feat: support platform arg in docker build script

Signed-off-by: Sebastian Davids <[email protected]>

Author: sdavids

docs/user-guide/modules/ROOT/pages/scripts/docker/docker-build.adoc

@@ -9,6 +9,7 @@ The following parameters are supported:
 
 `d` :: the path to the https://docs.docker.com/reference/cli/docker/image/build/#file[Dockerfile] (`$PWD/Dockerfile` if not given) to be used
 `n` :: do not use the cache when building the image
+`p` :: the https://docs.docker.com/reference/cli/docker/buildx/build/#platform[target platform] for the build (if not given the platform of the BuildKit daemon where the build runs is used)
 `t` :: one of the two image's https://docs.docker.com/engine/reference/commandline/image_build/#tag[tags] (`local` if not given);
 the image will always be tagged with `latest`
 
@@ -58,6 +59,13 @@ $ SOURCE_DATE_EPOCH=0 scripts/docker/docker_build.sh -d scripts/docker/Dockerfil
 ...
 "org.opencontainers.image.revision":"46cca5eff61eabb008ed43e81988e6a9099aa469-next"
 ...
+
+$ scripts/docker/docker_build.sh -d scripts/docker/Dockerfile -t amd -p linux/amd64
+$ docker inspect --format='{{.Os}}/{{.Architecture}}' de.sdavids/sdavids-shell-misc:amd
+linux/amd64
+$ scripts/docker/docker_build.sh -d scripts/docker/Dockerfile -t arm -p linux/arm64
+$ docker inspect --format='{{.Os}}/{{.Architecture}}' de.sdavids/sdavids-shell-misc:arm
+linux/arm64
 ----
 
 == Prerequisites
@@ -69,3 +77,8 @@ $ SOURCE_DATE_EPOCH=0 scripts/docker/docker_build.sh -d scripts/docker/Dockerfil
 * xref:scripts/docker/docker-start.adoc[]
 * xref:scripts/docker/docker-remove.adoc[]
 * xref:scripts/docker/docker-cleanup.adoc[]
+
+== More Information
+
+* https://docs.docker.com/reference/cli/docker/buildx/build/#platform[Docker build - platform]
+* https://docs.docker.com/reference/cli/docker/buildx/build/#tag[Docker build - tag]

scripts/docker/docker_build.sh

@@ -5,19 +5,22 @@
 
 set -Eeu -o pipefail -o posix
 
-while getopts ':d:nt:' opt; do
+while getopts ':d:np:t:' opt; do
   case "${opt}" in
     d)
       dockerfile="${OPTARG}"
       ;;
     n)
       no_cache='--pull --no-cache'
       ;;
+    p)
+      platform="${OPTARG}"
+      ;;
     t)
       tag="${OPTARG}"
       ;;
     ?)
-      echo "Usage: $0 [-d Dockerfile] [-n] [-t tag]" >&2
+      echo "Usage: $0 [-d Dockerfile] [-n] [-p platform] [-t tag]" >&2
       exit 1
       ;;
   esac
@@ -27,6 +30,9 @@ readonly dockerfile="${dockerfile:-$PWD/Dockerfile}"
 
 readonly no_cache="${no_cache:-}"
 
+# https://docs.docker.com/reference/cli/docker/buildx/build/#platform
+readonly platform="${platform:-}"
+
 readonly tag="${tag:-local}"
 
 if [ ! -f "${dockerfile}" ]; then
@@ -98,15 +104,28 @@ readonly commit
 
 # https://github.com/opencontainers/image-spec/blob/master/annotations.md
 # shellcheck disable=SC2086
-docker image build \
-  ${no_cache} \
-  --file "${dockerfile}" \
-  --tag "${image_name}:latest" \
-  --tag "${image_name}:${tag}" \
-  --label "${label_group}=${repository}" \
-  --label "org.opencontainers.image.revision=${commit}" \
-  --label "org.opencontainers.image.created=${created_at}" \
-  .
+if [ -n "${platform}" ]; then
+  docker image build \
+    ${no_cache} \
+    --file "${dockerfile}" \
+    --platform="${platform}" \
+    --tag "${image_name}:latest" \
+    --tag "${image_name}:${tag}" \
+    --label "${label_group}=${repository}" \
+    --label "org.opencontainers.image.revision=${commit}" \
+    --label "org.opencontainers.image.created=${created_at}" \
+    .
+else
+  docker image build \
+    ${no_cache} \
+    --file "${dockerfile}" \
+    --tag "${image_name}:latest" \
+    --tag "${image_name}:${tag}" \
+    --label "${label_group}=${repository}" \
+    --label "org.opencontainers.image.revision=${commit}" \
+    --label "org.opencontainers.image.created=${created_at}" \
+    .
+fi
 
 echo