conky-config/conky.conf

--------------------------------------------------------------------------------
-- Loading Sequence Overview
--
-- Since this is the most over-engineered conky config ever (actually probably),
-- here are the approximate loading steps:
--
-- 1. bootstrap (this file)
--    1. set up paths
--    2. find valid config (a yaml file, see convoluted reasoning below)
--    3. set up conky variables
-- 2. run startup hook which does some insane dark magic including
--    1. arranging all modules on the screen
--    2. 'compiling' super fast functions that don't make computer lag
--    3. pre-drawing all the crap that doesn't change
--    4. checking various paths/exes so things don't crash for unknown reasons
-- 3. run main loop
--
-- NOTE: For all brave souls/AIs trying to understand this program, the biggest
-- 'hack' is the fact that this file (conky.conf) is actually not really a
-- config file. The 'real' config file is a yaml file which is validated
-- using a yaml schema. This file is effectively a bootstrap file, but it is
-- not meant to be 'configured' when migrating to a new machine.
--
-- Why bother doing this? Because I got tired of hacking my hard-coded config
-- when switching to different machines.

--------------------------------------------------------------------------------
-- set up paths

local conky_dir = debug.getinfo(1).source:match("@?(.*/)")
local subdirs = {
   'src/?.lua',
   'src/modules/?.lua',
   'src/widget/?.lua',
   'src/widget/arc/?.lua',
   'src/widget/text/?.lua',
   'src/widget/timeseries/?.lua',
   'src/widget/rect/?.lua',
   'src/widget/line/?.lua',
   'lib/share/lua/5.4/?.lua',
   'lib/share/lua/5.4/?/init.lua',
}

for i = 1, #subdirs do
   subdirs[i] = conky_dir..subdirs[i]
end

package.path = table.concat(subdirs, ';')

package.cpath = conky_dir..'lib/lib/lua/5.4/?.so;'

--------------------------------------------------------------------------------
-- select global config to use (fallback to default if none found)

local yaml = require 'lyaml'
local i_o = require 'i_o'
local validate = require 'validate'

local config_path = '/tmp/conky.yml'

local try_read_config = function(path)
   local cmd = string.format('dhall-to-yaml --file %s > %s', path, config_path)
   return i_o.exit_code_cmd(cmd)
end

local find_valid_config = function(paths)
   for i = 1, #paths do
      local path = paths[i]
      local rc = try_read_config(path)
      if rc == 0 then
         i_o.infof('Using config at %s', path)
         local config = yaml.load(i_o.read_file(config_path))
         validate.validate_config(config)
         return config
      else
         i_o.warnf('could not read %s; trying next', path)
      end
   end
   i_o.assertf(false, 'could not load valid config')
end

local get_config_dir = function()
   return (os.getenv("XDG_CONFIG_HOME") or os.getenv("HOME")..'/.config')..'/'
end

local try_config_paths = {
   get_config_dir()..'conky.dhall',
   conky_dir..'config/fallback.dhall'
}

local config = find_valid_config(try_config_paths)

local bootstrap = config.bootstrap

local startup_hook = string.format(
   'start %f %s %s %s',
   bootstrap.update_interval,
   config_path,
   package.path,
   package.cpath
)

conky.config = {
	background = false,

	-- adjust cpu dial sensitivity (1-14)
	cpu_avg_samples = 4,
	net_avg_samples = 1,

	out_to_console = false,

	own_window = true,
	own_window_type = 'override',
	own_window_transparent = true,
	own_window_hints = 'undecorated,below,sticky,skip_taskbar,skip_pager',
    xinerama_head = 0,

	double_buffer = true,
	minimum_width = bootstrap.dimensions.x,
	minimum_height = bootstrap.dimensions.y,

	draw_shades = false,
	draw_outline = false,
	draw_borders = false,
	gap_x = 0,
	gap_y = 0,
	alignment = 'top_left',

	no_buffers = true,

	-- Lua Load
	lua_load = conky_dir..'main.lua',
	lua_draw_hook_post = 'main',
	lua_startup_hook = startup_hook
}

--control updates entirely in lua

conky.text = [[]]