NGINX cache purge using cache_proxy_bypass

nginx-config-example

location / { 
	add_header X-Cached $upstream_cache_status;
	.... 
	proxy_cache_bypass $http_cache_purge;
	.... 
	proxy_pass ... ;
}

ngx_cache_purge

#!/usr/bin/env bash
echo "Before purging:"
exec 6<>/dev/tcp/127.0.0.1/80
echo -ne "GET $1 HTTP/1.0\r\n\r\n" >&6
while read -r -u 6
do
        if [[ ${REPLY} =~ ^$ ]]; then
                break
        elif [[ ${REPLY} =~ ^(Last-Modified|X-Cached):(.*)$ ]]; then
                case ${BASH_REMATCH[1]} in
                        Last-Modified)
                                echo -ne "\tFile date:\t\t${BASH_REMATCH[2]}\n"
                        ;;
                        X-Cached)
                                echo -ne "\tStatus:\t\t${BASH_REMATCH[2]}\n"
                        ;;
                esac
        fi
done
exec 6>&-
echo "Purging file."
exec 6<>/dev/tcp/127.0.0.1/80
echo -ne "GET $1 HTTP/1.0\r\nCache-Purge: 1\r\n\r\n" >&6
while read -r -u 6
do
        if [[ ${REPLY} =~ ^$ ]]; then
                break
        elif [[ ${REPLY} =~ ^(Last-Modified|X-Cached):(.*)$ ]]; then
                case ${BASH_REMATCH[1]} in
                        Last-Modified)
                                echo -ne "\tFile date:\t\t${BASH_REMATCH[2]}\n"
                        ;;
                        X-Cached)
                                echo -ne "\tStatus:\t\t${BASH_REMATCH[2]}\n"
                        ;;
                esac
        fi
done
exec 6>&-
echo "After purging:"
exec 6<>/dev/tcp/127.0.0.1/80
echo -ne "GET $1 HTTP/1.0\r\n\r\n" >&6
while read -r -u 6
do
        if [[ ${REPLY} =~ ^$ ]]; then
                break
        elif [[ ${REPLY} =~ ^(Last-Modified|X-Cached):(.*)$ ]]; then
                case ${BASH_REMATCH[1]} in
                        Last-Modified)
                                echo -ne "\tFile date:\t\t${BASH_REMATCH[2]}\n"
                        ;;
                        X-Cached)
                                echo -ne "\tStatus:\t\t${BASH_REMATCH[2]}\n"
                        ;;
                esac
        fi
done
exec 6>&-