Fix overriding null configuration options in default.yml.

Null values in default.yml were being treated as a special null type by
lyaml, which was preventing overrides from actually overriding the
null type. This prevented the omniauth-ldap and omniauth-cas options
from being set (see
#278 (comment))

src/api-umbrella/cli/read_config.lua

@@ -102,6 +102,7 @@ local function read_runtime_config()
     f:close()
 
     config = lyaml.load(content)
+    nillify_yaml_nulls(config)
   end
 end
 
@@ -110,6 +111,7 @@ end
 local function read_default_config()
   local content = file.read(path.join(src_root_dir, "config/default.yml"), true)
   config = lyaml.load(content)
+  nillify_yaml_nulls(config)
 end
 
 -- Handle setup of random secret tokens that should be be unique for API
@@ -159,6 +161,7 @@ local function read_system_config()
       if content then
         local overrides = lyaml.load(content)
         deep_merge_overwrite_arrays(config, overrides)
+        nillify_yaml_nulls(config)
       end
     else
       print("WARNING: Config file does not exist: ", config_path)

src/api-umbrella/proxy/models/file_config.lua

@@ -17,7 +17,9 @@ local function read_file()
   local content = f:read("*all")
   f:close()
 
-  return lyaml.load(content)
+  local data = lyaml.load(content)
+  nillify_yaml_nulls(data)
+  return data
 end
 
 local function set_defaults(data)
@@ -78,7 +80,6 @@ end
 
 local function read()
   local data = read_file()
-  nillify_yaml_nulls(data)
   set_defaults(data)
   cache_computed_settings(data["apiSettings"])
 

test/integration/config.js

@@ -0,0 +1,35 @@
+'use strict';
+
+require('../test_helper');
+
+var fs = require('fs'),
+    path = require('path'),
+    yaml = require('js-yaml');
+
+describe('config', function() {
+  describe('overriding null values', function() {
+    shared.runServer({
+      web: {
+        admin: {
+          auth_strategies: {
+            ldap: {
+              options: {
+                host: 'example.com',
+              }
+            },
+          },
+        },
+      },
+    });
+
+    it('overrides a default null value', function() {
+      var defaultConfig = yaml.safeLoad(fs.readFileSync(path.resolve(__dirname, '../../config/default.yml')).toString());
+      var runtimeConfig = yaml.safeLoad(fs.readFileSync('/tmp/api-umbrella-test/var/run/runtime_config.yml').toString());
+
+      should.not.exist(defaultConfig.web.admin.auth_strategies.ldap.options);
+      runtimeConfig.web.admin.auth_strategies.ldap.options.should.eql({
+        host: 'example.com',
+      });
+    });
+  });
+});