NGINX in Containers and Kubernetes

Configuration as part of the image

In containers, NGINX typically runs in the foreground with daemon off; (the official image does this) and logs to stdout and stderr, which the official image achieves by linking log files to /dev/stdout and /dev/stderr. Build images with your configuration copied in, or mount it as a ConfigMap in Kubernetes. The official image supports templates: files in /etc/nginx/templates/*.template are processed with envsubst at start-up, so you can inject environment variables such as backend addresses. For static sites, a common pattern is a multi-stage build: build the frontend in a Node image, copy the output into a small nginx image. In Kubernetes, NGINX often appears as an ingress controller. The community ingress-nginx controller, long the most popular, was announced for retirement by the Kubernetes project, with maintenance ending in 2026; new clusters should evaluate Gateway API implementations (including F5's NGINX Gateway Fabric) or other maintained controllers such as F5's NGINX Ingress Controller, Traefik or cloud-provider gateways.

NGINX in a container

Configuration is baked into the image or mounted; logs go to stdout for the platform to collect.

Multi-stage build for a single-page app

Build with Node, serve with NGINX, inject the API address at start-up.

# Dockerfile
FROM node:22-alpine AS build
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY . .
RUN npm run build

FROM nginx:stable-alpine
COPY --from=build /app/dist /usr/share/nginx/html
COPY nginx/default.conf.template /etc/nginx/templates/default.conf.template
# at start-up the image runs envsubst: ${API_UPSTREAM} -> real value
EXPOSE 80

# nginx/default.conf.template
# server {
#     listen 80;
#     root /usr/share/nginx/html;
#     location /api/ { proxy_pass ${API_UPSTREAM}; }
#     location / { try_files $uri $uri/ /index.html; }
# }

envsubst touches every $

Template substitution replaces ${VAR} placeholders; the official image restricts substitution to defined environment variables so NGINX variables like $uri survive, but test your rendered configuration with nginx -T inside the container.

Quick check: Why should new Kubernetes clusters avoid adopting the community ingress-nginx controller?

• It cannot route HTTP
• It only supports UDP
• The Kubernetes project announced its retirement, so it no longer receives maintenance
• It requires NGINX Plus