Add build for armv7 buf binaries (#3450)

Author: nimish-ks

make/buf/scripts/release.bash

@@ -27,6 +27,7 @@ goarch() {
     x86_64) echo amd64 ;;
     arm64) echo arm64 ;;
     aarch64) echo arm64 ;;
+    armv7) echo arm ;;
     *) return 1 ;;
   esac
 }
@@ -83,7 +84,7 @@ mkdir -p "${RELEASE_DIR}"
 cd "${RELEASE_DIR}"
 
 for os in Darwin Linux Windows; do
-  for arch in x86_64 arm64; do
+  for arch in x86_64 arm64 armv7; do
     # our goal is to have the binaries be suffixed with $(uname -s)-$(uname -m)
     # on mac, this is arm64, on linux, this is aarch64, for historical reasons
     # this is a hacky way to not have to rewrite this loop (and others below)
@@ -100,15 +101,27 @@ for os in Darwin Linux Windows; do
       buf \
       protoc-gen-buf-breaking \
       protoc-gen-buf-lint; do
-      CGO_ENABLED=0 GOOS=$(goos "${os}") GOARCH=$(goarch "${arch}") \
-        go build -a -ldflags "-s -w" -trimpath -buildvcs=false -o "${dir}/bin/${binary}${extension}" "${DIR}/cmd/${binary}"
+      if [ "${arch}" == "armv7" ]; then
+        if [ "${os}" == "Linux" ]; then
+          CGO_ENABLED=0 GOOS=$(goos "${os}") GOARCH=$(goarch "${arch}") GOARM=7 \
+            go build -a -ldflags "-s -w" -trimpath -buildvcs=false -o "${dir}/bin/${binary}${extension}" "${DIR}/cmd/${binary}"
+        else
+          continue
+        fi 
+      else
+        CGO_ENABLED=0 GOOS=$(goos "${os}") GOARCH=$(goarch "${arch}") \
+          go build -a -ldflags "-s -w" -trimpath -buildvcs=false -o "${dir}/bin/${binary}${extension}" "${DIR}/cmd/${binary}"
+      fi
       cp "${dir}/bin/${binary}${extension}" "${binary}-${os}-${arch}${extension}"
     done
   done
 done
 
 for os in Darwin Linux Windows; do
-  for arch in x86_64 arm64; do
+  for arch in x86_64 arm64 armv7; do
+    if [ "${arch}" == "armv7" ] && [ "${os}" != "Linux" ]; then
+      continue
+    fi
     if [ "${os}" == "Linux" ] && [ "${arch}" == "arm64" ]; then
       arch="aarch64"
     fi
@@ -128,7 +141,10 @@ for os in Darwin Linux Windows; do
 done
 
 for os in Darwin Linux; do
-  for arch in x86_64 arm64; do
+  for arch in x86_64 arm64 armv7; do
+    if [ "${arch}" == "armv7" ] && [ "${os}" != "Linux" ]; then
+      continue
+    fi
     if [ "${os}" == "Linux" ] && [ "${arch}" == "arm64" ]; then
       arch="aarch64"
     fi