Development: Add build-script and instructions

Author: Kjarrigan

.gitignore

@@ -0,0 +1,3 @@
+hcloud/
+packer/
+*.pem

README.md

@@ -32,3 +32,18 @@ These files will also be used to provide the documentation on https://docs.hetzn
 ### Metadata
 
 This file will contain some metadata which we use while displaying the app to you via our Cloud Console or public API.
+
+### Development
+
+You can build a snapshot yourself either for testing or to use as your personal app-template via
+
+```sh
+$ export HCLOUD_TOKEN=[...]
+$ ./build.sh
+
+Usage: ./build.sh <app> <arch>
+* app: subfolder in apps/hetzner/
+* arch: either amd64 or arm64
+
+$ ./build.sh wireguard arm64
+```

build.sh

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+#!/usr/bin/env bash
+set -e
+
+if [ $# != 2 ]; then
+    echo "Usage: $0 <app> <arch>"
+    echo "* app: subfolder in apps/hetzner/"
+    echo "* arch: either amd64 or arm64"
+    echo ""
+    exit 1
+fi
+
+APP=$1
+ARCH=$2
+
+if [ -z "$HCLOUD_TOKEN" ]; then
+  echo "No HCLOUD_TOKEN set"
+  exit 1
+fi
+
+GIT_REVISION=`git symbolic-ref HEAD 2> /dev/null | cut -b 12-`-`git log --pretty=format:\"%h\" -1 | xargs`
+SNAPSHOT_NAME=${APP}-${ARCH}-${GIT_REVISION}-${CI_PIPELINE_ID}
+
+export HCLOUD_SERVER_LOCATION="fsn1"
+
+# Target architecture for the new VM created by Packer
+if [ "$ARCH" == "amd64" ]; then
+	export HCLOUD_SERVER_TYPE_BEFORE_UPSCALE="cx11"
+	export HCLOUD_SERVER_TYPE="cpx21"
+fi
+if [ "$ARCH" == "arm64" ]; then
+    export HCLOUD_SERVER_TYPE_BEFORE_UPSCALE="cax11"
+	export HCLOUD_SERVER_TYPE="cax21"
+fi
+
+# Local architecture (used to execute hcloud and packer)
+LOCAL_ARCH='amd64'
+if [ $(uname -i) == 'aarch64' ]; then
+    LOCAL_ARCH='arm64'
+fi
+
+if [ -z "$CI_JOB_ID" ]; then
+    export CI_JOB_ID=`date +%s`
+fi
+
+# Download dependencies
+rm -rf hcloud || true
+mkdir hcloud
+cd hcloud
+wget -q "https://cs1.hetzner.de/cloud/hcloud-linux-${LOCAL_ARCH}.tar.gz"
+tar xzf hcloud-linux-${LOCAL_ARCH}.tar.gz
+export PATH=$PATH:$(pwd)
+
+cd ..
+rm -rf packer || true
+mkdir packer
+cd packer
+wget -q "https://releases.hashicorp.com/packer/1.10.3/packer_1.10.3_linux_${LOCAL_ARCH}.zip"
+unzip packer_1.10.3_linux_${LOCAL_ARCH}.zip
+export PATH=$PATH:$(pwd)
+cd ..
+
+# Check syntax
+packer validate -syntax-only apps/hetzner/${APP}/
+
+# Create VMs, install one-click-apps, create snapshot
+packer build -color=false -on-error=abort -var snapshot_name=${SNAPSHOT_NAME} apps/hetzner/${APP}/
+
+# Tag the resulting image with the application it contains
+snapshot_id=$(hcloud image list -o noheader -o "columns=id,description" | grep "${SNAPSHOT_NAME}" | awk '{print $1}')
+hcloud image add-label $snapshot_id app=${APP}
+
+# Cleanup any VMs, etc. that might be remaining
+./cleanup.sh ${APP}

cleanup.sh

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+#!/bin/bash
+set -e
+
+if [ -z "$1" ];
+then
+	echo "please specify app label"
+	exit 1
+fi
+
+##
+# Remove old snapshots, keep last 2
+ids=$(hcloud image list --selector app=$1 -o noheader -o columns=id | head -n -2)
+
+for i in $ids
+do
+  hcloud image delete $i
+done
+
+##
+# Remove old snapshots in case of an workflow failure in the past
+keys=$(hcloud ssh-key list | grep packer | awk '{ print $1 }')
+for k in $keys
+do
+  hcloud ssh-key delete $k
+done