Submitted metrics not showing up on prometheus endpoint - python-3.x

Question

I have a code which looks like this, it is supposed to collect some custom metrics and expose it over prometheus.
def collect_metrics():
registry = prometheus_client.CollectorRegistry()
label_names = ['parent', 'namespace','team', 'name', 'status']
sib = Gauge(f'disk_sizeInBytes','Gets the size of the disk in bytes.', label_names, registry=registry)
msib = Gauge(f'disk_maxSizeInMegabytes', 'Gets or sets the maximum size of the disk in megabytes, which is the size of memory allocated for the disk.', label_names, registry=registry)
...
sib.labels(parent=parent_name, namespace=namespace_name, team=team, name=disk_name, status=disk_status).set(disk_list[dp]["sizeInBytes"])
msib.labels(parent=parent_name, namespace=namespace_name, team=team, name=disk_name, status=disk_status).set(disk_list[dp]["maxSizeInMegabytes"])
print(f'{datetime.datetime.now()} | disk_name: {disk_name} | sib: {disk_list[dp]["sizeInBytes"]} | msib: {disk_list[dp]["maxSizeInMegabytes"]}')
...
if __name__ == '__main__':
...
start_htdp_server(8005)
collect_metrics()
The code works fine without any errors, however I don’t see anything being shown over endpoint http://localhost:8005/, though i see some default metrics being shown such as:
# HELP python_gc_objects_collected_total Objects collected during gc
# TYPE python_gc_objects_collected_total counter
python_gc_objects_collected_total{generation="0"} 403.0
python_gc_objects_collected_total{generation="1"} 0.0
python_gc_objects_collected_total{generation="2"} 0.0
# HELP python_gc_objects_uncollectable_total Uncollectable object found during GC
# TYPE python_gc_objects_uncollectable_total counter
python_gc_objects_uncollectable_total{generation="0"} 0.0
python_gc_objects_uncollectable_total{generation="1"} 0.0
python_gc_objects_uncollectable_total{generation="2"} 0.0
# HELP python_gc_collections_total Number of times this generation was collected
# TYPE python_gc_collections_total counter
python_gc_collections_total{generation="0"} 39.0
python_gc_collections_total{generation="1"} 3.0
python_gc_collections_total{generation="2"} 0.0
# HELP python_info Python platform information
# TYPE python_info gauge
python_info{implementation="CPython",major="3",minor="10",patchlevel="4",version="3.10.4"} 1.0
Can someone point me, what is the issue here?

Answer 1

Couple of things:
Remove registry = prometheus_client.CollectorRegistry()
Remove registry=registry from the Gauge declarations
Add a loop to keep the process running.
import datetime
import re
import time
from prometheus_client import CollectorRegistry,Gauge
from prometheus_client import start_http_server
def collect_metrics():
label_names = ['parent', 'namespace','team', 'name', 'status']
sib = Gauge(
'disk_sizeInBytes',
'Gets the size of the disk in bytes.',
label_names,
)
msib = Gauge(
'disk_maxSizeInMegabytes',
'Gets or sets the maximum size of the disk in megabytes, which is the size of memory allocated for the disk.',
label_names,
)
sib.labels(
parent="parent_name",
namespace="namespace_name",
team="team",
name="disk_name",
status="disk_status",
).set(10.0)
msib.labels(
parent="parent_name",
namespace="namespace_name",
team="team",
name="disk_name",
status="disk_status",
).set(5.0)
if __name__ == '__main__':
...
start_http_server(8005)
collect_metrics()
while True:
time.sleep(5)
# HELP disk_sizeInBytes Gets the size of the disk in bytes.
# TYPE disk_sizeInBytes gauge
disk_sizeInBytes{name="disk_name",namespace="namespace_name",parent="parent_name",status="disk_status",team="team"} 10.0
# HELP disk_maxSizeInMegabytes Gets or sets the maximum size of the disk in megabytes, which is the size of memory allocated for the disk.
# TYPE disk_maxSizeInMegabytes gauge
disk_maxSizeInMegabytes{name="disk_name",namespace="namespace_name",parent="parent_name",status="disk_status",team="team"} 5.0