feat: enable drone ci builds + add img metadata

* also add build status badges to README
* add metadata to the image at build time using a build hook

.drone.yml

@@ -0,0 +1,29 @@
+---
+kind: pipeline
+name: dockerhub-build-trigger
+
+platform:
+  os: linux
+  arch: amd64
+
+clone:
+  disable: true
+
+trigger:
+  branch:
+    - master
+  event:
+    - push
+    - cron
+
+steps:
+- name: call webhook
+  pull: always
+  image: bash:latest
+  environment:
+    ENDPOINT:
+      from_secret: DOCKERHUB_ENDPOINT
+  commands:
+    - apk add --no-cache curl
+    - curl -sO https://git.dotya.ml/${DRONE_REPO}/raw/branch/master/curl.it
+    - bash ./curl.it $ENDPOINT

Dockerfile

@@ -1,5 +1,12 @@
 FROM frolvlad/alpine-java:jdk8-full as build
 MAINTAINER wanderer <wanderer at git.dotya.ml>
+ARG BUILD_DATE
+ARG VCS_REF
+
+LABEL org.label-schema.build-date=$BUILD_DATE \
+      org.label-schema.vcs-url="https://git.dotya.ml/wanderer/docker-alpine-android.git" \
+      org.label-schema.vcs-ref=$VCS_REF \
+      org.label-schema.license=GPL-3.0
 
 ENV VERSION_SDK_TOOLS "3859397"
 ENV VERSION_TOOLS "6609375"

README.md

@@ -1,5 +1,8 @@
 # docker-alpine-android
 
+[![Build Status](https://drone.dotya.ml/api/badges/wanderer/docker-alpine-android/status.svg)](https://drone.dotya.ml/wanderer/docker-alpine-android)
+[![Docker Cloud Build Status](https://img.shields.io/docker/cloud/build/immawanderer/alpine-android)](https://hub.docker.com/r/immawanderer/alpine-android/builds)
+
 push mirror lives in [this GitHub repo](https://github.com/wULLSnpAXbWZGYDYyhWTKKspEQoaYxXyhoisqHf/docker-alpine-android)<br />
 development happens on [this Gitea instance](https://git.dotya.ml/wanderer/docker-alpine-android)
 

curl.it

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+if [ $# -gt 1 ]; then
+    curl -s -H 'Content-Type: application/json' --data '{"docker_tag":"nightly"}' -X POST $2
+else
+    curl -s -H 'Content-Type: application/json' --data '{"docker_tag":"latest"}' -X POST $1
+fi

hooks/build

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+# as per https://github.com/rossf7/label-schema-automated-build
+
+# $IMAGE_NAME var is injected into the build so the tag is correct.
+
+echo "Build hook running"
+docker build --build-arg BUILD_DATE=`date -u +"%Y-%m-%dT%H:%M:%SZ"` \
+             --build-arg VCS_REF=`git rev-parse --short HEAD` \
+             -t $IMAGE_NAME .