====== Installing telegram to send notification messages ======

===== Intro =====

If you look on internet, you will found thousands of recipes like this one: install telegram in order to send notification messages from one computer directly to your phone. 

**My goal with this recipe is to create a ''telegram_msg'' command that just send a text message**, nothing more. 

Although it might seem a simple goal, you will discover that it is not a simple one: the [[https://github.com/vysheng/tg|Telegram command line application]] doesn't have a "send message" combination of arguments to do so. Moreover, a combination of pipes --to simulate a writing from the console-- doesn't achieve the desired result because the telegram-cli program doesn't end: it keeps cyling over and over reading nothing from the pipe. 

To put things worst, [[https://github.com/vysheng/tg/issues/625|the first command you have to issue in ''telegram-cli'' is contact_list]]. It's a known error, at least on June, 2015.

Said that, the only approximation to my goal I've seen so far today is: 

  * Run telegram-cli as a daemon, and when it starts, issue a contact_list command the first time
  * After that, send the command through netcat (nc) command

===== Step 1: install necesary packages =====

<code>
$ sudo apt-get install libreadline-dev libconfig-dev libssl-dev lua5.2 liblua5.2-dev 
$ sudo apt-get install libevent-1.4-2 libevent1-dev
$ sudo apt-get install libpython3.4 libpython3.4-dev 
$ sudo apt-get install libjansson4 libjansson-dev
</code>

===== Step 2: download the project =====

It is not compulsory to have git installed in the destination machine. You can have git in another machine 
and use it to download the project: 

<code>
git clone https://github.com/vysheng/tg.git
</code>

**The project will appear in a directory called "tg".**

Afterwards you can move the project to the destination machine.

<WRAP center round important 60%>
Up to date (01/07/2015), this current version does not work. I've downloaded version 1.0.5.1 instead, 
which works correctly. 
</WRAP>

===== Step 3: configure and build the project =====

Nothing special here. Go to the directory where you have downloaded the project and:

<code>
$ ./configure
$ make 
</code>

===== Step 4: a basic test =====

Make a simple confirmation that the program is working. You can skip this test because we will have to create another user --telegramd-- to run the service and we will have to do it again. 

The program is called ''telegram-cli'' and it's under the ''bin'' directory. Go there, and execute: 

<code>
$ ./telegram-cli -k ../tg-server.pub
</code>

Something similar to this will appear: 

<code>
$:~/tg-1.0.5.1/bin$ ./telegram-cli ../tg-server.pub -k ../tg-server.pub 
Telegram-cli version 1.0.5, Copyright (C) 2013-2014 Vitaly Valtman
Telegram-cli comes with ABSOLUTELY NO WARRANTY; for details type `show_license'.
This is free software, and you are welcome to redistribute it
under certain conditions; type `show_license' for details.
Telephone number (with '+' sign): 
</code>

You have to provide the telephone number of this account --normally your telephone number-- but with your national prefix. 

Then the sms will be requested, so it is advisable to have this phone near when doing this. 

You can issue a contact_list command to check thet that this client is working:

<code>
> contact_list
....
....
</code>

===== Step 5: install the client =====

I've opted for manually install the client. I've copied the ''telegram-cli'' program under ''/usr/local/share/telegram'' and the public key of the server under /etc, with very restricted permissions for reading. 

<code>
# mkdir /usr/local/share/telegram
# cp telegram-cli /usr/local/share/telegram
</code>

I've also created a directory called ''/etc/telegram'' that will hold all the configuration and the public key:

</code>
# mkdir /etc/telegram 
# chmod u=rwx,g=rx,o=rx /etc/telegram
# cp tg-server.pub /etc/telegram
# chmod g=r,o=r,u=r /etc/telegram/tg-server.pub
</code>


===== Step 6: create the system user telegramd =====

In order to run the telegram-daemon as root, you will need to create the user telegramd. I've opted
to create this user as a system user: 

<code>
# useradd -M --user-group --system --shell=/bin/false telegramd
</code>


Impersonate this user and run the telegram-cli program again, to create a proper configuration file: 

<code>
telegramd@:~$ /usr/local/share/telegram/telegram-cli -k /etc/telegram/tg-server.pub 
Telegram-cli version 1.0.5, Copyright (C) 2013-2014 Vitaly Valtman
Telegram-cli comes with ABSOLUTELY NO WARRANTY; for details type `show_license'.
This is free software, and you are welcome to redistribute it
under certain conditions; type `show_license' for details.
Telephone number (with '+' sign): 

</code>



===== Step 7: create a daemon and install it =====

Telegram-cli has a bug that provokes that, unless ''contact_list'' is the first command issued, no message can be sent through the program. Moreover, there is no way to create a program that just sends a message and ends: the program waits forever even if you run through a pipe. __A more simple version to make automatic notifications from a machine would be desirable.__

Let's go for it. The code for the daemon is this (customize the adequate variables):


<code>
#!/bin/bash
#
# telegram.sh  - to start / stop a telegram server 
#
#

### BEGIN INIT INFO
# Provides:		telegram
# Required-Start:	$local_fs $network $syslog
# Required-Stop:	$local_fs $network $syslog
# Default-Start:	2 3 4 5
# Default-Stop:		0 1 6
# Short-Description:	Telegram server
### END INIT INFO

TELEGRAM_BIN="/usr/local/share/telegram/telegram-cli"
TELEGRAM_PORT=1234
TELEGRAM_ARGS="-p /home/telegramd/.telegram-cli -k /etc/telegram/tg-server.pub -d -P $TELEGRAM_PORT"
PID_FILE=/var/run/telegram.pidfile

umask 022

test -f "$TELEGRAM_BIN" || exit 0 


case $1 in
start)
    echo "Starting telegram server"
    $TELEGRAM_BIN $TELEGRAM_ARGS &
    echo $! > "$PID_FILE"
    # issue the command "contact_list" because it's needed
    # for sending messages
    sleep 5
    echo "contact_list" | nc 127.0.0.1 $TELEGRAM_PORT
    echo "done"    
    ;;
stop)
    echo "Stopping telegram server"
    # first make a gentle kill 
    kill $(cat "$PID_FILE")
    # then sleep and make a hard kill 
    sleep 4s
    kill -9 $(cat "$PID_FILE") 2> /dev/null
    rm "$PID_FILE"
    echo "done"
    ;;
reload)
    $0 stop
    $0 start
    ;;
status)
    if kill -0 $(cat "$PID_FILE") ; then 
    	echo "Telegram process is running"
    else
    	echo "Telegram process has stopped"
    fi
    ;;
*)
    echo "Usage: $0 start | stop | reload | status"
    ;;
esac 

exit 0 


</code>


Install it under ''/etc/init.d'' (in ubuntu): 

<code>
sudo mv telegram-daemon /etc/init.d
sudo chown root:root /etc/init.d/telegram-daemon
</code>


===== Step 8: install the telegram-msg program =====

After that I've created a ''telegram-msg'' program to just send a message through telegram. The program is pretty simple: 

<code>
#!/bin/bash
#
# telegram-msg - sends a telegram message 
#
#


echo "msg $1 $2" | nc 127.0.0.1 1234

</code>


===== Step 8: first test =====

<code>
$ sudo /etc/init.d/telegram-daemon start 
$ telegram-msg somebody "some message you want to send"
</code>