1. Install Lapis
2. Install OpenResty
3. Install LuaRocks
4. Setup the database and change pasta/src/config.lua
5. cd pasta && sudo luarocks make
6. cd pasta/src && lapis migrate
7. cd pasta/src && lapis server

If your Nginx has multiple workers, disable cache in config.lua.

You can also use it without OpenResty, but in Nginx with LuaJIT support. In Debian it can be installed with package nginx-extras. Copy file src/nginx.conf.compiled generated by lapis server production to /etc/nginx/sites-available/pasta and add a symlink to it in /etc/nginx/sites-enabled. Change it for your setup and add the following line after content_by_lua:

package.loaded.config = dofile "/path/to/your/config.lua"

See also Nginx configuration used for site pasta.cf: src/nginx-production.