Uniquify docker names

If you have two repos that are both building at the same time we don't want to have them stomp on each other as they deal with docker.  Work around this by hashing the KUBE_ROOT and mixing that in to the name.

build/common.sh

@@ -22,6 +22,9 @@ set -o pipefail
 KUBE_ROOT=$(dirname "${BASH_SOURCE}")/..
 cd "${KUBE_ROOT}"
 
+# This'll canonicalize the path
+KUBE_ROOT=$PWD
+
 source hack/config-go.sh
 
 # Incoming options
@@ -39,8 +42,10 @@ readonly KUBE_GCS_MAKE_PUBLIC="${KUBE_GCS_MAKE_PUBLIC:-y}"
 
 # Constants
 readonly KUBE_BUILD_IMAGE_REPO=kube-build
-readonly KUBE_BUILD_IMAGE_TAG=build
+# These get set in verify_prereqs with a unique hash based on KUBE_ROOT
-readonly KUBE_BUILD_IMAGE="${KUBE_BUILD_IMAGE_REPO}:${KUBE_BUILD_IMAGE_TAG}"
+# KUBE_BUILD_IMAGE_TAG=<hash>
+# KUBE_BUILD_IMAGE="${KUBE_BUILD_IMAGE_REPO}:${KUBE_BUILD_IMAGE_TAG}"
+# KUBE_BUILD_CONTAINER_NAME=kube-build-<hash>
 
 readonly KUBE_GO_PACKAGE="github.com/GoogleCloudPlatform/kubernetes"
 
@@ -53,7 +58,6 @@ readonly LOCAL_OUTPUT_ROOT="${KUBE_ROOT}/_output"
 readonly LOCAL_OUTPUT_BUILD="${LOCAL_OUTPUT_ROOT}/build"
 readonly REMOTE_OUTPUT_ROOT="/go/src/${KUBE_GO_PACKAGE}/_output"
 readonly REMOTE_OUTPUT_DIR="${REMOTE_OUTPUT_ROOT}/build"
-readonly DOCKER_CONTAINER_NAME=kube-build
 readonly DOCKER_MOUNT_ARGS=(--volume "${LOCAL_OUTPUT_BUILD}:${REMOTE_OUTPUT_DIR}")
 
 readonly KUBE_CLIENT_BINARIES=(
@@ -88,7 +92,14 @@ readonly RELEASE_DIR="${LOCAL_OUTPUT_ROOT}/release-tars"
 # ---------------------------------------------------------------------------
 # Basic setup functions
 
-# Verify that the right utilities and such are installed for building Kube.
+# Verify that the right utilities and such are installed for building Kube.  Set
+# up some dynamic constants.
+#
+# Vars set:
+#   KUBE_BUILD_IMAGE_TAG
+#   KUBE_BUILD_IMAGE
+#   KUBE_BUILD_CONTAINER_NAME
+#   KUBE_ROOT_HASH
 function kube::build::verify_prereqs() {
   if [[ -z "$(which docker)" ]]; then
     echo "Can't find 'docker' in PATH, please fix and retry." >&2
@@ -122,6 +133,11 @@ function kube::build::verify_prereqs() {
     } >&2
     return 1
   fi
+
+  KUBE_ROOT_HASH=$(kube::build::short_hash "$KUBE_ROOT")
+  KUBE_BUILD_IMAGE_TAG="build-${KUBE_ROOT_HASH}"
+  KUBE_BUILD_IMAGE="${KUBE_BUILD_IMAGE_REPO}:${KUBE_BUILD_IMAGE_TAG}"
+  KUBE_BUILD_CONTAINER_NAME="kube-build-${KUBE_ROOT_HASH}"
 }
 
 # ---------------------------------------------------------------------------
@@ -181,6 +197,22 @@ function kube::build::docker_image_exists() {
   docker images | grep -Eq "^${1}\s+${2}\s+"
 }
 
+# Takes $1 and computes a short has for it. Useful for unique tag generation
+function kube::build::short_hash() {
+  [[ $# -eq 1 ]] || {
+    echo "!!! Internal error.  No data based to short_hash." >&2
+    exit 2
+  }
+
+  local short_hash
+  if which md5 >/dev/null 2>&1; then
+    short_hash=$(md5 -q -s "$1")
+  else
+    short_hash=$(echo -n "$1" | md5sum)
+  fi
+  echo ${short_hash:0:5}
+}
+
 # ---------------------------------------------------------------------------
 # Building
 
@@ -312,18 +344,18 @@ function kube::build::run_build_command() {
   kube::build::prepare_output
 
   local -ra docker_cmd=(
-    docker run "--name=${DOCKER_CONTAINER_NAME}"
+    docker run "--name=${KUBE_BUILD_CONTAINER_NAME}"
     --interactive --tty
     "${DOCKER_MOUNT_ARGS[@]}" "${KUBE_BUILD_IMAGE}")
 
   # Remove the container if it is left over from some previous aborted run
-  docker rm "${DOCKER_CONTAINER_NAME}" >/dev/null 2>&1 || true
+  docker rm "${KUBE_BUILD_CONTAINER_NAME}" >/dev/null 2>&1 || true
   "${docker_cmd[@]}" "$@"
 
   # Remove the container after we run.  '--rm' might be appropriate but it
   # appears that sometimes it fails. See
   # https://github.com/docker/docker/issues/3968
-  docker rm "${DOCKER_CONTAINER_NAME}" >/dev/null 2>&1 || true
+  docker rm "${KUBE_BUILD_CONTAINER_NAME}" >/dev/null 2>&1 || true
 }
 
 # If the Docker server is remote, copy the results back out.
@@ -339,11 +371,11 @@ function kube::build::copy_output() {
     # container pointed at the same volume, tar the output directory and ship
     # that tar over stdou.
     local -ra docker_cmd=(
-      docker run -a stdout "--name=${DOCKER_CONTAINER_NAME}"
+      docker run -a stdout "--name=${KUBE_BUILD_CONTAINER_NAME}"
       "${DOCKER_MOUNT_ARGS[@]}" "${KUBE_BUILD_IMAGE}")
 
     # Kill any leftover container
-    docker rm "${DOCKER_CONTAINER_NAME}" >/dev/null 2>&1 || true
+    docker rm "${KUBE_BUILD_CONTAINER_NAME}" >/dev/null 2>&1 || true
 
     echo "+++ Syncing back _output directory from boot2docker VM"
     rm -rf "${LOCAL_OUTPUT_BUILD}"
@@ -354,13 +386,13 @@ function kube::build::copy_output() {
     # Remove the container after we run.  '--rm' might be appropriate but it
     # appears that sometimes it fails. See
     # https://github.com/docker/docker/issues/3968
-    docker rm "${DOCKER_CONTAINER_NAME}" >/dev/null 2>&1 || true
+    docker rm "${KUBE_BUILD_CONTAINER_NAME}" >/dev/null 2>&1 || true
 
     # I (jbeda) also tried getting rsync working using 'docker run' as the
     # 'remote shell'.  This mostly worked but there was a hang when
     # closing/finishing things off. Ug.
     #
-    # local DOCKER="docker run -i --rm --name=${DOCKER_CONTAINER_NAME} ${DOCKER_MOUNT} ${KUBE_BUILD_IMAGE}"
+    # local DOCKER="docker run -i --rm --name=${KUBE_BUILD_CONTAINER_NAME} ${DOCKER_MOUNT} ${KUBE_BUILD_IMAGE}"
     # DOCKER+=" bash -c 'shift ; exec \"\$@\"' --"
     # rsync --blocking-io -av -e "${DOCKER}" foo:${REMOTE_OUTPUT_DIR}/ ${LOCAL_OUTPUT_BUILD}
   fi
@@ -523,12 +555,7 @@ function kube::release::gcs::verify_prereqs() {
 # Create a unique bucket name for releasing Kube and make sure it exists.
 function kube::release::gcs::ensure_release_bucket() {
   local project_hash
-  if which md5 > /dev/null 2>&1; then
+  project_hash=$(kube::build::short_hash "$GCLOUD_PROJECT")
-    project_hash=$(md5 -q -s "$GCLOUD_PROJECT")
-  else
-    project_hash=$(echo -n "$GCLOUD_PROJECT" | md5sum)
-  fi
-  project_hash=${project_hash:0:5}
   KUBE_GCS_RELEASE_BUCKET=${KUBE_GCS_RELEASE_BUCKET-kubernetes-releases-${project_hash}}
   KUBE_GCS_RELEASE_PREFIX=${KUBE_GCS_RELEASE_PREFIX-devel/}
   KUBE_GCS_DOCKER_REG_PREFIX=${KUBE_GCS_DOCKER_REG_PREFIX-docker-reg/}