Support cross platform builds

Add support for cross building the following platforms:

- `linux/386`
- `linux/amd64`
- `linux/arm/v6`
- `linux/arm/v7`
- `linux/arm64`
- `linux/ppc64le`
- `linux/s390x`

To build for a different platform other than the local native platform the
`qemu-user-static` package must be installed.

Example to build AMD64, ARM64 and ARMv7 platforms:
```
make PLATFORM="linux/amd64 linux/arm64 linux/arm/v7" all-images
```

Makefile

@@ -16,31 +16,73 @@
 #
 
 BUILDER ?= docker
+PLATFORMS ?= linux/amd64
 VERSION ?= latest
 IMAGE ?= weechat
+REGISTRY ?= docker.io
+REGISTRY_PROJECT ?= weechat
+REGISTRY_PROJECT_URL = $(REGISTRY)/$(REGISTRY_PROJECT)
+REGISTRY_IMAGE = $(REGISTRY_PROJECT_URL)/$(IMAGE)
+
+ALPINE_BASE_IMAGE = alpine:3.15
+DEBIAN_BASE_IMAGE = debian:bullseye-slim
+
+ifeq ($(strip $(PUSH)),true)
+PUSH_ARG = "--push"
+endif
 
 .PHONY: all debian debian-slim alpine alpine-slim
 
 all: debian
 
 all-images: debian debian-slim alpine alpine-slim
 
-debian:
-	./build.py -b "$(BUILDER)" -d "debian" "$(VERSION)"
+debian: weechat-multiarch
+	./build.py -b "$(BUILDER)" -p $(PLATFORMS) -r "$(REGISTRY_PROJECT_URL)" $(PUSH_ARG)  -d "debian" "$(VERSION)"
+
+debian-slim: weechat-multiarch
+	./build.py -b "$(BUILDER)" -p $(PLATFORMS) -r "$(REGISTRY_PROJECT_URL)" $(PUSH_ARG) -d "debian" --slim "$(VERSION)"
 
-debian-slim:
-	./build.py -b "$(BUILDER)" -d "debian" --slim "$(VERSION)"
+alpine: weechat-multiarch
+	./build.py -b "$(BUILDER)" -p $(PLATFORMS) -r "$(REGISTRY_PROJECT_URL)" $(PUSH_ARG) -d "alpine" "$(VERSION)"
 
-alpine:
-	./build.py -b "$(BUILDER)" -d "alpine" "$(VERSION)"
+alpine-slim: weechat-multiarch
+	./build.py -b "$(BUILDER)" -p $(PLATFORMS) -r "$(REGISTRY_PROJECT_URL)" $(PUSH_ARG) -d "alpine" --slim "$(VERSION)"
 
-alpine-slim:
-	./build.py -b "$(BUILDER)" -d "alpine" --slim "$(VERSION)"
+weechat-multiarch:
+	if [ "$(BUILDER)" == "docker" ]; then \
+		docker buildx ls | grep weechat-multiarch || docker buildx create --name weechat-multiarch ; \
+		docker buildx use weechat-multiarch; \
+	fi
 
-test-container:
-	"$(BUILDER)" run "$(IMAGE)" weechat --version
-	"$(BUILDER)" run "$(IMAGE)" weechat-headless --version
+test-images:
+	for PLATFORM in $(PLATFORMS); do \
+		for TAG in $(VERSION)-{debian,alpine}{,-slim}; do \
+			REGISTRY_IMAGE_TAG=$(REGISTRY_IMAGE):$$TAG; \
+			echo "Testing $$REGISTRY_IMAGE_TAG for $$PLATFORM platform" ; \
+			$(BUILDER) pull --platform $$PLATFORM $$REGISTRY_IMAGE_TAG &>/dev/null; \
+			echo -n "weechat --version: "; \
+			$(BUILDER) run --rm --platform $$PLATFORM $$REGISTRY_IMAGE_TAG --version; \
+			echo -n "weechat-headless --version: "; \
+			$(BUILDER) run --rm --platform $$PLATFORM --entrypoint /usr/bin/weechat-headless $$REGISTRY_IMAGE_TAG --version ; \
+			$(BUILDER) rmi $$REGISTRY_IMAGE_TAG &>/dev/null; \
+	  done; \
+	done
 
+clean-images:
+	if [ "$(BUILDER)" == "podman" ]; then \
+		buildah rm --all; \
+		$(BUILDER) images --format="{{.Repository}}:{{.Tag}}" localhost/$(IMAGE) | xargs --no-run-if-empty $(BUILDER) rmi -f; \
+		$(BUILDER) images --format="{{.Repository}}:{{.Tag}}" $(REGISTRY_PROJECT)/$(IMAGE) | xargs --no-run-if-empty $(BUILDER) rmi -f; \
+		$(BUILDER) images --format="{{.Repository}}:{{.Tag}}" $(ALPINE_BASE_IMAGE) | xargs --no-run-if-empty $(BUILDER) rmi -f; \
+		$(BUILDER) images --format="{{.Repository}}:{{.Tag}}" $(DEBIAN_BASE_IMAGE) | xargs --no-run-if-empty $(BUILDER) rmi -f; \
+		$(BUILDER) image prune -f; \
+	fi
+	if [ "$(BUILDER)" == "docker" ]; then \
+		$(BUILDER) buildx rm weechat-multiarch; \
+		$(BUILDER) rmi moby/buildkit:buildx-stable-1
+	fi
+
 lint: flake8 pylint mypy bandit
 
 flake8:

README.md

@@ -31,6 +31,20 @@ The slim version includes all plugins except these ones:
 - scripting languages: perl, python, ruby, lua, tcl, guile, php
 - spell
 
+## Supported platforms
+
+It's possible to build for different linux platforms other than amd64,
+the only prerequisite is to have `qemu-user-static` package installed
+
+- `linux/386`
+- `linux/amd64`
+- `linux/arm/v6`
+- `linux/arm/v7`
+- `linux/arm64`
+- `linux/ppc64le`
+- `linux/s390x`
+
+
 ## Install from Docker Hub
 
 You can install directly the latest version from the Docker Hub:
@@ -72,6 +86,13 @@ Build all images with latest stable version of WeeChat:
 $ make all-images
 ```
 
+Build all images with latest stable version of WeeChat for AMD64 and ARM64 platforms
+and push them to the `docker.io/weechat` registry project:
+
+```
+$ make PLATFORMS="linux/amd64 linux/arm64" REGISTRY="docker.io" REGISTRY_PROJECT="weechat" PUSH=true all-images
+```
+
 Build an Alpine-based image with Podman, slim version, WeeChat 3.6:
 
 ```

alpine/Containerfile

@@ -18,21 +18,12 @@ ENV VERSION="${VERSION}"
 ARG SLIM=""
 ENV SLIM="${SLIM}"
 
-ARG HOME="/home/user"
+ARG HOME="/weechat"
 ENV HOME="${HOME}"
 
 ENV LANG="C.UTF-8"
 ENV TERM="xterm-256color"
 
-# create a user
-RUN set -eux ; \
-    adduser -u 1001 -D -h "$HOME" user ; \
-    mkdir -p "$HOME/.weechat" ; \
-    mkdir -p "$HOME/.config/weechat" ; \
-    mkdir -p "$HOME/.local/share/weechat" ; \
-    mkdir -p "$HOME/.cache/weechat" ; \
-    chown -R user:user "$HOME"
-
 # ==== build ====
 
 FROM base as build
@@ -126,6 +117,8 @@ RUN set -eux ; \
         libgcrypt \
         ncurses-libs \
         ncurses-terminfo \
+        shadow \
+        setpriv \
         tzdata \
         zlib \
         zstd \
@@ -151,8 +144,17 @@ COPY --from=build /opt/weechat /opt/weechat
 RUN ln -sf /opt/weechat/bin/weechat /usr/bin/weechat
 RUN ln -sf /opt/weechat/bin/weechat-headless /usr/bin/weechat-headless
 
-WORKDIR $HOME
+# create a user
+RUN set -eux ; \
+  adduser -u 1000 -D -h "$HOME" weechat; \
+  mkdir -p "$HOME/.weechat" ; \
+  mkdir -p "$HOME/.config/weechat" ; \
+  mkdir -p "$HOME/.local/share/weechat" ; \
+  mkdir -p "$HOME/.cache/weechat" ; \
+  chown -R weechat:weechat "$HOME"
 
-USER user
+ADD ../run.sh /
+
+WORKDIR $HOME
 
-CMD ["weechat"]
+ENTRYPOINT [ "/run.sh" ]

build.py

@@ -18,25 +18,54 @@
 
 """Build WeeChat container image."""
 
-from typing import List, Sequence, Tuple
+from typing import List, Sequence, Tuple, Dict
 
 import argparse
 import urllib.request
 import subprocess  # nosec
 
+BUILDERS: Sequence[str] = (
+    "docker",
+    "podman",
+)
+
 DISTROS: Sequence[str] = (
     "debian",
     "alpine",
 )
 
+SUPPORTED_PLATFORMS: Dict[str, Dict[str, List[str]]] = {
+  "linux": {
+    "386": [],
+    "amd64": [],
+    "arm": ["v6", "v7"],
+    "arm64": [],
+    "ppc64le": [],
+    "s390x": [],
+  },
+}
+
+
+def generate_valid_platforms() -> list[str]:
+    """Return the list of supported platforms."""
+    valid_platforms = []
+    for os_name, archs in SUPPORTED_PLATFORMS.items():
+        for arch, variants in archs.items():
+            if not variants:
+                valid_platforms.append(f"{os_name}/{arch}")
+            for variant in variants:
+                valid_platforms.append(f"{os_name}/{arch}/{variant}")
+    return valid_platforms
+
 
 def get_parser() -> argparse.ArgumentParser:
     """Return the command line parser."""
     parser = argparse.ArgumentParser(description="Build of WeeChat container")
     parser.add_argument(
         "-b",
         "--builder",
-        default="docker",
+        choices=BUILDERS,
+        default=BUILDERS[0],
         help=(
             "program used to build the container image, "
             "like docker (default) or podman"
@@ -47,7 +76,29 @@ def get_parser() -> argparse.ArgumentParser:
         "--distro",
         choices=DISTROS,
         default=DISTROS[0],
-        help="base Linux distribution for the container",
+        help="base Linux distribution for the container, default %(default)s",
+    )
+    parser.add_argument(
+        "-p",
+        "--platforms",
+        default="linux/amd64",
+        choices=generate_valid_platforms(),
+        nargs="+",
+        help="build platforms",
+    )
+    parser.add_argument(
+        "--push",
+        action="store_true",
+        default=False,
+        help=(
+            "push the images to the registry, default: %(default)s"
+        ),
+    )
+    parser.add_argument(
+        "-r",
+        "--registry-project",
+        default="docker.io/weechat",
+        help="registry project, default: %(default)s",
     )
     parser.add_argument(
         "-n",
@@ -81,7 +132,7 @@ def get_version_tags(
 
     :param version: x.y, x.y.z, "latest", "stable", "devel"
     :param distro: "debian" or "alpine"
-    :paral slim: slim version
+    :param slim: slim version
     :return: tuple (version, tags) where version if the version of WeeChat
         to build and tags is a list of tag arguments for command line,
         for example: ['-t', 'weechat:3.0-alpine',
@@ -111,25 +162,61 @@ def get_version_tags(
     tags_args = []
     for tag in reversed(tags):
         for suffix in suffixes:
-            tags_args.extend(
-                [
-                    "-t",
+            tags_args.append(
                     f"weechat:{tag}{suffix}",
-                    "-t",
-                    f"weechat/weechat:{tag}{suffix}",
-                ]
             )
     return (version, tags_args)
 
 
+def run_command(command: List[str], dry_run: bool) -> None:
+    """
+    Prints the command to run and runs it if 'dry_run=False'
+
+    :param command: ["docker", "images"]
+    :param dry_run: True
+    :return: None
+    """
+    print(f'Running: {" ".join(command)}')
+    if not dry_run:
+        try:
+            subprocess.run(command, check=False)  # nosec
+        except KeyboardInterrupt:
+            pass
+        except Exception as exc:  # pylint: disable=broad-except
+            print(exc)
+
+
 def main() -> None:
     """Main function."""
+    build_args = ["buildx", "build"]
     args = get_parser().parse_args()
     slim = ["--build-arg", "SLIM=1"] if args.slim else []
     version, tags = get_version_tags(args.version, args.distro, args.slim)
+
+    if args.builder == "docker":
+        docker_tags = []
+        for tag in tags:
+            docker_tags.extend(["-t", f"{args.registry_project}/{tag}"])
+        tags = docker_tags
+        if args.push:
+            build_args.append("--push")
+
+    podman_slim = ""
+    if args.slim:
+        podman_slim = "-slim"
+    podman_manifest_image = f"localhost/weechat:{version}" \
+        + f"-{args.distro}{podman_slim}-manifest"
+    podman_tags = [tag for tag in tags if tag.startswith("weechat:")]
+
+    if args.builder == "podman":
+        build_args = ["build", "--jobs", "0"]
+        tags = ["--manifest", podman_manifest_image]
+
     command = [
         f"{args.builder}",
-        "build",
+        *build_args,
+        "--platform",
+        ",".join(args.platforms),
         "-f",
         f"{args.distro}/Containerfile",
         "--build-arg",
@@ -138,14 +225,27 @@ def main() -> None:
         *tags,
         ".",
     ]
-    print(f'Running: {" ".join(command)}')
-    if not args.dry_run:
-        try:
-            subprocess.run(command, check=False)  # nosec
-        except KeyboardInterrupt:
-            pass
-        except Exception as exc:  # pylint: disable=broad-except
-            print(exc)
+    run_command(command, args.dry_run)
+
+    if args.builder == "podman":
+        command = [
+              f"{args.builder}",
+              "tag",
+              podman_manifest_image,
+              *[f"localhost/{tag}" for tag in podman_tags]
+        ]
+        run_command(command, args.dry_run)
+
+        if args.push:
+            for tag in podman_tags:
+                command = [
+                      f"{args.builder}",
+                      "manifest",
+                      "push",
+                      f"localhost/{tag}",
+                      f"{args.registry_project}/{tag}"
+                ]
+                run_command(command, args.dry_run)
 
 
 if __name__ == "__main__":