perf(camel): avoid closure allocation per request

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+### Performance
+- Camel Policy: avoid unnecessary closure allocation per request [PR #1584](https://github.com/3scale/APIcast/pull/1584)
+
 ### Fixed
 - Correct FAPI header to `x-fapi-interaction-id` [PR #1557](https://github.com/3scale/APIcast/pull/1557) [THREESCALE-11957](https://issues.redhat.com/browse/THREESCALE-11957)
 - Only validate oidc setting if authentication method is set to oidc [PR #1568](https://github.com/3scale/APIcast/pull/1568) [THREESCALE-11441](https://issues.redhat.com/browse/THREESCALE-11441)

gateway/src/apicast/policy/camel/camel.lua

@@ -1,5 +1,5 @@
 local policy = require('apicast.policy')
-local _M = policy.new('http_proxy', 'builtin')
+local _M = policy.new('camel_proxy', 'builtin')
 
 local resty_url = require 'resty.url'
 local ipairs = ipairs
@@ -21,19 +21,26 @@ function _M.new(config)
   end
 
   for _, proto in ipairs(proxies) do
-    local val, err =  resty_url.parse(config[string.format("%s_proxy", proto)])
-    if err then
-      ngx.log(ngx.WARN, proto, " proxy is not correctly defined, err: ", err)
+    local proxy_url =  config[string.format("%s_proxy", proto)]
+    if proxy_url then
+      local val, err =  resty_url.parse(proxy_url)
+      if err then
+        ngx.log(ngx.WARN, proto, " proxy is not correctly defined, err: ", err)
+      end
+      self.proxies[proto] = val
+    else
+      self.proxies[proto] = self.all_proxy
     end
-    self.proxies[proto] = val or self.all_proxy
+  end
+  -- This get_http_proxy function will be called in upstream just in case if a
+  -- proxy is defined.
+  self.get_http_proxy = function(uri)
+    if not uri.scheme then return nil end
+    return self.proxies[uri.scheme]
   end
   return self
 end
 
-local function find_proxy(self, scheme)
-  return self.proxies[scheme]
-end
-
 function _M:access(context)
   context.skip_https_connect_on_proxy = true
 
@@ -48,12 +55,7 @@ end
 function _M:rewrite(context)
   -- This get_http_proxy function will be called in upstream just in case if a
   -- proxy is defined.
-  context.get_http_proxy = function(uri)
-    if not uri.scheme then
-      return nil
-    end
-    return find_proxy(self, uri.scheme)
-  end
+  context.get_http_proxy = self.get_http_proxy
 end
 
 return _M

spec/policy/camel/camel_spec.lua

@@ -58,10 +58,48 @@ describe('Camel policy', function()
 
     it("invalid protocol", function()
       proxy:rewrite(context)
-      local result = context:get_http_proxy(
-        {}, {scheme="invalid"})
+      local result = context.get_http_proxy({scheme="invalid"})
       assert.is_nil(result)
     end)
 
+    it("nil scheme", function()
+      proxy:rewrite(context)
+      local result = context.get_http_proxy({})
+      assert.is_nil(result)
+    end)
+
+  end)
+
+  describe(".access", function()
+    it("sets skip_https_connect_on_proxy on context", function()
+      local proxy = camel_policy.new({ all_proxy = all_proxy_val })
+
+      local mock_upstream = { set_skip_https_connect_on_proxy = stub.new() }
+      context.get_upstream = function() return mock_upstream end
+
+      proxy:access(context)
+
+      assert.is_true(context.skip_https_connect_on_proxy)
+    end)
+
+    it("calls set_skip_https_connect_on_proxy on upstream", function()
+      local proxy = camel_policy.new({ all_proxy = all_proxy_val })
+
+      local mock_upstream = { set_skip_https_connect_on_proxy = stub.new() }
+      context.get_upstream = function() return mock_upstream end
+
+      proxy:access(context)
+
+      assert.stub(mock_upstream.set_skip_https_connect_on_proxy).was_called()
+    end)
+
+    it("does not error when get_upstream returns nil", function()
+      local proxy = camel_policy.new({ all_proxy = all_proxy_val })
+
+      context.get_upstream = function() return nil end
+
+      assert.has_no.errors(function() proxy:access(context) end)
+      assert.is_true(context.skip_https_connect_on_proxy)
+    end)
   end)
 end)