validate the nginx configuration in k8s.io/apps/k8s-io

out.log

❯ pwd
/Users/dsrinivas/go/src/k8s.io/k8s.io/apps/k8s-io

❯ ./validate-nginx.sh
Extracting nginx.conf from ConfigMap...
Extracted nginx.conf to: /var/folders/2x/b5xl9skd2fl0l6tj54fjxh540000gp/T/tmp.tAdbqYOEXU/nginx.conf
Config file size:      380 lines
Validating nginx configuration using Docker...
/docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
/docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
/docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
10-listen-on-ipv6-by-default.sh: info: /etc/nginx/conf.d/default.conf is not a file or does not exist
/docker-entrypoint.sh: Sourcing /docker-entrypoint.d/15-local-resolvers.envsh
/docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh
/docker-entrypoint.sh: Launching /docker-entrypoint.d/30-tune-worker-processes.sh
/docker-entrypoint.sh: Configuration complete; ready for start up
2025/09/21 20:33:50 [emerg] 1#1: "server" directive is not allowed here in /etc/nginx/nginx.conf:346
nginx: [emerg] "server" directive is not allowed here in /etc/nginx/nginx.conf:346
nginx: configuration file /etc/nginx/nginx.conf test failed

validate-nginx.sh

#!/bin/bash

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
CONFIGMAP_FILE="${SCRIPT_DIR}/configmap-nginx.yaml"
TEMP_DIR=$(mktemp -d)
NGINX_CONF="${TEMP_DIR}/nginx.conf"

cleanup() {
    rm -rf "${TEMP_DIR}"
}
trap cleanup EXIT

echo "Extracting nginx.conf from ConfigMap..."

# Extract the nginx.conf section from the ConfigMap YAML using yq
yq eval '.data."nginx.conf"' "${CONFIGMAP_FILE}" > "${NGINX_CONF}"

echo "Extracted nginx.conf to: ${NGINX_CONF}"
echo "Config file size: $(wc -l < "${NGINX_CONF}") lines"

echo "Validating nginx configuration using Docker..."

# Use the same nginx version as specified in the deployment
NGINX_IMAGE="nginx:1.26-alpine@sha256:5b44a5ab8ab467854f2bf7b835a32f850f32eb414b749fbf7ed506b139cd8d6b"

# Run nginx configuration test
docker run --rm \
    -v "${TEMP_DIR}:/etc/nginx:ro" \
    "${NGINX_IMAGE}" \
    nginx -c /etc/nginx/nginx.conf -t

echo "✅ Nginx configuration validation completed successfully!"