Tag: Hints and Tips

Use GMail’s SMTP gateway using the command line from Ubuntu without lots of config tips

JonTheNiceGuy 1 Comment

I’m writing a few little scripts at the moment, and one of them needed to be able to send an e-mail. I’d not got around to sorting out what my SMTP gateway was from my ISP – but I do tend to use GMail’s SMTP gateway for non-essential stuff.

I thought I could easily setup sendmail, but no, that’s SCARY stuff, and then I thought of Postfix, but that needs an awful lot of configuration for an TLS based SMTP connection, so I did a bit of digging.

Thanks to this post over at the Ubuntu Forums, I worked out how to get a local port 10025 to run, but PHP kept complaining, so I next looked for a “sendmail replacement”, in comes nullmailer.

So, thankfully this is all rather easy.

  • sudo apt-get install openssl xinetd nullmailer
  • sudo tee /usr/bin/gmail-smtp <<EOF >/dev/null
#!/bin/sh
# Thanks to http://ubuntuforums.org/showthread.php?t=918335 for this install guide
/usr/bin/openssl s_client -connect smtp.gmail.com:465 -quiet 2>/dev/null
EOF
sudo chmod +x /usr/bin/gmail-smtp
  • sudo tee /etc/xinetd.d/gmail-smtp <<EOF >/dev/null
# default: on
# description: Gmail SMTP wrapper for clients without SSL support
# Thanks to http://ubuntuforums.org/showthread.php?t=918335 for this install guide
service gmail-smtp
{
    disable         = no
    bind            = localhost
    port            = 10025
    socket_type     = stream
    protocol        = tcp
    wait            = no
    user            = root
    server          = /usr/bin/gmail-smtp
    type            = unlisted
}
EOF
sudo /etc/init.d/xinetd reload
  • sudo tee /etc/nullmailer/remotes <<EOF >/dev/null
127.0.0.1 smtp --port=10025 --user=your@user.tld --pass=Y0urC0mp3xGM@ilP@ssw0rd
EOF
sudo /etc/init.d/nullmailer reload

Setting all this lot up was pretty easy with these guides. There’s no reason why it wouldn’t work on any other version of Linux (provided you can install all these packages).

Good luck with your project!

Posted via web from Jon’s posterous

Supporting multiple machines in GNOME using VNC

JonTheNiceGuy Leave a comment

I was recently asked how to configure VNC for user support across a series of machines running GNOME. I’m in the process of trying out a few different platforms at the moment, and didn’t have my GNOME machine to hand and working right, so I decided to work it out from what I’ve done in the past. Here’s the bulk of the e-mail I sent him to try and help him out. Maybe this will help you at some point.

If you find any errors (especially around the option names in the actual dialogue boxes) please post a note so I can correct this!

Thanks!

On most GNOME based systems (which includes Fedora), you can active “Remote Desktop Sharing” for users.

Go to System -> Preferences -> Remote Desktop Sharing (or something similar). I’m afraid I’ve just recently moved my systems to KDE, so I don’t know the exact options, but I believe it’ll say something like “Enable remote connections” (tick that), and “User is prompted to permit connection” (this will be down to policy) and “Remote user needs to enter a password” (this will need some text to be entered).

Once you have these for one system, you can automatically set this for all the other computers.

From the command line, type
  gconftool-2 -R /desktop/gnome/remote_access

This will return all the settings you have made. Here’s mine:

 view_only = false                                         
 alternative_port = 5900                                   
 prompt_enabled = false                                    
 icon_visibility = client                                  
 lock_screen_on_disconnect = false                         
 disable_xdamage = false                                   
 mailto =                                                  
 use_alternative_port = false                              
 enabled = true                                            
 disable_background = false                                
 network_interface =                                       
 require_encryption = false                                
 authentication_methods = [vnc]                            
 vnc_password = &&&&&&&&&&&&                               
 use_upnp = false

(I’ve removed the password for my box)

You can use this gconftool to set the same variables on your computers you’ve already deployed, either per-user, as a default policy for each machine, or as a mandatory policy for each machine.

This article from Sun’s GNOME configuration guide explains how to set variables: http://docs.sun.com/app/docs/doc/806-6878/6jfpqt2t5?a=view while this is an overview of all of the GNOME configuration tool (including that article): http://docs.sun.com/app/docs/doc/806-6878/6jfpqt2sv?a=view and lastly, this is how “Vino” the VNC client for GNOME works: http://www.gnome.org/~markmc/remote-desktop.html

I hope this helps you!

Posted via web from Jon’s posterous

XRDP

JonTheNiceGuy Leave a comment

I recently was asked how to provide an RDP session to a Linux Machine. Phoowey! I replied, you can’t RDP to a Linux box, and yet, someone I work with pointed me in the direction of XRDP – a package on Sourceforge.

I performed the following steps on a VMWare host running Ubuntu 8.10, but there’s no reason why it shouldn’t work on 9.04 or even 8.04.

Why would you want to RDP to a Linux machine? If you’ve got a windows host, you don’t always want to be running more and more different software to access that remote host – like VNC or X over SSH, so this seems like an effective solution if you don’t want your client machines to need additional software.

Some people don’t like to permit SSH through their firewalls as you can do an awful lot with a badly configured SSHd. In another situation, we have been using a device (which I don’t manage I should add) to access a development network. This device acts as a reverse proxy, and permits access to various websites, but most importantly, also proxies access to RDP systems, so this request was driven by that need.

Here’s what I did to configure up the XRDP on this Ubuntu 8.10 desktop

# apt-get install build-essential libpam0g-dev libssl-dev tightvncserver

Visit https://sourceforge.net/projects/xrdp/ then click on Download, Browse all packages, click on the latest release (currently 0.4.1), Copy the link for filename xrdp-x.x.x.tar.gz

# wget http://path/to/file/xrdp-x.x.x.tar.gz
# tar xfz xrdp-x.x.x.tar.gz
# cd xrdp-x.x.x
# make
# sudo make install
# cp /usr/local/xrdp/xrdp_control.sh /etc/init.d/
# update-rc.d -f xrdp_control.sh defaults