Added Drone pipeline definition file.

Author: jlesage

.drone.yml

@@ -0,0 +1,86 @@
+#
+# Drone pipeline to build Docker image.
+#
+
+kind: pipeline
+type: docker
+name: default
+
+steps:
+
+- name: build-only
+  image: plugins/docker
+  settings:
+    repo: ${DRONE_REPO_NAMESPACE}/${DRONE_REPO_NAME##docker-}
+    build_args:
+    - DOCKER_IMAGE_VERSION=drone-ci
+    dry_run: true
+  when:
+    ref:
+      exclude:
+      - refs/tags/v*
+
+- name: set-docker-tags
+  image: alpine
+  commands:
+  # Always tag the Docker image with the Git tag (i.e. vX.Y.Z).
+  - printf "${DRONE_TAG}" >> .tags
+  # Tag the Docker image with with 'latest' only if not a prerelease.
+  - printf "${DRONE_TAG}" | grep -q '-' || printf ",latest" >> .tags
+  when:
+    ref:
+    - refs/tags/v*
+
+- name: build-and-push
+  image: plugins/docker
+  settings:
+    repo: ${DRONE_REPO_NAMESPACE}/${DRONE_REPO_NAME##docker-}
+    username:
+      from_secret: dockerhub_username
+    password:
+      from_secret: dockerhub_password
+    build_args:
+    - DOCKER_IMAGE_VERSION=${DRONE_TAG:1}
+  when:
+    ref:
+    - refs/tags/v*
+
+- name: push-dockerhub-readme
+  image: jlesage/drone-push-readme
+  settings:
+    repo: ${DRONE_REPO_NAMESPACE}/${DRONE_REPO_NAME##docker-}
+    username:
+      from_secret: dockerhub_username
+    password:
+      from_secret: dockerhub_password
+    readme: DOCKERHUB.md
+  when:
+    ref:
+    - refs/tags/v*
+
+- name: microbadger
+  image: plugins/webhook
+  settings:
+    urls:
+      from_secret: microbadger_webhook
+  failure: ignore
+  when:
+    ref:
+    - refs/tags/v*
+
+- name: notification
+  image: plugins/pushover
+  settings:
+    message: "{{ repo.owner }}/{{ repo.name }}#{{ truncate build.commit 8 }} ({{ build.branch }}) by {{ build.author }} - {{ build.message }}"
+    token:
+      from_secret: pushover_token
+    user:
+      from_secret: pushover_user
+  failure: ignore
+  when:
+    event:
+      exclude:
+      - pull_request
+    status:
+    - success
+    - failure