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Install Cerb on Ubuntu Linux 23.04


This guide will walk you through preparing an Ubuntu 23.04 server for installing Cerb, including Nginx, PHP-FPM, and MySQL.

Provision an Ubuntu server

If you don’t already have a server, you can use Docker or Amazon EC2.


docker run -it --rm -p 80:80 ubuntu:23.04 /bin/bash

For local evaluation, development, and testing, you can use the built-in Docker configuration instead.


  1. Launch an Amazon EC2 instance.

  2. Connect to your server using SSH:

     ssh ubuntu@
  3. sudo into the root user.

Install packages

It’s a good idea to update your installed packages first:

apt-get update && apt-get -y upgrade

Install PHP 8.1:

apt-get install -y php8.1 php8.1-fpm php8.1-mysql php8.1-mbstring php8.1-gd php8.1-curl \
   php8.1-yaml php8.1-gmp php8.1-zip php8.1-mailparse php8.1-dom php8.1-xml

Install common tools:

apt-get install -y git vim

Install the Nginx web server:

apt-get install -y nginx nginx-extras

Install MySQL

We recommend using a dedicated database server that replicates to a standby server. In Amazon Web Servers you should use RDS.

If you need to install MySQL on your Docker or EC2 instance instead, you can use these instructions:

apt-get install -y mysql-server-8.0

In Docker you need to start the MySQL service. You really should use the mysql:8.0 container instead.

service mysql start

Create the MySQL database

Connect to MySQL:

mysql -h localhost -u root -p

The default password is empty, just press <ENTER>.

If you're using a remote MySQL server, use its internal IP in place of localhost above.

Set a root password.

ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password by 's3cr3t';

Replace s3cr3t above with your own new password.

Create a new database and user for Cerb:


CREATE USER cerb@localhost IDENTIFIED BY 's3cr3t';

GRANT ALL PRIVILEGES ON cerb.* TO cerb@localhost;


Replace s3cr3t above with your own secret password. If you're using a remote database server, replace @localhost with a subnet used by your web servers, like: @'10.0.0.%'

Install Cerb

You should now be ready to install Cerb.

cd /usr/share/nginx/html/

git clone cerb

chown -R www-data:www-data cerb

cd cerb

You can test Cerb using PHP’s built in webserver:

service nginx stop

php -S

Type your server IP into a browser.

You should see the requirements checker with all tests passed:

If you’re just testing Cerb, you can use PHP’s built-in web server and skip the Nginx step below.

Type CTRL+C to kill the PHP web server process.

Since you just ran the web server as root, you should make sure any newly created files are owned by the www-data user and group:

chown -R www-data:www-data /usr/share/nginx/html/cerb/

Configure Nginx

We’re going to install Nginx as the web server. Cerb’s code will run in PHP-FPM.


Add your SSL certificate

If you’re using an Elastic Load Balancer you can configure SSL there and use internal IPs without SSL on your web servers. Amazon Certificate Manager can also generate SSL certificates for free.

Otherwise, you’ll need a valid SSL certificate for your server. We recommend Let’s Encrypt or a RapidSSL certificate from CheapSSLsecurity.

Enable Perfect Forward Secrecy (this may take a few minutes):

openssl dhparam -out /etc/ssl/certs/dhparam.pem 2048

Creating a self-signed SSL certificate

For testing, you can also create a self-signed SSL certificate. You should not use these instructions in production:

openssl req -x509 -nodes -days 365 -newkey rsa:2048 \
-keyout /etc/ssl/private/nginx-selfsigned.key \
-out /etc/ssl/certs/nginx-selfsigned.pem

Country Name (2 letter code) [AU]:US
State or Province Name (full name) [Some-State]:California
Locality Name (eg, city) []:
Organization Name (eg, company) [Internet Widgits Pty Ltd]:Example, Inc.
Organizational Unit Name (eg, section) []:Internet
Common Name (e.g. server FQDN or YOUR name) []:cerb.example
Email Address []:support@cerb.example

Add a virtual host

Add a new virtual host to Nginx:

vi /etc/nginx/sites-available/cerb

Type i to switch to insert mode and paste the following:

server {
  listen 80;
  server_name cerb.example;
  #access_log off;

  location /status/nginx {
    stub_status on;
    access_log off;
    deny all;

  location /status/fpm {
    access_log off;
    deny all;
    include fastcgi_params;
    fastcgi_pass   unix:/run/php/php8.1-fpm.sock;

  location / {
    return 301 https://$host$request_uri;

limit_req_zone $binary_remote_addr zone=cerb:10m rate=15r/s;

server {
  listen 443 ssl;
  server_name cerb.example;
  #access_log off;
  root /usr/share/nginx/html/cerb/;
  index index.php;

  # Increase upload max size from default of 1MB
  client_max_body_size 30m;
  charset utf-8;

  # SSL
  ssl_certificate /etc/ssl/certs/nginx-selfsigned.pem;
  ssl_certificate_key /etc/ssl/private/nginx-selfsigned.key;
  ssl_protocols TLSv1.2;
  ssl_prefer_server_ciphers on;
  ssl_dhparam /etc/ssl/certs/dhparam.pem;

  # DNS
  resolver valid=300s;
  resolver_timeout 5s;

  # Always let people see the favicon file
  location = /favicon.ico {
    allow all;

  # Always let people see the robots file
  location = /robots.txt {
    allow all;

  # Send PHP scripts to FPM
  location ~ ^/(index|ajax)\.php$ {
    limit_req zone=cerb burst=40 delay=15;
    proxy_connect_timeout 30;
    proxy_send_timeout 30;
    proxy_read_timeout 30;
    fastcgi_split_path_info ^(.+\.php)(/.+)$;
    fastcgi_pass   unix:/run/php/php8.1-fpm.sock;
    fastcgi_index  index.php;
    include    fastcgi_params;
    fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;

  # ============================
  # ============================
  location /install/ {
    location = /install/ {
      rewrite ^(.*)$ /install/index.php?$1 last;
    location ~ ^/install/(index|servercheck|phpinfo)\.php$ {
      fastcgi_split_path_info ^(.+\.php)(/.+)$;
      fastcgi_pass unix:/run/php/php8.1-fpm.sock;
      fastcgi_index  /install/index.php;
      include    fastcgi_params;
      fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
    location ~ ^/install/(.*)\.(css|js|svg)$ {
      allow all;
    #location ~ ^/install/ {
    #  deny all;
  # Deny direct access to all other PHP files
  location ~ \.php$ {
    deny all;
  # Send all other paths to the Devblocks front controller index.php
  location / {
    rewrite ^ /index.php last;

On lines 3 and 29 change cerb.example to the domain name of your server. If for some reason you don’t have one, you can temporarily use your server IP.

The first server block (lines 1-25) redirects all HTTP requests to HTTPS with SSL. It also defines some /status pages you can use to monitor the server (lines 6 and 13).

On lines 41-42, you should use your own SSL key and certificate.

Save the file with :wq

To enable the site we need to add a symlink:

ln -s /etc/nginx/sites-available/cerb /etc/nginx/sites-enabled/cerb

Test Nginx configuration

You can test the Nginx configuration file with:

nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

Restart Nginx and PHP-FPM

service nginx restart

service php8.1-fpm restart

For more information about Nginx + PHP-FPM, see:

Enable friendly URLs

touch .htaccess

Run the Cerb installer

Type the hostname of your server into a browser and follow the guided installer.

If you’re installing with Docker, use rather than localhost for the database server.