support --platform option for docker build

Author: xmik

CHANGELOG.md

@@ -1,3 +1,7 @@
+### 2.1.0 (2025-Apr-23)
+
+* add an option to set docker platform while building a docker image (https://docs.docker.com/reference/cli/docker/buildx/build/#platform)
+
 ### 2.0.1 (2019-Apr-23)
 
  * updated readme

README.md

@@ -178,7 +178,7 @@ When `image_registry=dockerhub` then image name prefix with registry is skipped.
 
 ## License
 
-Copyright 2019 Ewa Czechowska, Tomasz Sętkowski
+Copyright 2019-2025 Ava Czechowska, Tom Setkowski
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.

src/docker-ops

@@ -83,6 +83,7 @@ function docker_ops::create_imagerc {
   local image_short_name=${3?image_name not set}
   local image_tag=${4?image_tag not set}
   local image_registry=${5:-dockerhub}
+  local image_platform=${6:-platform}
 
   local image_name="$(docker_ops::make_image_name $image_short_name $image_registry)"
   local image_url="$(docker_ops::make_image_url $image_short_name $image_tag $image_registry)"
@@ -93,13 +94,15 @@ function docker_ops::create_imagerc {
   echo "export KUDU_DOCKER_IMAGE_NAME=\"${image_name}\"" >> "${image_dir}/${imagerc_filename}"
   echo "export KUDU_DOCKER_IMAGE_TAG=\"${image_tag}\"" >> "${image_dir}/${imagerc_filename}"
   echo "export KUDU_DOCKER_IMAGE_URL=\"${image_url}\"" >> "${image_dir}/${imagerc_filename}"
+  echo "export KUDU_DOCKER_IMAGE_PLATFORM=\"${image_platform}\"" >> "${image_dir}/${imagerc_filename}"
 
   echo "{ " > "${image_dir}/${imagerc_filename}.json"
   echo "\"docker_registry\": \"${image_registry}\"," >> "${image_dir}/${imagerc_filename}.json"
   echo "\"docker_image_short_name\": \"${image_short_name}\"," >> "${image_dir}/${imagerc_filename}.json"
   echo "\"docker_image_name\": \"${image_name}\"," >> "${image_dir}/${imagerc_filename}.json"
   echo "\"docker_image_tag\": \"${image_tag}\"," >> "${image_dir}/${imagerc_filename}.json"
   echo "\"docker_image_url\": \"${image_url}\"" >> "${image_dir}/${imagerc_filename}.json"
+  echo "\"docker_image_platform\": \"${image_platform}\"" >> "${image_dir}/${imagerc_filename}.json"
   echo "}" >> "${image_dir}/${imagerc_filename}.json"
 
   echo "---" > "${image_dir}/${imagerc_filename}.yml"
@@ -108,6 +111,7 @@ function docker_ops::create_imagerc {
   echo "docker_image_name: \"${image_name}\"" >> "${image_dir}/${imagerc_filename}.yml"
   echo "docker_image_tag: \"${image_tag}\"" >> "${image_dir}/${imagerc_filename}.yml"
   echo "docker_image_url: \"${image_url}\"" >> "${image_dir}/${imagerc_filename}.yml"
+  echo "docker_image_platform: \"${image_platform}\"" >> "${image_dir}/${imagerc_filename}.yml"
 }
 
 function docker_ops::docker_build {
@@ -116,10 +120,12 @@ function docker_ops::docker_build {
   local image_short_name=${3?image_short_name not set}
   local image_tag=${4:-}
   local image_registry=${5:-dockerhub}
+  local image_platform=${6:-}
 
   docker_ops::log_info "image_dir set to: ${image_dir}"
   docker_ops::log_info "image_short_name set to: ${image_short_name}"
   docker_ops::log_info "imagerc_filename set to: ${imagerc_filename}"
+  docker_ops::log_info "image_platform set to: ${image_platform}"
   initial_dir="$(pwd)"
   cd "${image_dir}"
   if [[ -z "${image_tag}" ]];then
@@ -131,9 +137,14 @@ function docker_ops::docker_build {
   local image_url="$(docker_ops::make_image_url $image_short_name $image_tag $image_registry)"
 
   set -x -e
-  docker build ${docker_build_options} -t "${image_url}" .
+  if [[ -z "${image_platform}" ]];then
+    docker_ops::log_info "image_platform was not set, not setting it further"
+    docker build ${docker_build_options} -t "${image_url}" .
+  else
+    docker build ${docker_build_options} --platform "${image_platform}" -t "${image_url}" .
+  fi
   cd "${initial_dir}"
-  docker_ops::create_imagerc "${image_dir}" "${imagerc_filename}" "${image_short_name}" "${image_tag}" "${image_registry}"
+  docker_ops::create_imagerc "${image_dir}" "${imagerc_filename}" "${image_short_name}" "${image_tag}" "${image_registry}" "${image_platform}"
 }
 
 function docker_ops::source_imagerc {

test/integration/02-public-simple.bats

@@ -20,14 +20,17 @@ function clean_docker_images {
 @test "./tasks build_public" {
   run /bin/bash -c "cd ${repo_dir} && ./tasks build_public"
   assert_output --partial "docker build -t ${docker_image_name}:temp ."
-  assert_output --partial "Successfully built"
+  assert_equal "$status" 0
+}
+@test "./tasks build_public with platform set" {
+  run /bin/bash -c "cd ${repo_dir} && ./tasks build_public_platform"
+  assert_output --partial "docker build --platform linux/amd64 -t ${docker_image_name}:temp ."
   assert_equal "$status" 0
 }
 @test "./tasks build" {
   rm -rf "${repo_dir}/.git" ${repo_dir}/image/imagerc*
   run /bin/bash -c "cd ${repo_dir} && git init && git add --all && git commit -m first && ./tasks build"
   assert_output --partial "docker build -t ${docker_image_name}"
-  assert_output --partial "Successfully built"
   assert_equal "$status" 0
 
   run cat ${repo_dir}/image/imagerc

test/integration/03-private-complex.bats

@@ -31,7 +31,6 @@ function clean_docker_images {
   run /bin/bash -c "cd ${repo_dir} && git init && git add --all && git commit -m first && dryrun=true ./tasks build"
   assert_output --partial "docker build -t ${docker_registry1}/${docker_image_name1}"
   assert_output --partial "docker build -t ${docker_registry1}/${docker_image_name2}"
-  assert_output --partial "Successfully built"
   assert_equal "$status" 0
 
   run cat ${repo_dir}/image1/imagerc1

test/integration/test-files/docker-public/tasks

@@ -27,7 +27,12 @@ command="$1"
 case "${command}" in
   build_public)
       image_tag="${2:-temp}"
-      docker_ops::docker_build "${image_dir}" "${imagerc_filename}" "${image_name}" "${image_tag}"
+      docker_ops::docker_build "${image_dir}" "${imagerc_filename}" "${image_name}" "${image_tag}" "${image_registry}"
+      exit $?
+      ;;
+  build_public_platform)
+      image_tag="${2:-temp}"
+      docker_ops::docker_build "${image_dir}" "${imagerc_filename}" "${image_name}" "${image_tag}" "${image_registry}" "linux/amd64"
       exit $?
       ;;
   test_public)