oeqa.utils.commands: limit runCmd exception output

Make it possible to limit the length of output lines shown in runCmd
exceptions. E.g when running bitbake we easily get thousands of lines of
log output, where only the last few (tens) are interesting or relevant
when an error occurs.

Signed-off-by: Markus Lehtonen <markus.lehtonen@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

diff --git a/meta/lib/oeqa/utils/commands.py b/meta/lib/oeqa/utils/commands.py
index 6528a98427a8504bc8cc07d9126587199b4b602d..cd7a5e3b12a669b1961d796cf8b08a4a420e2ad0 100644 (file)
--- a/meta/lib/oeqa/utils/commands.py
+++ b/meta/lib/oeqa/utils/commands.py
@@ -97,7 +97,8 @@ class Result(object):
     pass
 
 
-def runCmd(command, ignore_status=False, timeout=None, assert_error=True, native_sysroot=None, **options):
+def runCmd(command, ignore_status=False, timeout=None, assert_error=True,
+          native_sysroot=None, limit_exc_output=0, **options):
     result = Result()
 
     if native_sysroot:
@@ -117,10 +118,16 @@ def runCmd(command, ignore_status=False, timeout=None, assert_error=True, native
     result.pid = cmd.process.pid
 
     if result.status and not ignore_status:
+        exc_output = result.output
+        if limit_exc_output > 0:
+            split = result.output.splitlines()
+            if len(split) > limit_exc_output:
+                exc_output = "\n... (last %d lines of output)\n" % limit_exc_output + \
+                             '\n'.join(split[-limit_exc_output:])
         if assert_error:
-            raise AssertionError("Command '%s' returned non-zero exit status %d:\n%s" % (command, result.status, result.output))
+            raise AssertionError("Command '%s' returned non-zero exit status %d:\n%s" % (command, result.status, exc_output))
         else:
-            raise CommandError(result.status, command, result.output)
+            raise CommandError(result.status, command, exc_output)
 
     return result