Nginx

General

• HTTP and reverse proxy server, mail proxy server
• Employs event-based model and OS-dependent mechanisms to efficiently distribute requests among worker processes
• docs
• Beginner's Guide
• Alphabetical List of Directives
• Alphabetical index of VARIABLES - start with dollar sign $, like $uri, $document_root etc...
• Master process - read and evaluate configuration, and maintain worker processes
• Worker processes - do actual processing of requests; # is defined in the configuration file

Configuration File

• Comments start with hash #

Structure

• nginx modules controlled by directives
• two types of directives: simple and block directives
  • simple directive - directive name, followed by params, ends with a semicolon
  • block directives ("context") - same as simple, but instead of semicolon ends with curly braces

Common directives

• Regular expressions parameter arguments for location directives always start with a tilde ~ and usually are between ^ and $ opperators.

Contexts

events

• top-level "main" context, cannot be within another

http

• top-level "main" context, cannot be within another

server

• Within http context only
• Can have multiple server names
• Once nginx decides which server will process the request, it tests the URI specified in the request's header against the location directives defined in the server block.
• Order of precedence is longest to shortest prefix, so location '/' will match last, THEN regular expressions terminating on the first match
• listen on different ports
  • systemctl restart nginx
  • etstat -tlpn| grep nginx
  • semanage port -l
  • semanage port -a -t http_port_t -p tcp 3200
  • semanage port -m -t http_port_t -p tcp 3200

location

• server context, plus nested inside another location directive is possible, i guess?
• Performs mapping of URL to route to static files on server, or proxy, etc.
• The matching is performed against a normalized URI, after decoding the text encoded in the “%XX” form, resolving references to relative path components “.” and “..”, and possible compression of two or more adjacent slashes into a single slash.
• location can be prefix string or regular expression, e.g., location URIPREFIXARG { root /path/to/static/files;}

URI tokens

• Prefacing URI with = token sets up exact match, with search terminating immediately, speeding up processing.
• Prefacing URI with ~ token means case-sensitive matching
• Prefacing URI with ~* token means case-INsensitive matching
• Prefacing URI with ^~ token means TURN REGULAR EXPRESSION MATCHING OFF for the given prefix.
• The “@” prefix defines a named location. Such a location is not used for a regular request processing, but instead used for request redirection.

location directives

• root path;
  • Sets the root directory for requests.
  • SIMPLE mapping URI to filepath on server.
  • Path to the file is constructed by merely adding a URI to the value of the root directive.

• alias path;
  • Has all the functionality of root directive, plus rewrite capabilities
  • If location URI has a regular expression in it, you can use the $1, $2, etc capture groups in the argument to the alias directive.

• try_files file1, [file2, ...] uri|=code;
  • Checks the existence of files in the specified order and uses the first found file for request processing
  • The path to a file is constructed from the file parameter according to the root and alias directives.

• proxy_pass
• fastcgi_pass
• fastcgi_index
• fastcgi_param
• fastcgi_pass

Setup

• LEMP stack on CentOS7

1. yum install nginx
2. systemctl start nginx
3. systemctl enable nginx
4. ip addr show eth0 | grep inet | awk '{ print $2; }' | sed 's/\/.*$//'
5. yum install mariadb-server mariadb
6. systemctl start mariadb
7. mysql_secure_installation
8. systemctl enable mariadb
9. yum install php php-mysql php-fpm
10. vi /etc/php.ini
    1. cgi.fix_pathinfo=0
11. vi /etc/php-fpm.d/www.conf
    1. listen = /var/run/php-fpm/php-fpm.sock
    2. listen.owner = nobody
    3. listen.group = nobody
    4. user = nginx
    5. group = nginx
12. systemctl start php-fpm
13. systemctl enable php-fpm
14. Configure NGINX to to PHP with fpm
15. make a <?php phpinfo(); ?> tag and check that it works

FastCGI

PHP-fpm

• PHP FastCGI Process Manager

Perl

• Perl-FastCGI on Nginx Ubuntu 12.04