allow to specify should unlimited memlock be used or not (facebookinc…

…ubator#43)

Summary:
by default katran today requesting (during startup) unlimited amount
of locked memory. this is suboptimal for environments where
container managment system wants to enforce this number as well.
in this diff i'm adding a flag in katran's config, which would
allow us to bypas setting memlock limit to unlimited, and hence would
rely on external (to katran) managing system to do so

this diff wont change defautl behavior - by default we still would
try to set limit to RLIM_UNLIMITED

Tested By:
unittests + katran_tester
Pull Request resolved: facebookincubator#43

Pulled By: udippant

Reviewed By: sharma95

Differential Revision: D17097200

fbshipit-source-id: aff4f8aa956d24885fcaf911f52a3e17904e15bf

katran/lib/KatranLb.cpp

@@ -43,7 +43,7 @@ constexpr folly::StringPiece kEmptyString = "";
 
 KatranLb::KatranLb(const KatranConfig& config)
     : config_(config),
-      bpfAdapter_(!config.testing),
+      bpfAdapter_(config.memlockUnlimited),
       ctlValues_(kCtlMapSize),
       standalone_(true),
       forwardingCores_(config.forwardingCores),

katran/lib/KatranLbStructs.h

@@ -132,6 +132,7 @@ struct KatranMonitorConfig {
  * @param uint32_t maxDecapDst maximum number of destinations for inline decap
  * @param std::string hcInterface interface where we want to attach hc bpf prog
  * @param KatranMonitorConfig monitorConfig for katran introspection
+ * @param memlockUnlimited should katran set memlock to unlimited by default
  *
  * note about rootMapPath and rootMapPos:
  * katran has two modes of operation.
@@ -174,6 +175,7 @@ struct KatranConfig {
   std::string hcInterface = kDefaultHcInterface;
   uint32_t xdpAttachFlags = kNoFlags;
   struct KatranMonitorConfig monitorConfig;
+  bool memlockUnlimited = true;
 };
 
 /**

katran/lib/tests/KatranLbTest.cpp

@@ -42,7 +42,11 @@ class KatranLbTest : public ::testing::Test {
                         {},
                         {},
                         10,
-                        4}){};
+                        4,
+                        "eth0",
+                        0,
+                        {},
+                        false}){}
 
   void SetUp() override {
     v1.address = "fc01::1";