Included Tools: OPM & LuaRocks

Several docker-openresty flavors come with package managers for OpenResty and Lua, making it easy to extend your application with community modules.

OPM (OpenResty Package Manager)

OPM is the official package manager for OpenResty, used for distributing both Lua and Nginx C modules.

Availability:

opm is included in most upstream-package-based flavors, particularly the -fat variants (e.g., bookworm-fat, bullseye-fat) and the RPM-based flavors (centos, fedora).

Usage:

• alpine (source-built): The alpine image is minimal and does not include opm's dependencies. To use opm, you must install curl and perl first:

  FROM openresty/openresty:alpine
  
  RUN apk add --no-cache curl perl
  
  # Now you can use opm
  RUN opm get bungle/lua-resty-template

• Debian-based (bullseye, bookworm): The standard images are minimal. To use opm, you can either use the -fat variant or install the openresty-opm package in a custom build:

  FROM openresty/openresty:bookworm
  
  RUN apt-get update && apt-get install -y openresty-opm
  
  RUN opm get bungle/lua-resty-template

LuaRocks

LuaRocks is the package manager for the Lua programming language. It is used to install pure Lua modules or C modules that need to be compiled.

Availability:

LuaRocks is included in the build-from-source flavors (bionic, focal, jammy, noble), the -fat variants (alpine-fat), and the RPM-based flavors (centos, fedora).

It is located at /usr/local/openresty/luajit/bin/luarocks.

Usage:

You can install modules (known as "rocks") in your own Dockerfile like so:

FROM openresty/openresty:jammy

# Install a Lua module for Redis
RUN /usr/local/openresty/luajit/bin/luarocks install lua-resty-redis

# Install a C-based module (requires build tools)
# The 'jammy' image already includes build-essential
RUN /usr/local/openresty/luajit/bin/luarocks install lpeg

LUA_PATH and LUA_CPATH

The images that include LuaRocks have the LUA_PATH and LUA_CPATH environment variables pre-configured. This ensures that Lua modules installed via LuaRocks can be found by require() in your OpenResty application without any extra configuration.