replace invalid characters in ids (#106)

It is easy enough to break the spectatord line protocol, if any of the control
characters (`:,=`) are inserted in unexpected places. Since metric names and
tags are often programmatically generated, we want to only construct id strings
which are valid.

Author: copperlight

.gitignore

@@ -2,4 +2,5 @@
 .idea/
 cmake-build-debug
 cmake-build/
+spectator/valid_chars.inc
 venv/

CMakeLists.txt

@@ -39,6 +39,17 @@ add_library(spectator
     "spectator/registry.h"
     "spectator/stateful_meters.h"
     "spectator/stateless_meters.h"
+    "spectator/valid_chars.inc"
 )
 target_link_libraries(spectator ${CONAN_LIBS})
 target_link_options(spectator PRIVATE "$<$<CONFIG:Release>:-static-libstdc++>")
+
+#-- generator tools
+add_executable(gen_valid_chars "tools/gen_valid_chars.cc")
+
+#-- file generators, must exist where the outputs are referenced
+add_custom_command(
+    OUTPUT "spectator/valid_chars.inc"
+    COMMAND "${CMAKE_BINARY_DIR}/bin/gen_valid_chars" > "${CMAKE_SOURCE_DIR}/spectator/valid_chars.inc"
+    DEPENDS gen_valid_chars
+)

build.sh

@@ -10,8 +10,11 @@ NC="\033[0m"
 if [[ "$1" == "clean" ]]; then
   echo -e "${BLUE}==== clean ====${NC}"
   rm -rf $BUILD_DIR
-  # remove all packages and binaries from the local cache, to allow swapping between Debug/Release builds
-  conan remove '*' --force
+  rm -f spectator/*.inc
+  if [[ "$2" == "--force" ]]; then
+    # remove all packages and binaries from the local cache, to allow swapping between Debug/Release builds
+    conan remove '*' --force
+  fi
 fi
 
 if [[ "$OSTYPE" == "linux-gnu"* ]]; then

spectator/age_gauge_test.cc

@@ -25,4 +25,12 @@ TEST(AgeGauge, Set) {
   EXPECT_EQ(publisher.SentMessages(), expected);
 }
 
+TEST(AgeGauge, InvalidTags) {
+  TestPublisher publisher;
+  // test with a single tag, because tags order is not guaranteed in a flat_hash_map
+  auto id = std::make_shared<Id>("test`!@#$%^&*()-=~_+[]{}\\|;:'\",<.>/?foo",
+                                 Tags{{"tag1,:=", "value1,:="}});
+  AgeGauge g{id, &publisher};
+  EXPECT_EQ("A:test______^____-_~______________.___foo,tag1___=value1___:", g.GetPrefix());
+}
 }  // namespace

spectator/counter_test.cc

@@ -13,8 +13,8 @@ TEST(Counter, Activity) {
   TestPublisher publisher;
   auto id = std::make_shared<Id>("ctr.name", Tags{});
   auto id2 = std::make_shared<Id>("c2", Tags{{"key", "val"}});
-  Counter<TestPublisher> c{id, &publisher};
-  Counter<TestPublisher> c2{id2, &publisher};
+  Counter c{id, &publisher};
+  Counter c2{id2, &publisher};
   c.Increment();
   c2.Add(1.2);
   c.Add(0.1);
@@ -25,10 +25,18 @@ TEST(Counter, Activity) {
 
 TEST(Counter, Id) {
   TestPublisher publisher;
-  Counter<TestPublisher> c{std::make_shared<Id>("foo", Tags{{"key", "val"}}),
+  Counter c{std::make_shared<Id>("foo", Tags{{"key", "val"}}),
                            &publisher};
   auto id = std::make_shared<Id>("foo", Tags{{"key", "val"}});
   EXPECT_EQ(*(c.MeterId()), *id);
 }
 
+TEST(Counter, InvalidTags) {
+  TestPublisher publisher;
+  // test with a single tag, because tags order is not guaranteed in a flat_hash_map
+  auto id = std::make_shared<Id>("test`!@#$%^&*()-=~_+[]{}\\|;:'\",<.>/?foo",
+                                 Tags{{"tag1,:=", "value1,:="}});
+  Counter c{id, &publisher};
+  EXPECT_EQ("c:test______^____-_~______________.___foo,tag1___=value1___:", c.GetPrefix());
+}
 }  // namespace

spectator/dist_summary_test.cc

@@ -22,4 +22,12 @@ TEST(DistributionSummary, Record) {
   EXPECT_EQ(publisher.SentMessages(), expected);
 }
 
+TEST(DistributionSummary, InvalidTags) {
+  TestPublisher publisher;
+  // test with a single tag, because tags order is not guaranteed in a flat_hash_map
+  auto id = std::make_shared<Id>("test`!@#$%^&*()-=~_+[]{}\\|;:'\",<.>/?foo",
+                                 Tags{{"tag1,:=", "value1,:="}});
+  DistributionSummary d{id, &publisher};
+  EXPECT_EQ("d:test______^____-_~______________.___foo,tag1___=value1___:", d.GetPrefix());
+}
 }  // namespace

spectator/gauge_test.cc

@@ -24,4 +24,12 @@ TEST(Gauge, Set) {
   EXPECT_EQ(publisher.SentMessages(), expected);
 }
 
+TEST(Gauge, InvalidTags) {
+  TestPublisher publisher;
+  // test with a single tag, because tags order is not guaranteed in a flat_hash_map
+  auto id = std::make_shared<Id>("test`!@#$%^&*()-=~_+[]{}\\|;:'\",<.>/?foo",
+                                 Tags{{"tag1,:=", "value1,:="}});
+  Gauge g{id, &publisher};
+  EXPECT_EQ("g:test______^____-_~______________.___foo,tag1___=value1___:", g.GetPrefix());
+}
 }  // namespace

spectator/id_test.cc

@@ -17,6 +17,7 @@ TEST(Id, Create) {
   std::shared_ptr<Id> id_of{Id::of("name", Tags{{"k", "v"}, {"k1", "v1"}})};
   EXPECT_EQ(id_of->Name(), "name");
   EXPECT_EQ(id_of->GetTags().size(), 2);
+  fmt::format("{}", id);
 }
 
 TEST(Id, Tags) {

spectator/max_gauge_test.cc

@@ -24,4 +24,12 @@ TEST(MaxGauge, Set) {
   EXPECT_EQ(publisher.SentMessages(), expected);
 }
 
+TEST(MaxGauge, InvalidTags) {
+  TestPublisher publisher;
+  // test with a single tag, because tags order is not guaranteed in a flat_hash_map
+  auto id = std::make_shared<Id>("test`!@#$%^&*()-=~_+[]{}\\|;:'\",<.>/?foo",
+                                 Tags{{"tag1,:=", "value1,:="}});
+  MaxGauge g{id, &publisher};
+  EXPECT_EQ("m:test______^____-_~______________.___foo,tag1___=value1___:", g.GetPrefix());
+}
 }  // namespace

spectator/monotonic_counter_test.cc

@@ -22,4 +22,13 @@ TEST(MonotonicCounter, Set) {
   std::vector<std::string> expected = {"C:ctr:42.1", "C:ctr2,key=val:2", "C:ctr:43"};
   EXPECT_EQ(publisher.SentMessages(), expected);
 }
+
+TEST(MonotonicCounter, InvalidTags) {
+  TestPublisher publisher;
+  // test with a single tag, because tags order is not guaranteed in a flat_hash_map
+  auto id = std::make_shared<Id>("test`!@#$%^&*()-=~_+[]{}\\|;:'\",<.>/?foo",
+                                 Tags{{"tag1,:=", "value1,:="}});
+  MonotonicCounter c{id, &publisher};
+  EXPECT_EQ("C:test______^____-_~______________.___foo,tag1___=value1___:", c.GetPrefix());
+}
 }  // namespace