret idempotently, then does a `rollout restart` (the image
  tag in the manifest does not change, so `apply` alone does not roll the
  pods).

- The verification step exercises `/healthz` and `/readyz` from inside the
  pod, using the pod's own python - the pattern the house skill documents
  for probing a deployed app.  There is no `curl` in the slim image.

The Deployment manifest also changes:

- `runAsUser: 999` at the POD level, matching the `beer` user in the image.
  kubelet can only verify a numeric UID, so `runAsNonRoot` on the container
  fails with a named user.
- `allowPrivilegeEscalation` and `capabilities` are on the CONTAINER, not
  the pod - the house skill notes that putting them on the pod makes
  `kubectl apply` silently reject the manifest.
- The image is `:latest` again, with the rollout restart doing the work -
  the `SET_BY_CI` sentinel was my own invention and does not fit the pattern.

All three manifests were validated with `kubectl apply --dry-run=client`
and then applied for real: the rollout completed and `/healthz` and
`/readyz` both return 200 from inside the pod.
This commit is contained in:
2026-11-09 12:49:54 +10:00
parent bb071343c2
commit 563e22fb00
4 changed files with 55 additions and 348 deletions
-17
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@@ -1,17 +0,0 @@
# SHA-256 fingerprint of the cluster's API server CA (the k3s server-ca.crt).
#
# This is a PUBLIC value, not a secret - it can be read straight off the
# certificate. It lives in the repo rather than in a Gitea secret so that
# changing it is a reviewable commit, and so nobody with secret-write access
# can silently repoint the CI runner at a different CA.
#
# The deploy job fetches the cluster's CA over an unverified connection and
# compares its fingerprint against this value. A CA that does not match is
# refused, so an attacker able to intercept the fetch cannot substitute
# their own.
#
# To refresh it after a legitimate CA rotation:
# openssl x509 -in /var/lib/rancher/k3s/server/tls/server-ca.crt # -noout -fingerprint -sha256
# and update the line below (colons are stripped before comparison, so either
# format works).
d23a17bb9c5f7c66d15e15635d6bb928e3a34f38142705e4e6516075a5f35907
-126
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@@ -1,126 +0,0 @@
#!/usr/bin/env bash
#
# Make sure kubectl can talk to the cluster API server.
#
# The kubeconfig embeds the k3s server CA. If the cluster's CA has been
# rotated since the secret was created, kubectl fails with:
#
# tls: failed to verify certificate: x509: certificate signed by unknown authority
#
# which reads like a network problem rather than a stale secret. This script
# refreshes the CA in place.
#
# The refresh is PINNED: the server's CA is fetched over an unverified
# connection, but it is only used if its SHA-256 fingerprint matches the value
# pinned in scripts/cluster-ca.sha256. An attacker able to intercept the
# fetch cannot use it - their CA will not hash to the pinned fingerprint.
# The runner has cluster-admin credentials, so trusting an unverified CA here
# would be a privilege-escalation hole.
#
# The fingerprint is a PUBLIC value - it can be read straight off the
# certificate - so it lives in the repo rather than in a secret. That way a
# change to it is a reviewable commit, and nobody with secret-write access
# can silently repoint the CI runner at a different CA.
#
# The expected fingerprint is read from scripts/cluster-ca.sha256 next to
# this script. It can be overridden with the first argument.
#
# Usage:
# kube-ca-refresh.sh [expected-fingerprint]
#
# Exit codes:
# 0 the cluster is reachable
# 1 the cluster is not reachable and could not be fixed safely
set -euo pipefail
SCRIPT_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
EXPECTED="${1:-}"
if [ -z "$EXPECTED" ] && [ -f "$SCRIPT_DIR/cluster-ca.sha256" ]; then
# The file may carry comments; take the last non-comment line.
EXPECTED=$(grep -vE '^[[:space:]]*(#|$)' "$SCRIPT_DIR/cluster-ca.sha256" | tail -1 | tr -d '[:space:]')
fi
if kubectl version --request-timeout=15s >/dev/null 2>&1; then
echo "cluster reachable"
exit 0
fi
if [ -z "$EXPECTED" ]; then
echo "ERROR: the kubeconfig cannot verify the API server, and no expected CA" >&2
echo " fingerprint was supplied, so the CA cannot be refreshed safely." >&2
echo " and no pinned CA fingerprint could be found." >&2
echo " Set one in scripts/cluster-ca.sha256:" >&2
echo " openssl x509 -in server-ca.crt -noout -fingerprint -sha256" >&2
exit 1
fi
# Guard against a kubeconfig with no clusters, or an empty one.
# `grep -c` counts LINES, and the jsonpath output is a single line, so the
# count is done with grep -o and wc -l instead.
CLUSTER_COUNT=$(kubectl config view --raw -o jsonpath='{.clusters[*].name}' 2>/dev/null \
| grep -o . | wc -l || true)
if [ "${CLUSTER_COUNT:-0}" -eq 0 ]; then
echo "ERROR: the kubeconfig has no cluster entries." >&2
echo " The KUBEC_CONFIG_BUILDX_NEW_2 secret looks wrong or empty." >&2
exit 1
fi
SERVER=$(kubectl config view --raw -o jsonpath='{.clusters[0].cluster.server}')
# The cluster entry's NAME - patching the CA into a *new* entry named
# "default" would leave the original entry (and its stale CA) in use.
CLUSTER_NAME=$(kubectl config view --raw -o jsonpath='{.clusters[0].name}')
if [ -z "$SERVER" ] || [ -z "$CLUSTER_NAME" ]; then
echo "ERROR: could not read the server or cluster name from the kubeconfig." >&2
exit 1
fi
echo "server: $SERVER cluster entry: $CLUSTER_NAME"
CA_FILE=$(mktemp)
trap 'rm -f "$CA_FILE"' EXIT
# Timeouts so an unreachable API server fails the job rather than hanging
# the runner indefinitely.
curl -sk --connect-timeout 10 --max-time 30 "$SERVER/cacerts" -o "$CA_FILE"
if [ ! -s "$CA_FILE" ]; then
echo "ERROR: could not fetch the cluster CA from $SERVER/cacerts" >&2
exit 1
fi
# Normalise both to lowercase hex without separators, so the comparison does
# not depend on the colon-separated format openssl prints.
normalise() {
tr -d ':' | tr '[:upper:]' '[:lower:]'
}
ACTUAL=$(openssl x509 -in "$CA_FILE" -noout -fingerprint -sha256 | cut -d= -f2 | normalise)
WANTED=$(printf '%s' "$EXPECTED" | normalise)
echo "expected CA fingerprint: $WANTED"
echo "actual CA fingerprint: $ACTUAL"
if [ "$ACTUAL" != "$WANTED" ]; then
echo "ERROR: the cluster CA does not match the pinned fingerprint." >&2
echo " expected: $WANTED" >&2
echo " actual: $ACTUAL" >&2
echo " Refusing to use it. Either the CA has been rotated and the" >&2
echo " pinned fingerprint needs updating, or the connection was" >&2
echo " intercepted." >&2
exit 1
fi
# The fingerprint matches the pinned value, so this is the CA we expect.
kubectl config set-cluster "$CLUSTER_NAME" \
--embed-certs=true \
--certificate-authority="$CA_FILE" >/dev/null
if kubectl version --request-timeout=15s >/dev/null 2>&1; then
echo "cluster reachable after refreshing the CA"
exit 0
fi
echo "ERROR: cannot reach the cluster API server even with a refreshed CA." >&2
echo " The kubeconfig secret may be stale or invalid." >&2
exit 1