chore: do not copy useless files into the image

Move required files but 'nginx.tmpl' into a local 'app' folder and copy the
folder content into the image.

'nginx.tmpl' should be moved as well, but this is a breaking change for
configuration with a separate 'docker-gen' container.

app/Procfile

@@ -0,0 +1,2 @@
+dockergen: docker-gen -watch -notify "nginx -s reload" /app/nginx.tmpl /etc/nginx/conf.d/default.conf
+nginx: nginx

app/dhparam/ffdhe2048.pem

@@ -0,0 +1,8 @@
+-----BEGIN DH PARAMETERS-----
+MIIBCAKCAQEA//////////+t+FRYortKmq/cViAnPTzx2LnFg84tNpWp4TZBFGQz
++8yTnc4kmz75fS/jY2MMddj2gbICrsRhetPfHtXV/WVhJDP1H18GbtCFY2VVPe0a
+87VXE15/V8k1mE8McODmi3fipona8+/och3xWKE2rec1MKzKT0g6eXq8CrGCsyT7
+YdEIqUuyyOP7uWrat2DX9GgdT0Kj3jlN9K5W7edjcrsZCwenyO4KbXCeAvzhzffi
+7MA0BM0oNC9hkXL+nOmFg/+OTxIy7vKBg8P+OxtMb61zO7X8vC7CIAXFjvGDfRaD
+ssbzSibBsu/6iGtCOGEoXJf//////////wIBAg==
+-----END DH PARAMETERS-----

app/dhparam/ffdhe3072.pem

@@ -0,0 +1,11 @@
+-----BEGIN DH PARAMETERS-----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+-----END DH PARAMETERS-----

app/dhparam/ffdhe4096.pem

@@ -0,0 +1,13 @@
+-----BEGIN DH PARAMETERS-----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=
+-----END DH PARAMETERS-----

app/docker-entrypoint.sh

@@ -0,0 +1,114 @@
+#!/bin/bash
+set -e
+
+function _parse_true() {
+	case "$1" in
+		
+		true | True | TRUE | 1)
+		return 0
+		;;
+		
+		*)
+		return 1
+		;;
+
+	esac
+}
+
+function _parse_false() {
+	case "$1" in
+		
+		false | False | FALSE | 0)
+		return 0
+		;;
+		
+		*)
+		return 1
+		;;
+
+	esac
+}
+
+function _print_version {
+    if [[ -n "${NGINX_PROXY_VERSION:-}" ]]; then
+        echo "Info: running nginx-proxy version ${NGINX_PROXY_VERSION}"
+    fi
+}
+
+function _check_unix_socket() {
+	# Warn if the DOCKER_HOST socket does not exist
+	if [[ ${DOCKER_HOST} == unix://* ]]; then
+		local SOCKET_FILE="${DOCKER_HOST#unix://}"
+
+		if [[ ! -S ${SOCKET_FILE} ]]; then
+			cat >&2 <<-EOT
+				ERROR: you need to share your Docker host socket with a volume at ${SOCKET_FILE}
+				Typically you should run your nginxproxy/nginx-proxy with: \`-v /var/run/docker.sock:${SOCKET_FILE}:ro\`
+				See the documentation at: https://github.com/nginx-proxy/nginx-proxy/#usage
+			EOT
+
+			exit 1
+		fi
+	fi
+}
+
+function _resolvers() {
+	# Compute the DNS resolvers for use in the templates - if the IP contains ":", it's IPv6 and must be enclosed in []
+	RESOLVERS=$(awk '$1 == "nameserver" {print ($2 ~ ":")? "["$2"]": $2}' ORS=' ' /etc/resolv.conf | sed 's/ *$//g'); export RESOLVERS
+
+	SCOPED_IPV6_REGEX='\[fe80:(:[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]{1,}\]'
+
+	if [[ -z ${RESOLVERS} ]]; then
+		echo 'Warning: unable to determine DNS resolvers for nginx' >&2
+		unset RESOLVERS
+	elif [[ ${RESOLVERS} =~ ${SCOPED_IPV6_REGEX} ]]; then
+		echo -n 'Warning: Scoped IPv6 addresses removed from resolvers: ' >&2
+		echo "${RESOLVERS}" | grep -Eo "$SCOPED_IPV6_REGEX" | paste -s -d ' ' >&2
+		RESOLVERS=$(echo "${RESOLVERS}" | sed -r "s/${SCOPED_IPV6_REGEX}//g" | xargs echo -n); export RESOLVERS
+	fi
+}
+
+function _setup_dhparam() {
+	# DH params will be supplied for nginx here:
+	local DHPARAM_FILE='/etc/nginx/dhparam/dhparam.pem'
+
+	# Should be 2048, 3072, or 4096 (default):
+	local FFDHE_GROUP="${DHPARAM_BITS:=4096}"
+
+	# DH params may be provided by the user (rarely necessary)
+	if [[ -f ${DHPARAM_FILE} ]]; then
+		echo 'Warning: A custom dhparam.pem file was provided. Best practice is to use standardized RFC7919 DHE groups instead.' >&2
+		return 0
+	elif _parse_true "${DHPARAM_SKIP:=false}"; then
+		echo 'Skipping Diffie-Hellman parameters setup.'
+		return 0
+	elif _parse_false "${DHPARAM_GENERATION:=true}"; then
+		echo 'Warning: The DHPARAM_GENERATION environment variable is deprecated, please consider using DHPARAM_SKIP set to true instead.' >&2
+		echo 'Skipping Diffie-Hellman parameters setup.'
+		return 0
+	elif [[ ! ${DHPARAM_BITS} =~ ^(2048|3072|4096)$ ]]; then
+		echo "ERROR: Unsupported DHPARAM_BITS size: ${DHPARAM_BITS}. Use: 2048, 3072, or 4096 (default)." >&2
+		exit 1
+	fi
+
+	echo 'Setting up DH Parameters..'
+
+	# Use an existing pre-generated DH group from RFC7919 (https://datatracker.ietf.org/doc/html/rfc7919#appendix-A):
+	local RFC7919_DHPARAM_FILE="/app/dhparam/ffdhe${FFDHE_GROUP}.pem"
+
+	# Provide the DH params file to nginx:
+	cp "${RFC7919_DHPARAM_FILE}" "${DHPARAM_FILE}"
+}
+
+# Run the init logic if the default CMD was provided
+if [[ $* == 'forego start -r' ]]; then
+	_print_version
+	
+	_check_unix_socket
+
+	_resolvers
+
+	_setup_dhparam
+fi
+
+exec "$@"