Merge pull request #1621 from ArthurHoaro/feature/tag-separators

[github/shaarli/Shaarli.git] / doc / md / Server-configuration.md

# Server configuration

## Requirements

### Operating system and web server

Shaarli can be hosted on dedicated/virtual servers, or shared hosting.

You need write access to the Shaarli installation directory - you should have received instructions from your hosting provider on how to connect to the server using SSH (or FTP for shared hosts).

Examples in this documentation are given for [Debian](https://www.debian.org/), a GNU/Linux distribution widely used in server environments. Please adapt them to your specific Linux distribution.

A $5/month VPS (1 CPU, 1 GiB RAM and 25 GiB SSD) will run any Shaarli installation without problems. Some hosting providers: [DigitalOcean](https://www.digitalocean.com/) ([1](https://www.digitalocean.com/docs/droplets/overview/), [2](https://www.digitalocean.com/pricing/), [3](https://www.digitalocean.com/docs/droplets/how-to/create/), [4](https://www.digitalocean.com/docs/droplets/how-to/add-ssh-keys/), [5](https://www.digitalocean.com/community/tutorials/initial-server-setup-with-debian-8), [6](https://www.digitalocean.com/community/tutorials/an-introduction-to-securing-your-linux-vps)), [Gandi](https://www.gandi.net/en), [OVH](https://www.ovh.co.uk/), [RackSpace](https://www.rackspace.com/), etc.


### Network and domain name

Try to host the server in a region that is geographically close to your users.

A **domain name** ([DNS record](https://opensource.com/article/17/4/introduction-domain-name-system-dns)) pointing to the server's public IP address is required to obtain a SSL/TLS certificate and setup HTTPS to secure client traffic to your Shaarli instance.

You can obtain a domain name from a [registrar](https://en.wikipedia.org/wiki/Domain_name_registrar) ([1](https://www.ovh.co.uk/domains), [2](https://www.gandi.net/en/domain)), or from free subdomain providers ([1](https://freedns.afraid.org/)). If you don't have a domain name, please set up a private domain name ([FQDN](ttps://en.wikipedia.org/wiki/Fully_qualified_domain_name)) in your clients' [hosts files](https://en.wikipedia.org/wiki/Hosts_(file)) to access the server (direct access by IP address can result in unexpected behavior).

Setup a **firewall** (using `iptables`, [ufw](https://www.digitalocean.com/community/tutorials/how-to-set-up-a-firewall-with-ufw-on-debian-10), [fireHOL](https://firehol.org/) or any frontend of your choice) to deny all incoming traffic except `tcp/80` and `tcp/443`, which are needed to access the web server (and any other posrts you might need, like SSH). If the server is in a private network behind a NAT, ensure these **ports are forwarded** to the server.

Shaarli makes outbound HTTP/HTTPS connections to websites you bookmark to fetch page information (title, thumbnails), the server must then have access to the Internet as well, and a working DNS resolver.


### Screencast

Here is a screencast of the installation procedure

[![asciicast](https://asciinema.org/a/z3RXxcJIRgWk0jM2ws6EnUFgO.svg)](https://asciinema.org/a/z3RXxcJIRgWk0jM2ws6EnUFgO)

--------------------------------------------------------------------------------

### PHP

Supported PHP versions:

Version | Status | Shaarli compatibility
:---:|:---:|:---:
8.0 | Supported | Yes
7.4 | Supported | Yes
7.3 | Supported | Yes
7.2 | Supported | Yes
7.1 | Supported | Yes
7.0 | EOL: 2018-12-03 | Yes (up to Shaarli 0.10.x)
5.6 | EOL: 2018-12-31 | Yes (up to Shaarli 0.10.x)
5.5 | EOL: 2016-07-10 | Yes
5.4 | EOL: 2015-09-14 | Yes (up to Shaarli 0.8.x)
5.3 | EOL: 2014-08-14 | Yes (up to Shaarli 0.8.x)

Required PHP extensions:

Extension | Required? | Usage
---|:---:|---
[`openssl`](http://php.net/manual/en/book.openssl.php) | required | OpenSSL, HTTPS
[`php-json`](http://php.net/manual/en/book.json.php) | required | configuration parsing
[`php-simplexml`](https://www.php.net/manual/en/book.simplexml.php) | required | REST API (Slim framework)
[`php-mbstring`](http://php.net/manual/en/book.mbstring.php) | CentOS, Fedora, RHEL, Windows, some hosting providers | multibyte (Unicode) string support
[`php-gd`](http://php.net/manual/en/book.image.php) | optional | required to use thumbnails
[`php-intl`](http://php.net/manual/en/book.intl.php) | optional | localized text sorting (e.g. `e->è->f`)
[`php-curl`](http://php.net/manual/en/book.curl.php) | optional | using cURL for fetching webpages and thumbnails in a more robust way
[`php-gettext`](http://php.net/manual/en/book.gettext.php) | optional | Use the translation system in gettext mode (faster)

Some [plugins](Plugins.md) may require additional configuration.

- [PHP: Supported versions](http://php.net/supported-versions.php)
- [PHP: Unsupported versions (EOL/End-of-life)](http://php.net/eol.php)
- [PHP 7 Changelog](http://php.net/ChangeLog-7.php)
- [PHP 5 Changelog](http://php.net/ChangeLog-5.php)
- [PHP: Bugs](https://bugs.php.net/)


## SSL/TLS (HTTPS)

We recommend setting up [HTTPS](https://en.wikipedia.org/wiki/HTTPS) (SSL/[TLS](https://en.wikipedia.org/wiki/Transport_Layer_Security)) on your webserver for secure communication between clients and the server.

### Let's Encrypt

For public-facing web servers this can be done using free SSL/TLS certificates from [Let's Encrypt](https://en.wikipedia.org/wiki/Let's_Encrypt), a non-profit certificate authority provididing free certificates.

 - [How to secure Apache with Let's Encrypt](https://www.digitalocean.com/community/tutorials/how-to-secure-apache-with-let-s-encrypt-on-debian-10)
 - [How to secure Nginx with Let's Encrypt](https://www.digitalocean.com/community/tutorials/how-to-secure-nginx-with-let-s-encrypt-on-debian-10)
 - [How To Use Certbot Standalone Mode to Retrieve Let's Encrypt SSL Certificates](https://www.digitalocean.com/community/tutorials/how-to-use-certbot-standalone-mode-to-retrieve-let-s-encrypt-ssl-certificates-on-debian-10).

In short:

```bash
# install certbot
sudo apt install certbot

# stop your webserver if you already have one running
# certbot in standalone mode needs to bind to port 80 (only needed on initial generation)
sudo systemctl stop apache2
sudo systemctl stop nginx

# generate initial certificates
# Let's Encrypt ACME servers must be able to access your server! port forwarding and firewall must be properly configured
sudo certbot certonly --standalone --noninteractive --agree-tos --email "admin@shaarli.mydomain.org" -d shaarli.mydomain.org
# this will generate a private key and certificate at /etc/letsencrypt/live/shaarli.mydomain.org/{privkey,fullchain}.pem

# restart the web server
sudo systemctl start apache2
sudo systemctl start nginx
```

On apache `2.4.43+`, you can also delegate LE certificate management to [mod_md](https://httpd.apache.org/docs/2.4/mod/mod_md.html) [[1](https://www.cyberciti.biz/faq/how-to-secure-apache-with-mod_md-lets-encrypt-on-ubuntu-20-04-lts/)] in which case you don't need certbot and manual SSL configuration in virtualhosts.

### Self-signed

If you don't want to rely on a certificate authority, or the server can only be accessed from your own network, you can also generate self-signed certificates. Not that this will generate security warnings in web browsers/clients trying to access Shaarli:

- [How To Create a Self-Signed SSL Certificate for Apache](https://www.digitalocean.com/community/tutorials/how-to-create-a-self-signed-ssl-certificate-for-apache-on-debian-10)
- [How To Create a Self-Signed SSL Certificate for Nginx](https://www.digitalocean.com/community/tutorials/how-to-create-a-self-signed-ssl-certificate-for-nginx-on-debian-10)
- [How to Create Self-Signed SSL Certificates with OpenSSL](http://www.xenocafe.com/tutorials/linux/centos/openssl/self_signed_certificates/index.php)
- [How do I create my own Certificate Authority?](https://workaround.org/certificate-authority)

--------------------------------------------------------------------------------

## Examples

The following examples assume a Debian-based operating system is installed. On other distributions you may have to adapt details such as package installation procedures, configuration file locations, and webserver username/group (`www-data` or `httpd` are common values). In these examples we assume the document root for your web server/virtualhost is at `/var/www/shaarli.mydomain.org/`:

```bash
# create the document root (replace with your own domain name)
sudo mkdir -p /var/www/shaarli.mydomain.org/
```

You can install Shaarli at the root of your virtualhost, or in a subdirectory as well. See [Directory structure](Directory-structure)


### Apache

```bash
# Install apache + mod_php and PHP modules
sudo apt update
sudo apt install apache2 libapache2-mod-php php-json php-mbstring php-gd php-intl php-curl php-gettext

# Edit the virtualhost configuration file with your favorite editor (replace the example domain name)
sudo nano /etc/apache2/sites-available/shaarli.mydomain.org.conf
```

```apache
<VirtualHost *:80>
    ServerName shaarli.mydomain.org
    DocumentRoot /var/www/shaarli.mydomain.org/

    # For SSL/TLS certificates acquired with certbot or self-signed certificates
    # Redirect HTTP requests to HTTPS, except Let's Encrypt ACME challenge requests
    RewriteEngine on
    RewriteRule ^.well-known/acme-challenge/ - [L]
    RewriteCond %{HTTP_HOST} =shaarli.mydomain.org
    RewriteRule  ^ https://shaarli.mydomain.org%{REQUEST_URI} [END,NE,R=permanent]
</VirtualHost>

# SSL/TLS configuration for Let's Encrypt certificates managed with mod_md
#MDomain shaarli.mydomain.org
#MDCertificateAgreement accepted
#MDContactEmail admin@shaarli.mydomain.org
#MDPrivateKeys RSA 4096

<VirtualHost *:443>
    ServerName   shaarli.mydomain.org
    DocumentRoot /var/www/shaarli.mydomain.org/

    # SSL/TLS configuration for Let's Encrypt certificates acquired with certbot standalone
    SSLEngine             on
    SSLCertificateFile    /etc/letsencrypt/live/shaarli.mydomain.org/fullchain.pem
    SSLCertificateKeyFile /etc/letsencrypt/live/shaarli.mydomain.org/privkey.pem
    # Let's Encrypt settings from https://github.com/certbot/certbot/blob/master/certbot-apache/certbot_apache/_internal/tls_configs/current-options-ssl-apache.conf
    SSLProtocol             all -SSLv2 -SSLv3 -TLSv1 -TLSv1.1
    SSLCipherSuite          ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384
    SSLHonorCipherOrder     off
    SSLSessionTickets       off
    SSLOptions +StrictRequire

    # SSL/TLS configuration for self-signed certificates
    #SSLEngine             on
    #SSLCertificateFile    /etc/ssl/certs/ssl-cert-snakeoil.pem
    #SSLCertificateKeyFile /etc/ssl/private/ssl-cert-snakeoil.key

    # Optional, log PHP errors, useful for debugging
    #php_flag  log_errors on
    #php_flag  display_errors on
    #php_value error_reporting 2147483647
    #php_value error_log /var/log/apache2/shaarli-php-error.log

    <Directory /var/www/shaarli.mydomain.org/>
        # Required for .htaccess support
        AllowOverride All
        Require all granted
    </Directory>

    <LocationMatch "/\.">
        # Prevent accessing dotfiles
        RedirectMatch 404 ".*"
    </LocationMatch>

    <LocationMatch "\.(?:ico|css|js|gif|jpe?g|png)$">
        # allow client-side caching of static files
        Header set Cache-Control "max-age=2628000, public, must-revalidate, proxy-revalidate"
    </LocationMatch>

    # serve the Shaarli favicon from its custom location
    Alias favicon.ico /var/www/shaarli.mydomain.org/images/favicon.ico

</VirtualHost>
```

```bash
# Enable the virtualhost
sudo a2ensite shaarli.mydomain.org

# mod_ssl must be enabled to use TLS/SSL certificates
# https://httpd.apache.org/docs/current/mod/mod_ssl.html
sudo a2enmod ssl

# mod_rewrite must be enabled to use the REST API
# https://httpd.apache.org/docs/current/mod/mod_rewrite.html
sudo a2enmod rewrite

# mod_headers must be enabled to set custom headers from the server config
sudo a2enmod headers

# mod_version must only be enabled if you use Apache 2.2 or lower
# https://httpd.apache.org/docs/current/mod/mod_version.html
# sudo a2enmod version

# restart the apache service
sudo systemctl restart apache2
```

- [How to install the Apache web server](https://www.digitalocean.com/community/tutorials/how-to-install-the-apache-web-server-on-debian-10)
- [Apache/PHP - error log per VirtualHost - StackOverflow](http://stackoverflow.com/q/176)
- [Apache - PHP: php_value vs php_admin_value and the use of php_flag explained](https://ma.ttias.be/php-php_value-vs-php_admin_value-and-the-use-of-php_flag-explained/)
- [Server-side TLS (Apache) - Mozilla](https://wiki.mozilla.org/Security/Server_Side_TLS#Apache)
- [Apache 2.4 documentation](https://httpd.apache.org/docs/2.4/)
- [Apache mod_proxy](https://httpd.apache.org/docs/2.4/mod/mod_proxy.html)
- [Apache Reverse Proxy Request Headers](https://httpd.apache.org/docs/2.4/mod/mod_proxy.html#x-headers)


### Nginx

This examples uses nginx and the [PHP-FPM](https://www.digitalocean.com/community/tutorials/how-to-install-linux-nginx-mariadb-php-lemp-stack-on-debian-10#step-3-%E2%80%94-installing-php-for-processing) PHP interpreter. Nginx and PHP-FPM must be running using the same user and group, here we assume the user/group to be `www-data:www-data`.


```bash
# install nginx and php-fpm
sudo apt update
sudo apt install nginx php-fpm

# Edit the virtualhost configuration file with your favorite editor
sudo nano /etc/nginx/sites-available/shaarli.mydomain.org
```

```nginx
server {
    listen       80;
    server_name  shaarli.mydomain.org;

    # redirect all plain HTTP requests to HTTPS
    return 301 https://shaarli.mydomain.org$request_uri;
}

server {
    # ipv4 listening port/protocol
    listen       443 ssl http2;
    # ipv6 listening port/protocol
    listen           [::]:443 ssl http2;
    server_name  shaarli.mydomain.org;
    root         /var/www/shaarli.mydomain.org;

    # log file locations
    # combined log format prepends the virtualhost/domain name to log entries
    access_log  /var/log/nginx/access.log combined;
    error_log   /var/log/nginx/error.log;

    # paths to private key and certificates for SSL/TLS
    ssl_certificate      /etc/ssl/shaarli.mydomain.org.crt;
    ssl_certificate_key  /etc/ssl/private/shaarli.mydomain.org.key;

    # Let's Encrypt SSL settings from https://github.com/certbot/certbot/blob/master/certbot-nginx/certbot_nginx/_internal/tls_configs/options-ssl-nginx.conf
    ssl_session_cache shared:le_nginx_SSL:10m;
    ssl_session_timeout 1440m;
    ssl_session_tickets off;
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_prefer_server_ciphers off;
    ssl_ciphers "ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384";

    # increase the maximum file upload size if needed: by default nginx limits file upload to 1MB (413 Entity Too Large error)
    client_max_body_size 100m;

    # relative path to shaarli from the root of the webserver
    location / {
        # default index file when no file URI is requested
        index index.php;
        try_files $uri /index.php$is_args$args;
    }

    location ~ (index)\.php$ {
        try_files $uri =404;
        # slim API - split URL path into (script_filename, path_info)
        fastcgi_split_path_info ^(.+\.php)(/.+)$;
        # pass PHP requests to PHP-FPM
        fastcgi_pass   unix:/var/run/php-fpm/php-fpm.sock;
        fastcgi_index  index.php;
        include        fastcgi.conf;
    }

    location ~ \.php$ {
        # deny access to all other PHP scripts
        # disable this if you host other PHP applications on the same virtualhost
        deny all;
    }

    location ~ /\. {
        # deny access to dotfiles
        deny all;
    }

    location ~ ~$ {
        # deny access to temp editor files, e.g. "script.php~"
        deny all;
    }

    location ~ /doc/ {
        default_type "text/html";
        try_files $uri $uri/ $uri.html =404;
    }

    location = /favicon.ico {
        # serve the Shaarli favicon from its custom location
        alias /var/www/shaarli/images/favicon.ico;
    }

    # allow client-side caching of static files
    location ~* \.(?:ico|css|js|gif|jpe?g|png)$ {
        expires    max;
        add_header Cache-Control "public, must-revalidate, proxy-revalidate";
        # HTTP 1.0 compatibility
        add_header Pragma public;
    }

}
```

```bash
# enable the configuration/virtualhost
sudo ln -s /etc/nginx/sites-available/shaarli.mydomain.org /etc/nginx/sites-enabled/shaarli.mydomain.org
# reload nginx configuration
sudo systemctl reload nginx
```

- [How to install the Nginx web server](https://www.digitalocean.com/community/tutorials/how-to-install-nginx-on-debian-10)
- [Nginx Beginner's guide](http://nginx.org/en/docs/beginners_guide.html)
- [Nginx documentation](https://nginx.org/en/docs/)
- [Nginx ngx_http_fastcgi_module](http://nginx.org/en/docs/http/ngx_http_fastcgi_module.html)
- [Nginx Pitfalls](http://wiki.nginx.org/Pitfalls)
- [Nginx PHP configuration examples - Karl Blessing](http://kbeezie.com/nginx-configuration-examples/)
- [Server-side TLS (Nginx) - Mozilla](https://wiki.mozilla.org/Security/Server_Side_TLS#Nginx)



## Reverse proxies

If Shaarli is hosted on a server behind a [reverse proxy](https://en.wikipedia.org/wiki/Reverse_proxy) (i.e. there is a proxy server between clients and the web server hosting Shaarli), configure it accordingly. See [Reverse proxy](Reverse-proxy.md) configuration.

## Using Shaarli without URL rewriting

By default, Shaarli uses Slim framework's URL, which requires
URL rewriting.

If you can't use URL rewriting for any reason (not supported by
your web server, shared hosting, etc.), you *can* use Shaarli
without URL rewriting.

You just need to prefix your URL by `/index.php/`.
Example: instead of accessing `https://shaarli.mydomain.org/`,
use `https://shaarli.mydomain.org/index.php/`.

**Recommended:**
  * after installation, in the configuration page, set your header link to `/index.php/`.
  * in your configuration file `config.json.php` set `general.root_url` to
    `https://shaarli.mydomain.org/index.php/`.

## Allow import of large browser bookmarks export

Web browser bookmark exports can be large due to the presence of base64-encoded images and favicons/long subfolder names. Edit the PHP configuration file.

- Apache: `/etc/php/<PHP_VERSION>/apache2/php.ini`
- Nginx + PHP-FPM: `/etc/php/<PHP_VERSION>/fpm/php.ini` (in addition to `client_max_body_size` in the [Nginx configuration](#nginx))

```ini
[...]
# (optional) increase the maximum file upload size:
post_max_size = 100M
[...]
# (optional) increase the maximum file upload size:
upload_max_filesize = 100M
```

To verify PHP settings currently set on the server, create a `phpinfo.php` in your webserver's document root

```bash
# example
echo '<?php phpinfo(); ?>' | sudo tee /var/www/shaarli.mydomain.org/phpinfo.php
#give read-only access to this file to the webserver user
sudo chown www-data:root /var/www/shaarli.mydomain.org/phpinfo.php
sudo chmod 0400 /var/www/shaarli.mydomain.org/phpinfo.php
```

Access the file from a web browser (eg. <https://shaarli.mydomain.org/phpinfo.php> and look at the _Loaded Configuration File_ and _Scan this dir for additional .ini files_ entries

It is recommended to remove the `phpinfo.php` when no longer needed as it publicly discloses details about your webserver configuration.


## Robots and crawlers

To opt-out of indexing your Shaarli instance by search engines, create a `robots.txt` file at the root of your virtualhost:

```
User-agent: *
Disallow: /
```

By default Shaarli already disallows indexing of your local copy of the documentation by default, using `<meta name="robots">` HTML tags. Your Shaarli instance may still be indexed by various robots on the public Internet, that do not respect this header or the robots standard.

- [Robots exclusion standard](https://en.wikipedia.org/wiki/Robots_exclusion_standard)
- [Introduction to robots.txt](https://support.google.com/webmasters/answer/6062608?hl=en)
- [Robots meta tag, data-nosnippet, and X-Robots-Tag specifications](https://developers.google.com/search/reference/robots_meta_tag)
- [About robots.txt](http://www.robotstxt.org)
- [About the robots META tag](https://www.robotstxt.org/meta.html)


## Fail2ban

[fail2ban](http://www.fail2ban.org/wiki/index.php/Main_Page) is an intrusion prevention framework that reads server (Apache, SSH, etc.) and uses `iptables` profiles to block brute-force attempts. You need to create a filter to detect shaarli login failures in logs, and a jail configuation to configure the behavior when failed login attempts are detected:

```ini
# /etc/fail2ban/filter.d/shaarli-auth.conf
[INCLUDES]
before = common.conf
[Definition]
failregex = \s-\s<HOST>\s-\sLogin failed for user.*$
ignoreregex =
```

```ini
# /etc/fail2ban/jail.local
[shaarli-auth]
enabled  = true
port     = https,http
filter   = shaarli-auth
logpath  = /var/www/shaarli.mydomain.org/data/log.txt
# allow 3 login attempts per IP address
# (over a period specified by findtime = in /etc/fail2ban/jail.conf)
maxretry = 3
# permanently ban the IP address after reaching the limit
bantime = -1
```

Then restart the service: `sudo systemctl restart fail2ban`


## What next?

[Shaarli installation](Installation.md)