# Fedora Server

- [Fedora Server](#fedora-server)
  - [Installation](#installation)
  - [Setup SSH](#setup-ssh)
  - [DNF](#dnf)
  - [Fail2Ban](#fail2ban)
  - [Automatic Updates](#automatic-updates)
  - [Disable Swap](#disable-swap)
  - [Selinux](#selinux)
  - [Firewalld](#firewalld)
  - [Extras](#extras)
  - [Downgrading Kernel](#downgrading-kernel)

<https://docs.fedoraproject.org/en-US/fedora-server/installation/postinstallation-tasks/#_manage_system_updates>

Note these instructions differentiate between an `operator` and a `server`. The operator can be
any machine that configure the server. A pipeline, laptop, dedicated server, etc. are all options.
The server can be its own operator, though that's not recommended since servers should be ephemeral
and the operator will store information about each server.

## Installation

1. Make sure to use `custom` disk partitioner and select `btrfs`.
2. Create an administrator. We'll give ssh root access later, but this gives you a cockpit user.
3. Ensure IPV6 connection is set to "eui64".
4. Set hostname

## Setup SSH

On the operator:

```bash
export SSH_HOST=kube
ssh-keygen -t rsa -b 4096 -C ducoterra@"$SSH_HOST".reeselink.com -f ~/.ssh/id_"$SSH_HOST"_rsa

# Note: If you get "too many authentication failures" it's likely because you have too many private
# keys in your ~/.ssh directory. Use `-o PubkeyAuthentication` to fix it.
ssh-copy-id -o PubkeyAuthentication=no -i ~/.ssh/id_"$SSH_HOST"_rsa.pub ducoterra@"$SSH_HOST".reeselink.com

cat <<EOF >> ~/.ssh/config

Host ${SSH_HOST}
    Hostname ${SSH_HOST}.reeselink.com
    User root
    ProxyCommand none
    ForwardAgent no
    ForwardX11 no
    Port 22
    KeepAlive yes
    IdentityFile ~/.ssh/id_${SSH_HOST}_rsa
EOF
```

On the server:

```bash
# Copy authorized_keys to root
sudo cp ~/.ssh/authorized_keys /root/.ssh/authorized_keys

# Change your password
passwd

sudo su -
echo "PasswordAuthentication no" > /etc/ssh/sshd_config.d/01-prohibit-password.conf
echo '%wheel    ALL=(ALL)   NOPASSWD: ALL' > /etc/sudoers.d/01-nopasswd-wheel
systemctl restart sshd
```

On the operator:

```bash
# Test if you can SSH with a password
ssh -o PubkeyAuthentication=no ducoterra@${SSH_HOST}.reeselink.com

# Test that you can log into the server with ssh config
ssh $SSH_HOST
```

## DNF

Configure dnf to use the fastest mirror:

```bash
echo 'fastestmirror=1' >> /etc/dnf/dnf.conf
dnf clean all
dnf update
```

## Fail2Ban

On the server:

```bash
dnf install -y fail2ban

# Setup initial rules
cat <<EOF > /etc/fail2ban/jail.local
# Jail configuration additions for local installation

# Adjust the default configuration's default values
[DEFAULT]
# Optional enter an trusted IP never to ban
# ignoreip = 2600:1700:1e6c:a81f::0/64
bantime  = 6600
backend = auto

# The main configuration file defines all services but
# deactivates them by default. We have to activate those neeeded
[sshd]
enabled = true
EOF

systemctl enable fail2ban --now
tail -f /var/log/fail2ban.log
```

## Automatic Updates

On the server:

```bash
dnf install dnf-automatic -y

systemctl enable --now dnf-automatic.timer
```

Edit the configuration to only do security updates.

## Disable Swap

```bash
swapoff -a
zramctl --reset /dev/zram0
dnf -y remove zram-generator-defaults
```

## Selinux

By default selinux will be enforcing. You can set it to permissive with

```bash
setenforce 0
```

And then make it permanent by editing `/etc/selinux/config` and inserting `SELINUX=permissive`.

## Firewalld

Set the default firewalld zone to `public`

```bash
firewall-cmd --set-default-zone=public
```

Firewalld will be on and blocking by default. You can check the zone and allowed ports with:

```bash
firewall-cmd --zone=public --list-ports
firewall-cmd --zone=public --list-services
```

Allow Cockpit with

```bash
firewall-cmd --permanent --zone=public --add-port=9090/tcp
firewall-cmd --reload
```

## Extras

On the server:

```bash
# Set vim as the default editor
dnf install -y vim-default-editor  --allowerasing

# Install glances for system monitoring
dnf install -y glances

# Install zsh with autocomplete and suggestions
dnf install -y zsh zsh-autosuggestions zsh-syntax-highlighting

cat <<EOF > ~/.zshrc
# Basic settings
autoload bashcompinit && bashcompinit
autoload -U compinit; compinit
zstyle ':completion:*' menu select

# Prompt settings
autoload -Uz promptinit
promptinit
prompt redhat
PROMPT_EOL_MARK=

# Syntax Highlighting
source /usr/share/zsh-syntax-highlighting/zsh-syntax-highlighting.zsh
source /usr/share/zsh-autosuggestions/zsh-autosuggestions.zsh

### Custom Commands and Aliases ###
EOF

chsh -s $(which zsh) && chsh -s $(which zsh) ducoterra
```

## Downgrading Kernel

```bash
dnf install koji

# Note: format is kernel-version.fedora-version
cd $(mktemp -d) && koji download-build --arch=x86_64 --arch=noarch kernel-6.11.3-300.fc41 && dnf install ./*

reboot
```
