Fargate: Unable to reach my PHP container from my other containers - php

Question

I have a task that has two containers on fargate: one java and one php/nginx container.
The java container maps its internal port 80 to the extenral port 8080 and the php container maps its internal port 80 to the external port 8081.
The task is using the awsvpc network mode. According to the aws documentation, they should be able to communicate with each other via localhost once they are on fargate.
I tried testing this by having the Java container send a request to the PHP container using "localhost:8081":
public boolean isPHPReachable() {
System.out.println("Attempting to make request to PHP");
try {
final URL url = new URL("http://localhost:8081/test");
final HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setRequestMethod("GET");
final int status = con.getResponseCode();
System.out.printf("Get request to PHP resulted in a %d: %s", status, con.getResponseMessage());
return status == 200;
} catch (final IOException err) {
err.printStackTrace();
return false;
}
The php code it should be hitting is this:
<?php
if ($_GET['q'] === 'test') {
echo('healthy');
die;
}
The 'q' is set by nginx (see below config).
However,I see that the cloudwatch logs are showing an eror when Java tries to send PHP the request:
22:55:04
Attempting to make request to PHP
22:55:04
java.net.ConnectException: Connection refused (Connection refused)
I tried to contact the PHP container directly, but I get timedout. This does not occur when I attempt to reach Java.
Potential Problem 1: Nginx is misconfigured
I suspect this might be an nginx issue. However, I am not able to reproduce the problem when I create the PHP container on my local machine -- it's reachable when I ping localhost:8081.
The problem is only occuring in Fargate.
Here is my configuration:
# For more information on configuration, see:
# * Official English Documentation: http://nginx.org/en/docs/
# * Official Russian Documentation: http://nginx.org/ru/docs/
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;
# Load dynamic modules. See /usr/share/doc/nginx/README.dynamic.
include /usr/share/nginx/modules/*.conf;
events {
worker_connections 1024;
}
http {
log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';
access_log /var/log/nginx/access.log main;
sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 2048;
include /etc/nginx/mime.types;
default_type application/octet-stream;
# Load modular configuration files from the /etc/nginx/conf.d directory.
# See http://nginx.org/en/docs/ngx_core_module.html#include
# for more information.
include /etc/nginx/conf.d/*.conf;
server {
# Reject requests not matching any server block
listen 80 default_server;
server_name "";
return 410;
}
server {
listen 80;
root /var/www/public_html;
server_name localhost;
index index.php;
set_real_ip_from 0.0.0.0/0; # we trust that the webserver is firewalled
real_ip_header X-Forwarded-For;
set $webroot $document_root;
error_page 404 410 /404_empty.html;
autoindex off;
# Disable server signature
# (i.e. remove "nginx 1.10" or similar from error pages and response headers)
server_tokens off;
#################
# PHP locations #
#################
location / {
rewrite ^/(.*)$ /sites/all/index.php?q=$1;
error_page 404 /sites/all/index.php;
}
}
2. Misconfigured security groups:
I do not believe this is the case. The security group attached to this container allows inbound TCP requests to any port from any destination. It also allows all outbound requests.
Anyone spot an immediate issue? Any debugging tips?