enabled & status fields for service models

new PM back-end for OpenRC
reload configuration only when service running

3 files changed, 61 insertions, 17 deletions

diff --git a/acf2/model/service.lua b/acf2/model/service.lua
index 2ed84e8..4db634e 100644
--- a/acf2/model/service.lua
+++ b/acf2/model/service.lua
@@ -3,26 +3,34 @@ Copyright (c) 2012-2013 Kaarle Ritvanen
 See LICENSE file for license details
 --]]
 
-local model = require('acf2.model.model')
+local fld = require('acf2.model.field')
+local new = require('acf2.model.model').new
 local super = require('acf2.object').super
+local pth = require('acf2.path')
 local DataStore = require('acf2.persistence')
 
 return function(name)
-	  local res = model.new()
+	  local res = new()
 
-	  local function afunc(action)
-	     return function() os.execute('rc-service '..name..' '..action) end
+	  local addr = pth.join('/service', name)
+	  local eaddr = pth.join(addr, 'enabled')
+	  res.enabled = fld.Boolean{addr=eaddr, required=true}
+	  res.status = fld.String{addr=pth.join(addr, 'status')}
+
+	  local function is_enabled() return DataStore:get(eaddr) end
+	  local enabled
+	  local function pre() enabled = is_enabled() end
+	  local function post()
+	     if enabled and is_enabled() then
+		os.execute('rc-service '..name..' reload')
+	     end
 	  end
 
-	  local reload = afunc('reload')
 	  function res:init(context)
-	     DataStore:trigger(context.addr, reload)
+	     DataStore:trigger('pre', context.addr, pre)
+	     DataStore:trigger('post', context.addr, post)
 	     super(self, res):init(context)
 	  end
 
-	  for _, action in ipairs{'start', 'stop', 'restart'} do
-	     res[action] = model.Action{func=afunc(action)}
-	  end
-
 	  return res
        end
diff --git a/acf2/persistence/backends/service.lua b/acf2/persistence/backends/service.lua
new file mode 100644
index 0000000..2163184
--- /dev/null
+++ b/acf2/persistence/backends/service.lua
@@ -0,0 +1,32 @@
+--[[
+Copyright (c) 2012-2013 Kaarle Ritvanen
+See LICENSE file for license details
+--]]
+
+local rc = require('rc')
+local stringy = require('stringy')
+
+
+local backend = require('acf2.object').class()
+
+function backend:get(path, top)
+   if #path == 1 then return {'enabled', 'status'} end
+   assert(#path == 2)
+   local status = rc.service_status(path[1])
+   if path[2] == 'status' then return status end
+   if path[2] == 'enabled' then return stringy.startswith(status, 'start') end
+end
+
+function backend:set(mods)
+   for _, mod in ipairs(mods) do
+      local path, value = unpack(mod)
+      assert(#path == 2 and path[2] == 'enabled')
+
+      local name = path[1]
+      if value then rc.service_add(name)
+      else rc.service_delete(name) end
+      os.execute('rc-service '..name..' '..(value and 'start' or 'stop'))
+   end
+end
+
+return backend
diff --git a/acf2/persistence/init.lua b/acf2/persistence/init.lua
index 1cdea75..74ca447 100644
--- a/acf2/persistence/init.lua
+++ b/acf2/persistence/init.lua
@@ -27,11 +27,11 @@ function DataStore:init()
       function(m) return m() end,
       loadmods('persistence/backends')
    )
-   self.triggers = {}
+   self.triggers = {pre={}, post={}}
 end
 
-function DataStore:trigger(path, func)
-   local funcs = setdefault(self.triggers, path, {})
+function DataStore:trigger(phase, path, func)
+   local funcs = setdefault(self.triggers[phase], path, {})
    if not contains(funcs, func) then table.insert(funcs, func) end
 end
 
@@ -98,11 +98,15 @@ function DataStore:_set_multiple(mods)
       table.insert(setdefault(bms, backend, {}), {comps, value})
    end
 
-   for backend, bm in pairs(bms) do backend:set(bm) end
-
-   for path, _ in pairs(trigger) do
-      for _, func in ipairs(self.triggers[path] or {}) do func() end
+   local function exec_triggers(phase)
+      for path, _ in pairs(trigger) do
+	 for _, func in ipairs(self.triggers[phase][path] or {}) do func() end
+      end
    end
+
+   exec_triggers('pre')
+   for backend, bm in pairs(bms) do backend:set(bm) end
+   exec_triggers('post')
 end