Allow user to select random blog bost

I've started using Django 2.0 and Python 3.6.3 to develop a website which will display customized "Posts", as in a blog Post.

I want the user to be able to click a button that basically says "Random Post". This button will take them to a template which loads a random blog post.

Here's my Post model:

class Post(models.Model):
    post_id = models.AutoField(primary_key=True)
    ... other fields
    ... other fields

    def publish(self):
        self.published_date = timezone.now()
        self.save()

    def __str__(self):
        return self.title     

Here are some relevant views:

class PostListView(ListView):
    model = Post
    template_name = 'blog/post_list.html'

class PostDetailView(DetailView):
    model = Post
    template_name = 'blog/post_detail.html'

Here is my problematic view:

import random

def random_post(request):
    post_ids = Post.objects.all().values_list('post_id', flat=True) 
    random_obj = Post.objects.get(post_id=random.choice(post_ids))
    context = {'random_post': random_obj,}
    return render(request, 'blog/random_post.html', context)

Here I am trying to create a Values List of all post_id values for the Post model. Then I'm trying to get a random choice from this Values List, which would be a random id. Then I'm trying to create a context and render a template using this logic.

Here are relevant urlpatterns:

urlpatterns = [
    path('post/<int:pk>/', 
        views.PostDetailView.as_view(),name='post_detail'),
    path('post/random/<int:pk>', views.random_post, name='random_post'),

Needless to say this is not working.

If I leave off the "int:pk" it renders a blank template with no data - no blog Post. If I include the , it causes an error - No Arguments Found. I assume that no data is being queried in the view, or the data isn't being properly sent from the view to the template.

I am new to Django. I appreciate your help!