Docker: Nginx and php5-fpm dockers are not talking
I’d like to make a fully dockerized Drupal install. My first step is to get containers running with Nginx and php5-fpm, both Debian based. I’m on CoreOS alpha channel (using Digital Ocean.)
My Dockerfiles are the following:
Nginx:
FROM debian
MAINTAINER fvhemert
RUN apt-get update && apt-get install -y nginx && echo "\ndaemon off;" >> /etc/nginx/nginx.conf
CMD ["nginx"]
EXPOSE 80
This container build and runs nicely. I see the default Nginx page on my server ip.
Php5-fpm:
FROM debian
MAINTAINER fvhemert
RUN apt-get update && apt-get install -y \
php5-fpm \
&& sed 's/;daemonize = yes/daemonize = no/' -i /etc/php5/fpm/php-fpm.conf
CMD ["php5-fpm"]
EXPOSE 9000
This container also builds with no problems and it keeps running when started.
I start the php5-fpm container first with:
docker run -d --name php5-fpm freek/php5-fpm:1
Ad then I start Nginx,, linked to php5-fpm:
docker run -d -p 80:80 --link php5-fpm:phpserver --name nginx freek/nginx-php:1
The linking seems to work, there is an entry in /etc/hosts with name phpserver. Both dockers run:
core@dockertest ~ $ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
fd1a9ae0f1dd freek/nginx-php:4 "nginx" 38 minutes ago Up 38 minutes 0.0.0.0:80->80/tcp nginx
3bd12b3761b9 freek/php5-fpm:2 "php5-fpm" 38 minutes ago Up 38 minutes 9000/tcp php5-fpm
I have adjusted some of the config files. For the Nginx container I edited /etc/nginx/sites-enabled/default and changed:
server {
#listen 80; ## listen for ipv4; this line is default and implied
#listen [::]:80 default_server ipv6only=on; ## listen for ipv6
root /usr/share/nginx/www;
index index.html index.htm index.php;
(I added the index.php)
And further on:
location ~ \.php$ {
fastcgi_split_path_info ^(.+\.php)(/.+)$;
# # NOTE: You should have "cgi.fix_pathinfo = 0;" in php.ini
#
# # With php5-cgi alone:
fastcgi_pass phpserver:9000;
# # With php5-fpm:
# fastcgi_pass unix:/var/run/php5-fpm.sock;
fastcgi_index index.php;
include fastcgi_params;
}
In the php5-fpm docker I changed /etc/php5/fpm/php.ini:
cgi.fix_pathinfo=0
php5-fpm runs:
[21-Nov-2014 06:15:29] NOTICE: fpm is running, pid 1
[21-Nov-2014 06:15:29] NOTICE: ready to handle connections
I also changed index.html to index.php, it looks like this (/usr/share/nginx/www/index.php):
<html>
<head>
<title>Welcome to nginx!</title>
</head>
<body bgcolor="white" text="black">
<center><h1>Welcome to nginx!</h1></center>
<?php
phpinfo();
?>
</body>
</html>
I have scanned the 9000 port from the Nginx docker, it appears as closed. Not a good sign of course:
root@fd1a9ae0f1dd:/# nmap -p 9000 phpserver
Starting Nmap 6.00 ( http://nmap.org ) at 2014-11-21 06:49 UTC
Nmap scan report for phpserver (172.17.0.94)
Host is up (0.00022s latency).
PORT STATE SERVICE
9000/tcp closed cslistener
MAC Address: 02:42:AC:11:00:5E (Unknown)
Nmap done: 1 IP address (1 host up) scanned in 0.13 seconds
The Nginx logs:
root@fd1a9ae0f1dd:/# vim /var/log/nginx/error.log
2014/11/20 14:43:46 [error] 13#0: *1 connect() failed (111: Connection refused) while connecting to upstream, client: 194.171.252.110, server: localhost, request: "GET / HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "128.199.60.95"
2014/11/21 06:15:51 [error] 9#0: *1 connect() failed (111: Connection refused) while connecting to upstream, client: 145.15.244.119, server: localhost, request: "GET / HTTP/1.0", upstream: "fastcgi://172.17.0.94:9000", host: "128.199.60.95"
Yes, that goes wrong and I keep getting a 502 bad gateway error when browsing to my Nginx instance.
My question is: What exactly goes wrong? My guess is that I’m missing some setting in the php config files.
EDIT FOR MORE DETAILS: This is the result (from inside the php5-fpm container, after apt-get install net-tools):
root@3bd12b3761b9:/# netstat -tapen
Active Internet connections
(servers and established) Proto Recv-Q Send-Q Local Address
Foreign Address State User Inode PID/Program name
From inside the Nginx container:
root@fd1a9ae0f1dd:/# netstat -tapen
Active Internet connections
(servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State User Inode PID/Program name tcp 0 0 0.0.0.0:80 0.0.0.0:*
LISTEN 0 1875387 -
EDIT2: Progression!
In the php5-fpm container, in the file:
/etc/php5/fpm/pool.d/www.conf
I changed the listen argument from some socket name to:
listen = 9000
Now when I go to my webpage I get the error: "No input file specified."
Probably I have trailing / wrong somewhere. I'll look into it more closely!
EDIT3:
So I have rebuild the dockers with the above mentioned alterations and it seems that they are talking. However, my webpage tells me: "file not found." I'm very sure it has to do with the document that nginx sents to php-fpm but I have no idea how it should look like. I used the defaults when using the socket method which always worked. Now it doesn't work anymore. What should be in /etc/nginx/sites-enabled/default under location ~ .php$ { ?
Answer
The reason it doesn't work is, as you have discovered yourself, that nginx only sends the path of the PHP file to PHP-FPM, not the file itself (which would be quite inefficient). The solution is to use a third, data-only VOLUME container to host the files, and then mount it on both docker instances.
FROM debian
VOLUME /var/www
CMD ['true']
Build the above Dockerfile and create an instance (call it for example: storage-www), then run both the nginx and the PHP-FPM containers with the option:
--volumes-from storage-www
That will work if you run both containers on the same physical server. But you still could use different servers, if you put that data-only container on a networked file-system, such as GlusterFS, which is quite efficient and can be distributed over a large-scale network.
Hope that helps.
Update:
As of 2015, the best way to make persistent links between containers is to use docker-compose.