Fix path munging funcs and usage

Our `realpath` and `readlink -f` functions (required only because of MacOS,
thanks Steve) were poor substitutes at best.  Mostly they were downright
broken.  This thoroughly overhauls them and adds a test (in comments, since we
don't seem to have shell tests).  For all the interesting cases I could think
of, the fakes act just like the real thing.

Then use those and canonicalize KUBE_ROOT.  In order to make recursive calls of
our shell tool not additively grow `pwd` we have to essentially make the
sourcing of init.sh idempotent.

build/common.sh

@@ -26,11 +26,8 @@ DOCKER_HOST=${DOCKER_HOST:-""}
 DOCKER_MACHINE_NAME=${DOCKER_MACHINE_NAME:-"kube-dev"}
 readonly DOCKER_MACHINE_DRIVER=${DOCKER_MACHINE_DRIVER:-"virtualbox --virtualbox-memory 4096 --virtualbox-cpu-count -1"}
 
-KUBE_ROOT=$(dirname "${BASH_SOURCE}")/..
-cd "${KUBE_ROOT}"
-
-# This'll canonicalize the path
-KUBE_ROOT=$PWD
+# This will canonicalize the path
+KUBE_ROOT=$(cd $(dirname "${BASH_SOURCE}")/.. && pwd -P)
 
 source hack/lib/init.sh
 

hack/lib/golang.sh

@@ -309,7 +309,7 @@ kube::golang::setup_env() {
   # resultant binaries.  Go will not let us use GOBIN with `go install` and
   # cross-compiling, and `go install -o <file>` only works for a single pkg.
   local subdir
-  subdir=$(pwd | sed "s|$KUBE_ROOT||")
+  subdir=$(kube::realpath . | sed "s|$KUBE_ROOT||")
   cd "${KUBE_GOPATH}/src/${KUBE_GO_PACKAGE}/${subdir}"
 
   # Unset GOBIN in case it already exists in the current session.

hack/lib/init.sh

@@ -19,12 +19,7 @@ set -o nounset
 set -o pipefail
 
 # The root of the build/dist directory
-KUBE_ROOT=$(
-  unset CDPATH
-  kube_root=$(dirname "${BASH_SOURCE}")/../..
-  cd "${kube_root}"
-  pwd
-)
+KUBE_ROOT=$(cd $(dirname "${BASH_SOURCE}")/../.. && pwd -P)
 
 KUBE_OUTPUT_SUBPATH="${KUBE_OUTPUT_SUBPATH:-_output/local}"
 KUBE_OUTPUT="${KUBE_ROOT}/${KUBE_OUTPUT_SUBPATH}"
@@ -44,15 +39,83 @@ KUBE_GIT_UPSTREAM="${KUBE_GIT_UPSTREAM:-upstream}"
 
 KUBE_OUTPUT_HOSTBIN="${KUBE_OUTPUT_BINPATH}/$(kube::util::host_platform)"
 
-# emulates "readlink -f" which is not available on BSD (OS X).
-function readlinkdashf {
-  path=$1
-  # Follow links until there are no more links to follow.
-  while readlink "$path"; do
-    path="$(readlink $path)"
-  done
-  # Convert to canonical path.
-  path=$(cd "$(dirname "${path}")" && pwd -P)
-  echo "$path"
+# This emulates "readlink -f" which is not available on MacOS X.
+# Test:
+# T=/tmp/$$.$RANDOM
+# mkdir $T
+# touch $T/file
+# mkdir $T/dir
+# ln -s $T/file $T/linkfile
+# ln -s $T/dir $T/linkdir
+# function testone() {
+#   X=$(readlink -f $1 2>&1)
+#   Y=$(kube::readlinkdashf $1 2>&1)
+#   if [ "$X" != "$Y" ]; then
+#     echo readlinkdashf $1: expected "$X", got "$Y"
+#   fi
+# }
+# testone /
+# testone /tmp
+# testone $T
+# testone $T/file
+# testone $T/dir
+# testone $T/linkfile
+# testone $T/linkdir
+# testone $T/nonexistant
+# testone $T/linkdir/file
+# testone $T/linkdir/dir
+# testone $T/linkdir/linkfile
+# testone $T/linkdir/linkdir
+function kube::readlinkdashf {
+  # run in a subshell for simpler 'cd'
+  (
+    if [[ -d "$1" ]]; then # This also catch symlinks to dirs.
+      cd "$1"
+      pwd -P
+    else
+      cd $(dirname "$1")
+      local f
+      f=$(basename "$1")
+      if [[ -L "$f" ]]; then
+        readlink "$f"
+      else
+        echo "$(pwd -P)/${f}"
+      fi
+    fi
+  )
 }
 
+# This emulates "realpath" which is not available on MacOS X
+# Test:
+# T=/tmp/$$.$RANDOM
+# mkdir $T
+# touch $T/file
+# mkdir $T/dir
+# ln -s $T/file $T/linkfile
+# ln -s $T/dir $T/linkdir
+# function testone() {
+#   X=$(realpath $1 2>&1)
+#   Y=$(kube::realpath $1 2>&1)
+#   if [ "$X" != "$Y" ]; then
+#     echo realpath $1: expected "$X", got "$Y"
+#   fi
+# }
+# testone /
+# testone /tmp
+# testone $T
+# testone $T/file
+# testone $T/dir
+# testone $T/linkfile
+# testone $T/linkdir
+# testone $T/nonexistant
+# testone $T/linkdir/file
+# testone $T/linkdir/dir
+# testone $T/linkdir/linkfile
+# testone $T/linkdir/linkdir
+kube::realpath() {
+  if [[ ! -e "$1" ]]; then
+    echo "$1: No such file or directory" >&2
+    return 1
+  fi
+  kube::readlinkdashf "$1"
+}

hack/lib/util.sh

@@ -18,12 +18,6 @@ kube::util::sortable_date() {
   date "+%Y%m%d-%H%M%S"
 }
 
-# this mimics the behavior of linux realpath which is not shipped by default with
-# mac OS X
-kube::util::realpath() {
-  [[ $1 = /* ]] && echo "$1" | sed 's/\/$//' || echo "$PWD/${1#./}"  | sed 's/\/$//'
-}
-
 kube::util::wait_for_url() {
   local url=$1
   local prefix=${2:-}