Completely revamp installation script

Instead of cluttering the $PREFIX during build (and requiring root to do so),
we now install everything into a temporary directrory that is copied in piecemeal
to the prefix). Additionally, the installer will now, on a fresh installation only,
copy the base config files from /conf to $PREFIX/etc/nginx. A existing installation
will not have this performed (unlike the upstream nginx installation rules), so your
configuration will be safe.

.gitignore

@@ -0,0 +1,2 @@
+# temporary
+install_root/

README.md

@@ -10,7 +10,7 @@ Essentially, this is OpenResty core (and a few Lua modules we actually use), and
 $ git clone --recursive https://git.computernewb.com/nginx-cn
 $ cd nginx-cn
 $ ./build
-# ./install
+# sudo ./install
-# ... (copy the base config from conf/ into /opt/nginx/etc/nginx and adjust/add to suit your configuration)
+# ... (adjust the configuration base to suit your needs)
 # profit?
 ```

build

@@ -1,11 +1,12 @@
 #!/bin/bash
 
-# installation prefix. unfortunately we have to vendor
+. ./config
-# certain dependencies (luajit) so this /opt path is 
-# (probably) going to unfortunately stick.
-PREFIX="/opt/nginx"
 
-TOP="$(pwd)"
+
+# make install prefix
+[[ ! -d "${INSTALL_PREFIX}" ]] && {
+	mkdir -p ${INSTALL_PREFIX}
+}
 
 # clean Nginx sources beforehand.
 pushd sources/nginx/
@@ -13,7 +14,7 @@ pushd sources/nginx/
 	git clean -dxf
 popd
 
-local BASE_CONFIGURE_FLAGS=(
+BASE_CONFIGURE_FLAGS=(
   # Build everything with Clang + ThinLTO
   --with-cc="clang"
   --with-cc-opt="-pipe -march=native -mtune=native -flto=thin"
@@ -75,12 +76,12 @@ popd
 # build and install luajit and the resty lua libraries into prefix
 pushd $TOP/sources/luajit2
 	git clean -dxf
-	make PREFIX=$PREFIX -j49
+	make PREFIX=$INSTALL_PREFIX -j49
-	sudo make PREFIX=$PREFIX install
+	make PREFIX=$INSTALL_PREFIX install
 popd
 
 # resty libs that can be installed
-local RESTY_LIBS=(
+RESTY_LIBS=(
 	lua-resty-{core,lrucache,websocket}
 )
 
@@ -88,15 +89,15 @@ local RESTY_LIBS=(
 for lib in ${RESTY_LIBS[@]}; do
 	echo "installing $lib"
 	pushd $TOP/sources/$lib
-		sudo make install PREFIX=$PREFIX
+		make install PREFIX=$INSTALL_PREFIX
 	popd
 done
 
 pushd $TOP/sources/nginx
 
 # needed for lua-nginx-module
-export LUAJIT_INC="$PREFIX/include/luajit-2.1"
+export LUAJIT_INC="$INSTALL_PREFIX/include/luajit-2.1"
-export LUAJIT_LIB="$PREFIX/lib"
+export LUAJIT_LIB="$INSTALL_PREFIX/lib"
 
 # TODO: see ./install for --sbin-path
 ./auto/configure \
@@ -118,3 +119,12 @@ export LUAJIT_LIB="$PREFIX/lib"
 
 make -j $(($(nproc)+1))
 popd
+
+# Strip nginx and install it into the staging prefix
+pushd $TOP/sources
+	cp nginx/objs/nginx nginx/objs/nginx.unstripped
+	strip nginx/objs/nginx
+	
+	[[ ! -d "${INSTALL_PREFIX}/bin" ]] && mkdir -p ${INSTALL_PREFIX}/bin
+	cp nginx/objs/nginx $INSTALL_PREFIX/bin/nginx
+popd

config

@@ -0,0 +1,13 @@
+# Shared configuration for build/install scripts
+
+# Installation prefix. unfortunately we have to vendor
+# certain dependencies (luajit) for OpenResty,
+# so this /opt path is going to unfortunately stick
+# Change to what you like I suppose, but make sure to update the systemd files..
+PREFIX="/opt/nginx"
+
+TOP="$(pwd)"
+
+# The staging prefix used to install everything before actually installing it to
+# $PREFIX.
+INSTALL_PREFIX="${TOP}/install_root"

install

@@ -1,23 +1,40 @@
 #!/bin/bash
-# Installs nginx-cn
+# Installs nginx-cn into the configured PREFIX.
+#
+# N.B: We do not use nginx's `make install` because it's very very bad
+# and it overwrites $PREFIX/etc unconditionally. It's bad design choice,
+# and I personally do not like it.
 
-TOP="$(pwd)"
+. ./config
 
-[[ ! -d "$TOP/sources/nginx/objs" ]] && {
+# Check for the install prefix directory. If it doesn't exist,
+# then a build likely hasn't been done, so we can't proceed.
+[[ ! -d "${INSTALL_PREFIX}" ]] && {
 	echo "You haven't built nginx-cn yet. Do so with ./build"
 	exit 1
 }
 
-# N.B: We do not use nginx's `make install` because it's very very bad
+# We're replacing an existing installation.
-# and it overwrites $PREFIX/etc unconditionally. It's bad. I don't like it.
+# Make sure not to overwrite a user's existing configuration
-pushd $TOP/sources
+[[ -d "${PREFIX}/etc/nginx" ]] && {
-sudo systemctl stop nginx-cn
+	echo "You seem to have a configuration in your PREFIX."
-	# strip binary of unneeded fluff (saving the original)
+	echo "I will not touch it."
-	cp nginx/objs/nginx nginx/objs/nginx.unstripped
-	strip nginx/objs/nginx
-	sudo cp nginx/objs/nginx /opt/nginx/bin
-sudo systemctl start nginx-cn
-#sudo make install
-	echo "Binary installed. You should probably copy the sample configuration to /opt/nginx/etc/nginx."
-popd
 
+	# Remove old files and replace them with the install prefix versions
+	rm -rf ${PREFIX}/{bin,lib,share}
+	cp -r ${INSTALL_PREFIX}/bin ${PREFIX}/bin
+	cp -r ${INSTALL_PREFIX}/lib ${PREFIX}/lib
+	cp -r ${INSTALL_PREFIX}/share ${PREFIX}/share
+}
+
+# A new installation.
+# We SHOULD copy over the configuration now.
+[[ ! -d "${PREFIX}" ]] && {
+	mkdir -p ${PREFIX} ${PREFIX}/etc/nginx
+	cp -r ${INSTALL_PREFIX}/bin ${PREFIX}/bin
+	cp -r ${INSTALL_PREFIX}/lib ${PREFIX}/lib
+	cp -r ${INSTALL_PREFIX}/share ${PREFIX}/share
+	cp -r ${TOP}/conf ${PREFIX}/etc/nginx/
+}
+
+echo "nginx-cn has been installed/updated."