fixup release process (#328)

Author: dragonsinth

releasing/README.md

@@ -53,22 +53,7 @@ This will create the release in GitHub with provisional release notes that just
 
 ### Docker Hub Releases
 
-To re-run only the Docker Hub release steps, we need to build an image with the right tag and then push to Docker Hub.
-
-```sh
-# from the root of the repo
-echo v2.3.4 > VERSION
-docker build -t fullstorydev/grpcurl:v2.3.4 .
-docker build -t fullstorydev/grpcurl:v2.3.4-alpine --target alpine .
-# now that we have it built, push to Docker Hub
-docker push fullstorydev/grpcurl:v2.3.4
-docker push fullstorydev/grpcurl:v2.3.4-alpine
-# push "latest" tag, too
-docker tag fullstorydev/grpcurl:v2.3.4 fullstorydev/grpcurl:latest
-docker tag fullstorydev/grpcurl:v2.3.4-alpine fullstorydev/grpcurl:latest-alpine
-docker push fullstorydev/grpcurl:latest
-docker push fullstorydev/grpcurl:latest-alpine
-```
+To re-run only the Docker Hub release steps, you can manually run through each step in the "Docker" section of `do_release.sh`.
 
 If the `docker push ...` steps fail, you may need to run `docker login`, enter your Docker Hub login credentials, and then try to push again.
 

releasing/do-release.sh

@@ -50,8 +50,7 @@ export DOCKER_CLI_EXPERIMENTAL=enabled
 $PREFIX docker buildx create --use --name multiarch-builder --node multiarch-builder0
 # push to docker hub, both the given version as a tag and for "latest" tag
 $PREFIX docker buildx build --platform linux/amd64,linux/s390x,linux/arm64,linux/ppc64le --tag fullstorydev/grpcurl:${VERSION} --tag fullstorydev/grpcurl:latest --push --progress plain --no-cache .
-rm VERSION
-$PREFIX docker buildx build --platform linux/amd64,linux/s390x,linux/arm64 --tag fullstorydev/grpcurl:${VERSION}-alpine --tag fullstorydev/grpcurl:latest-alpine --push --progress plain --no-cache --target alpine .
+$PREFIX docker buildx build --platform linux/amd64,linux/s390x,linux/arm64,linux/ppc64le --tag fullstorydev/grpcurl:${VERSION}-alpine --tag fullstorydev/grpcurl:latest-alpine --push --progress plain --no-cache --target alpine .
 rm VERSION
 
 # Homebrew release