How to use nginx as proxy to s3 aws? - node.js

Question

I try to build nginx in docker as proxy to aws s3.
The problem is there is a variables that I don't understand where they come from?
First, this is how my bucket look like:
Inside this bucket I have pic.png file.
When I using nginx I start from docker using docker-compose:
web:
image: nginx
volumes:
- ./example.com.conf:/etc/nginx/conf.d/default.conf
ports:
- '8080:80'
And I start the docker using docker-compose up.
I have my aws_access_key and aws_secret_key from IAM key.
This is how I defined my example.com.conf file:
server {
listen 80;
server_name localhost;
location ~ '^/([^/]+)/(.*)$' {
set $bucket 'my-bucket';
set $key '';
# Setup AWS Authorization header
set $aws_signature '';
# the only reason we need lua is to get the current date
set_by_lua $now "return ngx.cookie_time(ngx.time())";
#the access key
set $aws_access_key 'AKIA6*******';
set $aws_secret_key '1wLXpiNN0***********';
# the actual string to be signed
# see: http://docs.amazonwebservices.com/AmazonS3/latest/dev/RESTAuthentication.html
set $string_to_sign "$request_method\n\n\n\nx-amz-date:$now\n/$bucket/$key";
# create the hmac signature
set_hmac_sha1 $aws_signature $aws_secret_key $string_to_sign;
# encode the signature with base64
set_encode_base64 $aws_signature $aws_signature;
proxy_set_header x-amz-date $now;
proxy_set_header Authorization "AWS $aws_access_key:$aws_signature";
rewrite .* /$key break;
# we need to set the host header here in order to find the bucket
proxy_set_header Host $bucket.s3.amazonaws.com;
rewrite .* /$key break;
# another solution would be to use the bucket in the url
# rewrite .* /$bucket/$key break;
proxy_pass http://s3.amazonaws.com;
}
}
But I getting error when I run docker with nginx:
nginx: [emerg] unknown directive "set_by_lua" in /etc/nginx/conf.d/default.conf:13
So I'm not sure I doing this right.
I need an explanation and an example of how to do it right please.
for example what is $key? what the the request should look like? http://localhost:8080/pic.png?

Answer 1

try to use nginx with lua installed:
web:
image: firesh/nginx-lua
volumes:
- ./example.com.conf:/etc/nginx/conf.d/default.conf
ports:
- '8080:80'
the problem is set_by_lua need nginx to be compiled with ngx_devel_kit
UPDATE
it seems that you miss many modules , I suggest you to use this Dockerfile
example:
docker run -v /path/to/example.com.conf:/etc/nginx/conf.d/default.conf openresty/openresty:centos

Answer 2

An alternative to using lua for proxying S3 is to use njs to do the proxying. This project shows an example with nginx proxying S3 and running in Docker.