Add script to upload ARM tarballs correctly

We keep uploading them to the wrong place on accident.

scripts/upload-arm.sh

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+
+set -o errexit
+set -o nounset
+set -o pipefail
+
+
+usage () {
+    printf "usage: $0 <path_to_rootfs_tarball> <arch> <version>\n"
+    printf "\n"
+    printf "example: $0 ./armhf-trusty-libs.tgz arm32 v3\n"
+}
+
+
+upload () {
+    local -r local_filename="$1"
+    local -r arch="$2"
+    local -r version="$3"
+
+    if [[ "${arch}" == "arm32" ]]; then
+        local -r triple="arm-unknown-linux-gnueabihf"
+    elif [[ "${arch}" == "arm64" ]]; then
+        local -r triple="aarch64-unknown-linux-gnu"
+    else
+        printf >&2 "$0: assert: unknown arch $2 passed to upload()\n"
+        return 1
+    fi
+
+    local -r remote_location="s3://servo-rust/ARM/${triple}-trusty-libs/${version}/${triple}-trusty-libs-${version}.tgz"
+    printf "Uploading ${local_filename} to ${remote_location}. Proceed? [Y/n]"
+    local proceed
+    read proceed
+    if [[ "${proceed}" == "N" || "${proceed}" == "n" ]]; then
+        printf "Upload aborted.\n"
+        return 0
+    fi
+    s3cmd put "${local_filename}" "${remote_location}"
+}
+
+main () {
+    if [[ "$#" != 3 ]]; then
+        usage >&2
+        exit 1
+    fi
+    if [[ ! -e "$1" ]]; then
+        printf >&2 "$0: $1 does not exist for uploading\n"
+        exit 1
+    fi
+    if [[ "$2" != "arm32" && "$2" != "arm64" ]]; then
+        printf >&2 "$0: unknown arch $2, please specify either arm32 or arm64\n"
+        exit 1
+    fi
+    if [[ "$3" != v* ]]; then
+        printf >&2 "$0: version $3 must start with a v\n"
+        exit 1
+    fi
+
+    upload "$@"
+}
+
+main "$@"