Pod Operations¶

Exec a command¶

Exec a command in a Pod using Pod.exec().

Sync

from kr8s.objects import Pod

pod = Pod.get("my-pod")

command = pod.exec(["uptime"])
print(command.stdout.decode())
# 13:49:05 up 23:03,  0 users,  load average: 0.66, 0.87, 0.85

Async

from kr8s.asyncio.objects import Pod

pod = await Pod.get("my-pod")

command = await pod.exec(["uptime"])
print(command.stdout.decode())
# 13:49:05 up 23:03,  0 users,  load average: 0.66, 0.87, 0.85

Exec a command and redirect stdout/stderr¶

Run a command in a Pod using Pod.exec() and write the output to sys.stdout and sys.stderr.

Sync

import sys
from kr8s.objects import Pod

pod = Pod.get("my-pod")

# Call `ls /` and direct stdout/stderr to the current process
# Also skip checking the return code of the command to avoid raising an exception
pod.exec(["ls", "/"], stdout=sys.stdout.buffer, stderr=sys.stderr.buffer, check=False)

Async

import sys
from kr8s.asyncio.objects import Pod

pod = await Pod.get("my-pod")

# Call `ls /` and direct stdout/stderr to the current process
# Also skip checking the return code of the command to avoid raising an exception
await pod.exec(["ls", "/"], stdout=sys.stdout.buffer, stderr=sys.stderr.buffer, check=False)

Open a port forward and communicate with the Pod¶

Open a port forward with Pod using Pod.portforward() and communicate with the application on the other side.

Sync

import requests
from kr8s.objects import Pod

pod = Pod.get("my-pod")

with pod.portforward(remote_port=1234) as local_port:
    # Make an API request
    resp = requests.get(f"http://localhost:{local_port}")
    # Do something with the response

# Listen on port 8888 on all addresses, forwarding to 5000 in the pod
with pod.portforward(remote_port=5000, local_port=8888, address=["0.0.0.0"])
    # Make an API request
    resp = requests.get(f"http://0.0.0.0:{local_port}")
    # Do something with the response
  
# Listen on port 8888 on localhost and selected IP, forwarding to 5000 in the pod
pf = pod.portforward(port=5000, local_port=8888, address=["127.0.0.1", "10.19.21.1"])
    # Make an API request
    resp = requests.get(f"http://10.19.21.1:{local_port}")
    # Do something with the response
    

Async

import httpx
from kr8s.asyncio.objects import Pod

pod = await Pod.get("my-pod")

async with pod.portforward(remote_port=1234) as local_port, httpx.AsyncClient() as client:
    # Make an API request
    resp = await client.get(f"http://localhost:{local_port}")
    # Do something with the response

Tip

This also works with Service objects.

Open a port forward permanently¶

Open a port forward with Pod using Pod.portforward() and block. This is useful when you need to access the port forward from another process, like you would with kubectl.

Sync

from kr8s.objects import Pod

pod = Pod.get("my-pod")
pod.portforward(1234, local_port=5678).run_forever()

Async

from kr8s.asyncio.objects import Pod

pod = await Pod.get("my-pod")
await pod.portforward(1234, local_port=5678).run_forever()

Tip

This also works with Service objects.

Open a port forward in the background¶

Open a port forward with Pod using Pod.portforward() as a background task/thread.

Sync

from kr8s.objects import Pod

pod = Pod.get("my-pod")
pf = pod.portforward(remote_port=1234, local_port=5678)

# Starts the port forward in a background thread
pf.start()

# Your other code goes here

# Optionally stop the port forward thread (it will exit with Python anyway)
pf.stop()

Async

from kr8s.asyncio.objects import Pod

pod = await Pod.get("my-pod")
pf = pod.portforward(remote_port=1234, local_port=5678)

# Starts the port forward in a background task
await pf.start()

# Your other code goes here
# WARNING: Your code must be async and non-blocking as the port forward and your code are sharing the same event loop

# Optionally stop the port forward task (it will exit with Python anyway)
await pf.stop()

Tip

This also works with Service objects.