Is there a way to share or reuse Apache configurations

Question

I have the following directory structure on my Apache server

/var/www/domain.com/
    index.html
    site-1/
    site-2/
    .
    .
    .
    site-N/

Each site uses the following configuration file, where the variables "port", "site", and "hub" are the only values which change

<IfModule mod_ssl.c>
    <VirtualHost *:443>
        # DOMAIN CONFIGURATION
        Define domain domain.dev

        ServerName ${domain}
        ServerAlias www.${domain}
        DocumentRoot /var/www/${domain}

        <Directory "/var/www/${domain}">
            AuthType Basic
            AuthName "${domain} Authentication"
            AuthUserFile /etc/apache2/.htpasswd
            Require valid-user
            <Files "manifest.json">
                Require all granted
            </Files>
        </Directory>

        SSLEngine on
        RewriteEngine on
        SSLProxyEngine on
        SSLProxyVerify none
        SSLProxyCheckPeerCN off
        SSLProxyCheckPeerName off
        SSLProxyCheckPeerExpire off

        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined

        SSLCertificateFile /etc/letsencrypt/live/${domain}/cert.pem
        SSLCertificateKeyFile /etc/letsencrypt/live/${domain}/privkey.pem
        SSLCertificateChainFile /etc/letsencrypt/live/${domain}/fullchain.pem

        <FilesMatch "\.(cgi|shtml|phtml|php)$">
            SSLOptions +StdEnvVars
        </FilesMatch>

        <Directory /usr/lib/cgi-bin>
            SSLOptions +StdEnvVars
        </Directory>

        # SITE CONFIGURATION
        Define site site-1
        Define port 5001
        Define protocol https
        Define hub site-1-hub

        ProxyPassMatch "^/${site}/api/(.+)" "${protocol}://localhost:${port}/api/$1"
        ProxyPassReverse "/" "${protocol}://localhost:${port}/"

        ProxyPassMatch "^/${site}/${hub}/(.+)" "${protocol}://localhost:${port}/${hub}/$1"
        ProxyPassReverse "/" "${protocol}://localhost:${port}/${hub}"

        RewriteCond %{HTTP:UPGRADE} ^WebSocket$ [NC]
        RewriteCond %{HTTP:CONNECTION} Upgrade$ [NC]
        RewriteRule "^/${site}/(.+)" "wss://localhost:${port}/$1" [P]
    </VirtualHost>

Is there a way to share, reuse or centralize the "Domain Configuration" and "Site Configuration" sections so I don't have to duplicate configurations across multiple sites under the same domain? If so, I would be able to make a change in one shared configuration that would apply to any domain or site using it.

apache2ctl -S output

        VirtualHost configuration:
    *:80                   localhost (/etc/apache2/sites-enabled/000-default.conf:1)
    ServerRoot: "/etc/apache2"
    Main DocumentRoot: "/var/www/html"
    Main ErrorLog: "/var/log/apache2/error.log"
    Mutex ssl-stapling: using_defaults
    Mutex proxy: using_defaults
    Mutex ssl-cache: using_defaults
    Mutex default: dir="/var/run/apache2/" mechanism=default 
    Mutex watchdog-callback: using_defaults
    Mutex rewrite-map: using_defaults
    Mutex ssl-stapling-refresh: using_defaults
    PidFile: "/var/run/apache2/apache2.pid"
    Define: DUMP_VHOSTS
    Define: DUMP_RUN_CFG
    User: name="www-data" id=33
    Group: name="www-data" id=33

Here is a working implementation of the solution provided by Esa Jokinen (Note: The mod_macro module needs to be enabled by running sudo a2enmod macro at the command line)

/etc/apache2/sites-available/domain.dev.conf contents:

<Macro Domain $domain>
    ServerName $domain
    ServerAlias www.$domain
    DocumentRoot /var/www/$domain

    # Basic authentication
    <Directory "/var/www/$domain">
        AuthType Basic
        AuthName "$domain Authentication"
        AuthUserFile /etc/apache2/.htpasswd
        Require valid-user
        <Files "manifest.json">
            Require all granted
        </Files>
    </Directory>

    RewriteEngine on
    
    SSLEngine on
    SSLProxyEngine on
    SSLProxyVerify none
    SSLProxyCheckPeerCN off
    SSLProxyCheckPeerName off
    SSLProxyCheckPeerExpire off

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

    SSLCertificateFile /etc/letsencrypt/live/$domain/cert.pem
    SSLCertificateKeyFile /etc/letsencrypt/live/$domain/privkey.pem
    SSLCertificateChainFile /etc/letsencrypt/live/$domain/fullchain.pem

    <FilesMatch "\.(cgi|shtml|phtml|php)$">
        SSLOptions +StdEnvVars
    </FilesMatch>

    <Directory /usr/lib/cgi-bin>
        SSLOptions +StdEnvVars
    </Directory>
</Macro>

<Macro Site $site $port $protocol $hub>
    ProxyPassMatch "^/$site/api/(.+)" "$protocol://localhost:$port/api/$1"
    ProxyPassReverse "/" "$protocol://localhost:$port/"

    ProxyPassMatch "^/$site/$hub/(.+)" "$protocol://localhost:$port/$hub/$1"
    ProxyPassReverse "/" "$protocol://localhost:$port/$hub"

    RewriteCond %{HTTP:UPGRADE} ^WebSocket$ [NC]
    RewriteCond %{HTTP:CONNECTION} Upgrade$ [NC]
    RewriteRule "^/$site/(.+)" "wss://localhost:$port/$1" [P]
</Macro>

<IfModule mod_ssl.c>
    <VirtualHost *:443>
        Use Domain domain.dev

        Use Site site-1 5003 https site-1-hub
        Use Site site-2 5004 https site-2-hub
        .
        .
        .
        Use Site site-N 500N https site-N-hub
    </VirtualHost>
</IfModule>

I would template them out using ansible, is that something you are familiar with? — Tom, Jun 10 '20 at 00:31
I am not familiar with [Ansible](https://en.wikipedia.org/wiki/Ansible_(software)), I will check it out thank you. — Mark Davich, Jun 10 '20 at 15:43

Esa Jokinen · Accepted Answer · 2020-06-10T04:02:25.077

Apache Module mod_macro might be just what you are looking for. You can define a macro:

<Macro MyProxySites $site $port $protocol $hub>
    ProxyPassMatch "^/$site/api/(.+)" "$protocol://localhost:$port/api/$1"
    ProxyPassReverse "/" "$protocol://localhost:$port/"

    ProxyPassMatch "^/$site/$hub/(.+)" "$protocol://localhost:$port/$hub/$1"
    ProxyPassReverse "/" "$protocol://localhost:$port/$hub"

    RewriteCond %{HTTP:UPGRADE} ^WebSocket$ [NC]
    RewriteCond %{HTTP:CONNECTION} Upgrade$ [NC]
    RewriteRule "^/$site/(.+)" "wss://localhost:$port/$1" [P]
</Macro>

And then use it in your configuration several times, e.g.

<IfModule mod_ssl.c>
    <VirtualHost *:443>
        ServerName example.com
        ServerAlias www.example.com
        DocumentRoot /var/www/example.com

        # . . .
        Use MyProxySites site-1 5001 https site-1-hub
        Use MyProxySites site-2 5002 https site-2-hub
    </VirtualHost>
    <VirtualHost *:443>
        ServerName example.net
        ServerAlias www.example.net
        DocumentRoot /var/www/example.net

        # . . .
        Use MyProxySites site-3 5003 https site-3-hub
        Use MyProxySites site-4 5004 https site-4-hub
    </VirtualHost>
</IfModule>

From your question it's hard to say your exact goal, but if the domain changes for every site and a domain only has a single proxy, you could build that directly into the macro, too:

<Macro MyProxySites $domain $site $port $protocol $hub>
    <VirtualHost *:443>
        ServerName $domain
        ServerAlias www.$domain
        DocumentRoot /var/www/$domain

        ProxyPassMatch "^/$site/api/(.+)" "$protocol://localhost:$port/api/$1"
        ProxyPassReverse "/" "$protocol://localhost:$port/"

        ProxyPassMatch "^/$site/$hub/(.+)" "$protocol://localhost:$port/$hub/$1"
        ProxyPassReverse "/" "$protocol://localhost:$port/$hub"

        RewriteCond %{HTTP:UPGRADE} ^WebSocket$ [NC]
        RewriteCond %{HTTP:CONNECTION} Upgrade$ [NC]
        RewriteRule "^/$site/(.+)" "wss://localhost:$port/$1" [P]
    </VirtualHost>
</Macro>

Use MyProxySites example.com site-1 5001 https site-1-hub
Use MyProxySites example.net site-2 5002 https site-2-hub
Use MyProxySites example.org site-3 5003 https site-3-hub

That is a good ***working*** solution and solves the problem. I just didn't want to keep copying the same config over and over. I was basically asking if there was a way to reuse configurations. I am so new to Apache (web servers in general) that I have trouble formulating a coherent question, that being said; do you have any thoughts on rewording my question so it is more helpful to the community? — Mark Davich, Jun 10 '20 at 16:32

Is there a way to share or reuse Apache configurations

1 Answers1