Revert "Revert "ARMでもAMD64でも使えるDockerfileに""

This reverts commit 4f67086.

Dockerfile

@@ -5,11 +5,22 @@ ARG OYAKI_VERSION
 WORKDIR /go/src/oyaki
 COPY . /go/src/oyaki
 
-RUN CGO_ENABLED=0 go build -ldflags "-s -w -X main.version=${OYAKI_VERSION}" -o /go/bin/oyaki
-RUN apt update && apt install -y curl \
- && curl https://storage.googleapis.com/downloads.webmproject.org/releases/webp/libwebp-1.3.1-linux-x86-64.tar.gz --output libwebp.tar.gz \
- && tar vzxf libwebp.tar.gz \
- && mv libwebp-1.3.1-linux-x86-64/bin/cwebp /go/bin/
+ARG TARGETARCH
+ENV LIBWEBP_VERSION=1.3.1
+ENV BASE_URL=https://storage.googleapis.com/downloads.webmproject.org/releases/webp
+RUN apt-get update && apt-get install -y curl tar
+RUN if [ "${TARGETARCH}" = "amd64" ]; then \
+        ARCH='amd64'; \
+    elif [ "${TARGETARCH}" = "arm64" ]; then \
+        ARCH='aarch64'; \
+    else \
+        echo "Unsupported arch: ${TARGETARCH}"; exit 1; \
+    fi && \
+    curl https://storage.googleapis.com/downloads.webmproject.org/releases/webp/libwebp-1.3.1-linux-${ARCH}.tar.gz --output libwebp.tar.gz \
+    tar -zxf libwebp.tar.gz --strip-components=1 -C /go/bin && \
+    rm libwebp.tar.gz
+
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=$TARGETARCH go build -ldflags "-s -w -X main.version=${OYAKI_VERSION}" -o /go/bin/oyaki
 
 FROM gcr.io/distroless/static-debian11