Plugin support in Gitano

This patch adds support for Gitano to load plugins from a colon separated set
of paths.  While colon separation is not the best mechanism, it is in common
use.  We explicitly do not add any escaping rules such as :: -> : in order to
remain compatible with things like PATH processing.

Signed-off-by: Daniel Silverstone <daniel.silverstone@codethink.co.uk>

3 files changed, 67 insertions, 2 deletions

diff --git a/Makefile b/Makefile
index 7fa7d11..775f5cc 100644
--- a/Makefile
+++ b/Makefile
@@ -43,7 +43,7 @@ MODS := gitano 								\
 	gitano.actions gitano.config gitano.lace gitano.log		\
 	gitano.markdown gitano.repository gitano.supple 		\
 	gitano.command gitano.admincommand gitano.usercommand		\
-	gitano.repocommand gitano.copycommand gitano.auth
+	gitano.repocommand gitano.copycommand gitano.auth gitano.plugins
 
 SKEL_FILES := gitano-admin/rules/selfchecks.lace			\
 	      gitano-admin/rules/aschecks.lace 				\
diff --git a/lib/gitano.lua b/lib/gitano.lua
index b57bd71..31e62d5 100644
--- a/lib/gitano.lua
+++ b/lib/gitano.lua
@@ -15,6 +15,7 @@ local lace = require 'gitano.lace'
 local markdown = require 'gitano.markdown'
 local supple = require 'gitano.supple'
 local auth = require 'gitano.auth'
+local plugins = require 'gitano.plugins'
 
 return {
    util = util,
@@ -26,5 +27,6 @@ return {
    lace = lace,
    markdown = markdown,
    supple = supple,
-   auth = auth
+   auth = auth,
+   plugins = plugins,
 }
diff --git a/lib/gitano/plugins.lua b/lib/gitano/plugins.lua
new file mode 100644
index 0000000..bdc6d1e
--- /dev/null
+++ b/lib/gitano/plugins.lua
@@ -0,0 +1,63 @@
+-- gitano.plugins
+--
+-- Plugin loading support for Gitano
+--
+-- Copyright 2014 Daniel Silverstone <daniel.silverstone@codethink.co.uk>
+
+local util = require "gitano.util"
+local log = require "gitano.log"
+
+local luxio = require "luxio"
+local sio = require "luxio.simple"
+
+local gfind = string.gfind
+
+local plugin_name_pattern = "^(.+)%.lua$"
+
+local function find_plugins(path)
+   local ret = {}
+   for _, entry in ipairs(path) do
+      local dirp, err = sio.opendir(entry)
+      if not dirp then
+         log.warning(("Unable to scan plugin directory '%s': %s")
+                     :format(entry, err))
+      else
+         for filename, fileinfo in dirp:iterate() do
+            local plugin_name = filename:match(plugin_name_pattern)
+            if plugin_name and fileinfo.d_type == luxio.DT_REG then
+               if not ret[plugin_name] then
+                  ret[plugin_name] = entry
+                  ret[#ret + 1] = plugin_name
+               end
+            end
+         end
+      end
+   end
+   table.sort(ret)
+   return ret
+end
+
+local function load_plugins(path)
+   local to_load = find_plugins(path)
+   for _, plugin_name in ipairs(to_load) do
+      local filepath = util.path_join(to_load[plugin_name],
+                                      plugin_name .. ".lua")
+      local chunk, err = loadfile(filepath)
+      if not chunk then
+         log.warning(("Failure loading plugin '%s' from '%s': %s")
+                     :format(plugin_name, to_load[plugin_name],
+                             err))
+      else
+         local ok, err = pcall(chunk)
+         if not ok then
+            log.warning(("Failure running plugin '%s' from '%s': %s")
+                        :format(plugin_name, to_load[plugin_name],
+                                err))
+         end
+      end
+   end
+end
+
+return {
+   load_plugins = load_plugins,
+}