Add JDK installer

.install/gradlr.sh

@@ -0,0 +1,10 @@
+#!/bin/sh
+
+set -e
+source ./.versions
+
+echo
+echo "Installing gradlr..."
+echo
+
+yarn global add gradlr

.install/jdk.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+
+set -e
+source ./.versions
+
+echo
+echo "Installing OpenJDK $JDK_NUMBER $JDK_VERSION..."
+echo
+
+apk add --no-cache --virtual .build-deps \
+	curl \
+	tar
+
+#curl -fLo jdk.tar.gz https://download.java.net/java/GA/jdk$JDK_NUMBER/$JDK_VERSION/binaries/openjdk-${JDK_VERSION}_linux-x64_bin.tar.gz
+curl -fLo jdk.tar.gz https://download.java.net/java/early_access/alpine/$JDK_VERSION/binaries/openjdk-$JDK_NUMBER-ea+$JDK_VERSION_linux-x64-musl_bin.tar.gz
+tar -C /usr/local -xzf jdk.tar.gz
+ln -s /usr/local/jdk$JDK_NUMBER /usr/local/jdk
+rm jdk.tar.gz
+
+apk del .build-deps

.versions

@@ -9,5 +9,9 @@ export YARN_VERSION=1.5.1
 
 export KUBECTL_VERSION=1.10.0
 
+export JDK_NUMBER=11
+export JDK_VERSION=4
+
+
 export CADDY_VERSION=0.10.12