svanderburg / disnix-stafftracker-php-example

A PHP/MySQL-based toy system to test Disnix's deployment features

disnix-stafftracker-php-example

This is an example case representing a system to manage staff of a university department. The system uses data stored in several databases, such as a database to store zipcodes, room numbers and staff members. A web application front-end is provided for end-users to retrieve and edit staff members.

Architecture

The above figure shows the architecture of this example, consisting of two layers. The data layer contains various MySQL databases storing data sets. The presentation layer contains a web application front-end which can be used by end users to manage staff of a university. All the components in the figure are distributable components (or services) which can deployed to various machines in the network.

Usage

The deployment/DistributedDeployment sub folder contains all neccessary Disnix models, such as a services, infrastructure and distribution models required for deployment.

The models come in two variants:

• The standard variant, e.g. services.nix, infrastructure.nix and distribution.nix can be used to deploy services to a network of machines that already provide pre-deployed container services, e.g. MySQL and an Apache HTTP server (supporting PHP).
• The self-contained variant, e.g. services-with-containers.nix, distribution-with-containers.nix deploy both the application services and their underlying container services, e.g. MySQL and Apache HTTPD, using the experimental Nix process management framework

Deployment using Disnix to a predeployed network of container services

First, you must manually install a network of machines running the Disnix service. Then you must adapt the infrastructure model to match to properties of your network and the distribution model to map the services to the right machines.

To deploy the databases you must install MySQL. To deploy the web application services you must install the Apache HTTP server and the PHP plugin.

Check the instructions of your Linux distribution or the software distributions themselves how to install these system services. Dysnomia detects the presence of these system services and configures the corresponding modules to use them.

The system can be deployed by running the following command:

$ disnix-env -s services.nix -i infrastructure.nix -d distribution.nix

Deployment of the self-contained example with Disnix

It is also possible to deploy the self-contained example with the basic Disnix toolset:

$ disnix-env -s services-with-containers.nix -i infrastructure.nix -d distribution-with-containers.nix

To make the above example work, a network of machines that have the Disnix service installed are required with a infrastructure.nix model providing their connectivity settings.

Deployment using the NixOS test driver

This system can be deployed without adapting any of the models in deployment/DistributedDeployment. By running the following instruction, the variant without the proxy can be deployed in a network of QEMU virtual machines:

$ disnixos-vm-env -s services.nix -n network.nix -d distribution.nix

We can also deploy the self-contained variant as follows:

$ disnixos-vm-env -s services.nix -n network.nix -d distribution.nix

Deployment using NixOps for infrastructure and Disnix for service deployment

It's also possible to use NixOps for deploying the infrastructure (machines) and let Disnix do the deployment of the services to these machines.

A virtualbox network deploying a network of machines with Disnix and container services (e.g. Apache HTTPD and MySQL) can be deployed as follows:

$ nixops create ./network.nix ./network-virtualbox.nix -d vboxtest
$ nixops deploy -d vboxtest

The services can be deployed by running the following commands:

$ export NIXOPS_DEPLOYMENT=vboxtest
$ disnixos-env -s services.nix -n network.nix -d distribution.nix --use-nixops

Deploying a bare machine network with NixOps and Disnix to deploy all services

Similar commands can be used to deploy the self-contained variant as well. The following command deploys a network of machines with a basic configuration (only SSH connectivity and the Disnix service):

$ nixops create ./network-bare.nix ./network-virtualbox.nix -d vboxtest
$ nixops deploy -d vboxtest

The following command deploys all container and application services:

$ export NIXOPS_DEPLOYMENT=vboxtest
$ disnixos-env -s services-with-containers.nix -n network-bare.nix -d distribution-with-containers.nix --use-nixops

Running the system

After the system has been deployed, open a web browser and type the following URL:

http://test1/stafftracker/index.php

The test1 part must be replaced by the real hostname of the machine to which the web application front-end is deployed. Check the distribution model for this. If the network expression is used included in this example, the third machine in the network machine automatically boots into IceWM and includes the Mozilla Firefox web browser for convenience.

License

This package is released under the MIT license.