luci-app-lxc: fix "plain-vanilla" integration, part 2

I've tried to get the lxc app in a more usable state. Tested with mips
and amd64 targets.

* check /etc/config/lxc in controller, not in cbi
* more controller cleanups
* remove unused 'fork_exec' function
* check path before container creation
* check space requirements before container creation
  * support new uci options 'min_space' and 'min_temp',
    default for both is 100000 KB
  * both options are configurable via LuCI CBI template
* write messages to log in case of an error
* validate the container name during creation,
  automatically remove invalid chars
* inform the user that only a stopped container can be destroyed
* add experimental ssl support (untested, disabled by default)

Signed-off-by: Dirk Brenken <dev@brenken.org>

1 files changed, 27 insertions, 12 deletions

diff --git a/applications/luci-app-lxc/luasrc/model/cbi/lxc.lua b/applications/luci-app-lxc/luasrc/model/cbi/lxc.lua
index 7040f0ecff..8a8fc2be0d 100644
--- a/applications/luci-app-lxc/luasrc/model/cbi/lxc.lua
+++ b/applications/luci-app-lxc/luasrc/model/cbi/lxc.lua
@@ -14,20 +14,35 @@ Author: Petar Koretic <petar.koretic@sartura.hr>
 
 ]]--
 
-local fs = require "nixio.fs"
-
 m = Map("lxc", translate("LXC Containers"),
 	translate("<b>Please note:</b> For LXC Containers you need a custom OpenWrt image.<br />")
 	.. translate("The image should include at least support for 'kernel cgroups', 'kernel namespaces' and 'miscellaneous LXC related options'."))
-
-if fs.access("/etc/config/lxc") then
-	m:section(SimpleSection).template = "lxc"
-
-	s = m:section(TypedSection, "lxc", translate("Options"))
-	s.anonymous = true
-	s.addremove = false
-
-	s:option(Value, "url", translate("Containers URL"))
-end
+m:section(SimpleSection).template = "lxc"
+
+s = m:section(TypedSection, "lxc", translate("Options"))
+s.anonymous = true
+
+o1 = s:option(Value, "url", translate("Containers URL"))
+o1:value("images.linuxcontainers.org")
+o1:value("repo.turris.cz/lxc", "repo.turris.cz/lxc (SSL req.)")
+o1.default = "images.linuxcontainers.org"
+o1.rmempty = false
+
+o2 = s:option(Flag, "ssl_enabled", translate("Enable SSL"),
+	translate("Enable optional SSL encryption support. This requires additional packages like 'wget', 'ca-certificates', 'gnupg' and 'gnupg-utils'."))
+o2.default = o2.disabled
+o2.rmempty = false
+
+o3 = s:option(Value, "min_space", translate("Free Space Threshold"),
+	translate("Minimum required free space for LXC Container creation in KB"))
+o3.default = "100000"
+o3.datatype = "min(50000)"
+o3.rmempty = false
+
+o4 = s:option(Value, "min_temp", translate("Free Temp Threshold"),
+	translate("Minimum required free temp space for LXC Container creation in KB"))
+o4.default = "100000"
+o4.datatype = "min(50000)"
+o4.rmempty = false
 
 return m