enable Cloudflare zlib performance library by default for Nginx zlib

- set CLOUDFLARE_ZLIB='y' by default. Very little risk as the routine now has error checking so if Cloudflare zlib library install fails, Centmin Mod will fall back to standard custom zlib 1.2.11 library install for Nginx zlib
- with Cloudflare zlib performance library usage, Nginx HTTP gzip compressed request performance can improve up to 29% over standard zlib 1.2.11 library

centmin.sh

@@ -558,7 +558,7 @@ OPENSSL_VERSIONFALLBACK='1.0.2n'   # fallback if OPENSSL_VERSION uses openssl 1.
 OPENSSL_THREADS='y'        # control whether openssl 1.1 branch uses threading or not
 OPENSSL_CUSTOMPATH='/opt/openssl'  # custom directory path for OpenSSL 1.0.2+
 CLOUDFLARE_PATCHSSL='n'    # set 'y' to implement Cloudflare's chacha20 patch https://github.com/cloudflare/sslconfig
-CLOUDFLARE_ZLIB='n'        # use Cloudflare optimised zlib fork https://blog.cloudflare.com/cloudflare-fights-cancer/
+CLOUDFLARE_ZLIB='y'        # use Cloudflare optimised zlib fork https://blog.cloudflare.com/cloudflare-fights-cancer/
 CLOUDFLARE_ZLIBPHP='n'     # use Cloudflare optimised zlib fork for PHP-FPM zlib instead of system zlib
 CLOUDFLARE_ZLIBDEBUG='n'   # make install debug verbose mode
 CLOUDFLARE_ZLIBVER='1.3.0'

inc/zlib.inc

@@ -64,6 +64,20 @@ zlibng_install() {
 }
 
 install_cfzlib() {
+    if [[ "$CLOUDFLARE_ZLIB" = [yY] && "$(cat /proc/cpuinfo | grep -o 'sse4_2' | uniq)" = 'sse4_2' ]]; then
+        # disable clang compiler and switch to gcc compiler due to clang 3.4.2 errors when enabling
+        # cloudflare zlib
+        if [[ "$CLANG" = [yY] && "$CENTOS_SEVEN" -eq '7' ]]; then
+            CLANG='y'
+            CLANG_FOUR='y'
+        elif [[ "$CLANG" = [yY] && "$CENTOS_SIX" -eq '6' ]]; then
+            CLANG='n'
+            DEVTOOLSETSIX='y'
+        else
+            CLANG='n'
+            DEVTOOLSETSIX='y'
+        fi
+        install_cfzlibstartdir=$(pwd)
         echo
         echo "install zlib cloudflare..."
         echo
@@ -88,35 +102,18 @@ install_cfzlib() {
         # ps aufxwww > zlib-process.log
         if [[ "$CLOUDFLARE_ZLIBDEBUG" = [Yy] ]]; then
             make -d install
+            cfzlib_check=$?
             if [[ "$(uname -m)" = 'x86_64' ]]; then
                 ln -sf /usr/local/zlib-cf/lib /usr/local/zlib-cf/lib64
             fi
         else
             make install
+            cfzlib_check=$?
             if [[ "$(uname -m)" = 'x86_64' ]]; then
                 ln -sf /usr/local/zlib-cf/lib /usr/local/zlib-cf/lib64
             fi
         fi
         popd
-}
-
-nginxzlib_install() {
-  if [[ "$NGINX_ZLIBCUSTOM" = [yY] ]]; then
-    if [[ "$CLOUDFLARE_ZLIB" = [yY] && "$(cat /proc/cpuinfo | grep -o 'sse4_2' | uniq)" = 'sse4_2' ]]; then
-        # disable clang compiler and switch to gcc compiler due to clang 3.4.2 errors when enabling
-        # cloudflare zlib
-        if [[ "$CLANG" = [yY] && "$CENTOS_SEVEN" -eq '7' ]]; then
-            CLANG='y'
-            CLANG_FOUR='y'
-        elif [[ "$CLANG" = [yY] && "$CENTOS_SIX" -eq '6' ]]; then
-            CLANG='n'
-            DEVTOOLSETSIX='y'
-        else
-            CLANG='n'
-            DEVTOOLSETSIX='y'
-        fi
-        install_cfzlibstartdir=$(pwd)
-        install_cfzlib
         cd install_cfzlibstartdir
         if [ -f /usr/local/lib/libz.so ]; then
             echo
@@ -206,7 +203,10 @@ nginxzlib_install() {
         echo
         echo "zlib cloudflare installed"
         echo
-    else
+    fi
+}
+
+install_stdzlib() {
         echo
         echo "install zlib ${NGINX_ZLIBVER}..."
         echo
@@ -310,6 +310,18 @@ nginxzlib_install() {
         echo
         echo "zlib ${NGINX_ZLIBVER} installed"
         echo
+}
+
+nginxzlib_install() {
+  if [[ "$NGINX_ZLIBCUSTOM" = [yY] ]]; then
+    if [[ "$CLOUDFLARE_ZLIB" = [yY] && "$(cat /proc/cpuinfo | grep -o 'sse4_2' | uniq)" = 'sse4_2' ]]; then
+        install_cfzlib
+        if [[ "$cfzlib_check" -ne '0' ]]; then
+            CLOUDFLARE_ZLIB='n'
+            install_stdzlib
+        fi
+    else
+        install_stdzlib
     fi
   fi
 }