cloudwatch: add a protobuf definition (#410)

This will be used for storing data points in a cache
such as redis. The benefit is that it supports efficient
updates for the data points as new items are received.

atlas-cloudwatch/src/main/protobuf/CloudWatchMetric.proto

@@ -0,0 +1,28 @@
+syntax = "proto2";
+
+package com.netflix.atlas.cloudwatch;
+
+option java_multiple_files = true;
+option java_package = "com.netflix.atlas.cloudwatch";
+option java_outer_classname = "CloudWatchMetric";
+
+message CloudWatchDimension {
+ required string name = 1;
+ required string value = 2;
+}
+
+message CloudWatchValue {
+ required int64 timestamp = 1;
+ optional double sum = 2;
+ optional double min = 3;
+ optional double max = 4;
+ optional double count = 5;
+}
+
+message CloudWatchCacheEntry {
+ required string namespace = 1;
+ required string metric = 2;
+ required string unit = 3;
+ repeated CloudWatchDimension dimensions = 4;
+ repeated CloudWatchValue data = 5;
+}

build.sbt

@@ -39,6 +39,7 @@ lazy val `atlas-aggregator` = project
 
 lazy val `atlas-cloudwatch` = project
  .configure(BuildSettings.profile)
+ .enablePlugins(ProtobufPlugin)
  .settings(libraryDependencies ++= Seq(
  Dependencies.atlasCore,
  Dependencies.atlasJson,
@@ -55,6 +56,7 @@ lazy val `atlas-cloudwatch` = project
  Dependencies.log4jCore,
  Dependencies.log4jSlf4j,
  Dependencies.openHFT,
+ Dependencies.protobuf,
 
  Dependencies.atlasWebApi % "test",
  Dependencies.akkaHttpTestkit % "test",

project/Dependencies.scala

@@ -72,6 +72,7 @@ object Dependencies {
  val mockitoScala = "org.mockito" % "mockito-scala_2.13" % "1.10.4"
  val munit = "org.scalameta" %% "munit" % "0.7.29"
  val openHFT = "net.openhft" % "zero-allocation-hashing" % "0.16"
+ val protobuf = "com.google.protobuf" % "protobuf-java" % "3.22.0"
  val scalaCompiler = "org.scala-lang" % "scala-compiler" % scala
  val scalaLibrary = "org.scala-lang" % "scala-library" % scala
  val scalaLogging = "com.typesafe.scala-logging" %% "scala-logging" % "3.9.5"

project/plugins.sbt

@@ -7,5 +7,8 @@ addSbtPlugin("com.typesafe.sbt" % "sbt-native-packager" % "1.3.12")
 
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.4.6")
 
+// for compiling protobuf in the Cloud Watch module
+addSbtPlugin("com.github.sbt" % "sbt-protobuf" % "0.7.1")
+
 // Convenient helpers, not required
 addSbtPlugin("com.timushev.sbt" % "sbt-updates" % "0.6.4")