Odoo is the most popular all-in-one business software in the world. It offers a range of business applications, including CRM, website, e-Commerce, billing, accounting, manufacturing, warehouse, project management, inventory, and much more, all seamlessly integrated.

This tutorial explains how to install Odoo 13 from the source inside a Python virtual environment on a CentOS 8 machine. We’ll download the Odoo source from Github and configure Nginx as a reverse proxy.

Prerequisites

You need to be logged in as root or user with sudo privileges to complete the installation.

Installing Dependencies

Install Python 3, Git, pip, and all the libraries and tools required to build Odoo from source:

sudo dnf install python3 python3-devel git gcc redhat-rpm-config libxslt-devel bzip2-devel openldap-devel libjpeg-devel freetype-devel

Creating a System User

Create a new system user and group with home directory /opt/odoo that will run the Odoo service:

sudo useradd -m -U -r -d /opt/odoo13 -s /bin/bash odoo13

You can name the user whatever you like, just make sure you create a PostgreSQL user with the same name.

Installing and Configuring PostgreSQL

We’ll install PostgreSQL 10 from the standard CentOS 8 repositories:

sudo dnf install @postgresql:10

Once the installation is completed, create a new PostgreSQL database cluster:

sudo postgresql-setup initdb

Enable and start the PostgreSQL service:

sudo systemctl enable --now postgresql

Create a PostgreSQL user with the same name as the previously created system user, in our case that is “odoo13”:

sudo su - postgres -c "createuser -s odoo13"

Installing Wkhtmltopdf

The wkhtmltox package provides a set of open-source command-line tools that can render HTML into PDF and various image formats. To print PDF reports, you will need the wkhtmltopdf tool. The recommended version for Odoo is 0.12.5, which is not available in the official CentOS 8 repositories.

Install the rpm package from Github by typing:

sudo dnf install https://github.com/wkhtmltopdf/wkhtmltopdf/releases/download/0.12.5/wkhtmltox-0.12.5-1.centos8.x86_64.rpm

Installing and Configuring Odoo 13

Before starting with the installation process, change to user “odoo13”:

sudo su - odoo13

Start by cloning the Odoo 13 source code from the Odoo GitHub repository:

git clone https://www.github.com/odoo/odoo --depth 1 --branch 13.0 /opt/odoo13/odoo

Navigate to the /opt/odoo13 directory and create a new Python virtual environment for the Odoo installation:

cd /opt/odoo13python3 -m venv venv

Activate the environment using the source command:

source venv/bin/activate

Install the required Python modules:

pip3 install -r odoo/requirements.txt

Once the installation is complete, deactivate the environment:

deactivate

Create a new directory for the custom addons:

mkdir /opt/odoo13/odoo-custom-addons

Switch back to your sudo user:

exit

Next, open your text editor and create the following configuration file:

sudo nano /etc/odoo13.conf

[options]
; This is the password that allows database operations:
admin_passwd = superadmin_passwd
db_host = False
db_port = False
db_user = odoo13
db_password = False
addons_path = /opt/odoo13/odoo/addons, /opt/odoo13/odoo-custom-addons

Save and close the file.

Creating Systemd Unit File

Open your text editor and create a file named odoo13.service inside the /etc/systemd/system/ directory:

sudo nano /etc/systemd/system/odoo13.service

Paste the following content:

[Unit]
Description=Odoo13
Requires=postgresql.service
After=network.target postgresql.service

[Service]
Type=simple
SyslogIdentifier=odoo13
PermissionsStartOnly=true
User=odoo13
Group=odoo13
ExecStart=/opt/odoo13/venv/bin/python3 /opt/odoo13/odoo/odoo-bin -c /etc/odoo13.conf
StandardOutput=journal+console

[Install]
WantedBy=multi-user.target

Save the file and close the editor.

Notify Systemd that a new unit file exists:

sudo systemctl daemon-reload

Start and enable the Odoo service by executing:

sudo systemctl enable --now odoo13

You can check the service status with the following command:

sudo systemctl status odoo13

● odoo13.service - Odoo13
   Loaded: loaded (/etc/systemd/system/odoo13.service; enabled; vendor preset: disabled)
   Active: active (running) since Wed 2019-12-11 20:04:52 UTC; 5s ago
 Main PID: 28539 (python3)
    Tasks: 4 (limit: 11524)
   Memory: 94.6M
   CGroup: /system.slice/odoo13.service
           └─28539 /opt/odoo13/venv/bin/python3 /opt/odoo13/odoo/odoo-bin -c /etc/odoo13.conf

To see the messages logged by the Odoo service, use the following command:

sudo journalctl -u odoo13

Test the Installation

Open your browser and type: http://<your_domain_or_IP_address>:8069

Assuming the installation is successful, a screen similar to the following will appear:

If you can’t access the page, then probably your firewall is blocking port 8069.

Use the following commands to open the necessary port:

sudo firewall-cmd --permanent --zone=public --add-port=8069/tcpsudo firewall-cmd --reload

Configuring Nginx as SSL Termination Proxy

The default Odoo web server is serving traffic over HTTP. To make the Odoo deployment more secure, we will configure Nginx as an SSL termination proxy that will serve the traffic over HTTPS.

SSL termination proxy is a proxy server that handles the SSL encryption/decryption. This means that the termination proxy (Nginx) will process and decrypt incoming TLS connections (HTTPS), and pass on the unencrypted requests to the internal service (Odoo). The traffic between Nginx and Odoo will not be encrypted (HTTP).

Using a reverse proxy gives you many benefits such as Load Balancing, SSL Termination, Caching, Compression, Serving Static Content, and more.

Ensure that you have met the following prerequisites before continuing with this section:

• Domain name pointing to your public server IP. We’ll use example.com.
• Nginx installed.
• SSL certificate for your domain. You can install a free Let’s Encrypt SSL certificate.

Open your text editor and create/edit the domain server block:

sudo nano /etc/nginx/conf.d/example.com

The following configuration sets up SSL Termination, HTTP to HTTPS redirection, WWW to non-WWW redirection, cache the static files and enable GZip compression.

# Odoo servers
upstream odoo {
 server 127.0.0.1:8069;
}

upstream odoochat {
 server 127.0.0.1:8072;
}

# HTTP -> HTTPS
server {
    listen 80;
    server_name www.example.com example.com;

    include snippets/letsencrypt.conf;
    return 301 https://example.com$request_uri;
}

# WWW -> NON WWW
server {
    listen 443 ssl http2;
    server_name www.example.com;

    ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;
    ssl_trusted_certificate /etc/letsencrypt/live/example.com/chain.pem;
    include snippets/ssl.conf;

    return 301 https://example.com$request_uri;
}

server {
    listen 443 ssl http2;
    server_name example.com;

    proxy_read_timeout 720s;
    proxy_connect_timeout 720s;
    proxy_send_timeout 720s;

    # Proxy headers
    proxy_set_header X-Forwarded-Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
    proxy_set_header X-Real-IP $remote_addr;

    # SSL parameters
    ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;
    ssl_trusted_certificate /etc/letsencrypt/live/example.com/chain.pem;
    include snippets/ssl.conf;
    include snippets/letsencrypt.conf;

    # log files
    access_log /var/log/nginx/odoo.access.log;
    error_log /var/log/nginx/odoo.error.log;

    # Handle longpoll requests
    location /longpolling {
        proxy_pass http://odoochat;
    }

    # Handle / requests
    location / {
       proxy_redirect off;
       proxy_pass http://odoo;
    }

    # Cache static files
    location ~* /web/static/ {
        proxy_cache_valid 200 90m;
        proxy_buffering on;
        expires 864000;
        proxy_pass http://odoo;
    }

    # Gzip
    gzip_types text/css text/less text/plain text/xml application/xml application/json application/javascript;
    gzip on;
}

Once you’re done, restart the Nginx service:

sudo systemctl restart nginx

Next, we need to tell Odoo to use the proxy. To do so, open the configuration file and add the following line:

proxy_mode = True

Restart the Odoo service for the changes to take effect:

sudo systemctl restart odoo13

At this point, the reverse proxy is configured, and you can access your Odoo instance at: https://example.com

Changing the Binding Interface

This step is optional, but it is a good security practice.

By default, Odoo server listens to port 8069 on all interfaces. To disable direct access to the Odoo instance, you can either block the port 8069 for all public interfaces or force Odoo to listen only on the local interface.

We’ll configure Odoo to listen only on 127.0.0.1. Open the configuration add the following two lines at the end of the file:

xmlrpc_interface = 127.0.0.1
netrpc_interface = 127.0.0.1

Save the configuration file and restart the Odoo server for the changes to take effect:

sudo systemctl restart odoo13

Enabling Multiprocessing

By default, Odoo is working in multithreading mode. For production deployments, it is recommended to change to the multiprocessing server as it increases stability, and make better usage of the system resources.

To enable multiprocessing, you need to edit the Odoo configuration and set a non-zero number of worker processes. The number of workers is calculated based on the number of CPU cores in the system and the available RAM memory.

According to the official Odoo documentation to calculate the workers’ number and required RAM memory size, you can use the following formulas and assumptions:

Worker number calculation

• Theoretical maximal number of worker = (system_cpus * 2) + 1
• 1 worker can serve ~= 6 concurrent users
• Cron workers also require CPU

RAM memory size calculation

• We will consider that 20% of all requests are heavy requests, and 80% are lighter ones. Heavy requests are using around 1 GB of RAM while the lighter ones are using around 150 MB of RAM
• Needed RAM = number_of_workers * ( (light_worker_ratio * light_worker_ram_estimation) + (heavy_worker_ratio * heavy_worker_ram_estimation) )

If you do not know how many CPUs you have on your system, use the following grep command:

grep -c ^processor /proc/cpuinfo

Let’s say you have a system with 4 CPU cores, 8 GB of RAM memory, and 30 concurrent Odoo users.

• 30 users / 6 = **5** (5 is theoretical number of workers needed )
• (4 * 2) + 1 = **9** ( 9 is the theoretical maximum number of workers)

Based on the calculation above, you can use 5 workers + 1 worker for the cron worker that is a total of 6 workers.

Calculate the RAM memory consumption based on the number of workers:

• RAM = 6 * ((0.8*150) + (0.2*1024)) ~= 2 GB of RAM

The calculation shows that the Odoo installation will need around 2GB of RAM.

To switch to multiprocessing mode, open the configuration file and append the calculated values:

limit_memory_hard = 2684354560
limit_memory_soft = 2147483648
limit_request = 8192
limit_time_cpu = 600
limit_time_real = 1200
max_cron_threads = 1
workers = 5

Restart the Odoo service for the changes to take effect:

sudo systemctl restart odoo13

The rest of the system resources will be used by other services that run on this system. In this guide, we installed Odoo along with PostgreSQL and Nginx on the same server. Depending on your set up you may also have other services running on your server.

Conclusion

This tutorial walked you through the installation of Odoo 13 on CentOS 8 in a Python virtual environment using Nginx as a reverse proxy. We’ve also shown you how to enable multiprocessing and optimize Odoo for a production environment.

Source: https://linuxize.com/post/how-to-install-odoo-13-on-centos-8/