Day: January 23, 2011

setup your public SSH key to another UNIX Host

Philipp2 Comments

Normally you would prefer to use your public ssh key for login into a remote linux machine.
I created a script to perform the basic steps for inserting your public key into the hosts authorized_keys files.

The script looks like this:

#!/bin/bash

HOST=$1;
echo ">> setup your ssh keys for $HOST"
echo ""
echo ">> creating ssh keys on $HOST if necessary"
echo "(you need to enter your password)"
echo ""
ssh $HOST 'if [ ! -d ~/.ssh  ] ; then ssh-keygen -t rsa; fi'
echo ""
PUBKEY=`cat ~/.ssh/id_dsa.pub`
echo "=========================================================="
echo "your id_dsa.pub:"
echo "$PUBKEY"
echo "=========================================================="
echo ""
echo ">> transfering your public ssh key"
scp ~/.ssh/authorized_keys $HOST:~/.ssh/authorized_keys
ssh $HOST 'chmod 600 ~/.ssh/authorized_keys'
echo ""
echo ">> login with your public key"
echo "(should work without a password)"
ssh $HOST

A typical run might look like this:

imotep:~ philipp$ setupssh philipp@192.168.178.55
>> setup your ssh keys for philipp@192.168.178.55

>> creating ssh keys on philipp@192.168.178.55 if necessary
(you need to enter your password)

The authenticity of host '192.168.178.55 (192.168.178.55)' can't be established.
RSA key fingerprint is ...
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.168.178.55' (RSA) to the list of known hosts.
philipp@192.168.178.55's password:
Enter file in which to save the key (/home/philipp/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Generating public/private rsa key pair.
Created directory '/home/philipp/.ssh'.
Your identification has been saved in /home/philipp/.ssh/id_rsa.
Your public key has been saved in /home/philipp/.ssh/id_rsa.pub.
The key fingerprint is:
... philipp@debian
The key's randomart image is:
+--[ RSA 2048]----+
|...              |
+-----------------+

==========================================================
your id_dsa.pub:
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx......xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
==========================================================

>> transfering your public ssh key
philipp@192.168.178.55's password:
authorized_keys                                                                         100%  610     0.6KB/s   00:00    

>> login with your public key
(should work without a password)
Linux debian 2.6.26-2-amd64 #1 SMP Thu Nov 25 04:30:55 UTC 2010 x86_64

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Sun Jan 23 17:31:16 2011 from imotep.fritz.box
philipp@debian:~$

Show Build-Information in your iOS App About Panel

PhilippLeave a comment

Sometimes it might be useful to have an exact piece of information about what version of an app you have currently running. Especially if you have a decent Testing-Group, it is important to track the versions in which a bug appears. The goal of this post is to achieve a info panel like this in your application.
You get the Application version (from the Application Bundle), the Repository Revision and the Date of the last Commit.

Picture 1: Example Application About Dialog

 

We are using here the build-in functions of subversion to update given keywords with the repository information. More about this topic here. There is also a way to use this method with git, but i did not test it yet. You may find out more about this here
The first step is to create a File-Template you can import in your code, with which you can access all the necessary details:

#define APP_VERSION   
[[[NSBundle mainBundle] infoDictionary]   
objectForKey:@"CFBundleVersion"]
#define APP_EXECUTABLE   
[[[NSBundle mainBundle] infoDictionary]   
objectForKey:@"CFBundleExecutable"]
#define APP_NAME   
[[[NSBundle mainBundle] infoDictionary]   
objectForKey:@"CFBundleName"]
#define APP_BUILD_REVISION @"$Rev$"
#define APP_BUILD_DATE @"$Date$"
#define APP_LAST_AUTHOR @"$Author$"

Code 1: version.h template
The next step is to tell Subversion to replace the placeholder with the subversion values.
You can do this with setting the subversion keyword for that file.
After that, with every commit of the file “version.h” the values will be updated.

svn propset svn:keywords 'Revision Author Date' version.h

Code 2: version.h template
The very last step is to make sure, that “version.h” will be updated each time you make a change to your application. Assuming you build your app every time you made a change, you can use the functions, build into Xcode to force an update on “version.h”. We use the trick, that every change on the propsets of “version.h” is equal to a file modification itself.
So we create a small bash script, setting the propset “build” to a new value. After that, “version.h” needs to be commited as a new version.

#!/bin/sh
DATE=`date`
HOST=`hostname`
svn propset build "$HOST $DATE" Version.h

Code 3: buildUpdate.sh
Now we need to add the run of “buildUpdate.sh” to our Build-Cycle. (Picture 2 & Picture 3).

Picture 2: Project Target Settings

 


Picture 3: Insert Script Call

After a successful commit, the file “version.h” will look something like this:

#define APP_VERSION   
[[[NSBundle mainBundle] infoDictionary]   
objectForKey:@"CFBundleVersion"]
#define APP_EXECUTABLE   
[[[NSBundle mainBundle] infoDictionary]   
objectForKey:@"CFBundleExecutable"]
#define APP_NAME   
[[[NSBundle mainBundle] infoDictionary]   
objectForKey:@"CFBundleName"]
#define APP_BUILD_REVISION @"$Rev: 1047 $"
#define APP_BUILD_DATE @"$Date: 2011-01-21 18:53:38 +0100 (Fri, 21 Jan 2011) $"
#define APP_LAST_AUTHOR @"$Author: phaus $"

Code 4: updated version.h
You might modify the output (e.g. filter out the $s or reformat the date) to get a more stylish output.