diff --git a/packer-template-script.sh b/packer-template-script.sh
index 3a4a4c7..d366615 100644
--- a/packer-template-script.sh
+++ b/packer-template-script.sh
@@ -1,6 +1,5 @@
 #!/usr/bin/env bash
 
-export TARGET=tulip_chiphd-userdebug
 export USE_CCACHE=true
 export CCACHE_DIR=/android/ccache
 export ANDROID_JACK_VM_ARGS="-Xmx4g -Dfile.encoding=UTF-8 -XX:+TieredCompilation"
@@ -14,9 +13,12 @@ message() {
 set -ve
 
 message "Installing dependencies..."
-sudo add-apt-repository -y ppa:openjdk-r/ppa
-sudo apt-get update -y
-sudo apt-get install -y openjdk-7-jdk python git-core gnupg flex bison gperf build-essential \
+apt-get update -y
+apt-get install -y software-properties-common
+
+add-apt-repository -y ppa:openjdk-r/ppa
+apt-get update -y
+apt-get install -y openjdk-${JDK_VERSION}-jdk python git-core gnupg flex bison gperf build-essential \
   zip curl zlib1g-dev gcc-multilib g++-multilib libc6-dev-i386 \
   lib32ncurses5-dev x11proto-core-dev libx11-dev lib32z-dev ccache \
   libgl1-mesa-dev libxml2-utils xsltproc unzip mtools u-boot-tools \
@@ -33,23 +35,15 @@ mkdir -p /android
 cd /android
 
 rm -rf .repo/local_manifests
-~/bin/repo init -u https://android.googlesource.com/platform/manifest -b android-6.0.1_r74 --depth=1
-git clone https://github.com/ayufan-pine64/local_manifests -b marshmallow .repo/local_manifests
+~/bin/repo init -u https://android.googlesource.com/platform/manifest -b "${MANIFEST}" --depth=1
+git clone https://github.com/ayufan-pine64/local_manifests -b "${VARIANT}" .repo/local_manifests
 
 message "Syncing repositories..."
 ~/bin/repo sync -j 20 -c --force-sync
 
-message "Building..."
-source build/envsetup.sh
-lunch "${TARGET}"
-command make -j$(($(nproc)+1)) || command make -j$(($(nproc)+1)) || true
-
-message "Cleaning objects..."
-command make installclean
-
-message "Building squashfs image..."
+message "Building squashfs image (repositories)..."
 cd /
-mksquashfs -Xcompression-level 7 /android /android.squashfs
+mksquashfs /android /android.squashfs -Xcompression-level 7
 
 message "Cleanup squashfs mount..."
 rm -rf /android
@@ -57,8 +51,28 @@ rm -rf /android
 message "Prepare squashfs mount..."
 mkdir -p /mnt/android /android/{overlay,work}/
 
-cat <<EOF > /etc/rc.local
+cat <<"EOF" > /etc/rc.local
 #!/bin/sh -e
 mount -t squashfs /android.squashfs /mnt/android
 mount -t overlay overlay -o lowerdir=/mnt/android,upperdir=/android/overlay,workdir=/android/work /android
 EOF
+
+message "Mounting squash image..."
+/etc/rc.local
+
+message "Configuring ccache..."
+cd /android
+prebuilts/misc/linux-x86/ccache/ccache -M 0 -F 0
+
+message "Building..."
+source build/envsetup.sh
+lunch "${BUILD_TARGET}"
+make -j $(nproc) || make -j $(nproc) || make -j $(nproc)
+
+message "Cleaning..."
+make installclean
+
+message "Updating squashfs..."
+cd /
+umount /android /mnt/android
+mksquashfs /android/overlay /android.squashfs -Xcompression-level 7
diff --git a/packer-template.json b/packer-template.json
index d775337..aa0a104 100644
--- a/packer-template.json
+++ b/packer-template.json
@@ -1,20 +1,39 @@
 {
   "variables": {
-    "do_api_token": "{{env `DIGITALOCEAN_API_TOKEN`}}"
+    "jdk_version": "7",
+    "build_target": "tulip_chiphd_atv-userdebug",
+    "manifest": "android-6.0.1_r74",
+    "variant": "marshmallow",
+
+    "do_api_token": "{{env `DIGITALOCEAN_API_TOKEN`}}",
+    "do_region": "ams2",
+    "do_size": "8gb",
   },
 
   "builders": [{
     "type": "digitalocean",
     "api_token": "{{user `do_api_token`}}",
-    "size": "8gb",
-    "region": "ams2",
+    "size": "{{user `do_size`}}",
+    "region": "{{user `do_region`}}",
     "image": "ubuntu-16-04-x64",
-    "droplet_name": "android-6.0-pine64-packer",
-    "snapshot_name": "android-6.0-pine64-squashfs-{{timestamp}}"
+    "droplet_name": "{{user `manifest`}}-pine64-build-env",
+    "snapshot_name": "{{user `manifest`}}-pine64-build-env-{{timestamp}}",
+    "state_timeout": "180m"
+  }, {
+    "type": "docker",
+    "image": "ubuntu:xenial",
+    "privileged": true,
+    "commit": true
   }],
 
   "provisioners": [{
     "type": "shell",
-    "script": "install-script.sh"
+    "script": "packer-template-script.sh",
+    "environment_vars": [
+      "JDK_VERSION={{user `jdk_version`}}",
+      "BUILD_TARGET={{user `build_target`}}",
+      "MANIFEST={{user `manifest`}}",
+      "VARIANT={{user `variant`}}"
+    ]
   }]
 }