Travis to deploy multi-arch docker build. Attempt #1

.travis.yml

@@ -1,11 +1,30 @@
-language: python
 sudo: required
 dist: xenial
+language: python
 python:
-- '3.5'
-- '3.6'
-- '3.7'
+  - '3.5'
+  - '3.6'
+  - '3.7'
 install:
-- pip install .
-- pip install -r requirements.txt
-script: python setup.py test
+  - pip install .
+  - pip install -r requirements.txt
+script: python setup.py test
+deploy:
+  provider: script
+  script: ./.travis/deploy.sh
+  if: type != pull_request
+  on:
+    all_branches: true
+    condition: $TRAVIS_BRANCH =~ ^(dev)$
+    addons:
+      apt:
+        sources:
+          - sourceline: 'deb https://download.docker.com/linux/ubuntu/ xenial stable'
+            key_url: 'https://download.docker.com/linux/ubuntu/gpg'
+        packages:
+          - docker-ce
+          - docker-ce-cli
+          - containerd.io
+    language: python
+    python: '3.6'
+    script: ./.travis/deploy.sh

.travis/deploy.sh

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+
+set -e
+export BRANCH=$(if [ "$TRAVIS_PULL_REQUEST" == "false" ]; then echo $TRAVIS_BRANCH; else echo $TRAVIS_PULL_REQUEST_BRANCH; fi)
+export DOCKER_IMAGE_TAG=$(if [ "$BRANCH" == "master" ]; then echo "latest"; else echo "$BRANCH-latest"; fi)
+echo "$DOCKER_PASSWORD" | docker login -u "$DOCKER_USERNAME" --password-stdin
+export DOCKER_CLI_EXPERIMENTAL=enabled
+docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
+docker buildx create --use
+docker buildx build --progress plain --platform linux/amd64,linux/arm64,linux/arm/v7 -t $DOCKER_USERNAME/pai:$DOCKER_IMAGE_TAG . --push