Added some POD to main module

lib/Sys/Linux/Namespace.pm

@@ -110,3 +110,88 @@ sub setup {
 }
 
 1;
+
+__END__
+=head1 NAME
+
+Sys::Linux::Namespace - A Module for setting up linux namespaces
+
+=head1 SYNOPSIS
+
+    use Sys::Linux::Namespace;
+    
+    # Create a namespace with a private /tmp
+    my $ns1 = Sys::Linux::Namespace->new(private_tmp => 1);
+    
+    $ns1->setup(code => sub {
+        # This code has it's own completely private /tmp filesystem
+        open(my $fh, "</tmp/private");
+        print $fh "Hello Void";
+    });	
+    
+    # The private /tmp has been destroyed and we're back to our previous state
+    
+    # Let's do it again, but this time with a private PID space too
+    my $ns2 = Sys::Linux::Namespace->new(private_tmp => 1, private_pid => 1);
+    $ns2->setup(code => sub {
+        # I will only see PID 1.  I can fork anything I want and they will only see me
+        # if I die they  die too.
+        use Data::Dumper;
+        print Dumper([glob "/proc/*"]);
+    });
+    # We're back to our previous global /tmp and PID namespace
+    # all processes and private filesystems have been removed
+    
+    # Now let's set up a private /tmp 
+    $ns1->setup();
+    # We're now permanently (for this process) using a private /tmp.
+
+=head1 REQUIREMENTS
+
+This module requires your script to either have CAP_SYS_ADMIN, usually by running as C<root>.  Without that it will fail to setup the namespaces and cause your program to exit.
+
+=head1 METHODS
+
+=over 1
+
+=item C<new>
+
+Construct a new Sys::Linux::Namespace object.  This collects all the options you want to enable, but does not engage them.
+
+=item C<setup>
+
+Engage the namespaces.  Without a C<code> parameter it will alter the current process and place it whatever namespaces are configured.
+If called with a C<code> parameter, it will run the coderef in the namespace with a child process.  
+This method also accepts an overriding C<code> parameter so you can run multiple coderefs in a configured namespace without creating new objects.
+
+=back
+
+=head1 OPTIONS
+
+=over 1
+
+=item C<private_mount>
+
+Setup a private mount namespace, this makes every currently mounted filesystem private to our process.
+This means we can unmount and mount new filesystems without other processes seeing the mounts.
+
+=item C<private_tmp>
+
+Sets up the private mount namespace as above, but also automatically sets up /tmp to be a clean private tmpfs mount.
+Takes either a true value, or a hashref with options to pass to the mount syscall.  See C<man 8 mount> for a list of possible options.
+
+=item C<private_pid>
+
+Create a private PID namespace.  This requires a C<code> parameter either to C<new()> or to C<setup()>
+
+=item C<private_net>
+
+TODO This is not yet implemented.  Once done however, it will allow a child process to execute with a private network preventing communication.  Will require a C<code> parameter to C<new()> or C<setup>.
+
+=back
+
+=head1 AUTHOR
+
+Ryan Voots L<simcop@cpan.org|mailto:SIMCOP@cpan.org>
+
+=cut