SERVER-30839 prevent buildscripts/combine_reports.py from overwriting report.json

4 files changed, 63 insertions, 40 deletions

diff --git a/buildscripts/collect_resource_info.py b/buildscripts/collect_resource_info.py
index c6f7b1ac527..5fc6c614afa 100755
--- a/buildscripts/collect_resource_info.py
+++ b/buildscripts/collect_resource_info.py
@@ -7,7 +7,6 @@ Collect system resource information on processes running in Evergreen on a given
 from __future__ import absolute_import
 from __future__ import print_function
 
-import contextlib
 from datetime import datetime
 import optparse
 import os
@@ -17,30 +16,13 @@ import time
 from bson.json_util import dumps
 import requests
 
-@contextlib.contextmanager
-def open_or_use_stdout(filename):
-    """
-    Opens the specified file for writing, or returns sys.stdout if filename is "-".
-    """
 
-    if filename == "-":
-        yield sys.stdout
-        return
-
-    line_buffered = 1
-    try:
-        fp = open(filename, "w", line_buffered)
-    except IOError:
-        print("Could not open file {}".format(filename), file=sys.stderr)
-        sys.exit(1)
-
-    try:
-        yield fp
-    finally:
-        fp.close()
+# Get relative imports to work when the package is not installed on the PYTHONPATH.
+sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+from buildscripts.resmokelib import utils
+    
 
 def main():
-
     usage = "usage: %prog [options]"
     parser = optparse.OptionParser(description=__doc__, usage=usage)
     parser.add_option("-i", "--interval",
@@ -58,7 +40,7 @@ def main():
 
     (options, _) = parser.parse_args()
 
-    with open_or_use_stdout(options.outfile) as fp:
+    with utils.open_or_use_stdout(options.outfile) as fp:
         while True:
             # Requires the Evergreen agent to be running on port 2285.
             response = requests.get("http://localhost:2285/status")
@@ -109,5 +91,6 @@ def main():
                     os.fsync(fp.fileno())
             time.sleep(options.interval)
 
+
 if __name__ == "__main__":
     main()
diff --git a/buildscripts/combine_reports.py b/buildscripts/combine_reports.py
index d7fe0eb5ece..e0e81569a80 100755
--- a/buildscripts/combine_reports.py
+++ b/buildscripts/combine_reports.py
@@ -14,9 +14,9 @@ import sys
 from optparse import OptionParser
 
 # Get relative imports to work when the package is not installed on the PYTHONPATH.
-if __name__ == "__main__" and __package__ is None:
-    sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
-    from buildscripts.resmokelib.testing import report
+sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+from buildscripts.resmokelib.testing import report
+from buildscripts.resmokelib import utils
 
 
 def read_json_file(json_file):
@@ -37,8 +37,18 @@ def report_exit(combined_test_report):
     return ret
 
 
-def main():
+def check_error(input_count, output_count):
+    """
+    Error if both input and output exist, or if neither exist.
+    """
+    if (not input_count) and (not output_count):
+        raise ValueError("None of the input file(s) or output file exists")
+
+    elif input_count and output_count:
+        raise ValueError("Both input file and output files exist")
 
+
+def main():
     usage = "usage: %prog [options] report1.json report2.json ..."
     parser = OptionParser(description=__doc__, usage=usage)
     parser.add_option("-o", "--output-file",
@@ -47,10 +57,6 @@ def main():
                       help="If '-', then the combined report file is written to stdout."
                            " Any other value is treated as the output file name. By default,"
                            " output is written to stdout.")
-    parser.add_option("-m", "--ignore-missing-reports",
-                      dest="ignore_missing",
-                      action="store_true",
-                      help="Ignore any input report file that does not exist.")
     parser.add_option("-x", "--no-report-exit",
                       dest="report_exit",
                       default=True,
@@ -63,25 +69,33 @@ def main():
         sys.exit("No report files were specified")
 
     report_files = args
+    report_files_count = len(report_files)
     test_reports = []
+
     for report_file in report_files:
         try:
             report_file_json = read_json_file(report_file)
             test_reports.append(report.TestReport.from_dict(report_file_json))
         except IOError as e:
             # errno.ENOENT is the error code for "No such file or directory".
-            if options.ignore_missing and e.errno == errno.ENOENT:
-                print("Ignoring missing file {}".format(report_file))
+            if e.errno == errno.ENOENT:
+                report_file_count -= 1
                 continue
             raise
 
     combined_test_report = report.TestReport.combine(*test_reports)
     combined_report = combined_test_report.as_dict()
-    if options.outfile != "-":
-        with open(options.outfile, "w") as fstream:
-            json.dump(combined_report, fstream)
+
+    if options.outfile == "-":
+        outfile_exists = False  # Nothing will be overridden when writing to stdout.
     else:
-        print(json.dumps(combined_report))
+        outfile_exists = os.path.exists(options.outfile)
+
+    check_error(report_files_count, outfile_exists)
+
+    if not outfile_exists:
+        with utils.open_or_use_stdout(options.outfile) as fh:
+            json.dump(combined_report, fh)
 
     if options.report_exit:
         sys.exit(report_exit(combined_test_report))
diff --git a/buildscripts/resmoke.py b/buildscripts/resmoke.py
index 29591ef57a3..aa8d437d815 100755
--- a/buildscripts/resmoke.py
+++ b/buildscripts/resmoke.py
@@ -12,9 +12,8 @@ import sys
 import time
 
 # Get relative imports to work when the package is not installed on the PYTHONPATH.
-if __name__ == "__main__" and __package__ is None:
-    sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
-    from buildscripts import resmokelib
+sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+from buildscripts import resmokelib
 
 
 def _execute_suite(suite):
diff --git a/buildscripts/resmokelib/utils/__init__.py b/buildscripts/resmokelib/utils/__init__.py
index 77cc6952fb0..fa782f34301 100644
--- a/buildscripts/resmokelib/utils/__init__.py
+++ b/buildscripts/resmokelib/utils/__init__.py
@@ -3,12 +3,38 @@ Helper functions.
 """
 
 from __future__ import absolute_import
+from __future__ import print_function
 
+import contextlib
 import os.path
+import sys
 
 import yaml
 
 
+@contextlib.contextmanager
+def open_or_use_stdout(filename):
+    """
+    Opens the specified file for writing, or returns sys.stdout if filename is "-".
+    """
+
+    if filename == "-":
+        yield sys.stdout
+        return
+
+    line_buffered = 1
+    try:
+        fp = open(filename, "w", line_buffered)
+    except IOError:
+        print("Could not open file {}".format(filename), file=sys.stderr)
+        sys.exit(1)
+
+    try:
+        yield fp
+    finally:
+        fp.close()
+
+
 def default_if_none(value, default):
     return value if value is not None else default
 
@@ -60,6 +86,7 @@ def dump_yaml(value):
     # Use block (indented) style for formatting YAML.
     return yaml.safe_dump(value, default_flow_style=False).rstrip()
 
+
 def load_yaml(value):
     """
     Attempts to parse 'value' as YAML.