feat(ngx-conf) do not unnecessarily create C* shm

When using PostgreSQL as a datastore, there is no need for the C* shm, to be created and left unused.
elloooooo · Jun 20, 2017 · e811282 · e811282
1 parent f51c871
commit e811282
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Showing 5 changed files with 27 additions and 3 deletions.
diff --git a/kong/constants.lua b/kong/constants.lua
@@ -70,7 +70,6 @@ return {
   DICTS = {
     "kong",
     "kong_cache",
-    "kong_cassandra",
     "kong_process_events",
     "kong_cluster_events",
   },

diff --git a/kong/dao/db/cassandra.lua b/kong/dao/db/cassandra.lua
@@ -37,6 +37,13 @@ function _M.new(kong_config)
     prepared = true
   }
 
+  if not ngx.shared.kong_cassandra then
+    error("cannot use Cassandra datastore: missing shared dict "            ..
+          "'kong_cassandra' in Nginx configuration, are you using a "       ..
+          "custom template? Make sure the 'lua_shared_dict kong_cassandra " ..
+          "[SIZE];' directive is defined.")
+  end
+
   local cluster_options = {
     shm = "kong_cassandra",
     contact_points = kong_config.cassandra_contact_points,

diff --git a/kong/templates/nginx_kong.lua b/kong/templates/nginx_kong.lua
@@ -31,9 +31,11 @@ lua_max_running_timers 4096;
 lua_max_pending_timers 16384;
 lua_shared_dict kong                4m;
 lua_shared_dict kong_cache          ${{MEM_CACHE_SIZE}};
-lua_shared_dict kong_cassandra      5m;
 lua_shared_dict kong_process_events 1m;
 lua_shared_dict kong_cluster_events 1m;
+> if database == "cassandra" then
+lua_shared_dict kong_cassandra      5m;
+> end
 lua_socket_log_errors off;
 > if lua_ssl_trusted_certificate then
 lua_ssl_trusted_certificate '${{LUA_SSL_TRUSTED_CERTIFICATE}}';

diff --git a/spec/01-unit/003-prefix_handler_spec.lua b/spec/01-unit/003-prefix_handler_spec.lua
@@ -165,6 +165,20 @@ describe("NGINX conf compiler", function()
       local nginx_conf = prefix_handler.compile_kong_conf(conf)
       assert.matches("client_body_buffer_size 128k", nginx_conf, nil, true)
     end)
+    it("writes kong_cassandra shm if using Cassandra", function()
+      local conf = assert(conf_loader(nil, {
+        database = "cassandra",
+      }))
+      local nginx_conf = prefix_handler.compile_kong_conf(conf)
+      assert.matches("lua_shared_dict%s+kong_cassandra", nginx_conf)
+    end)
+    it("does not write kong_cassandra shm if not using Cassandra", function()
+      local conf = assert(conf_loader(nil, {
+        database = "postgres",
+      }))
+      local nginx_conf = prefix_handler.compile_kong_conf(conf)
+      assert.not_matches("lua_shared_dict%s+kong_cassandra", nginx_conf)
+    end)
 
     describe("user directive", function()
       it("is not included by default", function()

diff --git a/spec/fixtures/custom_nginx.template b/spec/fixtures/custom_nginx.template
@@ -44,9 +44,11 @@ http {
     lua_max_pending_timers 16384;
     lua_shared_dict kong                4m;
     lua_shared_dict kong_cache          ${{MEM_CACHE_SIZE}};
-    lua_shared_dict kong_cassandra      5m;
     lua_shared_dict kong_process_events 1m;
     lua_shared_dict kong_cluster_events 1m;
+> if database == "cassandra" then
+    lua_shared_dict kong_cassandra      5m;
+> end
     lua_socket_log_errors off;
 > if lua_ssl_trusted_certificate then
     lua_ssl_trusted_certificate '${{LUA_SSL_TRUSTED_CERTIFICATE}}';