events {
}
http {
include mime.types;
default_type application/octet-stream;
sendfile on;
server {
listen 80;
server_name localhost;
location / {
root /var/www;
autoindex on; # list directory
}
}
}
from: https://gist.github.com/jemmanuel/481bdac23690aa002c894cfc3a691b6f
/path/to/sbin/nginx # just run the command and the daemon will be started
nginx -s [stop|quit|reopen|reload] # send different signals
nginx -t # check configuration file syntax
nginx -c # set configuration file location
nginx -V # this will show the configuration parameters
nginx -g # set configuration directives
Imagine all the directives are functions taking different parameters. Each block enable an environment, and some directives are only available inside a block. Last but not least, configuration is inherited within children blocks.
This is the largest module provides the http functionality
http -> server -> location
A server defines a server or a virtual host
listen [address][:port] [options{default_server|ssl|spdy…]
which address to listen
server_name [hostname1][hostname2…]
accepts wildcards by defualt, also accepts re, in nginx , re starts with `~`
sendfile
this shoule be on to use the `sendfile` system call
root
set the htdocs root
alias
addition htdocs directory
error_page code1 [code2…] [=repalcement code] [@block|URL]
set error page or substitute
access_log
set access log location
log_format
set log format
if_modified_since
define if_modified_since behavior
index // accepts variables
define the index page name
autoindex on|off
shows the directory structure
add_header [name] [value] [always]
add headers, always is set for error codes
expires off|[time_value]|epoch|max
automatically set expires header
charset [charset]|off
set response charset
try_files // accept variables
try to server files in different name
limit_except METHOD1 [METHOD2] {
allow | deny | auth_basic …
}
limit_rate
configure the tranfic
location
allow ip/CIDR/unix/all
deny [see above]
auth_basic on/off
auth-basic_user_file // file_format user:password
satisfy
Request headers are avaiable as $http_[header_name] format Reponse headers are avaible as $sent_http_[header_name] format, but they only exist after the header has been sent. Use set to define variables Important Nginx variables
$arg_XXX Get parameters
$args/$query_string All parameters in a query string
$cookie_XXX Cookie variable
$document_root Root directory of current request
$document_uri/$uri Current serving document
$host Http host header
$hostname Server's hostname
$https 'on' if its https request
$is_args `?` if args exist, empty other wise
$msec Current time in milliseconds
$remote_addr/port/user Remote address/port/user
$request_body `-` if empty
$request_body_file /path/to/temp/file if body was saved
$request_method/time/uri Request method/time/uri
$scheme Http or https
$server_addr This call is expensive
$server_name/port/protocol Server's name/port/protocol
$time_iso8601/local Time
Location [modifiers] pattern {…}
Nothing Accept trailing slash and extra characters
= Exact match, no extra characters
~ Re
~* Case insensitive re
^~ Re, but stops searching for other patterns if conditions are met, this is usually what you want
@ Define a block
This module reverse proxies nginx requests to upstream servers
proxy_pass http(s)://[address|unix_socket|upstream]
upstream [name] {
server address;
...
}
proxy_method METHOD
rewrite the proxy method
proxy_redirect off|default|<url rewrite>
proxy_cache zonename
defines a cache zone
proxy_cache_key [a string consists of $vars]
defines a cache key
proxy_cache_path path [use_temp_path=on|off] [levels=numbers keys_zone=name:size inactive=time max_size=size]
use_temp_path will use the path defined in proxy_temp_path
`levels` is usually 1:2
`keys_zone` defines zone's size in memory
`inactive` TTL
`max_size` the maximum size of the ENTIRE cache
proxy_temp_path
path for proxy temporary files
proxy_cache_methods METHOD1 [METHOD2]
defines the methods used for cache
proxy_cache_min_uses 1
defines how many hits we need to cache the key
proxy_cache_valid code time
defines valid time of cache for each method
proxy_cache_use_stale [updating] [error] [timeout] [invalid_header] [http_500]
whether nginx should use stale content if the following conditions are met
proxy_max_temp_file_size
maximum temp file size of proxy cache
proxy_temp_file_write_size
size of write buffer
proxy_set_body
set the body transferred to backend server
proxy_set_header
set the header transfeerred to backend server
proxy_store
store a binary representation of a request without expiration
proxy_store_access
defines file access of proxy store
proxy_http_version 1.0|1.1
defaults to 1.0, need to be set to 1.1 if you want to use keepalive
proxy_cookie_domain/path
modifies the cookie domain or path on the fly
proxy_timeout and next_stream settings not covered
$proxy_host Hostname of the BACKEND server
$proxy_port Port of the BACKEND server
Nginx has two methods to cache content:
http {
upstream myapp1 {
server srv1.example.com;
server srv2.example.com;
server srv3.example.com;
}
server {
listen 80;
location / {
proxy_pass http://myapp1;
}
}
}
The most important issue is session affinity. By default, nginx uses the round-robin algorithm to maintain no session affinity.
upstream [name] {
server ip:port [weight=1] [fail_timeout=x] [max_fails=x] [backup] [down]
hash $var; // use some variable to distribute the traffic and maintain session affinity
There exists a module called stream which implements TCP layer 4 load balancing, so no http variables can be used
stream {
upstream {
hash $no_http_var;
}
}
Nginx supports FastCGI, WSSI and SCGI, and their directives are identical.
fastcgi_pass address|unix:/path/to/unix.socket|upstream
fastcgi_param PARAM_NAME value // SCRIPT_FILENAME and QUERY_STRINIG is required
fastcgi_store on|off // store generated html file to local disk
fastcgi_cache zonename
Apache still does not know the real ip of remote user, we might need a plugin called mod_rpaf.
External requests originate from the client side. Internal requests are triggered by nginx via specific directives. Internal requests consist of internal redirects and sub-requests.
rewrite [re] [repalcement] [flags], this is the key of rewriting
Note: nginx automatically add query string to the repalcement url, if you don't like that, you should add a ? to the url
You might get yourself into infinite loop, nginx stop that by set max rewrite times to 10, redirect more than 10 times gives a 500 error
If statement
The if statement in nginx is like the if statement in shell script, it uses =/!=/~/-f/-d/-e/-x to determine whether the conditions are met.
https://www.nginx.com/resources/glossary/layer-7-load-balancing/ https://www.nginx.com/resources/glossary/layer-4-load-balancing/ https://www.nginx.com/resources/glossary/load-balancing/ https://www.nginx.com/resources/glossary/round-robin-load-balancing/ https://devcentral.f5.com/articles/intro-to-load-balancing-for-developers-ndash-the-algorithms