TL;DR :
I have an application consisting in a nginx container linked to a php container and I get a connection refused (502 - Bad Gateway in the browser) if I try to reach my app while using a fully unrestricted (0777 mode) unix socket that both containers have access to.
I use docker-compose to manage my app and it runs on OSX with a docker-machine.
My problem :
I've set up a little project with two containers (nginx+php) and it works well with TCP sockets.
But I'd like to switch to unix sockets, and I get a 502 - Bad Gateway and the following logs when trying to reach my app :
nginx_1 | 2017/07/27 19:12:09 [error] 5#5: *1 connect() to unix:/sock/php.sock failed (111: Connection refused) while connecting to upstream, client: 192.168.99.1, server: 192.168.99.100, request: "GET / HTTP/1.1", upstream: "fastcgi://unix:/sock/php.sock:", host: "192.168.99.100:10080"
nginx_1 | 192.168.99.1 - - [27/Jul/2017:19:12:09 +0000] "GET / HTTP/1.1" 502 173 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:52.0) Gecko/20100101 Firefox/52.0"
nginx_1 | 192.168.99.1 - - [27/Jul/2017:19:12:09 +0000] "GET /favicon.ico HTTP/1.1" 502 173 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:52.0) Gecko/20100101 Firefox/52.0"
I've made the directory containing the sockets a named volume mounted on both containers (cf. docker-compose.yml bellow)
I don't understand why since the unix socket is accessible from both containers and is fully unrestricted :
From the php container :
/sock # ls -la
total 8
drwxrwxrwx 2 root root 4096 Jul 27 17:56 .
drwxr-xr-x 57 root root 4096 Jul 27 17:33 ..
-rwxrwxrwx 1 root root 0 Jul 27 17:30 php.sock
From the nginx container :
# cd /sock
# ls -la
total 8
drwxrwxrwx 2 root root 4096 Jul 27 17:56 .
drwxr-xr-x 31 root root 4096 Jul 27 17:33 ..
-rwxrwxrwx 1 root root 0 Jul 27 17:30 php.sock
I checked : modifying the /sock content in one container modifies also the content of the same directory in the other container.
What could the problem be?
Details about my project :
My project consists in the following arborescence :
.
├── docker-compose.yml
├── index.php
├── services
│ ├── app
│ │ └── Dockerfile
│ └── nginx
│ └── nginx.conf
├── [Other php sources files and directories]
└── static
└── foo.html
Here is my docker-compose.yml :
version: '3'
services:
db: # I have no problem with the DB so far.
image: mysql
environment:
- MYSQL_ROOT_PASSWORD=XXXXXXXX
- MYSQL_USER=XXXXXXXX
- MYSQL_PASSWORD=XXXXXXXX
- MYSQL_DATABASE=XXXXXXXX
volumes:
- /var/lib/app/app_DB:/var/lib/mysql
nginx:
image: nginx
volumes:
- /var/lib/app/media:/var/www/media:ro
- /Users/vmonteco/Code/web/app/static:/var/www/static:ro
- /Users/vmonteco/Code/web/app/services/nginx/nginx.conf:/etc/nginx/nginx.conf:ro
- /Users/vmonteco/Code/web/app:/var/www/html:ro
- unix_socket:/sock
ports:
- "10080:80"
- "10443:443"
app:
build:
context: services/app
# ports:
# - "19000:9000"
links:
- db
volumes:
- /var/lib/app/media:/var/www/media
- /Users/vmonteco/Code/web/app/static:/var/www/static:ro
- /Users/vmonteco/Code/web/app:/var/www/html:ro
- unix_socket:/sock
depends_on:
- db
volumes:
unix_socket:
Here is the app Dockerfile :
FROM php:7.1-fpm-alpine
RUN docker-php-ext-install pdo pdo_mysql
RUN mkdir /sock && chmod -R 777 /sock
VOLUME /sock
RUN sed -i '/;listen.mode = 0660/c\listen.mode = 0777' /usr/local/etc/php-fpm.d/www.conf && sed -i '/listen = 127.0.0.1:9000/c\listen = /sock/php.sock' /usr/local/etc/php-fpm.d/www.conf
The nginx configuration file :
worker_processes 1;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
sendfile on;
keepalive_timeout 65;
root /var/www/html/;
server {
listen 80;
server_name 192.168.99.100;
location /media/ {
alias /var/www/media/;
autoindex off;
}
location /static/ {
alias /var/www/static/;
autoindex off;
}
location / {
try_files $uri $uri/ /index.php;
index index.html index.php;
}
location ~ \.php$ {
#try_files $uri =404;
#fastcgi_pass 192.168.99.100:19000;
fastcgi_pass unix:/sock/php.sock;
fastcgi_split_path_info ^(.+\.php)(/.*)$;
include fastcgi_params;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_param HTTPS off;
fastcgi_index index.php;
}
}
}
(note that I have no problem to access /static/ or /media/ URLs.)
And all the uncommented lines in /usr/local/etc/php-fpm.d/www.conf file in the php container, that is modified at build :
[www]
user = www-data
group = www-data
listen = /sock/php.sock
listen.mode = 0777
pm = dynamic
pm.max_children = 5
pm.start_servers = 2
pm.min_spare_servers = 1
pm.max_spare_servers = 3
