Python Client Examples¶
These examples show the sync and async Session interfaces.
Assumption
Authenticated via CLI
canfar login cadc
Create Sessions¶
Notebook¶
from canfar.sessions import Session
session = Session()
ids = session.create(
name="my-notebook",
image="images.canfar.net/skaha/astroml:latest",
kind="notebook",
)
print(ids) # ["d1tsqexh"]
session.connect(ids)
from canfar.sessions import Session
session = Session()
ids = session.create(
name="my-notebook",
image="images.canfar.net/skaha/astroml:latest",
kind="notebook",
cores=2,
ram=4,
)
print(ids) # ["d1tsqexh"]
session.connect(ids)
from canfar.sessions import AsyncSession
session = AsyncSession()
ids = await session.create(
name="my-notebook",
image="images.canfar.net/skaha/astroml:latest",
kind="notebook",
)
print(ids) # ["d1tsqexh"]
await session.connect(ids)
Headless¶
- Headless Sessions are containers that execute a command and exit when complete without user interaction.
- They are useful for batch processing and distributed computing.
from canfar.sessions import Session
session = Session()
ids = session.create(
name="my-headless",
image="images.canfar.net/skaha/astroml:latest",
kind="headless",
cmd="echo",
args="Hello, World!",
)
print(ids) # ["d1tsqexh"]
from canfar.sessions import AsyncSession
session = AsyncSession()
ids = await session.create(
name="my-headless",
image="images.canfar.net/skaha/astroml:latest",
kind="headless",
cmd="echo",
args="Hello, World!",
)
print(ids) # ["d1tsqexh"]
Replica Environment Variables
All containers receive the following environment variables:
- REPLICA_COUNT — common total number of replicas
- REPLICA_ID — 1-based index of the replica (1..N)
Use these to partition work deterministically. See Helpers API Reference for chunk and stripe.
Private Container Registry Access
Use a private Harbor image by providing registry credentials via configuration.
import asyncio
from canfar.sessions import AsyncSession
from canfar.models.registry import ContainerRegistry
from canfar.models.config import Configuration
async def main():
cfg = Configuration(registry=ContainerRegistry(username="username", secret="CLI_SECRET"))
session = AsyncSession(config=cfg)
ids = await session.create(
name="private-job",
image="images.canfar.net/your/private-image:latest",
kind="headless",
cmd="python",
args="/app/run.py",
)
print(ids)
asyncio.run(main())
Resource Allocation Modes¶
CANFAR supports two resource allocation modes for your sessions. See the resource allocation guide for more information.
Examples¶
from canfar.sessions import Session
session = Session()
# No cores/ram specification - uses flexible allocation
ids = session.create(
name="flexible-notebook",
image="images.canfar.net/skaha/astroml:latest",
kind="notebook"
)
from canfar.sessions import Session
session = Session()
# Specify exact resources for guaranteed allocation
ids = session.create(
name="fixed-notebook",
image="images.canfar.net/skaha/astroml:latest",
kind="notebook",
cores=4,
ram=8
)
Discover and Filter Sessions¶
from canfar.sessions import Session
session = Session()
all_sessions = session.fetch()
print(len(all_sessions))
from canfar.sessions import AsyncSession
async with AsyncSession() as session:
all_sessions = await session.fetch()
print(len(all_sessions))
from canfar.sessions import Session
session = Session()
running = session.fetch(kind="notebook", status="Running")
print(running)
session.connect([item["id"] for item in running])
from canfar.sessions import AsyncSession
async with AsyncSession() as session:
running = await session.fetch(kind="notebook", status="Running")
print(running)
await session.connect([item["id"] for item in running])
from canfar.sessions import Session
session = Session()
completed = session.fetch(kind="headless", status="Succeeded")
print(completed)
from canfar.sessions import AsyncSession
async with AsyncSession() as session:
completed = await session.fetch(kind="headless", status="Succeeded")
print(completed)
Kinds & Status
You can use any combination of the following kinds and status to filter sessions:
- Kinds:
desktop,notebook,carta,headless,firefly,desktop-app,contributed - Statuses:
Pending,Running,Terminating,Succeeded,Error,Failed
Inspect Sessions¶
Detailed information about the session, including resource usage, user IDs, and more.
from canfar.sessions import Session
session = Session()
info = session.info(ids)
print(info)
from canfar.sessions import AsyncSession
async with AsyncSession() as session:
info = await session.info(ids)
print(info)
Events¶
Events describe the steps taken by the Science Platform to launch your session
from canfar.sessions import Session
session = Session()
events = session.events(ids, verbose=True)
print(events)
from canfar.sessions import AsyncSession
async with AsyncSession() as session:
events = await session.events(ids, verbose=True)
print(events)
Logs¶
Logs contain the output from your session's containers.
Log Retention
Logs are retained until your session is deleted. A completed session, i.e., Succeeded, Failed, or Error is kept for 24 hours before being deleted.
from canfar.sessions import Session
session = Session()
logs = session.logs(ids, verbose=True)
from canfar.sessions import AsyncSession
async with AsyncSession() as session:
logs = await session.logs(ids, verbose=True)
Cleanup Sessions¶
Permanent Action
Deleted sessions cannot be recovered.
from canfar.sessions import Session
session = Session()
result = session.destroy(ids)
print(result) # {"id": True, ...}
from canfar.sessions import AsyncSession
async with AsyncSession() as session:
result = await session.destroy(ids)
print(result) # {"id": True, ...}
from canfar.sessions import Session
session = Session()
result = session.destroy_with(prefix="test-", kind="headless", status="Succeeded")
print(result) # {"id": True, ...}
from canfar.sessions import AsyncSession
async with AsyncSession() as session:
result = await session.destroy_with(prefix="test-", kind="headless", status="Succeeded")
print(result) # {"id": True, ...}