docker hub 公式のnginx Dockerfileを元にしてAlpine Linux環境でlua-nginx-moduleをビルドしたメモ

nginxでrequest_bodyの内容によって挙動を変えるような処理をしたかった時に、lua-nginx-moduleを導入した際のメモ。

この記事は以下環境を利用しました。
docker hub 公式のnginx
( https://hub.docker.com/_/nginx/ )
1.15.8-alpine tagのDockerfile
( https://github.com/nginxinc/docker-nginx/blob/2364fdc54af554d28ef95b7be381677d10987986/mainline/alpine/Dockerfile )

lua-nginx-modul導入の大枠の流れとしては以下の手順を参考にして進めています。
https://github.com/openresty/lua-nginx-module#installation
http://luajit.org/install.html
https://github.com/simplresty/ngx_devel_kit#usage-for-users


主な変更、差分
-

#####インストールバージョンと環境変数の指定

```diff:DIFF1
  ENV NGINX_VERSION 1.15.8

+ ENV LUAJIT2_VERSION 2.1-20190131
+ ENV NGX_DEVEL_KIT_VERSION 0.3.1rc1
+ ENV LUA_NGINX_MODULE_VERSION 0.10.14rc5
+
+ ENV LUAJIT_LIB /usr/local/lib
+ ENV LUAJIT_INC /usr/local/include/luajit-2.1
+
  RUN GPG_KEYS=B0F4253373F8F6F510D42178520A9993A1C052F8 \
```

#####各モジュール追加のためのコンフィグオプション部分

```diff:DIFF2
                --with-http_v2_module \
+               --with-ld-opt='-Wl,-rpath,/usr/local/lib' \
+               --add-module=/usr/src/ngx_devel_kit-$NGX_DEVEL_KIT_VERSION \
+               --add-module=/usr/src/lua-nginx-module-$LUA_NGINX_MODULE_VERSION \
        " \
```

#####モジュールのソースコードダウンロード

```diff:DIFF3
        && curl -fSL https://nginx.org/download/nginx-$NGINX_VERSION.tar.gz.asc  -o nginx.tar.gz.asc \
+       && curl -fSL https://github.com/openresty/luajit2/archive/v$LUAJIT2_VERSION.tar.gz -o luajit2.tar.gz \
+       && curl -fSL https://github.com/simplresty/ngx_devel_kit/archive/v$NGX_DEVEL_KIT_VERSION.tar.gz -o ngx_devel_kit.tar.gz \
+       && curl -fSL https://github.com/openresty/lua-nginx-module/archive/v$LUA_NGINX_MODULE_VERSION.tar.gz -o lua-nginx-module.tar.gz \
        && export GNUPGHOME="$(mktemp -d)" \
```

#####ソースコードの展開とluajit2のインストール、利用後ファイルの削除

```diff:DIFF4
        && tar -zxC /usr/src -f nginx.tar.gz \
!       && tar -zxC /usr/src -f luajit2.tar.gz \
!       && tar -zxC /usr/src -f ngx_devel_kit.tar.gz \
!       && tar -zxC /usr/src -f lua-nginx-module.tar.gz \
!       && rm nginx.tar.gz luajit2.tar.gz ngx_devel_kit.tar.gz lua-nginx-module.tar.gz \
!       && cd /usr/src/luajit2-$LUAJIT2_VERSION \
!       && make \
!       && make install \
        && cd /usr/src/nginx-$NGINX_VERSION \
```

#####利用後ディレクトリの削除

```diff:DIFF5
        && strip /usr/lib/nginx/modules/*.so \
!       && rm -rf /usr/src/nginx-$NGINX_VERSION /usr/src/luajit2-$LUAJIT2_VERSION /usr/src/ngx_devel_kit-$NGX_DEVEL_KIT_VERSION /usr/src/lua-nginx-module-$LUA_NGINX_MODULE_VERSION  \
        \
```

#####挙動に必要なライブラリの追加

```diff:DIFF6
        && ln -sf /dev/stderr /var/log/nginx/error.log

+ RUN apk add --no-cache libgcc
+
  COPY nginx.conf /etc/nginx/nginx.conf
```

つまずいた部分
-
つまずいた部分として、上記のようにlibgccを入れておかないと起動時に以下エラーで落ちてしまった点。

```
Error loading shared library libgcc_s.so.1: No such file or directory (needed by /usr/local/lib/libluajit-5.1.so.2)
Error relocating /usr/local/lib/libluajit-5.1.so.2: _Unwind_DeleteException: symbol not found
Error relocating /usr/local/lib/libluajit-5.1.so.2: _Unwind_SetGR: symbol not found
Error relocating /usr/local/lib/libluajit-5.1.so.2: _Unwind_SetIP: symbol not found
Error relocating /usr/local/lib/libluajit-5.1.so.2: _Unwind_GetCFA: symbol not found
Error relocating /usr/local/lib/libluajit-5.1.so.2: _Unwind_RaiseException: symbol not found
```

元々のDockerfileの流れだとコンパイル時に使っていたパッケージを削除してしまうので、lua-nginx-module導入に関連して必要ライブラリが参照できなくてエラーになっていました。

OpenRestyの方でも似たような議論が昔あったのを参考に、libgccを追加するようにしてみました。
https://github.com/openresty/docker-openresty/issues/5

Dockerfile全体
-

```Dockerfile:Dockerfile
FROM alpine:3.9

ENV NGINX_VERSION 1.15.8

ENV LUAJIT2_VERSION 2.1-20190131
ENV NGX_DEVEL_KIT_VERSION 0.3.1rc1
ENV LUA_NGINX_MODULE_VERSION 0.10.14rc5

ENV LUAJIT_LIB /usr/local/lib
ENV LUAJIT_INC /usr/local/include/luajit-2.1

RUN GPG_KEYS=B0F4253373F8F6F510D42178520A9993A1C052F8 \
	&& CONFIG="\
		--prefix=/etc/nginx \
		--sbin-path=/usr/sbin/nginx \
		--modules-path=/usr/lib/nginx/modules \
		--conf-path=/etc/nginx/nginx.conf \
		--error-log-path=/var/log/nginx/error.log \
		--http-log-path=/var/log/nginx/access.log \
		--pid-path=/var/run/nginx.pid \
		--lock-path=/var/run/nginx.lock \
		--http-client-body-temp-path=/var/cache/nginx/client_temp \
		--http-proxy-temp-path=/var/cache/nginx/proxy_temp \
		--http-fastcgi-temp-path=/var/cache/nginx/fastcgi_temp \
		--http-uwsgi-temp-path=/var/cache/nginx/uwsgi_temp \
		--http-scgi-temp-path=/var/cache/nginx/scgi_temp \
		--user=nginx \
		--group=nginx \
		--with-http_ssl_module \
		--with-http_realip_module \
		--with-http_addition_module \
		--with-http_sub_module \
		--with-http_dav_module \
		--with-http_flv_module \
		--with-http_mp4_module \
		--with-http_gunzip_module \
		--with-http_gzip_static_module \
		--with-http_random_index_module \
		--with-http_secure_link_module \
		--with-http_stub_status_module \
		--with-http_auth_request_module \
		--with-http_xslt_module=dynamic \
		--with-http_image_filter_module=dynamic \
		--with-http_geoip_module=dynamic \
		--with-threads \
		--with-stream \
		--with-stream_ssl_module \
		--with-stream_ssl_preread_module \
		--with-stream_realip_module \
		--with-stream_geoip_module=dynamic \
		--with-http_slice_module \
		--with-mail \
		--with-mail_ssl_module \
		--with-compat \
		--with-file-aio \
		--with-http_v2_module \
		--with-ld-opt='-Wl,-rpath,/usr/local/lib' \
		--add-module=/usr/src/ngx_devel_kit-$NGX_DEVEL_KIT_VERSION \
		--add-module=/usr/src/lua-nginx-module-$LUA_NGINX_MODULE_VERSION \
	" \
	&& addgroup -S nginx \
	&& adduser -D -S -h /var/cache/nginx -s /sbin/nologin -G nginx nginx \
	&& apk add --no-cache --virtual .build-deps \
		gcc \
		libc-dev \
		make \
		openssl-dev \
		pcre-dev \
		zlib-dev \
		linux-headers \
		curl \
		gnupg1 \
		libxslt-dev \
		gd-dev \
		geoip-dev \
	&& curl -fSL https://nginx.org/download/nginx-$NGINX_VERSION.tar.gz -o nginx.tar.gz \
	&& curl -fSL https://nginx.org/download/nginx-$NGINX_VERSION.tar.gz.asc  -o nginx.tar.gz.asc \
	&& curl -fSL https://github.com/openresty/luajit2/archive/v$LUAJIT2_VERSION.tar.gz -o luajit2.tar.gz \
	&& curl -fSL https://github.com/simplresty/ngx_devel_kit/archive/v$NGX_DEVEL_KIT_VERSION.tar.gz -o ngx_devel_kit.tar.gz \
	&& curl -fSL https://github.com/openresty/lua-nginx-module/archive/v$LUA_NGINX_MODULE_VERSION.tar.gz -o lua-nginx-module.tar.gz \
	&& export GNUPGHOME="$(mktemp -d)" \
	&& found=''; \
	for server in \
		ha.pool.sks-keyservers.net \
		hkp://keyserver.ubuntu.com:80 \
		hkp://p80.pool.sks-keyservers.net:80 \
		pgp.mit.edu \
	; do \
		echo "Fetching GPG key $GPG_KEYS from $server"; \
		gpg --keyserver "$server" --keyserver-options timeout=10 --recv-keys "$GPG_KEYS" && found=yes && break; \
	done; \
	test -z "$found" && echo >&2 "error: failed to fetch GPG key $GPG_KEYS" && exit 1; \
	gpg --batch --verify nginx.tar.gz.asc nginx.tar.gz \
	&& rm -rf "$GNUPGHOME" nginx.tar.gz.asc \
	&& mkdir -p /usr/src \
	&& tar -zxC /usr/src -f nginx.tar.gz \
	&& tar -zxC /usr/src -f luajit2.tar.gz \
	&& tar -zxC /usr/src -f ngx_devel_kit.tar.gz \
	&& tar -zxC /usr/src -f lua-nginx-module.tar.gz \
	&& rm nginx.tar.gz luajit2.tar.gz ngx_devel_kit.tar.gz lua-nginx-module.tar.gz \
	&& cd /usr/src/luajit2-$LUAJIT2_VERSION \
	&& make \
	&& make install \
	&& cd /usr/src/nginx-$NGINX_VERSION \
	&& ./configure $CONFIG --with-debug \
	&& make -j$(getconf _NPROCESSORS_ONLN) \
	&& mv objs/nginx objs/nginx-debug \
	&& mv objs/ngx_http_xslt_filter_module.so objs/ngx_http_xslt_filter_module-debug.so \
	&& mv objs/ngx_http_image_filter_module.so objs/ngx_http_image_filter_module-debug.so \
	&& mv objs/ngx_http_geoip_module.so objs/ngx_http_geoip_module-debug.so \
	&& mv objs/ngx_stream_geoip_module.so objs/ngx_stream_geoip_module-debug.so \
	&& ./configure $CONFIG \
	&& make -j$(getconf _NPROCESSORS_ONLN) \
	&& make install \
	&& rm -rf /etc/nginx/html/ \
	&& mkdir /etc/nginx/conf.d/ \
	&& mkdir -p /usr/share/nginx/html/ \
	&& install -m644 html/index.html /usr/share/nginx/html/ \
	&& install -m644 html/50x.html /usr/share/nginx/html/ \
	&& install -m755 objs/nginx-debug /usr/sbin/nginx-debug \
	&& install -m755 objs/ngx_http_xslt_filter_module-debug.so /usr/lib/nginx/modules/ngx_http_xslt_filter_module-debug.so \
	&& install -m755 objs/ngx_http_image_filter_module-debug.so /usr/lib/nginx/modules/ngx_http_image_filter_module-debug.so \
	&& install -m755 objs/ngx_http_geoip_module-debug.so /usr/lib/nginx/modules/ngx_http_geoip_module-debug.so \
	&& install -m755 objs/ngx_stream_geoip_module-debug.so /usr/lib/nginx/modules/ngx_stream_geoip_module-debug.so \
	&& ln -s ../../usr/lib/nginx/modules /etc/nginx/modules \
	&& strip /usr/sbin/nginx* \
	&& strip /usr/lib/nginx/modules/*.so \
	&& rm -rf /usr/src/nginx-$NGINX_VERSION /usr/src/luajit2-$LUAJIT2_VERSION /usr/src/ngx_devel_kit-$NGX_DEVEL_KIT_VERSION /usr/src/lua-nginx-module-$LUA_NGINX_MODULE_VERSION  \
	\
	# Bring in gettext so we can get `envsubst`, then throw
	# the rest away. To do this, we need to install `gettext`
	# then move `envsubst` out of the way so `gettext` can
	# be deleted completely, then move `envsubst` back.
	&& apk add --no-cache --virtual .gettext gettext \
	&& mv /usr/bin/envsubst /tmp/ \
	\
	&& runDeps="$( \
		scanelf --needed --nobanner --format '%n#p' /usr/sbin/nginx /usr/lib/nginx/modules/*.so /tmp/envsubst \
			| tr ',' '\n' \
			| sort -u \
			| awk 'system("[ -e /usr/local/lib/" $1 " ]") == 0 { next } { print "so:" $1 }' \
	)" \
	&& apk add --no-cache --virtual .nginx-rundeps $runDeps \
	&& apk del .build-deps \
	&& apk del .gettext \
	&& mv /tmp/envsubst /usr/local/bin/ \
	\
	# Bring in tzdata so users could set the timezones through the environment
	# variables
	&& apk add --no-cache tzdata \
	\
	# forward request and error logs to docker log collector
	&& ln -sf /dev/stdout /var/log/nginx/access.log \
	&& ln -sf /dev/stderr /var/log/nginx/error.log

RUN apk add --no-cache libgcc

COPY nginx.conf /etc/nginx/nginx.conf
COPY nginx.vh.default.conf /etc/nginx/conf.d/default.conf

EXPOSE 80

STOPSIGNAL SIGTERM

CMD ["nginx", "-g", "daemon off;"]
```