Add template support

scripts/lua/modules/template_utils.lua

@@ -0,0 +1,32 @@
+local template = require "resty.template"
+
+-- This can be used inside templates
+-- range(a) returns an iterator from 1 to a (step = 1)
+-- range(a, b) returns an iterator from a to b (step = 1)
+-- range(a, b, step) returns an iterator from a to b, counting by step.
+function range(a, b, step)
+  if not b then
+    b = a
+    a = 1
+  end
+  step = step or 1
+  local f =
+    step > 0 and
+      function(_, lastvalue)
+        local nextvalue = lastvalue + step
+        if nextvalue <= b then return nextvalue end
+      end or
+    step < 0 and
+      function(_, lastvalue)
+        local nextvalue = lastvalue + step
+        if nextvalue >= b then return nextvalue end
+      end or
+      function(_, lastvalue) return lastvalue end
+  return f, nil, a - step
+end
+
+function template.gen(template_file, context)
+  return template.compile(dirs.installdir.."/httpdocs/templates/"..template_file, nil, nil)(context)
+end
+
+return template