Use alpine base image instead of glib image.

docker/Dockerfile

@@ -1,7 +1,13 @@
-FROM gronis/alpine-glibc
+FROM alpine
 
-RUN ARCH=$(uname -m | sed 's/x86_64/amd64/g' | sed 's/aarch64/arm64/g' | sed 's/armv7l/arm/g') && \
-    SUPERCRONIC_SHA1SUM=$(echo $ARCH | sed 's/amd64/5ddf8ea26b56d4a7ff6faecdd8966610d5cb9d85/g' | sed 's/arm64/e2714c43e7781bf1579c85aa61259245f56dbba1/g' | sed 's/arm/47481c3341bc3a1ae91a728e0cc63c8e6d3791ad/g') && \
+RUN \
+    ARCH=$(if [ $(uname -m) == "x86_64" ] && [ $(getconf LONG_BIT) == "64" ]; then echo "amd64"; \
+         elif [ $(uname -m) == "x86_64" ] && [ $(getconf LONG_BIT) == "32" ]; then echo "386"; \
+         elif [ $(uname -m) == "aarch64" ]; then echo "arm64"; \
+         elif [ $(uname -m) == "armv7l" ]; then echo "arm"; \
+         elif [ $(uname -m) == "armv6l" ]; then echo "arm"; fi;) && \
+    echo "Building for $ARCH" 1>&2 && \
+    SUPERCRONIC_SHA1SUM=$(echo $ARCH | sed 's/386/e0126b0102b9f388ecd55714358e3ad60d0cebdb/g' | sed 's/amd64/5ddf8ea26b56d4a7ff6faecdd8966610d5cb9d85/g' | sed 's/arm64/e2714c43e7781bf1579c85aa61259245f56dbba1/g' | sed 's/arm/47481c3341bc3a1ae91a728e0cc63c8e6d3791ad/g') && \
     SUPERCRONIC_URL=https://github.com/aptible/supercronic/releases/download/v0.1.9/supercronic-linux-$ARCH && \
     SUPERCRONIC=supercronic-linux-$ARCH && \
     # Install SeaweedFS and Supercronic ( for cron job mode )

docker/README.md

@@ -27,3 +27,10 @@ docker-compose -f seaweedfs-dev-compose.yml -p seaweedfs up
 cd $GOPATH/src/github.com/chrislusf/seaweedfs/docker
 make
 ```
+
+## Build and push a multiarch build
+
+Make sure that `docker buildx` is supported.
+```bash
+docker buildx build --pull --push --platform linux/386,linux/amd64,linux/arm64,linux/arm/v7,linux/arm/v6 . -t chrislusf/seaweedfs
+```