Online courses

I've signed up to Code School to try it out. So far, have done three different courses:

* Try Ruby
* Javscript Roadtrip 1
* Try Git

All three seem really basic, geared towards people that don't know how to program. Site doesn't appear to have very many free courses and costs $29USD per month to get full access.

Apparently the two other sites which offer courses of a similar nature are Treehouse and Codecademy.

I've also had recommended the Crypto 101 course and will probably be trying that one out next.

Whatever course site (MOOC?) I sign up for, it would be really great if they integrated Open Badges.

Getting Firefox Sync server running

Have been setting up Firefox Sync, following the instructions found at: https://docs.services.mozilla.com/howtos/run-sync-1.5.html

The instructions were pretty straight-forward, got it up and running in no time (even ran the tests to ensure everything was passing).

However, after reconfiguring the browser to point to the new Sync URL, nothing happened. (In the end it turned out I forgot the "/token/" part of the URL: https://bugzilla.mozilla.org/show_bug.cgi?id=1032039)

Debugging Tips:

* By default if you run the server using "local/bin/pserve syncserver.ini" the server logs to console.

* The database the server saves to (by default) is "syncserver/syncserver.db", which you can view using SQLite Browser.

* To manually start a Sync, you can go to "Tools" -> "Sync Now"

* To view the browser (client) sync logs, enter "about:sync-log" in the URL bar. You can turn on logging on successful sync by toggling the "services.sync.log.appender.file.logOnSuccess" configuration variable.

* At time of writing there's a bug where the URL can be set back to the default in some instances: https://bugzilla.mozilla.org/show_bug.cgi?id=1003708

* You can modify the "services.sync.syncInterval" variable to make the browser attempt to sync more frequently (value is in milliseconds).

Getting Risk of Rain working

I bought the Humble Indie Bundle 13 and downloaded Risk of Rain (non-Steam version). Tried firing it up, when it wouldn't run, giving error:

"error while loading shared libraries: libopenal.so.1"

Found that it required a bunch of 32-bit packages, namely:

* libopenal1:i386
* libxrandr2:i386
* libglu1-mesa:i386

 which you had to install with "sudo apt-get install [package name]"

NOTE: To get "Shadowrun Returns" working, also had to install the "libxcursor1:i386" package.

NOTE2: Am running Ubuntu 14.04LTS 64-bit

Firewall configuration in CentOS 7

CentOS 7 introduced firewalld to replace iptables. As a result, the "system-config-firewall-tui" command no longer works (unless you re-install iptables).

The equivalent way of adding in a couple of ports to the firewall rules is as follows:

sudo firewall-cmd --add-port=4505/tcp
sudo firewall-cmd --add-port=4506/tcp

The above will add rules to open the ports, but the change won't survive a reboot. To make the changes permanent, just add the "--permanent" flag to the command.

Configuring PostgreSQL to listen on all IPs

Tested on CentOS 6. Modify the line:

listen_addresses = '*'

In the /var/lib/pgsql/data/postgresql.conf file.

Setting root password on CentOS MySQL install

After installing and starting up mysqld run the following commands to set the root password:

# /usr/bin/mysqladmin -u root password '[password here]'
# /usr/bin/mysqladmin -u root -h [hostname here] password '[password here]'

Common SELinux problems and tasks

List current selinux context labels on files:

[root@machine1:/var/www/html]# ls -alZ
total 124K
drwxr-xr-x. root   root   system_u:object_r:httpd_sys_content_t:s0 ./
drwxr-xr-x. root   root   system_u:object_r:httpd_sys_content_t:s0 ../
drwxr-xr-x. apache apache unconfined_u:object_r:httpd_sys_content_t:s0 administrator/
drwxr-xr-x. apache apache unconfined_u:object_r:httpd_sys_content_t:s0 bin/
drwxr-xr-x. apache apache unconfined_u:object_r:httpd_sys_content_t:s0 cache/
drwxr-xr-x. apache apache unconfined_u:object_r:httpd_sys_content_t:s0 cli/
...


Change the selinux context:

[root@machine1:/var/www/html]# chcon -Rv --type=httpd_sys_content_t ./*
changing security context of `./administrator/templates/hathor/less/forms.less'
changing security context of `./administrator/templates/hathor/less/buttons.less'
...


Enable Apache to make outbound database connections:

[root@machine1:/var/www/html]# setsebool -P httpd_can_network_connect=1

Enable Apache to use sendmail:

[root@machine1:/var/www/html]# setsebool httpd_can_sendmail 1