per-platform jobs

.travis.yml

@@ -1,5 +1,9 @@
 dist: bionic
 sudo: required
+env:
+  - DOCKER_BUILD_PLATFORM=linux/amd64
+  - DOCKER_BUILD_PLATFORM=linux/arm/v7
+  - DOCKER_BUILD_PLATFORM=linux/arm64
 
 before_install:
   - curl -fsSL https://get.docker.com | sh

.travis/docker-release.sh

@@ -7,14 +7,14 @@ export DOCKER_PROJECT="democratic-csi"
 export DOCKER_REPO="${DOCKER_ORG}/${DOCKER_PROJECT}"
 
 if [[ -n "${TRAVIS_TAG}" ]]; then
-  docker buildx build --progress plain --pull --push --platform linux/amd64,linux/arm/v7,linux/arm64 -t ${DOCKER_REPO}:${TRAVIS_TAG} .
+  docker buildx build --progress plain --pull --push --platform "${DOCKER_BUILD_PLATFORM}" -t ${DOCKER_REPO}:${TRAVIS_TAG} .
   docker push ${DOCKER_REPO}:${TRAVIS_TAG}
 elif [[ -n "${TRAVIS_BRANCH}" ]]; then
   if [[ "${TRAVIS_BRANCH}" == "master" ]]; then
-    docker buildx build --progress plain --pull --push --platform linux/amd64,linux/arm/v7,linux/arm64 -t ${DOCKER_REPO}:latest .
+    docker buildx build --progress plain --pull --push --platform "${DOCKER_BUILD_PLATFORM}" -t ${DOCKER_REPO}:latest .
     docker push ${DOCKER_REPO}:latest
   else
-    docker buildx build --progress plain --pull --push --platform linux/amd64,linux/arm/v7,linux/arm64 -t ${DOCKER_REPO}:${TRAVIS_BRANCH} .
+    docker buildx build --progress plain --pull --push --platform "${DOCKER_BUILD_PLATFORM}" -t ${DOCKER_REPO}:${TRAVIS_BRANCH} .
     docker push ${DOCKER_REPO}:${TRAVIS_BRANCH}
   fi
 else

Dockerfile

@@ -1,5 +1,7 @@
 FROM debian:10-slim
 
+ENV DEBIAN_FRONTEND=noninteractive
+
 ARG TARGETPLATFORM
 ARG BUILDPLATFORM