ssh-copy-id behavior

Keep an eye out for this one. When using ssh-copy-id to copy my public key to a remote host, I found that it had not properly appended my id to the remote ~/.ssh/authorized_keys file. It concatenated it on to the end, with no linefeed. Just be sure to check for that!

Original remote ~/.ssh/authorized_keys

ssh-dss AAA...== forest@machine

After ssh-copy-id did its work:

ssh-dss AAA...== forest@machinessh-dss AAAAB...gdA== forest@laptop

Ubuntu batch photo processing

Way-cool batch photo processing on Ubuntu, GNU/Linux, Windows, and Mac with Phatch.

Enabling Apache’s PHP execution in User Directories on Ubuntu Lucid

Ubuntu Lucid ships with PHP disabled for user directories. That’s a sensible security default, but it won’t allow your developers to get their work done. And if you’re working with Drupal, you’ll need all the steps listed here.

First, you’ll need to install Apache:
sudo apt-get install apache2

Then the compiled PHP binary (or “shared object” in Apache lingo):
sudo apt-get install php5

You may need to do sudo /etc/init.d/apache2 restart or sudo service apache2 restart to have it pick up the updated configuration file that loads the PHP5 module. Try visiting your own box at “localhost” to see if you get a nice “welcome” page. You can put an “info.php” file in /var/www to test if PHP is working (the contents of your info.php file are simply <?php phpinfo(); ?>), and visit that in your browser.

Once you’ve gotten PHP running under Apache, edit /etc/apache2/mods-available/php5.conf and comment out the lines as instructed:

<IfModule mod_php5.c>
    <FilesMatch "\.ph(p3?|tml)$">
        SetHandler application/x-httpd-php
    <FilesMatch "\.phps$">
        SetHandler application/x-httpd-php-source
    # To re-enable php in user directories comment the following lines
    # (from <IfModule ...> to </IfModule>.) Do NOT set it to On as it
    # prevents .htaccess files from disabling it.
#    <IfModule mod_userdir.c>
#        <Directory /home/*/public_html>
#            php_admin_value engine Off
#        </Directory>
#    </IfModule>

If you’re developing with Drupal, the following step may also be necessary: In /etc/apache2/mods-available/userdir.conf, you should allow Drupal’s local .htaccess file to override the Apache-wide configuration file, with:

        <Directory /home/*/public_html>
                AllowOverride All
                #AllowOverride FileInfo AuthConfig Limit Indexes
                #Options MultiViews Indexes SymLinksIfOwnerMatch IncludesNoExec

Restart Apache with sudo /etc/init.d/apache2 restart and you might be done!

SSH public RSA key errors

Seen these before when trying to login via SSH with your new RSA public key?

Nov 2 12:09:17 hostname sshd[12712]: error: buffer_get_ret: trying to get more bytes 257 than in buffer 73
Nov 2 12:09:17 hostname sshd[12712]: error: buffer_get_string_ret: buffer_get failed
Nov 2 12:09:17 hostname sshd[12712]: error: buffer_get_bignum2_ret: invalid bignum
Nov 2 12:09:17 hostname sshd[12712]: error: key_from_blob: can't read rsa key
Nov 2 12:09:17 hostname sshd[12712]: error: key_read: key_from_blob AAAAB3N[...] failed

In my case these were the result of copying a public key from e-mail, which tends to mangle long text lines. I usually don’t have this problem because I use the ssh-copy-id script to copy my keys to a remote host before attempting to log in.