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There is an Ubuntu server with LAMP stack.
There are hosted some quantity of sites on a single IP address.
IP address "white" and there are no any problems with access to server. Server stands for NAT with forwarded ports.

The situation is: there are some domains hosted on the server with a single IP address, for example domain1, domain2 and domain3. In the act of irrelevant inquiries to the server, for example to domain3 as domain3/123 or subdomain.domain3 (the directory 123 and subdomain has no exist) or direct inquiry on IP address, the server will forward this inquiry to the first domain (domain1) in the list.

How can I change it? I need next action: within irrelevant inquiries, the response has to be from the domain which has been requested. Another way, if there are no such directories, server has to returned answer about not existing requested site or had ignoring those requests.

In present time is realized the next scheme: there are on the server has been created a directory with name domain0 and was launched the virtual server for it and were uploaded custom pages with errors 403 and 404. If an irrelevant inquiry to any non-existing domain names has come, then Apache server will forward this inquiry to the first directory in the list to domain0 and then the user will get the page with error code.

So, I forced to ask my question to Stack Overflow community to help me with that issue. How do I can to implement Apache server settings for correct interpretation of incoming inquiries?

Thanks in advance!

Apache configuration:

# This is the main Apache server configuration file.  It contains the
# configuration directives that give the server its instructions.
# See http://httpd.apache.org/docs/2.4/ for detailed information about
# the directives and /usr/share/doc/apache2/README.Debian about Debian specific
# hints.
#
#
# Summary of how the Apache 2 configuration works in Debian:
# The Apache 2 web server configuration in Debian is quite different to
# upstream's suggested way to configure the web server. This is because Debian's
# default Apache2 installation attempts to make adding and removing modules,
# virtual hosts, and extra configuration directives as flexible as possible, in
# order to make automating the changes and administering the server as easy as
# possible.

# It is split into several files forming the configuration hierarchy outlined
# below, all located in the /etc/apache2/ directory:
#
#   /etc/apache2/
#   |-- apache2.conf
#   |   `--  ports.conf
#   |-- mods-enabled
#   |   |-- *.load
#   |   `-- *.conf
#   |-- conf-enabled
#   |   `-- *.conf
#   `-- sites-enabled
#       `-- *.conf
#
#
# * apache2.conf is the main configuration file (this file). It puts the pieces
#   together by including all remaining configuration files when starting up the
#   web server.
#
# * ports.conf is always included from the main configuration file. It is
#   supposed to determine listening ports for incoming connections which can be
#   customized anytime.
#
# * Configuration files in the mods-enabled/, conf-enabled/ and sites-enabled/
#   directories contain particular configuration snippets which manage modules,
#   global configuration fragments, or virtual host configurations,
#   respectively.
#
#   They are activated by symlinking available configuration files from their
#   respective *-available/ counterparts. These should be managed by using our
#   helpers a2enmod/a2dismod, a2ensite/a2dissite and a2enconf/a2disconf. See
#   their respective man pages for detailed information.
#
# * The binary is called apache2. Due to the use of environment variables, in
#   the default configuration, apache2 needs to be started/stopped with
#   /etc/init.d/apache2 or apache2ctl. Calling /usr/bin/apache2 directly will not
#   work with the default configuration.

ServerSignature Off
ServerTokens Prod

# Global configuration
#

#
# ServerRoot: The top of the directory tree under which the server's
# configuration, error, and log files are kept.
#
# NOTE!  If you intend to place this on an NFS (or otherwise network)
# mounted filesystem then please read the Mutex documentation (available
# at <URL:http://httpd.apache.org/docs/2.4/mod/core.html#mutex>);
# you will save yourself a lot of trouble.
#
# Do NOT add a slash at the end of the directory path.
#
#ServerRoot "/etc/apache2"

#
# The accept serialization lock file MUST BE STORED ON A LOCAL DISK.
#
#Mutex file:${APACHE_LOCK_DIR} default

#
# The directory where shm and other runtime files will be stored.
#

DefaultRuntimeDir ${APACHE_RUN_DIR}

#
# PidFile: The file in which the server should record its process
# identification number when it starts.
# This needs to be set in /etc/apache2/envvars
#
PidFile ${APACHE_PID_FILE}

#
# Timeout: The number of seconds before receives and sends time out.
#
Timeout 300

#
# KeepAlive: Whether or not to allow persistent connections (more than
# one request per connection). Set to "Off" to deactivate.
#
KeepAlive On

#
# MaxKeepAliveRequests: The maximum number of requests to allow
# during a persistent connection. Set to 0 to allow an unlimited amount.
# We recommend you leave this number high, for maximum performance.
#
MaxKeepAliveRequests 100

#
# KeepAliveTimeout: Number of seconds to wait for the next request from the
# same client on the same connection.
#
KeepAliveTimeout 5


# These need to be set in /etc/apache2/envvars
User ${APACHE_RUN_USER}
Group ${APACHE_RUN_GROUP}

#
# HostnameLookups: Log the names of clients or just their IP addresses
# e.g., www.apache.org (on) or 204.62.129.132 (off).
# The default is off because it'd be overall better for the net if people
# had to knowingly turn this feature on, since enabling it means that
# each client request will result in AT LEAST one lookup request to the
# nameserver.
#
HostnameLookups Off

# ErrorLog: The location of the error log file.
# If you do not specify an ErrorLog directive within a <VirtualHost>
# container, error messages relating to that virtual host will be
# logged here.  If you *do* define an error logfile for a <VirtualHost>
# container, that host's errors will be logged there and not here.
#
ErrorLog ${APACHE_LOG_DIR}/error.log

#
# LogLevel: Control the severity of messages logged to the error_log.
# Available values: trace8, ..., trace1, debug, info, notice, warn,
# error, crit, alert, emerg.
# It is also possible to configure the log level for particular modules, e.g.
# "LogLevel info ssl:warn"
#
LogLevel warn

# Include module configuration:
IncludeOptional mods-enabled/*.load
IncludeOptional mods-enabled/*.conf

# Include list of ports to listen on
Include ports.conf


# Sets the default security model of the Apache2 HTTPD server. It does
# not allow access to the root filesystem outside of /usr/share and /var/www.
# The former is used by web applications packaged in Debian,
# the latter may be used for local directories served by the web server. If
# your system is serving content from a sub-directory in /srv you must allow
# access here, or in any related virtual host.
<Directory />
  Options FollowSymLinks
  AllowOverride none
  Require all denied
</Directory>

<Directory /usr/share>
  AllowOverride None
  Require all granted
</Directory>

<Directory /var/www/>
  Options -Indexes
  AllowOverride All
  Require all granted
</Directory>

#<Directory /srv/>
#   Options Indexes FollowSymLinks
#   AllowOverride None
#   Require all granted
#</Directory>


# AccessFileName: The name of the file to look for in each directory
# for additional configuration directives.  See also the AllowOverride
# directive.
#
AccessFileName .htaccess

#
# The following lines prevent .htaccess and .htpasswd files from being
# viewed by Web clients.
#
<FilesMatch "^\.ht">
  Require all denied
</FilesMatch>


#
# The following directives define some format nicknames for use with
# a CustomLog directive.
#
# These deviate from the Common Log Format definitions in that they use %O
# (the actual bytes sent including headers) instead of %b (the size of the
# requested file), because the latter makes it impossible to detect partial
# requests.
#
# Note that the use of %{X-Forwarded-For}i instead of %h is not recommended.
# Use mod_remoteip instead.
#
LogFormat "%v:%p %h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" vhost_combined
LogFormat "%h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" combined
LogFormat "%h %l %u %t \"%r\" %>s %O" common
LogFormat "%{Referer}i -> %U" referer
LogFormat "%{User-agent}i" agent

# Include of directories ignores editors' and dpkg's backup files,
# see README.Debian for details.

# Include generic snippets of statements
IncludeOptional conf-enabled/*.conf

# Include the virtual host configurations:
IncludeOptional sites-enabled/*.conf

# vim: syntax=apache ts=4 sw=4 sts=4 sr noet

Virtual Hosts configuration (identical for all VH):

<VirtualHost *:80>
# The ServerName directive sets the request scheme, hostname and port that
# the server uses to identify itself. This is used when creating
# redirection URLs. In the context of virtual hosts, the ServerName
# specifies what hostname must appear in the request's Host: header to
# match this virtual host. For the default virtual host (this file) this
# value is not decisive as it is used as a last resort host regardless.
# However, you must set it for any further virtual host explicitly.
ServerName domen3.name
ServerAlias www.domen3.name

ServerAdmin webmaster@localhost
DocumentRoot /var/www/domen3.name

# Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
# error, crit, alert, emerg.
# It is also possible to configure the loglevel for particular
# modules, e.g.
#LogLevel info ssl:warn

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

# For most configuration files from conf-available/, which are
# enabled or disabled at a global level, it is possible to
# include a line for only one particular virtual host. For example the
# following line enables the CGI configuration for this host only
# after it has been globally disabled with "a2disconf".
#Include conf-available/serve-cgi-bin.conf
RewriteEngine on
RewriteCond %{SERVER_NAME} =domen3.name
RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,NE,R=permanent]

</VirtualHost>

# vim: syntax=apache ts=4 sw=4 sts=4 sr noet

<VirtualHost *:443>
Protocols h2 http/1.1
<IfModule mod_headers.c>
Header always set Strict-Transport-Security "max-age=63072000; includeSubDomains; preload"
</IfModule>
<IfModule mod_ssl.c>
# The ServerName directive sets the request scheme, hostname and port that
# the server uses to identify itself. This is used when creating
# redirection URLs. In the context of virtual hosts, the ServerName
# specifies what hostname must appear in the request's Host: header to
# match this virtual host. For the default virtual host (this file) this
# value is not decisive as it is used as a last resort host regardless.
# However, you must set it for any further virtual host explicitly.
ServerName domen3.name
ServerAlias www.domen3.name

ServerAdmin webmaster@localhost
DocumentRoot /var/www/domen3.name

# Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
# error, crit, alert, emerg.
# It is also possible to configure the loglevel for particular
# modules, e.g.
#LogLevel info ssl:warn

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

# For most configuration files from conf-available/, which are
# enabled or disabled at a global level, it is possible to
# include a line for only one particular virtual host. For example the
# following line enables the CGI configuration for this host only
# after it has been globally disabled with "a2disconf".
#Include conf-available/serve-cgi-bin.conf

SSLCertificateFile /etc/letsencrypt/live/domen3.name/fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/domen3.name/privkey.pem
Include /etc/letsencrypt/options-ssl-apache.conf
</IfModule>
</VirtualHost>
neerro
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  • If Apache cannot match the request to a specific VirtualHost, it will answer the request with the first VirtulaHost configuration it finds in the configuration files (top to bottom). Edit your question and show us your configuration. – Nic3500 Sep 09 '21 at 01:04
  • @Nic3500, I have added an Apache and VH code configuration. – neerro Sep 09 '21 at 09:13

1 Answers1

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You have multiple possible scenarios (since your question is not super clear to me).

Assumptions

  • your server responds to IP 1.1.1.1
  • you use Apache 2.4 or higher

Scenario 1

For http (port 80) traffic only:

Listen 80

<VirtualHost *:80>
    ServerName www.example1.com
    # REST OF CONFIG
</VirtualHost>

<VirtualHost *:80>
    ServerName www.example2.com
    # REST OF CONFIG
</VirtualHost>

<VirtualHost *:80>
    ServerName www.example3.com
    # REST OF CONFIG
</VirtualHost>

Here, if you ask for http://www.example1.com, it will use the first one. http://www.example2.com, it will use the second one, etc.

If you ask for http://1.1.1.1/, Apache does not have a name to select which VirtualHost, so it will use the first one as it is the default. There is no way around this. You do not tell Apache which domain you want, so it defaults.

If you ask for http://www.example4.com, assuming www.example4.com == 1.1.1.1, Apache will again use the first one since it was not able to match any other VirtualHost to that name.

If you ask for http://www.example3.com/some_directory_error, you will receive a 404 message from the third VirtualHost. Whatever domain you ask for, with some illegal path, will be answered by the VirtualHost for that domain. The validity of the request is only checked after the VirtualHost is selected.


Scenario 2

Lets assume that it works for port 80. Now for port 443...

Listen 443

<VirtualHost *:443>
    ServerName www.example1.com
    # REST OF CONFIG
    # SSL for example1
</VirtualHost>

<VirtualHost *:443>
    ServerName www.example2.com
    # REST OF CONFIG
    # SSL for example2
</VirtualHost>

<VirtualHost *:443>
    ServerName www.example3.com
    # REST OF CONFIG
    # SSL for example3
</VirtualHost>

Here, whatever what your request (i.e. https://www.example1.com, https://www.example2.com, https://1.1.1.1/, https://www.example4.com) Apache will always use the first one. This is an SSL limitation.

The reason is that Apache only knows what IP address the requester wanted, but not the domain name. For SSL, Apache must first negotiate with the browser for the cipher, encryption and certificate. Then it will know which VirtualHost to use. So for certificate negotiation, the first VirtualHost for port 443 is always used!

Ways around this are:


Conclusion

You could setup a default VirtualHost. That one is the first one, and does not specify a ServerName or ServerAlias. Only the default DocumentRoot and default 404 configuration. See Apache default VirtualHost


Tip

Split your log files per domain.

# Modify to the desired level
LogLevel debug

Listen 80
<VirtualHost *:80>
    ServerName www.example1.com
    # REST OF CONFIG
    CustomLog logs/example1_80_access.log common
    ErrorLog logs/example1_80_error.log
</VirtualHost>

<VirtualHost *:80>
    ServerName www.example2.com
    # REST OF CONFIG
    CustomLog logs/example2_80_access.log common
    ErrorLog logs/example2_80_error.log
</VirtualHost>

<VirtualHost *:80>
    ServerName www.example3.com
    # REST OF CONFIG
    CustomLog logs/example3_80_access.log common
    ErrorLog logs/example3_80_error.log
</VirtualHost>

This way you will know what is going on, per VirtualHost. You already have a global log file, so any log that does not "belong" to a specific VirtualHost will end up in there (logs/error.log).

Nic3500
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  • Thanks @Nic3500, your answer has been good. Your clear explanation gave me the correct directions in my mind, and I was able to fix these issues. – neerro Aug 09 '22 at 22:46