Fail if python script not found; run from any dir

If the script was run from anywhere other than the directory above hack,
the python script could not be found, however since the error code was
ignored, this would pass.

Finding files and ignoring failed files was being done in one line. We
wanted to ignore errors from grep, however this has the side effect of
ignoring errors from the python script, e.g. if this script is run
from an unexpected directory and the python script is not found.

Lastly, filtering of dirs was being done in both `boilerplate.sh` and
`boilerplate.py` so now it will just be done in `boilerplate.sh`.

hack/boilerplate.sh

@@ -13,14 +13,13 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
-# Ignore these paths in the following tests.
-ignore="vendor\|out\|testdata"
-BOILERPLATEDIR=./hack/boilerplate
-# Grep returns a non-zero exit code if we don't match anything, which is good in this case.
-set +e
-files=$(python ${BOILERPLATEDIR}/boilerplate.py --rootdir . --boilerplate-dir ${BOILERPLATEDIR} | grep -v $ignore)
 set -e
+
+DIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
+BOILERPLATEDIR=$DIR/boilerplate
+
+files=$(python ${BOILERPLATEDIR}/boilerplate.py --rootdir . --boilerplate-dir ${BOILERPLATEDIR})
+
 if [[ ! -z ${files} ]]; then
 	echo "Boilerplate missing in:"
     echo "${files}"

hack/boilerplate/boilerplate.py

@@ -22,6 +22,10 @@
 import re
 import sys
 
+
+SKIPPED_DIRS = ["Godeps", "third_party", ".git", "vendor", "examples", "testdata"]
+SKIPPED_FILES = ["install_golint.sh"]
+
 parser = argparse.ArgumentParser()
 parser.add_argument("filenames", help="list of files to check, all files if unspecified", nargs='*')
 
@@ -103,17 +107,11 @@ def file_passes(filename, refs, regexs):
 def file_extension(filename):
     return os.path.splitext(filename)[1].split(".")[-1].lower()
 
-skipped_dirs = ['Godeps', 'third_party', '.git', "vendor", "examples", './hack/install_golint.sh']
-
 def normalize_files(files):
     newfiles = []
-    for pathname in files:
-        if any(x in pathname for x in skipped_dirs):
-            continue
-        newfiles.append(pathname)
-    for i, pathname in enumerate(newfiles):
+    for i, pathname in enumerate(files):
         if not os.path.isabs(pathname):
-            newfiles[i] = os.path.join(args.rootdir, pathname)
+            newfiles.append(os.path.join(args.rootdir, pathname))
     return newfiles
 
 def get_files(extensions):
@@ -122,17 +120,14 @@ def get_files(extensions):
         files = args.filenames
     else:
         for root, dirs, walkfiles in os.walk(args.rootdir):
-            # don't visit certain dirs. This is just a performance improvement
-            # as we would prune these later in normalize_files(). But doing it
-            # cuts down the amount of filesystem walking we do and cuts down
-            # the size of the file list
-            for d in skipped_dirs:
+            for d in SKIPPED_DIRS:
                 if d in dirs:
                     dirs.remove(d)
 
             for name in walkfiles:
-                pathname = os.path.join(root, name)
-                files.append(pathname)
+                if name not in SKIPPED_FILES:
+                    pathname = os.path.join(root, name)
+                    files.append(pathname)
 
     files = normalize_files(files)
     outfiles = []