Overview

Custom nginx image purpose-built to log all requests to a specific port and run as a sidecar. Log everything via Lua things, configure from env (e.g. template config as a pre-start)

Materials

Example nginx configuration:

log_format full_trace '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" "$http_user_agent" '
                      'req_headers: "$req_header" resp_headers: "$resp_header" '
                      '<"$request_body" >"$resp_body"';
server {
  listen 18080;
  lua_need_request_body on;
  set $resp_body "";
  body_filter_by_lua '
    local resp_body = string.sub(ngx.arg[1], 1, 1000)
    ngx.ctx.buffered = (ngx.ctx.buffered or "") .. resp_body
    if ngx.arg[2] then
      ngx.var.resp_body = ngx.ctx.buffered
    end
  ';
  set $req_header "";
  set $resp_header "";
  header_filter_by_lua_block{
    local function join_values(val)
      if type(val) == "table" then
          return table.concat(val, ", ")
      end
      return val
    end
    local h = ngx.req.get_headers();
    for k, v in pairs(h) do
      ngx.var.req_header = ngx.var.req_header .. k.."="..join_values(v).." ";
    end
      local rh = ngx.resp.get_headers();
    for k, v in pairs(rh) do
      ngx.var.resp_header = ngx.var.resp_header .. k.."="..join_values(v).." ";
    end
  }
  error_log /dev/stdout info;
  access_log /var/log/nginx/access.log full_trace;
  location / {
    proxy_pass http://localhost:8080;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
  }
}