My website is working well on my local environment, as well as it has been working well on heroku env until my recent deployment. Code is same on both environments and I referred to all 11 posts related to similar issue,example Reverse for 'todo-user' with arguments '('',)' not found. 1 pattern(s) tried
My issue looks different than what I have seen in other posts here, I think it is related to environment settings/variables, which I am not able to identify it yet. But the solutions provided on stack overflow, makes me think like the real problem of this issue is something else.
When I try to click on http://127.0.0.1:8000/catalog/mybooks/ link, local website works fine, however, production (heroku), same code throws following exception
NoReverseMatch at /catalog/mybooks/
Reverse for 'book-detail' with arguments '('',)' not found. 1 pattern(s) tried: ['catalog/book/(?P<pk>[0-9]+)$']
Request Method: GET
Request URL: https://<myapp>.herokuapp.com/catalog/mybooks/
Django Version: 2.2.5
Exception Type: NoReverseMatch
Exception Value:
Reverse for 'book-detail' with arguments '('',)' not found. 1 pattern(s) tried: ['catalog/book/(?P<pk>[0-9]+)$']
Exception Location: /app/.heroku/python/lib/python3.7/site-packages/django/urls/resolvers.py in _reverse_with_prefix, line 673
Python Executable: /app/.heroku/python/bin/python
Python Version: 3.7.3
Python Path:
['/app/.heroku/python/bin',
'/app',
'/app/.heroku/python/lib/python37.zip',
'/app/.heroku/python/lib/python3.7',
'/app/.heroku/python/lib/python3.7/lib-dynload',
'/app/.heroku/python/lib/python3.7/site-packages']
Server time: Wed, 9 Oct 2019 04:52:47 +0000
Error during template rendering
In template /app/catalog/templates/base_generic.html, error at line 7
Reverse for 'book-detail' with arguments '('',)' not found. 1 pattern(s) tried: ['catalog/book/(?P<pk>[0-9]+)$']
This looks like a misleading error to me.
Also, because the code is working as expected on my local (ie, showing me all the data), so it doesn't look like a coding issue and so I am not able to understand real problem here (and provided solutions for other similar issues)
I have applied all migrations, so environment looks okay:
$ heroku run python manage.py migrate --remote heroku-prod
Running python manage.py migrate on <my app>... starting, run.5216 (Free)
Running python manage.py migrate on <my app>... connecting, run.5216 (Free)
Running python manage.py migrate on <my app>... up, run.5216 (Free)
Operations to perform:
Apply all migrations: admin, auth, catalog, contenttypes, sessions, social_django
Running migrations:
No migrations to apply.
HP@HP-PC MINGW64 ~/git_projects/prod/django_local_library (master)
Code on DEV/staging, that is also same.
Code: urls.py for links related to book
urlpatterns = [
path('books/', views.BookListView.as_view(), name='books'),
path('book/<int:pk>', views.BookDetailView.as_view(), name='book-detail'),
path('mybooks/', views.LoanedBooksByUserListView.as_view(), name='my-borrowed'),
]
views.py
class BookDetailView(LoginRequiredMixin, generic.DetailView):
model = Book
def get_context_data(self, **kwargs):
context = super(BookDetailView, self).get_context_data(**kwargs)
process_data(self.request)
return context
class LoanedBooksByUserListView(LoginRequiredMixin, generic.ListView):
"""Generic class-based view listing books on loan to current user. """
model = BookInstance
template_name = 'catalog/bookinstance_list_borrowed_user.html'
def get_queryset(self):
return BookInstance.objects.filter(borrower=self.request.user).filter(status__exact='o').order_by('due_back')
def get_context_data(self, **kwargs):
context = super(LoanedBooksByUserListView, self).get_context_data(**kwargs)
process_data(self.request)
return context
Template
{% for bookinst in bookinstance_list %}
<li class="{% if bookinst.is_overdue %}text-danger{% endif %}">
<a href="{% url 'book-detail' bookinst.book.pk %}">{{bookinst.book.title}}</a> ({{ bookinst.due_back }})
</li>
{% endfor %}
Yesterday night, after this post, I turned off DEBUG for security purpose, ie set DEBUG=False for staging env, as well as for local and added host on ALLOWED_HOSTS, local and staging work fine, however prod is throwing 500 error:
FYI: staging and prod have same configurations, except host name
Ref Setting DEBUG = False causes 500 Error
If I rollback to previous committed code, it starts throwing error highighted in this ques
And if I verify directly on heroku
HP@HP-PC MINGW64 ~/git_projects/prod/django_local_library (master) $ heroku run python manage.py runserver --remote heroku-prod
It doesn't throw any exception:
Performing system checks...
System check identified no issues (0 silenced).
October 09, 2019 - 21:18:54
Django version 2.2.5, using settings 'locallibrary.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CONTROL-C.
Even the staging logs have no error.
Please help me if someone has ever faced any such issue.
