Dynamically bulid nginx.conf #jq #nginx

dynamic-upstreams.sh

#!/bin/bash

upstream_json="upstream-servers.json"

if [ ! -f $upstream_json ]; then
    echo "$upstream_json does not exists"
    return
    exit "$@"
fi

json=$(jq -c '.[]' $upstream_json)

for line in $json
do
    name=$(echo "$line" | jq -r .'upstream.name')
    server=$(echo "$line" | jq -r .'upstream.addresses.address | .[].name');
    
    upstream_block=$(
        printf '%s
        upstream %s {
            server %s;
        }
        ' "$upstream_block" "$name" "$server"
    )
    
    listen=$(echo "$line" | jq -r .'server.listen')
    server_name=$(echo "$line" | jq -r .'server.name')
    path=$(echo "$line" | jq -r .'server.location.path ')
    proxy_pass=$(echo "$line" | jq -r .'server.location.proxy_pass ')
    proxy_redirect=$(echo "$line" | jq -r .'server.location.proxy_redirect ')
    
    server_block=$(
        printf '%s
        server {
            listen %s;
            server_name %s
            location %s {
                proxy_pass %s
                proxy_redirect %s
            }
        }
        ' "$server_block" "$listen" "$server_name" "$path" "$proxy_pass" "$proxy_redirect"
    )
done;


http=$(
    printf '
    sendfile on;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Host $server_name;'
)

echo "worker_processes 1;
events {
    worker_connections 1024;
}
http {
    $http
    $upstream_block
    $server_block
}" > nginx.conf

upstream-servers.json

[
    {
        "upstream": {
            "name": "site_a",
            "addresses": {
                "address": [
                    {
                        "name": "site_a",
                        "args": {}
                    }
                ]
            }
        },
        "server": {
            "name": "my-site-a",
            "listen": 80,
            "location": {
                "path": "/",
                "proxy_pass": "http://site_a;",
                "proxy_redirect": "off"
            }
        }
    },
    {
        "upstream": {
            "name": "site_b",
            "addresses": {
                "address": [
                    {
                        "name": "site_b",
                        "args": {}
                    }
                ]
            }
        },
        "server": {
            "name": "my-site-a",
            "listen": 80,
            "location": {
                "path": "/",
                "proxy_pass": "http://site_b;",
                "proxy_redirect": "off"
            }
        }
    }
]