nginx interview questions
Top nginx frequently asked interview questions
I have this in Nginx configuration files
text/plain text/html text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript;
but Nginx give error when starting up
[warn]: duplicate MIME type "text/html" in /etc/nginx/nginx.conf:25
What is actually duplicate to text/html? Is it text/plain?
Source: (StackOverflow)
Configuration
- Ubuntu Server 11.10 64 bit
- Amazon AWS, Ec2, hosted on the cloud
- t1.micro instance
Before I write anything else, I'd like to state that I've checked both nginx 502 bad gateway and Nginx + PHP-FPM 502 Bad Gatway threads, which unfortunately haven't helped me in this regard.
The issue appears to be rather common: a misconfiguration of nginx or php-fpm can lead to a 502 Bad Gatway error, which is something that I haven't been able to get rid of. Note that this appears even when I go to my domain root, without specifying any particular directory.
I'm running an Amazon ec2 webserver, with port 9000 enabled, port 80 open, etc.
The question in particular is, how can I get rid of this nasty error? Or, better yet, how can I get php5-fpm to actually work.
What I Have Attempted so Far
Mostly consistent editing of configuration files, notably php-fpm.conf and nginx.conf.
i. php-fpm.conf
I've added the following, which hasn't quite helped much:
;;;;;;;;;;;;;
; Fpm Start ;
;;;;;;;;;;;;;
;pm.start_servers = 20
;pm.min_spare_servers = 5
;pm.max_spare_servers = 35
Now, afterward I tried including my configuration files:
include=/etc/php5/fpm/*.conf
Which only screwed me even further.
Full Configuration
;;;;;;;;;;;;;;;;;;;;;
; FPM Configuration ;
;;;;;;;;;;;;;;;;;;;;;
; All relative paths in this configuration file are relative to PHP's install
; prefix (/usr). This prefix can be dynamicaly changed by using the
; '-p' argument from the command line.
; Include one or more files. If glob(3) exists, it is used to include a bunch of
; files from a glob(3) pattern. This directive can be used everywhere in the
; file.
; Relative path can also be used. They will be prefixed by:
; - the global prefix if it's been set (-p arguement)
; - /usr otherwise
;include=/etc/php5/fpm/*.conf
;;;;;;;;;;;;;;;;;;
; Global Options ;
;;;;;;;;;;;;;;;;;;
[global]
; Pid file
; Note: the default prefix is /var
; Default Value: none
pid = /var/run/php5-fpm.pid
; Error log file
; Note: the default prefix is /var
; Default Value: log/php-fpm.log
error_log = /var/log/php5-fpm.log
; Log level
; Possible Values: alert, error, warning, notice, debug
; Default Value: notice
log_level = notice
; If this number of child processes exit with SIGSEGV or SIGBUS within the time
; interval set by emergency_restart_interval then FPM will restart. A value
; of '0' means 'Off'.
; Default Value: 0
;emergency_restart_threshold = 0
; Interval of time used by emergency_restart_interval to determine when
; a graceful restart will be initiated. This can be useful to work around
; accidental corruptions in an accelerator's shared memory.
; Available Units: s(econds), m(inutes), h(ours), or d(ays)
; Default Unit: seconds
; Default Value: 0
emergency_restart_interval = 0
; Time limit for child processes to wait for a reaction on signals from master.
; Available units: s(econds), m(inutes), h(ours), or d(ays)
; Default Unit: seconds
; Default Value: 0
;process_control_timeout = 0
; Send FPM to background. Set to 'no' to keep FPM in foreground for debugging.
; Default Value: yes
daemonize = no
;;;;;;;;;;;;;
; Fpm Start ;
;;;;;;;;;;;;;
;pm.start_servers = 20
;pm.min_spare_servers = 5
;pm.max_spare_servers = 35
;;;;;;;;;;;;;;;;;;;;
; Pool Definitions ;
;;;;;;;;;;;;;;;;;;;;
; Multiple pools of child processes may be started with different listening
; ports and different management options. The name of the pool will be
; used in logs and stats. There is no limitation on the number of pools which
; FPM can handle. Your system will tell you anyway :)
; To configure the pools it is recommended to have one .conf file per
; pool in the following directory:
include=/etc/php5/fpm/pool.d/*.conf
ii. nginx.conf
In all honesty this configuration is a smattering of a few websites I've visited, but I can tell you that before this 502 Bad Gateway business, the server was running fine (without PHP working. Period.).
The issue primarily lies in the fact that something is terribly, terribly wrong. And now, when I try to do a service php5-fpm restart, it hangs in what I'm guessing is an infinite loop or something, which I can't even CTRL-C out of.
Full Configuration
user www-data;
worker_processes 1;
pid /var/run/nginx.pid;
events {
worker_connections 64;
# multi_accept on;
}
http {
##
# Basic Settings
##
sendfile on;
tcp_nopush off;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 2048;
# server_tokens off;
# server_names_hash_bucket_size 64;
# server_name_in_redirect off;
include /etc/nginx/mime.types;
default_type application/octet-stream;
##
# Logging Settings
##
access_log /var/log/nginx/access.log;
error_log /var/log/nginx/error.log;
##
# Gzip Settings
##
gzip on;
gzip_disable "msie6";
# gzip_vary on;
# gzip_proxied any;
# gzip_comp_level 6;
# gzip_buffers 16 8k;
# gzip_http_version 1.1;
# gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript;
##
# Virtual Host Configs
##
include /etc/nginx/conf.d/*.conf;
include /etc/nginx/sites-enabled/*;
server {
listen 80;
server_name ec2-xx-xx-xx-xx.compute-x.amazonaws.com;
location ~ ^(.+\.php)(.*)$ {
root /home/wayvac/public;
fastcgi_pass unix:/var/run/php5-fpm.pid;
#fastcgi_pass 127.0.0.1:9000; #Un-comment this and comment "fastcgi_pass unix:/var/run/php-fpm/php-fpm.sock;" if you are not using php-fpm.
fastcgi_index index.php;
set $document_root2 $document_root;
if ($document_root2 ~ "^(.*\\\\).*?[\\\\|\/]\.\.\/(.*)$") { set $document_root2 $1$2; }
if ($document_root2 ~ "^(.*\\\\).*?[\\\\|\/]\.\.\/(.*)$") { set $document_root2 $1$2; }
if ($document_root2 ~ "^(.*\\\\).*?[\\\\|\/]\.\.\/(.*)$") { set $document_root2 $1$2; }
if ($document_root2 ~ "^(.*\\\\).*?[\\\\|\/]\.\.\/(.*)$") { set $document_root2 $1$2; }
if ($document_root2 ~ "^(.*\\\\).*?[\\\\|\/]\.\.\/(.*)$") { set $document_root2 $1$2; }
fastcgi_split_path_info ^(.+\.php)(.*)$;
fastcgi_param SCRIPT_FILENAME $document_root2$fastcgi_script_name;
fastcgi_param PATH_INFO $fastcgi_path_info;
fastcgi_param PATH_TRANSLATED $document_root2$fastcgi_path_info;
include fastcgi_params;
fastcgi_param DOCUMENT_ROOT $document_root2;
}
access_log /var/log/nginx/access.log;
error_log /var/log/nginx/error.log;
location / {
root /home/wayvac/public;
index index.html index.htm index.php;
}
location ~* \.(?:ico|css|js|gif|jpe?g|png)$ {
# Some basic cache-control for static files to be sent to the browser
expires max;
add_header Pragma public;
add_header Cache-Control "public, must-revalidate, proxy-revalidate";
}
#include drop.conf;
#include php.conf;
}
}
Source: (StackOverflow)
What to use for a medium to large python WSGI application, Apache + mod_wsgi or Nginx + mod_wsgi?
Which combination will need more memory and CPU time?
Which one is faster?
Which is known for being more stable than the other?
I am also thinking to use CherryPy's WSGI server but I hear it's not very suitable for a very high-load application, what do you know about this?
Note: I didn't use any Python Web Framework, I just wrote the whole thing from scratch.
Note': Other suggestions are also welcome.
Source: (StackOverflow)
I have nginx up and running with a Ruby/Sinatra app and all is well. However, I'm now trying to have a second application running from the same server and I noticed something weird. First, here's my nginx.conf:
pid /tmp/nginx.pid;
error_log /tmp/nginx.error.log;
events {
worker_connections 1024;
accept_mutex off;
}
http {
default_type application/octet-stream;
access_log /tmp/nginx.access.log combined;
sendfile on;
tcp_nopush on;
tcp_nodelay off;
gzip on;
gzip_http_version 1.0;
gzip_proxied any;
gzip_min_length 500;
gzip_disable "MSIE [1-6]\.";
gzip_types text/plain text/xml text/css
text/comma-separated-values
text/javascript application/x-javascript
application/atom+xml;
upstream app {
server unix:/var/www/app/tmp/sockets/unicorn.sock fail_timeout=0;
}
server {
listen 80;
client_max_body_size 4G;
server_name FAKE.COM;
keepalive_timeout 5;
root /var/www/app/public;
location / {
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_redirect off;
if (!-f $request_filename) {
proxy_pass http://app;
break;
}
}
error_page 500 502 503 504 /500.html;
location = /500.html {
root /var/www/app/public;
}
}
}
68,0-1 B
Notice how server_name is set to FAKE.COM yet the server is responding to all hosts that hit that server via other domain names. How can I make that particular server respond only to requests for FAKE.COM?
Source: (StackOverflow)
It seems like I have not clearly communicated my problem. I need to send a file (using AJAX) and I need to get the upload progress of the file using the Nginx HttpUploadProgressModule. I need a good solution to this problem. I have tried with the jquery.uploadprogress plugin, but I am finding myself having to rewrite much of it to get it to work in all browsers and to send the file using AJAX.
All I need is the code to do this and it needs to work in all major browsers (Chrome, Safari, FireFox, and IE). It would be even better If I could get a solution that will handle multiple file uploads.
I am using the jquery.uploadprogress plugin to get the upload progress of a file from the NginxHttpUploadProgressModule. This is inside an iframe for a facebook application. It works in firefox, but it fails in chrome/safari.
When I open the console I get this.
Uncaught ReferenceError: progressFrame is not defined
jquery.uploadprogress.js:80
Any idea how I would fix that?
I would like to also send the file using AJAX when it is completed. How would I implement that?
EDIT:
I need this soon and it is important so I am going to put a 100 point bounty on this question. The first person to answer it will receive the 100 points.
EDIT 2:
Jake33 helped me solve the first problem. First person to leave a response with how to send the file with ajax too will receive the 100 points.
Source: (StackOverflow)
I have setup an nginx server with php5-fpm. When I try to load the site I get a blank page with no errors. Html pages are served fine but not php. I tried turning on display_errors in php.ini but no luck. php5-fpm.log is not producing any errors and neither is nginx.
nginx.conf
server {
listen 80;
root /home/mike/www/606club;
index index.php index.html;
server_name mikeglaz.com www.mikeglaz.com;
error_log /var/log/nginx/error.log;
location ~ \.php$ {
#fastcgi_pass 127.0.0.1:9000;
# With php5-fpm:
fastcgi_pass unix:/var/run/php5-fpm.sock;
fastcgi_index index.php;
include fastcgi_params;
}
}
EDIT
here's my nginx error log:
2013/03/15 03:52:55 [error] 1020#0: *55 open() "/home/mike/www/606club/robots.txt" failed (2: No such file or directory), client: 199.30.20.40, server: mikeglaz.com, request: "GET /robots.txt HTTP/1.1", host: "mikeglaz.com"
Source: (StackOverflow)
I would like to host 2 different domains in the same server using nginx.
I redirected both domains to this host via @ property. Although I configure 2 different server blocks, whenever I try to access second domain, it redirects to first one.
Here is my config.
server {
listen www.domain1.com:80;
access_log /var/log/nginx/host.domain1.access.log main;
root /var/www/domain1;
server_name www.domain1.com;
location ~ \.php$ {
# Security: must set cgi.fixpathinfo to 0 in php.ini!
fastcgi_split_path_info ^(.+\.php)(/.+)$;
fastcgi_pass 127.0.0.1:9000;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_param PATH_INFO $fastcgi_path_info;
include /etc/nginx/fastcgi_params;
}
}
server {
listen www.domain2.com:80;
access_log /var/log/nginx/host.domain2.access.log main;
root /var/www/domain2;
server_name www.domain2.com;
location ~ \.php$ {
# Security: must set cgi.fixpathinfo to 0 in php.ini!
fastcgi_split_path_info ^(.+\.php)(/.+)$;
fastcgi_pass 127.0.0.1:9000;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_param PATH_INFO $fastcgi_path_info;
include /etc/nginx/fastcgi_params;
}
}
How can I fix this?
Thanks.
Source: (StackOverflow)
I'm confused what purpose Mongrel2 serves/provides that nginx doesn't already do.
(Yes, I've read the manual but I must to be too much of a noob to understand how it's fundamentally different than nginx)
My current web application stack is:
- nginx: webserver
- Lua: programming language
- FastCGI + LuaJIT: to connect nginx to Lua
- Postgres: database
Source: (StackOverflow)
I have a wildcard DNS set up so that all web requests to a custom domain (*.foo) map to the IP address of the Docker host. If I have multiple containers running Apache (or Nginx) instances, each container maps the Apache port (80) to some external inbound port.
What I would like to do is make a request to container-1.foo, which is already mapped to the correct IP address (of the Docker host) via my custom DNS server, but proxy the default port 80 request to the correct Docker external port such that the correct Apache instance from the specified container is able to respond based on the custom domain. Likewise, container-2.foo would proxy to a second container's apache, and so on.
Is there a pre-built solution for this, is my best bet to run an Nginx proxy on the Docker host, or should I write up a node.js proxy with the potential to manage Docker containers (start/stop/reuild via the web), or...? What options do I have that would make using the Docker containers more like a natural event and not something with extraneous ports and container juggling?
Source: (StackOverflow)
I have nginx installed with PHP-FPM on a CentOS 5 box, but am struggling to get it to serve any of my files - whether PHP or not.
Nginx is running as www-data:www-data, and the default "Welcome to nginx on EPEL" site (owned by root:root with 644 permissions) loads fine.
The nginx configuration file has an include directive for /etc/nginx/sites-enabled/*.conf, and I have a configuration file example.com.conf, thus:
server {
listen 80;
Virtual Host Name
server_name www.example.com example.com;
location / {
root /home/demo/sites/example.com/public_html;
index index.php index.htm index.html;
}
location ~ \.php$ {
fastcgi_pass 127.0.0.1:9000;
fastcgi_index index.php;
fastcgi_param PATH_INFO $fastcgi_script_name;
fastcgi_param SCRIPT_FILENAME /home/demo/sites/example.com/public_html$fastcgi_script_name;
include fastcgi_params;
}
}
Despite public_html being owned by www-data:www-data with 2777 file permissions, this site fails to serve any content -
[error] 4167#0: *4 open() "/home/demo/sites/example.com/public_html/index.html" failed (13: Permission denied), client: XX.XXX.XXX.XX, server: www.example.com, request: "GET /index.html HTTP/1.1", host: "www.example.com"
I've found numerous other posts with users getting 403s from nginx, but most that I have seen involve either more complex setups with Ruby/Passenger (which in the past I've actually succeeded with) or are only receiving errors when the upstream PHP-FPM is involved, so they seem to be of little help.
Have I done something silly here?
Source: (StackOverflow)
All of a sudden I am getting the below nginx error
* Restarting nginx
* Stopping nginx nginx
...done.
* Starting nginx nginx
nginx: [emerg] bind() to [::]:80 failed (98: Address already in use)
nginx: [emerg] bind() to [::]:80 failed (98: Address already in use)
nginx: [emerg] bind() to [::]:80 failed (98: Address already in use)
nginx: [emerg] bind() to [::]:80 failed (98: Address already in use)
nginx: [emerg] bind() to [::]:80 failed (98: Address already in use)
nginx: [emerg] still could not bind()
...done.
...done.
If I run
lsof -i :80 or sudo fuser -k 80/tcp
I get nothing. Nothing on port 80
Then I run the below:
sudo netstat -pan | grep ":80"
tcp 0 0 127.0.0.1:8070 0.0.0.0:* LISTEN 15056/uwsgi
tcp 0 0 10.170.35.97:39567 10.158.58.13:8080 TIME_WAIT -
tcp 0 0 10.170.35.97:39564 10.158.58.13:8080 TIME_WAIT -
tcp 0 0 10.170.35.97:39584 10.158.58.13:8080 TIME_WAIT -
tcp 0 0 10.170.35.97:39566 10.158.58.13:8080 TIME_WAIT -
tcp 0 0 10.170.35.97:39571 10.158.58.13:8080 TIME_WAIT -
tcp 0 0 10.170.35.97:39580 10.158.58.13:8080 TIME_WAIT -
tcp 0 0 10.170.35.97:39562 10.158.58.13:8080 TIME_WAIT -
tcp 0 0 10.170.35.97:39582 10.158.58.13:8080 TIME_WAIT -
tcp 0 0 10.170.35.97:39586 10.158.58.13:8080 TIME_WAIT -
tcp 0 0 10.170.35.97:39575 10.158.58.13:8080 TIME_WAIT -
tcp 0 0 10.170.35.97:39579 10.158.58.13:8080 TIME_WAIT -
tcp 0 0 10.170.35.97:39560 10.158.58.13:8080 TIME_WAIT -
tcp 0 0 10.170.35.97:39587 10.158.58.13:8080 TIME_WAIT -
tcp 0 0 10.170.35.97:39591 10.158.58.13:8080 TIME_WAIT -
tcp 0 0 10.170.35.97:39589 10.158.58.13:8080 TIME_WAIT -
I am stumped.
How to a debug?
I am using uwsgi with a
proxy pass on port 8070. uwsgi is running. Nginx is not. I am using ubuntu 12.4
Below are the relevant portions of my nginx conf file
upstream uwsgi_frontend {
server 127.0.0.1:8070;
}
server {
listen 80;
server_name 127.0.0.1;
location = /favicon.ico {
log_not_found off;
}
location / {
include uwsgi_params;
uwsgi_buffering off;
uwsgi_pass 127.0.0.1:8070;
}
}
Here is how I install nginx on ubuntu 12.04
nginx=stable;add-apt-repository ppa:nginx/$nginx;
apt-get update
apt get install nginx-full
Source: (StackOverflow)
I need to redirect every http://test.com request to http://www.test.com. How can this be done.
In the server block I tried adding
rewrite ^/(.*) http://www.test.com/$1 permanent;
but in browser it says
The page isn't redirecting properly
Firefox has detected that the server is redirecting the request for
this address in a way that will never complete.
my server block looks like
server {
listen 80;
server_name test.com;
client_max_body_size 10M;
client_body_buffer_size 128k;
root /home/test/test/public;
passenger_enabled on;
rails_env production;
#rewrite ^/(.*) http://www.test.com/$1 permanent;
#rewrite ^(.*)$ $scheme://www.test.com$1;
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
}
Source: (StackOverflow)
I need to serve my app through my app server at 8080, and my static files from a directory without touching the app server. The nginx config I have is something like this...
# app server on port 8080
# nginx listens on port 8123
server {
listen 8123;
access_log off;
location /static/ {
# root /var/www/app/static/;
alias /var/www/app/static/;
autoindex off;
}
location / {
proxy_pass http://127.0.0.1:8080;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}
}
Now, with this config, everything is working fine. Note that the root directive is commented out.
If I activate root and deactivate the alias -- it stops working. However, when I remove the trailing /static/ from the root it starts working again.
Can someone explain what's going on. Also please explain clearly and verbosely what are the differences between root and alias, and their purposes.
Source: (StackOverflow)
I update nginx to 1.4.7 and php to 5.5.12, After that I got the 502 error. Before I update everything works fine.
nginx-error.log
2014/05/03 13:27:41 [crit] 4202#0: *1 connect() to unix:/var/run/php5-fpm.sock failed (13: Permission denied) while connecting to upstream, client: xx.xxx.xx.xx, server: localhost, request: "GET / HTTP/1.1", upstream: "fastcgi://unix:/var/run/php5-fpm.sock:", host: "xx.xx.xx.xx"
nginx.conf
user www www;
worker_processes 1;
location / {
root /usr/home/user/public_html;
index index.php index.html index.htm;
}
location ~ [^/]\.php(/|$) {
fastcgi_split_path_info ^(.+?\.php)(/.*)$;
fastcgi_pass unix:/var/run/php5-fpm.sock;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME /usr/home/user/public_html$fastcgi_script_name;
include fastcgi_params;
}
Source: (StackOverflow)
I am running Django, FastCGI, and Nginx. I am creating an api of sorts that where someone can send some data via XML which I will process and then return some status codes for each node that was sent over.
The problem is that Nginx will throw a 504 Gateway Time-out if I take too long to process the XML -- I think longer than 60 seconds.
So I would like to set up Nginx so that if any requests matching the location /api will not time out for 120 seconds. What setting will accomplish that.
What I have so far is:
# Handles all api calls
location ^~ /api/ {
proxy_read_timeout 120;
proxy_connect_timeout 120;
fastcgi_pass 127.0.0.1:8080;
}
Edit: What I have is not working :)
Source: (StackOverflow)