Add support for an --image flag to atest.

scheduler/scheduler_models.py

Index: scheduler/scheduler_models.py
diff --git a/scheduler/scheduler_models.py b/scheduler/scheduler_models.py
index 870914d5de0b2a3d3aa76d211b15058762ac059d..644510db4ecd34a3981a6a819316342c23b827e5 100644
--- a/scheduler/scheduler_models.py
+++ b/scheduler/scheduler_models.py
@@ -861,6 +861,54 @@ class Job(DBObject):
         return entries
 
 
+    def is_image_update_job(self):
+        """
+        Discover if the current job requires an OS update.
+
+        @return: True/False if OS should be updated before job is run.
+        """
+        if not self.parameterized_job_id:
+            # All image update jobs have the parameterized_job_id set.

[DaleCurtis, 2011/01/11 00:46:05]

Nit, but I think comment should be on line above.

[pauldean_chromium, 2011/01/12 18:12:52]

Done.

+            return False
+
+        # Retrieve the ID of the ParameterizedJob this job is an instance of.
+        sql_str = ('SELECT test_id '

[DaleCurtis, 2011/01/11 00:46:05]

Use """ syntax like in the rest of the file.

Also, normally you never want to inject values directly into your query string
like this. With user-controlled values you could face SQL injection attacks.

The preferred method for populating values into the query string is to use some
marker character (? or %s in this case) and then pass the values in through
parameters=(...) on the execute call. See get_host_queue_entries() above.

Using parameters=(...) also takes care of having to worry about escaping or
quoting values. In your case if parameterized_job_id had spaces or any other
funny characters, the query would break.

[pauldean_chromium, 2011/01/12 18:12:52]

Cool, thanks for the info.  I've fixed that up.

+                   'FROM afe_parameterized_jobs '
+                   'WHERE id = %s' % self.parameterized_job_id)
+        rows = _db.execute(sql_str)
+        if not rows:
+            return False
+        test_id = rows[0][0]

[DaleCurtis, 2011/01/11 00:46:05]

Is it possible for rows[n] to be None or something similar? Do other areas of
code to any further checking?

[pauldean_chromium, 2011/01/12 18:12:52]

In the testing I've done with regular and the new mucked up jobs the rows return
have always been either nothing or the tuple value,  I've never seen None
returned.  I haven't found good documentation on the execute method so I'm just
going off of the behavior I've seen.

+
+        # Retrieve the ID of the known autoupdate_ParameterizedJob.
+        sql_str = ('SELECT id '

[DaleCurtis, 2011/01/11 00:46:05]

Same comment as above.

[pauldean_chromium, 2011/01/12 18:12:52]

Done.

+                   'FROM afe_autotests '
+                   'WHERE name = \"%s\"' % 'autoupdate_ParameterizedJob')
+        rows = _db.execute(sql_str)
+        if not rows:
+            return False
+        update_id = rows[0][0]

[DaleCurtis, 2011/01/11 00:46:05]

Same comment as above.

[pauldean_chromium, 2011/01/12 18:12:52]

Done.

+
+        # If the IDs are the same we've found an image update job.
+        if test_id == update_id:

[DaleCurtis, 2011/01/11 00:46:05]

Will all parameterized jobs always be image jobs? Is there a safer test for
this?

[pauldean_chromium, 2011/01/12 18:12:52]

For now image update jobs are the only parameterized jobs.  Parameterized jobs
are not being enabled generally and cannot be run natively.  

When we want to support parameterized jobs fully this test will no longer be
valid as this strategy would be trying to create a test job and an image update
job at the same time as the same job.  When that happens we will need a more
Autotest like solution like adding a field to the database like reboot_before.

+            # Finally, get the path to the OS image to install.
+            sql_str = ('SELECT parameter_value '

[DaleCurtis, 2011/01/11 00:46:05]

Same comment as above.

[pauldean_chromium, 2011/01/12 18:12:52]

Done.

+                       'FROM afe_parameterized_job_parameters '
+                       'WHERE parameterized_job_id = %s '
+                       % self.parameterized_job_id)
+            rows = _db.execute(sql_str)
+            if not rows:
+                # The image cannot be updated without an OS path.

[DaleCurtis, 2011/01/11 00:46:05]

Consider reflowing w/ else: return False below. Drops some code and possibly
more readable to say "if rows: blah blah; return True" Up to you.

Doing without the else: means if anyone modifies the code in the future is
harder for them to miss a case which returns no value or returns the wrong
value.

[pauldean_chromium, 2011/01/12 18:12:52]

Good point.  Fixed.

+                return False
+
+            # Save the path in update_image_path to use later as a command
+            # line parameter to autoserv.
+            self.update_image_path = rows[0][0]
+            return True
+        else:
+            return False
+
+
     def get_execution_details(self):
         """
         Get test execution details for this job.