Edit / hide Nginx Server header under Alpine Linux - docker

Question

When I use curl --head to test my website, it returns the server information.
I followed this tutorial to hide the nginx server header.
But when I run the command yum install nginx-module-security-headers
, it returns yum: not found.
I also tried apk add nginx-module-security-headers, and it shows that the package is missing.
I have used nginx:1.17.6-alpine as my base docker image. Does anyone know how to hide the server from header under this Alpine?

Answer 1

I think I have an easier solution here: https://gist.github.com/hermanbanken/96f0ff298c162a522ddbba44cad31081. Big thanks to hermanbanken on Github for sharing this gist.
The idea is to create a multi stage build with the nginx alpine image to be a base for compiling the module. This turns into the following Dockerfile:
ARG VERSION=alpine
FROM nginx:${VERSION} as builder
ENV MORE_HEADERS_VERSION=0.33
ENV MORE_HEADERS_GITREPO=openresty/headers-more-nginx-module
# Download sources
RUN wget "http://nginx.org/download/nginx-${NGINX_VERSION}.tar.gz" -O nginx.tar.gz && \
wget "https://github.com/${MORE_HEADERS_GITREPO}/archive/v${MORE_HEADERS_VERSION}.tar.gz" -O extra_module.tar.gz
# For latest build deps, see https://github.com/nginxinc/docker-nginx/blob/master/mainline/alpine/Dockerfile
RUN apk add --no-cache --virtual .build-deps \
gcc \
libc-dev \
make \
openssl-dev \
pcre-dev \
zlib-dev \
linux-headers \
libxslt-dev \
gd-dev \
geoip-dev \
perl-dev \
libedit-dev \
mercurial \
bash \
alpine-sdk \
findutils
SHELL ["/bin/ash", "-eo", "pipefail", "-c"]
RUN rm -rf /usr/src/nginx /usr/src/extra_module && mkdir -p /usr/src/nginx /usr/src/extra_module && \
tar -zxC /usr/src/nginx -f nginx.tar.gz && \
tar -xzC /usr/src/extra_module -f extra_module.tar.gz
WORKDIR /usr/src/nginx/nginx-${NGINX_VERSION}
# Reuse same cli arguments as the nginx:alpine image used to build
RUN CONFARGS=$(nginx -V 2>&1 | sed -n -e 's/^.*arguments: //p') && \
sh -c "./configure --with-compat $CONFARGS --add-dynamic-module=/usr/src/extra_module/*" && make modules
# Production container starts here
FROM nginx:${VERSION}
COPY --from=builder /usr/src/nginx/nginx-${NGINX_VERSION}/objs/*_module.so /etc/nginx/modules/
.... skipped inserting config files and stuff ...
# Validate the config
RUN nginx -t

Answer 2

Alpine repo probably doesn't have the ngx_security_headers module but, the mentioned tutorial also provides an option of using Headers More module. You should be able to install this module in your alpine distro using the command:
apk add nginx-mod-http-headers-more
Hope it helps.
Source

Answer 3

I found the alternate solution. The reason that it shows binary not compatible is because I have one nginx pre-installed under the target route, and it is not compatible with the header-more module I am using. That means I cannot simply install the third party library from Alpine package.
So I prepare a clean Alpine OS, and follow the GitHub repository to build Nginx from the source with additional feature. The path of build result is the prefix path you specified.