Add Drone CI pipeline for building Docker image

.drone-write-tags.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+# Write Docker tags for Drone CI: version-YYMMDD, version, major version, latest
+
+VERSION="$1"
+
+if test -z "$VERSION"; then
+    echo "Usage: $0 <version>"
+    exit 1
+fi
+
+if [[ "$VERSION" == *"alpha"* || "$VERSION" == *"dev"* ]]; then
+    # This should never trigger if reference based tagging is enabled
+    echo "ERROR: Pushing alpha / dev tags is not supported"
+    exit 1
+fi
+
+major_version="$(printf '%s' "$VERSION" | cut -d . -f 1)"
+
+# Date based tag
+printf '%s' "$VERSION-$(date +%Y%m%d),"
+# Program version
+printf '%s' "$VERSION,"
+
+if [[ "$VERSION" == *"beta"* ]]; then
+    printf '%s' "$major_version-beta,"
+    printf '%s' "latest-beta"
+else  # Stable or rc build
+    printf '%s' "$major_version,"
+    printf '%s' "latest"
+fi

.drone.yml

@@ -0,0 +1,37 @@
+---
+kind: pipeline
+type: docker
+name: build
+
+steps:
+- name: "test"
+  image: python:3.8
+  commands:
+    - "git submodule update --recursive --remote --init"
+    - "pip install -r requirements-docker.txt"
+    - "python3 setup.py install"
+    - "python3 -m unittest discover test/ --verbose"
+
+- name: "set Docker image tags"
+  image: bash
+  commands:
+    - "bash .drone-write-tags.sh $DRONE_TAG > .tags"
+    - "# Will build the following tags:"
+    - "cat .tags"
+
+- name: "build Docker image"
+  image: plugins/docker
+  settings:
+    repo: jlu5/pylink
+    username:
+      from_secret: docker_user
+    password:
+      from_secret: docker_token
+
+trigger:
+  event:
+  - tag
+  ref:
+    exclude:
+    - refs/tags/*alpha*
+    - refs/tags/*dev*