Grails and SAPUI5 are friends

Hello reader,

instead of the planned walk through the city park and drinking some beer(s) mother nature swinging moods changed my plans and in place of the shiny sun gave me hard rain and sour mouth. In a situation like that, alone and bored I decided to bore you too and share this short text about two good friends called Grails and SAPUI5 (respect to the OpenUI5 project too). ūüôā

I’ve been working hard with the Grails framework this couple of years and different situations led me to different scenarios. Lately I found myself in situation that asked bringing closer the powerful SAP services to the web/mobile clients. And what is better that using the outsourced JavaScript MVC framework made by SAP called SAPUI5 or if you prefer the open source project name OpenUI5 in conjunction with the versatile Grails Framework.

If you’re familiar with Grails then you certainly know that with the latest 3++ versions of Grails there is great support for already established and pretty much famous frameworks/libraries AngularJS and ReactJS in forms of Grails app profiles and plugins. But there is no “official” support for interbridging SAPUI5 and Grails and that is the main motive for writing this blog post and sharing it with you.

SAPUI5 is a single paged application where all the magic is done with JS so what we need is a single html file or in this case a single gsp file. We use that file to define the paths to the SAPUI5 runtime (or sdk) resources and to init the main SAPUI5 application via short JavaScript code. SAPUI5 is best when used with the OData services and that its where this software shines, however it has also great support when working with JSON and provides us with swift JSONModel that we can use to fill up the application data. And because we have JSON then we must have the Restful Grails controllers that will provide us with well defined JSON.

So the situation is pretty simple: Grails connects us with the backend via web services (or else?) or it provides us the data on its own via GORM or something else. Then Grails transforms the data into a JSON format that is a sweet cake for the SAPUI5 to consume and make it look great both on web browsers and on any mobile clients (Smart phones, tablets etc.).

Well this won’t be worth a penny without a working example, right? Because that’s the cause I’ve published a little demo of Grails and SAPUI5 playing together that you can check it on github. In short words we have a Spring Security Core plugin for the authentication and authorization, the JSON Views plugin for making the JSON even easier and also an example how to make it work via rest based http calls if your clients is native app . And of course the SAPUI5 application itself.

Here’s the link to the repo.

Thanks for reading,

cheers.

 

 

Deploying WordPress over Nginx and PHP-FPM

Welcome random web traveler. As the title suggests this post will deal with plain production ready examples of Nginx configuration (plus php-fpm) for WordPress site.

Before we move to the real thing, note that this examples are tested on both Debian 7 and CentOS 7 OSs. Since I don’t want to dive into setting up this servers for WordPress, I’m just giving your refined nginx configs that may be found useful. However the steps for building up WordPress on Linux are pretty simple:

РInstalling Nginx from package repository or compiling it from scratch;

– Installing php5, php-mysql, php-fpm and other php libraries if needed (like php-gd);

– Installing MySql or Maria-DB;

– And off course setting up php, nginx and mysql/mariadb.

OK lets start with the nginx server configuration.  Found in /etc/nginx/nginx.conf

user www-data;
worker_processes 4;
pid /var/run/nginx.pid;

events {
 worker_connections 768;
 # multi_accept on;
}

http {

 ##
 # Basic Settings
 ##

 sendfile on;
 tcp_nopush on;
 tcp_nodelay on;
 keepalive_timeout 65;
 types_hash_max_size 2048;
 server_tokens off;

 client_max_body_size 100m;

 client_header_buffer_size 1k;
 large_client_header_buffers 8 8k;

 # server_names_hash_bucket_size 64;
 # server_name_in_redirect off;

 include /etc/nginx/mime.types;
 default_type application/octet-stream;

 ##
 # Logging Settings
 ##

 access_log /var/log/nginx/access.log;
 error_log /var/log/nginx/error.log;

 ##
 # SSL settings
 ##
 ssl_session_cache shared:SSL:10m;
 ssl_session_timeout 10m;

 ##
 # Gzip Settings
 ##

 gzip on;
 gzip_disable "msie6";

 # gzip_vary on;
 # gzip_proxied any;
 # gzip_comp_level 6;
 # gzip_buffers 16 8k;
 # gzip_http_version 1.1;
 # gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript;

 ##
 # nginx-naxsi config
 ##
 # Uncomment it if you installed nginx-naxsi
 ##

 #include /etc/nginx/naxsi_core.rules;

 ##
 # nginx-passenger config
 ##
 # Uncomment it if you installed nginx-passenger
 ##

 #passenger_root /usr;
 #passenger_ruby /usr/bin/ruby;

 ##
 # Virtual Host Configs
 ##

 include /etc/nginx/conf.d/*.conf;
 include /etc/nginx/sites-enabled/*;
}

Pretty straightforward, right?

Next the Nginx magic behind WordPress. This example assumes that we want the administration of WordPress to go through SSL (https protocol). File: example.conf

server {
 ## Your website name goes here.
 server_name example.com www.example.com;
 listen 80;
 ## Your only path reference.
 root /opt/wordpress/;
 ## This should be in your http block and if it is, it's not needed here.
 index index.php;
 # port_in_redirect on;

 access_log /var/log/nginx/example_log;
 error_log /var/log/nginx/example_err warn;

 # rewrite all 403 to 404
 error_page 403 = 404;

 location = /favicon.ico {
 log_not_found off;
 access_log off;
 }

 location = /robots.txt {
 allow all;
 log_not_found off;
 access_log off;
 }

 # deny all access to .dot files
 location ~ /\. { access_log off; log_not_found off; deny all; }

 # deny access to files starting with a $, these are usually temp files
 location ~ ~$ { access_log off; log_not_found off; deny all; }

 location / {
 # This is cool because no php is touched for static content.
 # include the "?$args" part so non-default permalinks doesn't break when using query string
 try_files $uri $uri/ /index.php?$args;
 }

 location ~ /wp-admin/admin-ajax\.php {
 try_files $uri =404;

 # With php5-fpm
 fastcgi_intercept_errors on;
 fastcgi_pass 127.0.0.1:9000;

 fastcgi_index index.php;
 fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
 include fastcgi_params;

 }

 # Request to wp-login to go through HTTPS protocol
 location ~ /(wp-admin/|wp-login\.php) {
 return 301 https://$host$request_uri;
 #rewrite /wp-(admin|login) $scheme://$host$request_uri/ permanent;
 }

 location ~ \.php$ {
 try_files $uri =404;
 #NOTE: You should have "cgi.fix_pathinfo = 0;" in php.ini

 # With php5-fpm
 fastcgi_intercept_errors on;
 fastcgi_pass 127.0.0.1:9000;

 fastcgi_index index.php;
 fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
 include fastcgi_params;

 }

 location ~* \.(js|css|png|jpg|jpeg|gif|ico)$ {
 expires max;
 log_not_found off;
 }

 error_page 500 502 503 504 /50x.html;
 location = /50x.html {
 root /usr/share/nginx/www;
 }

}

server {
 listen 443 ssl;
 server_name example.com www.example.com;
 index index.php;

 root /opt/wordpress/;

 # Logs
 access_log /var/log/nginx/example_ssl_access.log;
 error_log /var/log/nginx/example_ssl_error.log info;

 ssl on;
 ssl_certificate /etc/ssl/certs/example.com.crt;
 ssl_certificate_key /etc/ssl/keys/example.com.key;

 ssl_protocols SSLv3 TLSv1 TLSv1.1 TLSv1.2;
 ssl_ciphers ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:ECDH+3DES:DH+3DES:RSA+AES:RSA+3DES:!aNULL:!MD5:!DSS;
 ssl_prefer_server_ciphers on;

 # Process requests to wp-admin/* and wp-login.php
 location ~ /wp-(admin|login|content|includes) {

 location ~ \.php$ {
 try_files $uri =404;
 #fastcgi_split_path_info ^(.+\.php)(/.+)$;

 # With php5-fpm
 fastcgi_intercept_errors on;
 fastcgi_pass 127.0.0.1:9000;

 fastcgi_index index.php;
 fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
 fastcgi_param HTTPS on;
 include fastcgi_params;

 }
 }

 # redirect everyone back to the non-ssl page
 location / { return 301 http://$host$request_uri; }

 location ~ !^(/wp-admin/|wp-login\.php) { return 301 http://$host$request_uri; }

 # rewrite all 403 to 404
 error_page 403 = 404;

 # deny all access to .dot files
 location ~ /\. { access_log off; log_not_found off; deny all; }

 # deny access to files starting with a $, these are usually temp files
 location ~ ~$ { access_log off; log_not_found off; deny all; }

 # keep logs clean by not logging access to favicon.
 location = /favicon.ico { access_log off; log_not_found off; }

 # keep logs clean by not logging access to robots.txt
 location = /robots.txt { access_log off; log_not_found off; }

}

FastCGI params that are defined in Nginx (/etc/nginx/fastcgi_params)


fastcgi_param QUERY_STRING $query_string;
fastcgi_param REQUEST_METHOD $request_method;
fastcgi_param CONTENT_TYPE $content_type;
fastcgi_param CONTENT_LENGTH $content_length;

fastcgi_param SCRIPT_FILENAME $request_filename;
fastcgi_param SCRIPT_NAME $fastcgi_script_name;
fastcgi_param REQUEST_URI $request_uri;
fastcgi_param DOCUMENT_URI $document_uri;
fastcgi_param DOCUMENT_ROOT $document_root;
fastcgi_param SERVER_PROTOCOL $server_protocol;

fastcgi_param GATEWAY_INTERFACE CGI/1.1;
fastcgi_param SERVER_SOFTWARE nginx/$nginx_version;

fastcgi_param REMOTE_ADDR $remote_addr;
fastcgi_param REMOTE_PORT $remote_port;
fastcgi_param SERVER_ADDR $server_addr;
fastcgi_param SERVER_PORT $server_port;
fastcgi_param SERVER_NAME $server_name;

fastcgi_param HTTPS $https;

# PHP only, required if PHP was built with --enable-force-cgi-redirect
fastcgi_param REDIRECT_STATUS 200;

You can see that 2 params are overwritten in the example.conf.

Blended with Nginx we use PHP FastCGI Process Manager or PHP-FPM. I like to start it like a daemon. For that reason we can use init script installed at /etc/init.d/php-fpm . Btw I borrowed it.


#!/bin/sh
### BEGIN INIT INFO
# Provides: php-fpm php5-fpm
# Required-Start: $remote_fs $network
# Required-Stop: $remote_fs $network
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: starts php5-fpm
# Description: Starts PHP5 FastCGI Process Manager Daemon
### END INIT INFO

# Author: Ondrej Sury <ondrej@debian.org>

PATH=/sbin:/usr/sbin:/bin:/usr/bin
DESC="PHP5 FastCGI Process Manager"
NAME=php5-fpm
DAEMON=/usr/sbin/$NAME
DAEMON_ARGS="--fpm-config /etc/php5/fpm/php-fpm.conf"
PIDFILE=/var/run/php5-fpm.pid
TIMEOUT=30
SCRIPTNAME=/etc/init.d/$NAME

# Exit if the package is not installed
[ -x "$DAEMON" ] || exit 0

# Read configuration variable file if it is present
[ -r /etc/default/$NAME ] && . /etc/default/$NAME

# Load the VERBOSE setting and other rcS variables
. /lib/init/vars.sh

# Define LSB log_* functions.
# Depend on lsb-base (>= 3.0-6) to ensure that this file is present.
. /lib/lsb/init-functions

#
# Function to check the correctness of the config file
#
do_check()
{
[ "$1" != "no" ] && $DAEMON $DAEMON_ARGS -t 2>&1 | grep -v "\[ERROR\]"
FPM_ERROR=$($DAEMON $DAEMON_ARGS -t 2>&1 | grep "\[ERROR\]")

if [ -n "${FPM_ERROR}" ]; then
echo "Please fix your configuration file..."
$DAEMON $DAEMON_ARGS -t 2>&1 | grep "\[ERROR\]"
return 1
fi
return 0
}

#
# Function that starts the daemon/service
#
do_start()
{
# Return
# 0 if daemon has been started
# 1 if daemon was already running
# 2 if daemon could not be started
start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON --test > /dev/null \
|| return 1
start-stop-daemon --start --quiet --pidfile $PIDFILE --exec $DAEMON -- \
$DAEMON_ARGS 2>/dev/null \
|| return 2
# Add code here, if necessary, that waits for the process to be ready
# to handle requests from services started subsequently which depend
# on this one. As a last resort, sleep for some time.
}

#
# Function that stops the daemon/service
#
do_stop()
{
# Return
# 0 if daemon has been stopped
# 1 if daemon was already stopped
# 2 if daemon could not be stopped
# other if a failure occurred
start-stop-daemon --stop --quiet --retry=QUIT/$TIMEOUT/TERM/5/KILL/5 --pidfile $PIDFILE --name $NAME
RETVAL="$?"
[ "$RETVAL" = 2 ] && return 2
# Wait for children to finish too if this is a daemon that forks
# and if the daemon is only ever run from this initscript.
# If the above conditions are not satisfied then add some other code
# that waits for the process to drop all resources that could be
# needed by services started subsequently. A last resort is to
# sleep for some time.
start-stop-daemon --stop --quiet --oknodo --retry=0/30/TERM/5/KILL/5 --exec $DAEMON
[ "$?" = 2 ] && return 2
# Many daemons don't delete their pidfiles when they exit.
rm -f $PIDFILE
return "$RETVAL"
}

#
# Function that sends a SIGHUP to the daemon/service
#
do_reload() {
#
# If the daemon can reload its configuration without
# restarting (for example, when it is sent a SIGHUP),
# then implement that here.
#
start-stop-daemon --stop --signal USR2 --quiet --pidfile $PIDFILE --name $NAME
return 0
}

case "$1" in
start)
[ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC" "$NAME"
do_check $VERBOSE
case "$?" in
0)
do_start
case "$?" in
0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
esac
;;
1) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
esac
;;
stop)
[ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC" "$NAME"
do_stop
case "$?" in
0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
esac
;;
status)
status_of_proc "$DAEMON" "$NAME" && exit 0 || exit $?
;;
check)
do_check yes
;;
reload|force-reload)
log_daemon_msg "Reloading $DESC" "$NAME"
do_reload
log_end_msg $?
;;
reopen-logs)
log_daemon_msg "Reopening $DESC logs" $NAME
if start-stop-daemon --stop --signal USR1 --oknodo --quiet \
--pidfile $PIDFILE --exec $DAEMON
then
log_end_msg 0
else
log_end_msg 1
fi
;;
restart)
log_daemon_msg "Restarting $DESC" "$NAME"
do_stop
case "$?" in
0|1)
do_start
case "$?" in
0) log_end_msg 0 ;;
1) log_end_msg 1 ;; # Old process is still running
*) log_end_msg 1 ;; # Failed to start
esac
;;
*)
# Failed to stop
log_end_msg 1
;;
esac
;;
*)
echo "Usage: $SCRIPTNAME {start|stop|status|restart|reload|force-reload}" >&2
exit 1
;;
esac

:

This script assumes that we have one main php-fpm.conf file where we define pid file, log file, pools that we will use etc. Every change we do to php configuration like max_upload_size and else can be applied by reloading of this daemon.

That’s it my dearest. Don’t forget that WordPress requires additional settings for working with SSL too. Any questions or suggestions, please write.

Hopes I saved a little precious time of yours ūüėČ

Resolving HTTP Error 416 Requested Range not satisfiable (IIS 7.5 example)

The chaos called HTTP often surprises us with some new sweet little error that put us in not so satisfiable position. For example the anonymous HTTP error 416.

This error is product of mismatch between the client (for example browser) and the server regarding to the Accept-Ranges header tag. In particular this error emerges when the client is requesting a bigger resource similar to pdf files or images and awaits for the response of the server. The initial response could be fine but the streaming of the resource could fail. Why?

Accept-Ranges: bytes means that the request can be served partially. After the initial content-length parameter the server should provides us Content-Range tag (bytes size) in the response with every ‘partial’ request to keep the consistency of the stream. If this doesn’t work¬†right, say hello to error 416. To be noted that this is highly influenced by how the client is implemented, not only the server.

To check if the server supports range header we could do a thing. Send HEAD request instead of GET to the wanted resource. If response 206 is returned range is supported. If the response code is 200 server side should change Accept-Range header to not foul clients.

Curl example: $ curl -i -X HEAD http://address/path/resource

Nevertheless let’s just solve the problem. Usually¬†I notice this error in relation IIS -> Chrome or Apache -> Chrome. But it occurs on Firefox too.

Setting Accept-Bytes: none in IIS: Intenet Information Service (IIS) Manager -> Server Node -> Sites -> Problematic Site -> HTTP Response Headers (In IIS section) -> Add (Action) -> Name: Accept-Bytes; Value: none .

Setting Accept-Bytes: none in Apache2 :¬†Enable¬†apache2 mod_headers. Add “Header set Accept-Ranges none” in configuration of host.

Restart changes to take effect.

Have a nice day : )

Setting Up Context in Apache Tomcat for Serving Static Files

The intro:

So I’ve heard you want to serve static files from your Tomcat Web App in a way that they won’t be deleted on WAR redeploy or Tomcat restarted?

You have a solution, and that is mapping a custom Context in your Apache Tomcat server.xml .

The scenario :

You have a site that allows users to upload images that are public,shared and not under a hood of some security filter. The most intuitive solution is to put them in some directory i.e. ‘uploads’ , but then you realize that the things in the exploded WAR rewrite on redeploy or if the war is in the webapps directory on Tomcat restart. (you can change this behaviour)

The solution is simple: save the files to some directory outside of the war (something like ‘/usr/share/tomcat/uploads’) and map that directory on the server context of your Tomcat AS (something like http://lesite:8080/uploads).

With workaround like this you will see your uploaded cute kitty picture like this: http://lesite:8080/uploads/kitty.jpg

The implementation:

Let’s use the same examples. The mapping is done in <CATALINA_HOME>/conf/server.xml (hopes you know what and where catalina_home is )

This is default situation on new Tomcat install (a snippet from sever.xml):

<Host name=”localhost” appBase=”webapps” unpackWARs=”true” autoDeploy=”true”>

<Valve className=”org.apache.catalina.valves.AccessLogValve” directory=”logs”
prefix=”localhost_access_log.” suffix=”.txt”
pattern=”%h %l %u %t &quot;%r&quot; %s %b” />

</Host>

But we want to change that in this:

<Host name=”localhost” appBase=”webapps” unpackWARs=”true” autoDeploy=”true”>

<Context docBase="/usr/share/tomcat/uploads" path="/uploads" />

<Valve className=”org.apache.catalina.valves.AccessLogValve” directory=”logs”
prefix=”localhost_access_log.” suffix=”.txt”
pattern=”%h %l %u %t &quot;%r&quot; %s %b” />

</Host>

And that’s it, end of setting. Restart , code and redeploy.

The cookie:

Java snippet of simple utilization:

public class UploadsServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletExcpetion, IOException {
        File file = new File("/usr/share/tomcat/uploads", request.getPathInfo());
        response.setHeader("Content-Type", Files.probeContentType(file.toPath()));
        response.setHeader("Content-Length", String.valueOf(file.length()));
        Files.copy(file.toPath(), response.getOutputStream());
    }

}

The conclusion:
In exact things the need for conclusion is deprecated. Everything should be concluded the one way :

return goToTopAndReadAgain();

The hint:

Maybe you won’t be impressed, and probably you have a better solution/implementation for/of the scenario. However let me give you a clue how this can be found useful in different situation. Proxying and load balancing, possibly with Nginx on front and couple of Tomcats behind. Defining new server contextses and getting a feel of that damn Superman speed.

Fiuuuuuuuuuuuuuuuuu…

(salutations and thanks to a friend of mine for collaboration)