This page contains steps to set up a computer to successfully run **ReCodEx**. Most steps are listed in two variants, for Red Hat based distributions (like RHEL, Centos or Fedora) and Debian based distibutions. Before starting, make sure you have completed basic OS installation and set up, including users and logins, SSH, Git, firewall, etc.
Install as new version of each package as possible, so mostly Debian packages are from testing repositories and RHEL packages are the newest ones from EPEL repositories.
Worker requirements are written in this section. Some parts of this guide may be different for each type of worker, for example Compiler principles worker is not fully covered here.
Installing this package will only speed up build process, otherwise libarchive is built from source.
- Debian package is `libarchive-dev`.
- RedHat packages are `libarchive` and `libarchive-devel`. These are probably not available for RHEL.
**Install Isolate from source**
First, we need to compile sandbox Isolate from source and install. Assume that we keep source code in `/opt/src` dir. For building man page you need to have package `asciidoc` installed.
For proper work Isolate depends on several advanced features of the Linux kernel. Make sure that your kernel is compiled with `CONFIG_PID_NS`, `CONFIG_IPC_NS`, `CONFIG_NET_NS`, `CONFIG_CPUSETS`, `CONFIG_CGROUP_CPUACCT`, `CONFIG_MEMCG`. If your machine has swap enabled, also check `CONFIG_MEMCG_SWAP`. Which flags was your kernel compiled with can be found in `/boot` directory, for example in `/boot/config-4.2.6-301.fc23.x86_64` file for kernel version 4.2.6-301. Red Hat distros should have these enabled by default, for Debian you you may want to add the parameters `cgroup_enable=memory swapaccount=1` to the kernel command-line, which can be set using `GRUB_CMDLINE_LINUX_DEFAULT` in `/etc/default/grub`.
For better reproducibility of results, some kernel parameters can be tweaked:
- Disable address space randomization. Create file `/etc/sysctl.d/10-recodex.conf` with content `kernel.randomize_va_space=0`. Changes will take effect after restart or run `sysctl kernel.randomize_va_space=0` command.
- Disable dynamic CPU frequency scaling. This requires setting the cpufreq scaling governor to _performance_.
_**TODO** - do we really need it and is it worth higher power consumption? [Red Hat setup](https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Power_Management_Guide/cpufreq_governors.html), [Debian setup](https://wiki.debian.org/HowTo/CpuFrequencyScaling)_
Installation steps are equal for both worker and broker. Following guide is for worker. It's supposed that your current working directory is that one with clonned worker source codes.
- Prepare environment running `mkdir build && cd build`
- Build sources by `cmake ..` following by `make -j#` where '#' symbol refers to number of your CPU threads.
Note that `rpm` and `deb` packages are build in the same time. You may need to have `rpmbuild` command (usually as `rpmbuild` or `rpm` package) or edit CPACK_GENERATOR variable _CMakeLists.txt_ file in root of source code tree.
- Install generated package through your package manager (`yum`, `dnf`, `dpkg`).
_Note:_ If you don't want to generate binary packages, you can just install the project with `make install` (as root). But installation through your distribution's package manager is preferred way to keep your system clean and manageable in long term horizon.
For compiling C and C++ programs is used `GCC` compiler. Maybe you could install install most of the staff by executing following command, but it's not needed.
```
# yum group install "Development Tools"
```
To install the compiler separately, you could install it from the distribution's repositories.
```
# yum install gcc gcc-c++ make
```
To get reasonably new version, you may consider installing [Red Hat Developer Toolset 4](https://access.redhat.com/documentation/en-US/Red_Hat_Developer_Toolset/4/html-single/4.0_Release_Notes/index.html), or install these from Fedora repo. In Debian, _testing_ repo can be used.
**C\#**
For new versions of **Mono**, we'll use [Xamarin repositories](http://www.mono-project.com/download/#download-lin). For Red Hat based OS:
$ echo "deb http://download.mono-project.com/repo/debian wheezy main" | sudo tee /etc/apt/sources.list.d/mono-xamarin.list
$ sudo apt-get update
$ sudo apt-get install mono-complete
```
**Free Pascal**
Free Pascal compiler 3.0.0 can be downloaded as `rpm` packages from [official website](http://www.freepascal.org/down/x86_64/linux-austria.var). In Debian, this version is [expetimental](https://packages.debian.org/experimental/fpc-3.0.0), but seems to be stable enough.
From beginning we are determined to support Windows operating system on which some of the workers may run (especially for projects in C# programming language). Support for Windows is quite hard and time consuming and there were several problems during this. To ensure capability of compilation on Windows we set up CI for Windows named [Appveyor](http://www.appveyor.com/). However installation should be easy due to Visual Studio NuGet package manager.
There are only two dependencies needed. **Windows 7 and higher** and **Visual Studio 2014**. Visual Studio itself contains all features needed for compilation. All dependencies as libraries and such are either installed through NuGet package manager or are managed as submodules in git repository.
