Automatically configure nginx to trust AWS Cloudfront IPs present in X-Fowarded-For

Dockerfile

FROM alpine:latest AS cloudfront
RUN apk --no-cache add curl jq
RUN curl https://ip-ranges.amazonaws.com/ip-ranges.json | \
    jq -r '.prefixes[] | select(.service=="CLOUDFRONT") | .ip_prefix' | \
    xargs -I '{}' echo 'set_real_ip_from {};' > /cloudfront.conf && \
    echo 'real_ip_header X-Forwarded-For;' >> /cloudfront.conf && \
    echo 'real_ip_recursive on;' >> /cloudfront.conf

FROM nginx:latest
COPY --from=cloudfront /cloudfront.conf /etc/nginx/conf.d/cloudfront.conf