curl Failed to connect to localhost port 80 - nginx

Question

My host's file maps 127.0.0.1 to localhost.
$ curl -I 'localhost'
curl: (7) Failed to connect to localhost port 80: Connection refused
And then
$ curl -I 127.0.0.1
HTTP/1.1 200 OK
Server: nginx/1.2.4
Date: Wed, 09 Apr 2014 04:20:47 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 23 Oct 2012 21:48:34 GMT
Connection: keep-alive
Accept-Ranges: bytes
In my host's file I have
127.0.0.1 localhost
It appears that the curl command fails to recognize entries in /etc/hosts. Can someone explain why?
update: I've yet to try this but I've discovered you can configure nginx to respond to ipv4 and ipv6

Answer 1

Since you have a ::1 localhost line in your hosts file, it would seem that curl is attempting to use IPv6 to contact your local web server.
Since the web server is not listening on IPv6, the connection fails.
You could try to use the --ipv4 option to curl, which should force an IPv4 connection when both are available.

Answer 2

If anyone else comes across this and the accepted answer doesn't work (it didn't for me), check to see if you need to specify a port other than 80. In my case, I was running a rails server at localhost:3000 and was just using curl http://localhost, which was hitting port 80.
Changing the command to curl http://localhost:3000 is what worked in my case.

Answer 3

In my case, the file ~/.curlrc had a wrong proxy configured.

Answer 4

I also had problem with refused connection on port 80. I didn't use localhost.
curl --data-binary "#/textfile.txt" "http://www.myserver.com/123.php"
Problem was that I had umlauts äåö in my textfile.txt.

Answer 5

I've encountered the same error before on my load balancer server. Am working with two servers and a load balancer. on my two servers I have NginX running, but on load balancer I have Haproxy. I discoved that accidentally Nginx was installed on the LB. Solution:
sudo rm /etc/nginx/nginx.conf
sudo rm -rf /etc/nginx/
sudo apt purge nginx
sudo service haproxy restart
Then run the command again curl -I localhost

Answer 6

In my case the problem was resolved when I added to nginx.conf: resolver, events, root and upstream (may be it will be useful for somebody). My nginx.conf (after I fixed the error):
worker_processes 1;
events {
worker_connections 1024;
}
http{
upstream back-stream {
server back:8080;
}
server {
listen 80;
listen [::]:80;
server_name test.com www.test.com;
location / {
root /usr/share/nginx/html;
resolver 121.0.0.11;
proxy_pass http://back-stream;
}
}
}
My docker-compose file:
version: '3.9'
services:
nginx-proxy:
image: nginx:stable-alpine
container_name: nginx-proxy
ports:
- 80:80
- 443:443
volumes:
- ./nginx.conf:/etc/nginx/nginx.conf
networks:
- network
back:
image: "mycustomimage"
container_name: back
restart: unless-stopped
ports:
- '81:8080'
networks:
- network
networks:
network:
driver: bridge

Answer 7

Sometimes You need to make sure the web server is running. In my case, I had forgotten starting the nginx webserver after I had stopped it.
sudo service nginx status
To start it if off:
sudo service nginx start
Note: Replace nginx with apache2 if it is what you are using
curl localhost