search

Cadasta / cadasta-platform

[DEPRECATED] Main repository of the Cadasta platform. Technology to help communities document their land rights around the world.
https://demo.cadasta.org
GNU Affero General Public License v3.0
54 stars 81 forks source link

Remove recursive template code #2023

Closed oliverroick closed 6 years ago

oliverroick commented 6 years ago

Proposed changes in this pull request

Why I made this change

After we deployed v1.17.0, the import pages in all projects throw a 502 Bad Gateway. Our debug logs show stack overflow for these events, which causes the server to crash and restart.

The issue is caused by an if statement in the template; if removed the page renders as expected.

I don't fully understand the purpose of the code in question, why it's there and what it does. Looking at the template itself and testing out different scenarios it seems like the condition is never met and the template in the else branch is always rendered. I'm assuming the code is not needed.

The reason we haven't seen the error before is likely because of some changes to our logging setup, when we switched from Opbeat to Sentry.

Description of the change

Removed the faulty code.

How someone else can test the change

Add the following logger to the LOGGING['loggers'] in the dev settings:

       'django.template': {
           'handlers': ['console'],
           'level': 'DEBUG',
       }

This will create the same logs that we see on production in debug.log.

Navigate to any project dashboard and click the big Import button.

On master, the dev server should crash.

These changes applied, the page should render successfully.

When should this PR be merged

ASAP, so we can get the latest release back on prod.

Risks

As I don't fully understand the purpose of the code I removed, there's a slight chance some import scenarios will fail. I've tested different scenarios but I might have missed some.

All functional tests should pass, so I'm assuming the commin scenaros will work with these changes applied.

Follow-up actions

—

Checklist (for reviewing)

General

Is this PR explained thoroughly? All code changes must be accounted for in the PR description.

Is the PR labeled correctly? It should have the migration label if a new migration is added.

Is the risk level assessment sufficient? The risks section should contain all risks that might be introduced with the PR and which actions we need to take to mitigate these risks. Possible risks are database migrations, new libraries that need to be installed or changes to deployment scripts.

Functionality

Are all requirements met? Compare implemented functionality with the requirements specification.

Does the UI work as expected? There should be no Javascript errors in the console; all resources should load. There should be no unexpected errors. Deliberately try to break the feature to find out if there are corner cases that are not handled.

Code

Do you fully understand the introduced changes to the code? If not ask for clarification, it might uncover ways to solve a problem in a more elegant and efficient way.

Does the PR introduce any inefficient database requests? Use the debug server to check for duplicate requests.

Are all necessary strings marked for translation? All strings that are exposed to users via the UI must be marked for translation.

Is the code documented sufficiently? Large and complex classes, functions or methods must be annotated with comments following our code-style guidelines.

Has the scalability of this change been evaluated?

Is there a maintenance plan in place?

Tests

Are there sufficient test cases? Ensure that all components are tested individually; models, forms, and serializers should be tested in isolation even if a test for a view covers these components.

If this is a bug fix, are tests for the issue in place? There must be a test case for the bug to ensure the issue won’t regress. Make sure that the tests break without the new code to fix the issue.

If this is a new feature or a significant change to an existing feature? has the manual testing spreadsheet been updated with instructions for manual testing?

Security

Confirm this PR doesn't commit any keys, passwords, tokens, usernames, or other secrets.

Are all UI and API inputs run through forms or serializers?

Are all external inputs validated and sanitized appropriately?

Does all branching logic have a default case?

Does this solution handle outliers and edge cases gracefully?

Are all external communications secured and restricted to SSL?

Documentation

Are changes to the UI documented in the platform docs? If this PR introduces new platform site functionality or changes existing ones, the changes must be documented in the Cadasta Platform Documentation.

Are changes to the API documented in the API docs? If this PR introduces new API functionality or changes existing ones, the changes must be documented in the API docs.

Are reusable components documented? If this PR introduces components that are relevant to other developers (for instance a mixin for a view or a generic form) they should be documented in the Wiki.

alukach commented 6 years ago

Although, it's worrisome that our testing didn't detect this error in the first place...

seav commented 6 years ago

This is all really weird. The code that is deleted in this PR appears to be the standard code for the wizard template as seen in the django-formtools docs: http://django-formtools.readthedocs.io/en/latest/wizard.html#creating-templates-for-the-forms

In fact, this same code is also used in the add project wizard as seen here, for example: https://github.com/Cadasta/cadasta-platform/blob/fa24aa9d6a22e889e6f60a557aaa725841b2e42f/cadasta/templates/organization/project_add_extents.html#L42-L49

While testing this, the removal of the code does not seem to affect anything and I am able to import data so this PR seems like a solution, but I have a nagging feeling that there is more to this than it seems because we are not encountering any errors for the add project wizard.

oliverroick commented 6 years ago

I do have one request, we should also remove the same code from the wizard's 3rd step's template as seen here (and fix the missing newlines so the template is more readable):

Done!