git: 3cb2f5f369ec - main - lualoader: add support for .lua configuration files
Date: Thu, 11 May 2023 04:11:15 UTC
The branch main has been updated by kevans:
URL: https://cgit.FreeBSD.org/src/commit/?id=3cb2f5f369ecfd6d15aeff2b47e21866551a20de
commit 3cb2f5f369ecfd6d15aeff2b47e21866551a20de
Author: Kyle Evans <kevans@FreeBSD.org>
AuthorDate: 2023-05-11 04:10:53 +0000
Commit: Kyle Evans <kevans@FreeBSD.org>
CommitDate: 2023-05-11 04:10:53 +0000
lualoader: add support for .lua configuration files
If a file is specified in loader_conf_files that ends in '.lua', lualoader
will now load and execute that file. These may be used in place of a
traditional loader.conf to use more complicated logic, where some values
may be set based on others or based on the environment that the C bits has
left us with.
Lua scripts are run in a limited environment. In particular, it does not get
access to any modules or, in-fact, anything except environment variable.
A config.buildenv hook has been added so that a local module can add
whatever it may need to to the environment.
When a global var is set in the lua script, it does not immediately alter
the loader environment. Instead, the script's environment is initially
empty and processed only if the whole script executes successfully.
Effectively, a lua configuration file either takes effect or it does not,
an error will not leave it in a half-baked state.
Reviewed by: bcr (manpages), imp
Differential Revision: https://reviews.freebsd.org/D28450
---
stand/defaults/loader.conf.5 | 3 ++
stand/lua/Makefile | 3 +-
stand/lua/config.lua | 90 +++++++++++++++++++++++++++++++++++++++-----
stand/lua/config.lua.8 | 8 ++++
stand/lua/hook.lua | 4 +-
stand/lua/hook.lua.8 | 4 +-
stand/lua/loader.conf.lua.5 | 77 +++++++++++++++++++++++++++++++++++++
7 files changed, 175 insertions(+), 14 deletions(-)
diff --git a/stand/defaults/loader.conf.5 b/stand/defaults/loader.conf.5
index 23a65935c95a..53c69f0f673c 100644
--- a/stand/defaults/loader.conf.5
+++ b/stand/defaults/loader.conf.5
@@ -427,10 +427,13 @@ It is not available in the default Forth-based loader.
default settings \(em do not change this file.
.It Pa /boot/loader.conf
user defined settings.
+.It Pa /boot/loader.conf.lua
+user defined settings written in lua.
.It Pa /boot/loader.conf.local
machine-specific settings for sites with a common loader.conf.
.El
.Sh SEE ALSO
+.Xr loader.conf.lua 5 ,
.Xr rc.conf 5 ,
.Xr boot 8 ,
.Xr cpucontrol 8 ,
diff --git a/stand/lua/Makefile b/stand/lua/Makefile
index fe6fd6f63c8e..bc7c294dfda0 100644
--- a/stand/lua/Makefile
+++ b/stand/lua/Makefile
@@ -2,7 +2,8 @@
.include <bsd.init.mk>
-MAN= cli.lua.8 \
+MAN= loader.conf.lua.5 \
+ cli.lua.8 \
color.lua.8 \
config.lua.8 \
core.lua.8 \
diff --git a/stand/lua/config.lua b/stand/lua/config.lua
index 04d5cda1e704..36be2b6b121e 100644
--- a/stand/lua/config.lua
+++ b/stand/lua/config.lua
@@ -45,6 +45,7 @@ local MSG_FAILSETENV = "Failed to '%s' with value: %s"
local MSG_FAILOPENCFG = "Failed to open config: '%s'"
local MSG_FAILREADCFG = "Failed to read config: '%s'"
local MSG_FAILPARSECFG = "Failed to parse config: '%s'"
+local MSG_FAILEXECLUA = "Failed to execute lua conf '%s': '%s'"
local MSG_FAILPARSEVAR = "Failed to parse variable '%s': %s"
local MSG_FAILEXBEF = "Failed to execute '%s' before loading '%s'"
local MSG_FAILEXAF = "Failed to execute '%s' after loading '%s'"
@@ -244,13 +245,15 @@ end
--
local pattern_table = {
{
+ luaexempt = true,
str = "(#.*)",
process = function(_, _) end,
groups = 1,
},
-- module_load="value"
{
- str = MODULEEXPR .. "_load%s*=%s*$VALUE",
+ name = MODULEEXPR .. "_load%s*",
+ val = "%s*$VALUE",
process = function(k, v)
if modules[k] == nil then
modules[k] = {}
@@ -261,7 +264,8 @@ local pattern_table = {
},
-- module_name="value"
{
- str = MODULEEXPR .. "_name%s*=%s*$VALUE",
+ name = MODULEEXPR .. "_name%s*",
+ val = "%s*$VALUE",
process = function(k, v)
setKey(k, "name", v)
setEnv(k .. "_name", v)
@@ -269,7 +273,8 @@ local pattern_table = {
},
-- module_type="value"
{
- str = MODULEEXPR .. "_type%s*=%s*$VALUE",
+ name = MODULEEXPR .. "_type%s*",
+ val = "%s*$VALUE",
process = function(k, v)
setKey(k, "type", v)
setEnv(k .. "_type", v)
@@ -277,7 +282,8 @@ local pattern_table = {
},
-- module_flags="value"
{
- str = MODULEEXPR .. "_flags%s*=%s*$VALUE",
+ name = MODULEEXPR .. "_flags%s*",
+ val = "%s*$VALUE",
process = function(k, v)
setKey(k, "flags", v)
setEnv(k .. "_flags", v)
@@ -285,7 +291,8 @@ local pattern_table = {
},
-- module_before="value"
{
- str = MODULEEXPR .. "_before%s*=%s*$VALUE",
+ name = MODULEEXPR .. "_before%s*",
+ val = "%s*$VALUE",
process = function(k, v)
setKey(k, "before", v)
setEnv(k .. "_before", v)
@@ -293,7 +300,8 @@ local pattern_table = {
},
-- module_after="value"
{
- str = MODULEEXPR .. "_after%s*=%s*$VALUE",
+ name = MODULEEXPR .. "_after%s*",
+ val = "%s*$VALUE",
process = function(k, v)
setKey(k, "after", v)
setEnv(k .. "_after", v)
@@ -301,7 +309,8 @@ local pattern_table = {
},
-- module_error="value"
{
- str = MODULEEXPR .. "_error%s*=%s*$VALUE",
+ name = MODULEEXPR .. "_error%s*",
+ val = "%s*$VALUE",
process = function(k, v)
setKey(k, "error", v)
setEnv(k .. "_error", v)
@@ -309,7 +318,9 @@ local pattern_table = {
},
-- exec="command"
{
- str = "exec%s*=%s*" .. QVALEXPR,
+ luaexempt = true,
+ name = "exec%s*",
+ val = "%s*" .. QVALEXPR,
process = function(k, _)
if cli_execute_unparsed(k) ~= 0 then
print(MSG_FAILEXEC:format(k))
@@ -319,7 +330,8 @@ local pattern_table = {
},
-- env_var="value" or env_var=[word|num]
{
- str = "([%w][%w%d-_.]*)%s*=%s*$VALUE",
+ name = "([%w][%w%d-_.]*)%s*",
+ val = "%s*$VALUE",
process = function(k, v)
local pv, msg = processEnvVar(v)
if not pv then
@@ -328,6 +340,8 @@ local pattern_table = {
end
if setEnv(k, pv) ~= 0 then
print(MSG_FAILSETENV:format(k, v))
+ else
+ return pv
end
end,
},
@@ -486,6 +500,18 @@ local function checkNextboot()
loader.setenv("nextboot_enable", "NO")
end
+local function processEnv(k, v)
+ for _, val in ipairs(pattern_table) do
+ if not val.luaexempt and val.name then
+ local matched = k:match(val.name)
+
+ if matched then
+ return val.process(matched, v)
+ end
+ end
+ end
+end
+
-- Module exports
config.verbose = false
@@ -511,7 +537,47 @@ function config.processFile(name, silent)
return silent
end
- return config.parse(text)
+ if name:match(".lua$") then
+ local cfg_env = setmetatable({}, {
+ indices = {},
+ __index = function(env, key)
+ if getmetatable(env).indices[key] then
+ return rawget(env, key)
+ end
+
+ return loader.getenv(key)
+ end,
+ __newindex = function(env, key, val)
+ getmetatable(env).indices[key] = true
+ rawset(env, key, val)
+ end,
+ })
+
+ -- Give local modules a chance to populate the config
+ -- environment.
+ hook.runAll("config.buildenv", cfg_env)
+ local res, err = pcall(load(text, name, "t", cfg_env))
+ if res then
+ for k, v in pairs(cfg_env) do
+ local t = type(v)
+ if t ~= "function" and t ~= "table" then
+ if t ~= "string" then
+ v = tostring(v)
+ end
+ local pval = processEnv(k, v)
+ if pval then
+ setEnv(k, pval)
+ end
+ end
+ end
+ else
+ print(MSG_FAILEXECLUA:format(name, err))
+ end
+
+ return res
+ else
+ return config.parse(text)
+ end
end
-- silent runs will not return false if we fail to open the file
@@ -522,6 +588,9 @@ function config.parse(text)
for line in text:gmatch("([^\n]+)") do
if line:match("^%s*$") == nil then
for _, val in ipairs(pattern_table) do
+ if val.str == nil then
+ val.str = val.name .. "=" .. val.val
+ end
local pattern = '^%s*' .. val.str .. '%s*(.*)';
local cgroups = val.groups or 2
local k, v, c = checkPattern(line, pattern)
@@ -805,6 +874,7 @@ function config.getModuleInfo()
}
end
+hook.registerType("config.buildenv")
hook.registerType("config.loaded")
hook.registerType("config.reloaded")
hook.registerType("kernel.loaded")
diff --git a/stand/lua/config.lua.8 b/stand/lua/config.lua.8
index 4fc51c90045f..cf4316204008 100644
--- a/stand/lua/config.lua.8
+++ b/stand/lua/config.lua.8
@@ -217,11 +217,19 @@ as well as a representation of
The following hooks are defined in
.Nm :
.Bl -tag -width "config.reloaded" -offset indent
+.It Fn config.buildenv env
.It Fn config.loaded
.It Fn config.reloaded
.It Fn kernel.loaded
.It Fn modules.loaded
.El
+.Pp
+Note that the
+.Fn config.buildenv
+hook is only invoked when an environment needs to be built to execute a lua
+configuration file that has been specified in
+.Ev loader_conf_files .
+It will be invoked for each configuration file encountered.
.Sh SEE ALSO
.Xr loader.conf 5 ,
.Xr loader 8 ,
diff --git a/stand/lua/hook.lua b/stand/lua/hook.lua
index 9c7e4deeb7e4..6826bcb5f7f1 100644
--- a/stand/lua/hook.lua
+++ b/stand/lua/hook.lua
@@ -60,7 +60,7 @@ end
-- Takes a hooktype and runs all functions associated with that specific hook
-- type in the order that they were registered in. This ordering should likely
-- not be relied upon.
-function hook.runAll(hooktype)
+function hook.runAll(hooktype, data)
local selected_hooks = registered_hooks[hooktype]
if selected_hooks == nil then
-- This message, and the print() above, should only be seen by
@@ -74,7 +74,7 @@ function hook.runAll(hooktype)
end
if #selected_hooks > 0 then
for _, func in ipairs(selected_hooks) do
- func()
+ func(data)
end
end
return #selected_hooks
diff --git a/stand/lua/hook.lua.8 b/stand/lua/hook.lua.8
index 1bc9ca96b509..f53d643d79bd 100644
--- a/stand/lua/hook.lua.8
+++ b/stand/lua/hook.lua.8
@@ -26,7 +26,7 @@
.\"
.\" $FreeBSD$
.\"
-.Dd June 9, 2018
+.Dd April 28, 2020
.Dt HOOK.LUA 8
.Os
.Sh NAME
@@ -39,6 +39,8 @@ Hooks are functions used to attach custom behaviors at pre-defined points in
loader execution.
These pre-defined points are what we refer to as
.Dq hook types .
+Hooks may also take an optional data parameter, which may or may not be
+populated by the caller.
.Pp
Before using the functionality provided by
.Nm ,
diff --git a/stand/lua/loader.conf.lua.5 b/stand/lua/loader.conf.lua.5
new file mode 100644
index 000000000000..5c8938c321f9
--- /dev/null
+++ b/stand/lua/loader.conf.lua.5
@@ -0,0 +1,77 @@
+.\"
+.\" SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+.\"
+.\" Copyright (c) 2020 Kyle Evans <kevans@FreeBSD.org>
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\" notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\" notice, this list of conditions and the following disclaimer in the
+.\" documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd May 10, 2023
+.Dt LOADER.CONF.LUA 5
+.Os
+.Sh NAME
+.Nm loader.conf.lua
+.Nd Lua-based system bootstrap configuration file
+.Sh DESCRIPTION
+When the lua-based
+.Xr loader 8
+encounters a filename in
+.Va loader_conf_files
+that has a
+.Dq .lua
+suffix, it will be loaded and executed by the lua interpreter in a limited
+environment.
+.Pp
+The limited environment does not contain the ability to reference or load other
+lua modules.
+Existing loader environment variables may be referenced as if they were already
+defined global variables.
+.Pp
+A lua configuration file may set any global variable, which will subsequently
+be processed and added to the environment after execution of the configuration
+file has completed.
+Other than the
+.Ar exec
+setting, all variables described in
+.Xr loader.conf 5
+operate the same in the
+.Nm
+environment.
+Note that the settings describing module options can only be set in the
+environment; there is currently no way for a
+.Pa loader.conf.lua
+to fetch them.
+At this time, global table and function values are ignored.
+.Pp
+The
+.Fn config.buildenv
+hook will be run with an empty environment provided to it that may be populated
+by a custom
+.Pa local.lua .
+.Sh SEE ALSO
+.Xr loader.conf 5
+.Sh AUTHORS
+The mechanism for loading
+.Nm
+files was originally written by
+.An Kyle Evans Aq Mt kevans@FreeBSD.org .