Features/reduce image size of bq extractor (#279)

* Change from openjdk to alpine, reduce image size from 600 something to 40 something mb

* Make a smaller, quicker java image

* Copy from the test dockerfile to the prod dockerfile

* Fixing typo

bq-metrics-extractor/Dockerfile

@@ -1,10 +1,28 @@
-FROM openjdk:8u171
+FROM alpine:3.7
 
 MAINTAINER CSI "[email protected]"
 
+#
+# Copy the files we need
+#
+
 COPY script/start.sh /start.sh
 COPY config/config.yaml /config/config.yaml
-
 COPY build/libs/bq-metrics-extractor-uber.jar /bq-metrics-extractor.jar
 
-CMD ["/start.sh"]
+#
+# Load, then dump the standard java classes into the
+# image being built, to speed up java load time
+# using Class Data Sharing. The "quit" command will
+# simply quit the program after it's dumped the list of
+# classes that should be cached.
+#
+
+CMD ["java", "-Dfile.encoding=UTF-8", "-Xshare:on", "-Xshare:dump", "-jar", "/bq-metrics-extractor.jar", "quit", "config/config.yaml"]
+
+
+#
+# Finally the actual entry point
+#
+
+ENTRYPOINT ["/start.sh"]

bq-metrics-extractor/Dockerfile.test

@@ -1,11 +1,29 @@
-FROM openjdk:8u171
+FROM alpine:3.7
 
 MAINTAINER CSI "[email protected]"
 
+#
+# Copy the files we need
+#
+
 COPY script/start.sh /start.sh
 COPY config/pantel-prod.json /secret/pantel-prod.json
 COPY config/config.yaml /config/config.yaml
-
 COPY build/libs/bq-metrics-extractor-uber.jar /bq-metrics-extractor.jar
 
-CMD ["/start.sh"]
+#
+# Load, then dump the standard java classes into the
+# image being built, to speed up java load time
+# using Class Data Sharing. The "quit" command will
+# simply quit the program after it's dumped the list of
+# classes that should be cached.
+#
+
+CMD ["java", "-Dfile.encoding=UTF-8", "-Xshare:on", "-Xshare:dump", "-jar", "/bq-metrics-extractor.jar", "quit", "config/config.yaml"]
+
+
+#
+# Finally the actual entry point
+#
+
+ENTRYPOINT ["/start.sh"]

bq-metrics-extractor/script/start.sh

@@ -2,5 +2,6 @@
 
 # Start app
 exec java \
-    -Dfile.encoding=UTF-8 \
-    -jar /bq-metrics-extractor.jar query --pushgateway pushgateway:8080 config/config.yaml
+     -Dfile.encoding=UTF-8 \
+     -Xshare:on \
+     -jar /bq-metrics-extractor.jar query --pushgateway pushgateway:8080 config/config.yaml

bq-metrics-extractor/src/main/java/org/ostelco/bqmetrics/BqMetricsExtractorApplication.kt

@@ -310,4 +310,14 @@ private class CollectAndPushMetrics : ConfiguredCommand<BqMetricsExtractorConfig
                 .required(true)
                 .help("The pushgateway to report metrics to, format is hostname:portnumber")
     }
+
+    private class CollectAndPushMetrics : ConfiguredCommand<BqMetricsExtractorConfig>(
+            "quit",
+            "Do nothing, only used to prime caches") {
+        override fun run(bootstrap: Bootstrap<BqMetricsExtractorConfig>?,
+                         namespace: Namespace?,
+                         configuration: BqMetricsExtractorConfig?) {
+            // Doing nothing, as advertised.
+        }
+    }
 }