The exact reason of why Tomcat cannot read the directories as in approach 1 and 3 are still unknown to me. However, it seems impossible for Tomcat to use any directory located under /home/user/... as a webapp, even if this means using symlinks to link to this location and setting correct permissions on the directories!

Although probably this is some kind of built-in protection. It is still strange because this behaviour is not listed in the Apache Tomcat documentation (correct me if I'm wrong).

The solution is therefore to use any other directory than /home/user/..., e.g. /usr/share/tomcat7/projects should work. But then again, it is best to set my Netbeans distribution output to the webapps directory directly as mentioned by another person (@user208992).

So in order to fix this problem, here is a list of instructions necessary to make Tomcat work with Netbeans using an external build/dist directory:

1. Configure Netbeans to distribute the build and dist directories to a directory outside of /home/user/NetbeansProjects/project.

   Edit the following file: /home/user/NetbeansProjects/project/nbproject/project.properties, and change the lines:

   build.dir=build
   dist.dir=dist
   

   to

   build.dir=/srv/tomcat/project/build
   dist.dir=/srv/tomcat/project/dist
   

   Note that you can use any directory (other than /home/...) instead of /srv/tomcat/project

2. Add a Context with a proper docBase to the Tomcat host.

   One way to do this is to edit the server.xml configuration file probably located in /etc/tomcat7/server.xml. Add a Context in the server.xml file:

   <Context docBase="/srv/tomcat/project/build/web/" path="/project"></Context>
   

   Make sure to place this within the <Host>-tag. Also you can add attributes to this tag when needed (reloadable, antiJARLocking etc). Or you could also place in xml file in CATALINA_HOME/engine(e.g. Catalina)/hostname(e.g. localhost)/project.xml, one of these approaches will be okay.

   I choose to point the docBase to .../build/web/ but you could also set this to .../dist/ if you want Tomcat to use the WAR-file.

3. Make sure tomcat is in the same users-group as you are. To do this, e.g.:

   usermod --append --groups users tomcat7
   

   Note: Any common group you have with tomcat will suffice. This way Netbeans and Tomcat can both access the same directory.

4. Fix ownership and permissions of the external project directory.

   sudo chown -R tomcat7:users /srv/tomcat/project
   sudo chmod -R 777 /srv/tomcat/project
   

   This assumes that you user are member of the group users, and tomcat7 is the name of tomcats user. You can check this incat /etc/passwd`.

   Note: Later on you can reduce the 777-permissions, but to make sure to let Tomcat have permissions you can start with the most accessible permissions.

5. Do clean/build in Netbeans, and restart tomcat service. This will apply the changes from the previous steps.

I hope this will be helpful to somebody dealing with a similar situation; Tomcat and permissions can be really hard to debug imho.

What @Schrute said in a comment (not an answer): Use option #1 (ln -s) and just allow linking in the Tomcat context.xml file. For Tomcat 7:

<?xml version="1.0" encoding="UTF-8"?>
<Context allowLinking="true">
...

Tomcat 8:

<Context>
    <Resources allowLinking="true"></Resources>
...

DO NOT DO THIS ON WINDOWS (or any other case-insensitive filesystem), as it will disable case sensitivity checks, allowing JSP source code disclosure, among other security problems. http://tomcat.apache.org/tomcat-8.0-doc/config/resources.html

Why don't you just let your netbeans build to your desired directory?

It might be worth trying setenforce 0 to disable selinux and retesting your above methods if selinux is enabled. If it works, re-enable selinux and start tracing down the permissions issues.

There are all kinds of security concerns here... (If you wanted to do something like this on Cent/Oracle/REHL... most sysadmins will tell you that you'll have to disable selinux or spend several hours chasing the audit log)

Long story short, there is nothing elegant about instantly publishing a build of software anywhere. The amount of problems that can potentially arise are things of nightmares (especially with java and tomcat lurking in the background).

You might do well to manually rsync from your development instance to a test instance. (IE Under Tomcat). If you want it to happen automatically.. You COULD add it to the build script.

Ps. I don't have time to look for supporting documentation... so: In my opinion it is neither best practice nor 'elegant' to combine the build and deploy stages of development (in almost all cases).

I do agree with lVlint67 about separating Build and Deploy, but I also often work with php/html/javascript in a dev URL where the separation just seems to get in the way. I use the symlink method, but the catch is that the permissions must be set to allow the web server to read the destination of the symlink.

I use:

host:~# mkdir dev
host:~# chown me.www-data dev
host:~# chmod g+rwx dev
host:~# cd /var/www
host:~# ln -s ~/dev ./

For this to work, you have to be a member of the www-data group, and remember to keep your project files readable by group, and any files your app needs to write to will need to be writable by group.

This is all without SELinux, so your mileage may vary depending on your server config.