fix(?): use nix to install lua and lua-language-server

Dockerfile

@@ -1,34 +1,7 @@
 # TODO: Use official alpine image with pinned package versions when lua-language-server is available
-FROM lspcontainers/lua-language-server:latest AS lua
+FROM nixos/nix:2.13.1 AS sumneko-lint
 
-ENV LUA_VERSION="5.1.5"
-ENV LUA_SHA1_CHECKSUM="b3882111ad02ecc6b972f8c1241647905cb2e3fc"
-
-RUN set -ex \
-    && cat /etc/*-release \
-    && apk upgrade \
-    && apk add --no-cache readline-dev \
-    && apk add --no-cache --virtual .build-deps \
-        make \
-        gcc \
-        libc-dev \
-        ncurses-dev \
-    && wget -cq https://www.lua.org/ftp/lua-${LUA_VERSION}.tar.gz \
-        -O lua.tar.gz \
-    && [ "$(sha1sum lua.tar.gz | cut -d' ' -f1)" = "${LUA_SHA1_CHECKSUM}" ] \
-    && tar -xzf lua.tar.gz \
-    && rm lua.tar.gz
-
-WORKDIR /lua-${LUA_VERSION}
-RUN make -j"$(nproc)" linux \
-    && make install
-
-WORKDIR /
-RUN rm -rf lua-${LUA_VERSION} \
-    && apk del .build-deps \
-    && rm -rf /var/cache/apk/*
-
-FROM lua AS sumneko-lint
+RUN nix-env -iA nixpkgs.lua5_1 nixpkgs.sumneko-lua-language-server
 
 COPY lua/entrypoint.lua /entrypoint.lua
 

lua/entrypoint.lua

@@ -66,7 +66,6 @@ local function lint(directory)
   local redirect = ' >' .. stdout_file .. ' 2>' .. stderr_file
   print(cmd)
   local exit_code = os.execute(cmd .. redirect)
-  os.execute('lua-language-server --version > stdout.txt')
   local stdout = read_file(stderr_file) or ''
   print(stdout)
   if exit_code ~= 0 then