How can I use environment variables with lua in nginx container - docker

Question

I want to use nginx on a container and that the nginx will read the environment variables of the container. I've searched and found that using lua modules makes it possible but for some reason I can't load the lua modules on the nginx itself. Please help, adding Dockerfile and nginx.conf
Dockerfile
FROM nginx:1.15-alpine
RUN mkdir -p /run/nginx && \
apk add nginx-mod-http-lua
WORKDIR /usr/src/app
COPY build /usr/src/app/build
COPY mime.types /usr/src/app
COPY nginx.conf /usr/src/app
EXPOSE 8080
CMD [ "nginx", "-c", "/usr/src/app/nginx.conf", "-g", "daemon off;" ]
nginx.conf
load_module /usr/lib/nginx/modules/ndk_http_module.so;
load_module /usr/lib/nginx/modules/ngx_http_lua_module.so;
pcre_jit on;
events {
}
http {
server {
listen 8080;
set_by_lua $db_api 'return os.getenv("DB_API")';
location /db/ {
proxy_pass $db_api;
}
location / {
root /usr/src/app/build;
index index.html;
}
}
}
and these are the errors I get:
2020/09/24 17:06:49 [alert] 1#1: detected a LuaJIT version which is not OpenResty's; many optimizations will be disabled and performance will be compromised (see https://github.com/openresty/luajit2 for OpenResty's LuaJIT or, even better, consider using the OpenResty releases from https://openresty.org/en/download.html)
nginx: [alert] detected a LuaJIT version which is not OpenResty's; many optimizations will be disabled and performance will be compromised (see https://github.com/openresty/luajit2 for OpenResty's LuaJIT or, even better, consider using the OpenResty releases from https://openresty.org/en/download.html)
2020/09/24 17:06:49 [error] 1#1: lua_load_resty_core failed to load the resty.core module from https://github.com/openresty/lua-resty-core; ensure you are using an OpenResty release from https://openresty.org/en/download.html (rc: 2, reason: module 'resty.core' not found:
no field package.preload['resty.core']
no file './resty/core.lua'
no file '/usr/share/luajit-2.1.0-beta3/resty/core.lua'
no file '/usr/local/share/lua/5.1/resty/core.lua'
no file '/usr/local/share/lua/5.1/resty/core/init.lua'
no file '/usr/share/lua/5.1/resty/core.lua'
no file '/usr/share/lua/5.1/resty/core/init.lua'
no file '/usr/share/lua/common/resty/core.lua'
no file '/usr/share/lua/common/resty/core/init.lua'
no file './resty/core.so'
no file '/usr/local/lib/lua/5.1/resty/core.so'
no file '/usr/lib/lua/5.1/resty/core.so'
no file '/usr/local/lib/lua/5.1/loadall.so'
no file './resty.so'
no file '/usr/local/lib/lua/5.1/resty.so'
no file '/usr/lib/lua/5.1/resty.so'
no file '/usr/local/lib/lua/5.1/loadall.so')
nginx: [error] lua_load_resty_core failed to load the resty.core module from https://github.com/openresty/lua-resty-core; ensure you are using an OpenResty release from https://openresty.org/en/download.html (rc: 2, reason: module 'resty.core' not found:
no field package.preload['resty.core']
no file './resty/core.lua'
no file '/usr/share/luajit-2.1.0-beta3/resty/core.lua'
no file '/usr/local/share/lua/5.1/resty/core.lua'
no file '/usr/local/share/lua/5.1/resty/core/init.lua'
no file '/usr/share/lua/5.1/resty/core.lua'
no file '/usr/share/lua/5.1/resty/core/init.lua'
no file '/usr/share/lua/common/resty/core.lua'
no file '/usr/share/lua/common/resty/core/init.lua'
no file './resty/core.so'
no file '/usr/local/lib/lua/5.1/resty/core.so'
no file '/usr/lib/lua/5.1/resty/core.so'
no file '/usr/local/lib/lua/5.1/loadall.so'
no file './resty.so'
no file '/usr/local/lib/lua/5.1/resty.so'
no file '/usr/lib/lua/5.1/resty.so'
no file '/usr/local/lib/lua/5.1/loadall.so')
and this is the docker build and run commands:
docker build -t client:1.0.0 --no-cache .
docker run -p 80:8080 -it -e DB_API=DB_API_URL client:1.0.0

Answer 1

Add env directive in the top and it works with the comments of the question it works