Tutorial by Examples: i

Our openstack tenant is already set: a virtual lan gives instances private IP a virtual router map public IP to private IP a security key has been generated we have default firewall configuration for ssh and port 80 we are able to launch an instance thanks to the OpenStack web interface ...

Let use 'os_server' command from module 'Cloud' [http://docs.ansible.com/ansible/os_server_module.html]. Variables are defined in ./group_vars/all. $vi launch_compute.yml - name: launch a compute instance hosts: localhost gather_facts: False tasks: - name: Create and launch the VM ...

Use the 'os_server_facts' command from module 'Cloud' [http://docs.ansible.com/ansible/os_server_module.html]. Variables are defined in ./group_vars/all and the instance name is in server: "MyOwnPersonalInstance". $vi get_compute_info.yml - name: Get and print instance IP hosts: loca...

Instead of printing all the informations, we print only IP address of the first instance whose name is "MyOwnPersonalInstance". It's usually all we need. $vi get_compute_ip.yml - name: Get and print instance IP hosts: localhost gather_facts: False tasks: - name: Get VM infos...

To delete our instance, reuse the os_server command with all authentication information and simply replace ' state: present' by ' state: absent'. $vi stop_compute.yml - name: launch a compute instance hosts: localhost gather_facts: False tasks: - name: Create and launch the VM os_...

This guide is explicitly for PostgreSQL 9.1 or higher on linux machines. It uses the postgres extensions-feature that will greatly improve the import of extensions to an existing postgres-installation. If you have to work with an older version of postgres, please refer to the official documentations...

To create a new empty database, run as postgres-user: createdb [yourdatabase] Connect to the database with a psql-session: psql -d [yourdatabase] In the psql-session run: CREATE EXTENSION postgis; CREATE EXTENSION postgis_topology; to create the neccesary geospatial extensions. Once thi...

The Laravel framework has a few system requirements. Of course, all of these requirements are satisfied by the Laravel Homestead virtual machine, so it's highly recommended that you use Homestead as your local Laravel development environment. However, if you are not using Homestead, you will need t...

The basic example Open routes/web.php file and paste the following code in file: Route::get('helloworld', function () { return '<h1>Hello World</h1>'; }); here 'helloworld' will act as page name you want to access, and if you don't want to create blade file and still want to ...

Open routes file. Paste the following code in: Route::get('helloworld', function () { return '<h1>Hello World</h1>'; }); after going to route http://localhost/helloworld it displays Hello World. The routes file is located /routes/web.php

Accessing pages and outputting data is fairly easy in Laravel. All of the page routes are located in app/routes.php. There are usually a few examples to get you started, but we're going to create a new route. Open your app/routes.php, and paste in the following code: Route::get('helloworld', functi...

Bullet This one particularly blew my mind. The bullet gem helps you kill all the N+1 queries, as well as unnecessarily eager loaded relations. Once you install it and start visiting various routes in development, alert boxes with warnings indicating database queries that need to be optimized will p...

In this example we will set up a geospatial database, import data from 2 different sources, and view the results in an application called QGIS. This guide is explicitly written for linux-machines, if you operate on another platform, some commands or paths might not work as expected. In order to vie...

Backreferences "Backreferences" are references in a search regex to capture groups in the same search regex. The "search regex" is the regex used in the "Find" field of the Find/Replace dialog box. Here is the most common backreference syntax: Absolute: (group one)...

Although it's not officially supported, you can use mouse input in your games: function _update60() x = stat(32) y = stat(33) if (x>0 and x<=128 and y>0 and y<=128) then -- left button if (band(stat(34),1)==1) then ball_x=x ball_y=y...

Typically we represent an anary tree (one with potentially unlimited children per node) as a binary tree, (one with exactly two children per node). The "next" child is regarded as a sibling. Note that if a tree is binary, this representation creates extra nodes. We then iterate over the s...

Plugins are .py files that changes the behaviour of Sublime Text 3. They are written, as you probably guessed, in Python. Because there is plenty of different sort of plugins (text manipulation, linting, formatting, preview, etc), we will not give any example to not over populate this page with a h...

Along with other more advanced text editors, Atom allows developers to open a single file or a directory. Opening Files To open files with Atom, either use File > Open File... in the menu as show below: or use the faster keyboard shortcut: Ctrl+O (For Mac OS: ⌘+O). This will open a file expl...

The settings, are, as many things on Sublime Text 3, simple JSON files. Though, the extension of the file isn't .json but .sublime-settings. As you probably understood, the settings changes how the packages affects Sublime Text 3. It is important to be aware of as much settings as possible to optimi...

In order to keep track of your projects' file structure, Atom, like many text editors and IDEs, uses a file tree model. These trees show the locations and names of your files and directory. To toggle the tree between visible and hidden, the keys Ctrl+\ may be used (⌘+\ for Mac OS). This tree also in...