# ==========
# Build dynamic Nginx module Brotli
# ==========

backup_date="$(date +%Y-%m-%d-%H%M)"

builddir=/usr/local/src/nginx
mkdir -p /usr/local/src/nginx
cd "${builddir}"

# Install needed development packages if not yet installed in the system
#
apt -y install git libpcre3 libpcre3-dev zlib1g zlib1g-dev openssl libssl-dev


# Find installed version of nginx
#
#    nginx -v
#
# output like:
#
#    nginx version: nginx/1.18.0
#
# For automated detection of currently installed NGINX version (not to be used 
# for auto-updating, see hooks in post), use:
#
ngver=$(nginx -v 2>&1 | grep -o '[0-9\.]*')

# Get configure parameters of installed NGINX. Not needed if NGINX was configured '--with-compat'.
# Uncomment one of the lines below if the script sucessfully builds modules but NGINX throws 
# a "not binary compatible" error.
confparams=$(nginx -V 2>&1 | grep -o -- '--prefix='.* | sed -e 's/ --add-dynamic-module=[^[:space:]]*//g')
[[ -z "${confparams}" ]] && confparams=$(nginx -V 2>&1 | grep -o -- '--[^with]'.* \
   | sed -e 's/ --add-dynamic-module=[^[:space:]]*//g')
[[ -z "${confparams}" ]] && confparams=$(nginx -V 2>&1 | grep -- '--' | sed "s/.*' //" \
   | sed -e 's/ --add-dynamic-module=[^[:space:]]*//g')
[[ -z "${confparams}" ]] && confparams=$(nginx -V 2>&1 | grep -o -- "--prefix='.*'$" \
   | sed -e 's/ --add-dynamic-module=[^[:space:]]*//g')


# To automatically select NGINX modules directory:
#
[ -d /usr/share/nginx/modules ] && moddir=/usr/share/nginx/modules
[ -d $(nginx -V 2>&1 | grep -o 'prefix=[^ ]*' | sed 's/prefix=//')/modules ] && moddir="$(nginx -V 2>&1 | grep -o 'prefix=[^ ]*' | sed 's/prefix=//')/modules"
[ -d $(nginx -V 2>&1 | grep -o 'modules-path=[^ ]*' | sed 's/modules-path=//') ] && moddir="$(nginx -V 2>&1 | grep -o 'modules-path=[^ ]*' | sed 's/modules-path=//')"

[ "${moddir}" ] || { echo '!! missing modules directory, exiting...'; exit 1; }


# ---
# Download and unpack NGINX
# ---
[ -d "nginx-${ngver}" ] && mv "nginx-${ngver}" "nginx-${ngver}.${backup_date}"
wget https://nginx.org/download/nginx-${ngver}.tar.gz

# Umpack nginx souce code archive
gunzip < nginx-${ngver}.tar.gz | tar -xf -

# Remove Downloadwed archive
rm nginx-${ngver}.tar.gz


# ---
# Download, initialize, and make Brotli dynamic modules
# ---
cd /usr/local/src
[ -d "ngx_brotli" ] && mv ngx_brotli ngx_brotli.${backup_date}
git clone https://github.com/google/ngx_brotli.git

cd ngx_brotli

# download (clone) also submodules 
#
#git submodule update --init --recursive
git submodule update --init



cd /usr/local/src/nginx/nginx-${ngver}

if [[ -z "${confparams}" ]] ; then
   nice -n 19 ionice -c 3 ./configure --with-compat --add-dynamic-module=/usr/local/src/ngx_brotli 
else
   nice -n 19 ionice -c 3 ./configure --add-dynamic-module=/usr/local/src/ngx_brotli ${confparams}
fi

# Build modules
#
nice -n 19 ionice -c 3 make modules


# Replace Brotli in modules directory
#
[ -f "${moddir}/ngx_http_brotli_filter_module.so" ] && mv "${moddir}/ngx_http_brotli_filter_module.so" "${moddir}/ngx_http_brotli_filter_module.${backup_date}"
cp -a "/usr/local/src/nginx/nginx-${ngver}/objs/ngx_http_brotli_filter_module.so" \
   "${moddir}/ngx_http_brotli_filter_module.so"


[ -f "${moddir}/ngx_http_brotli_static_module.so" ] && mv "${moddir}/ngx_http_brotli_static_module.so" "${moddir}/ngx_http_brotli_static_module.so.${backup_date}"
cp -a "/usr/local/src/nginx/nginx-${ngver}/objs//ngx_http_brotli_static_module.so" \
   "${moddir}/ngx_http_brotli_static_module.so"

# cp objs/*.so "${moddir}/"

chmod 644 "${moddir}/ngx_http_brotli_filter_module.so"
chmod 644 "${moddir}/ngx_http_brotli_static_module.so"


# Create load_module statements for the two brotli modules
#
cat <<EOF > /etc/nginx/modules-available/http-brotli-filter-module.conf
load_module ${moddir}/ngx_http_brotli_filter_module.so;
EOF

cat <<EOF > /etc/nginx/modules-available/http-brotli-static-module.conf
load_module ${moddir}/ngx_http_brotli_static_module.so;
EOF


# Eanable Modules
#
ln -s ../modules-available/http-brotli-filter-module.conf /etc/nginx/modules-enabled/60-http-brotli-filter-module.conf
ln -s ../modules-available/http-brotli-static-module.conf /etc/nginx/modules-enabled/60-http-brotli-static-module.conf


# Configure Brotli
#
cat <<EOF > /etc/nginx/conf.d/http-brotli.conf
##
# Brotli Settings
##

brotli  on;
brotli_comp_level   6;
brotli_static       on;
brotli_types        text/xml image/svg+xml application/x-font-ttf image/vnd.microsoft.icon application/x-font-opentype application/json font/eot application/vnd.ms-fontobject application/javascript font/otf application/xml application/xhtml+xml text/javascript  application/x-javascript text/plain application/x-font-truetype application/xml+rss image/x-icon font/opentype text/css image/x-win-bitmap;

# brotli_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;
EOF

# Verify if all is fine
#
nginx -t


# Restart Nginx webservice
#
systemctl restart nginx.service