Django displaying CPU average for many VMs using ListView - django-views

Question

I have a model that stores a list of VMs and their management IPs. I have another model that stores cpu consumption for all of the VMs tied to the foreign key of the VM. There is a cron job that will run every five minutes to populate the Cpu model with the cpu consumption of each VM.
What I want to do is create a table in a template that lists all VMs, with an average of the CPU consumption, and max CPU consumption.
'''
#models.py
from django.db import models
class VMs (models.Model):
mgmtIP = models.CharField(max_length=16)
hostName = models.CharField(max_length=128)
def __str__(self):
return self.hostName
class Cpu (models.Model):
hostName = models.ForeignKey(F5Model, on_delete=models.CASCADE)
cpuAverage = models.DecimalField(max_digits=3, decimal_places=2)
whenReported = models.DateTimeField(auto_now=False, auto_now_add=True)
#views.py
from .models import Cpu, VMs
class Report(ListView):
model = VMs
template_name = 'report.html'
def get_queryset(self):
queryset = Cpu.objects.filter(hostName= self.hostName).aggregate(Avg(cpuAverage))
return queryset
'''
I can get the basic ListView to show the VMs in my template but when I try to add the queryset it stops displaying anything.
!!!Update!!!
I am able to get it to sort of work with this
'''
class Report(ListView):
model = VMs
context_object_name = 'cpu_list'
template_name = 'report.html'
def get_context_data(self, **kwargs):
context = super(Report, self).get_context_data(**kwargs)
context.update({ 'cpuAverageReport':Cpu.objects.filter(hostName_id='1').aggregate(Avg('cpuAverage')),
})
return context
'''
The problem is I need the hostName id to be dynamic. It should be which ever host it is currently looping through. I put in '1' just to test the rest of my syntax... I've tried 'self.kwargs['id'], self.args['id'], just id, VMs.id, and probably a thousand other combinations...

Answer 1

The problem is aggregate only returns one line. I needed to change it for annotate.
'''
cpuAverageReport':Cpu.objects.values('hostName_id').annotate(Avg('cpuAverage'))
'''
Then I needed to add a for loop into my for loop and an if to match the records up with each other in my template. like so...
'''
<table style="width:100%">
<tr>
<td>Name</td><td>CPU Average</td>
</tr>
{% for x in report %}
<tr>
<td>{{ x.hostName }}</td>
{% for y in cpuAverageReport %}
{% if x.id == y.hostName_id %}
<td>{{ y.cpuAverage__avg }}</td>
{% endif %}
{% endfor %}
</tr>
{% endfor %}
</table>
'''