k8s-manifests/jupyter/base/charts/jupyterhub/files/hub/z2jh.py
Micke Nordin 324724c3b1
Jupytherhub:
Export 3.0.3 like so:
```
helm repo add jupyterhub https://hub.jupyter.org/helm-chart/
helm fetch jupyterhub/jupyterhub --version 3.0.3 --untar --untardir .
```
2023-09-25 16:29:56 +02:00

122 lines
3.5 KiB
Python

"""
Utility methods for use in jupyterhub_config.py and dynamic subconfigs.
Methods here can be imported by extraConfig in values.yaml
"""
import os
from collections.abc import Mapping
from functools import lru_cache
import yaml
# memoize so we only load config once
@lru_cache
def _load_config():
"""Load the Helm chart configuration used to render the Helm templates of
the chart from a mounted k8s Secret, and merge in values from an optionally
mounted secret (hub.existingSecret)."""
cfg = {}
for source in ("secret/values.yaml", "existing-secret/values.yaml"):
path = f"/usr/local/etc/jupyterhub/{source}"
if os.path.exists(path):
print(f"Loading {path}")
with open(path) as f:
values = yaml.safe_load(f)
cfg = _merge_dictionaries(cfg, values)
else:
print(f"No config at {path}")
return cfg
@lru_cache
def _get_config_value(key):
"""Load value from the k8s ConfigMap given a key."""
path = f"/usr/local/etc/jupyterhub/config/{key}"
if os.path.exists(path):
with open(path) as f:
return f.read()
else:
raise Exception(f"{path} not found!")
@lru_cache
def get_secret_value(key, default="never-explicitly-set"):
"""Load value from the user managed k8s Secret or the default k8s Secret
given a key."""
for source in ("existing-secret", "secret"):
path = f"/usr/local/etc/jupyterhub/{source}/{key}"
if os.path.exists(path):
with open(path) as f:
return f.read()
if default != "never-explicitly-set":
return default
raise Exception(f"{key} not found in either k8s Secret!")
def get_name(name):
"""Returns the fullname of a resource given its short name"""
return _get_config_value(name)
def get_name_env(name, suffix=""):
"""Returns the fullname of a resource given its short name along with a
suffix, converted to uppercase with dashes replaced with underscores. This
is useful to reference named services associated environment variables, such
as PROXY_PUBLIC_SERVICE_PORT."""
env_key = _get_config_value(name) + suffix
env_key = env_key.upper().replace("-", "_")
return os.environ[env_key]
def _merge_dictionaries(a, b):
"""Merge two dictionaries recursively.
Simplified From https://stackoverflow.com/a/7205107
"""
merged = a.copy()
for key in b:
if key in a:
if isinstance(a[key], Mapping) and isinstance(b[key], Mapping):
merged[key] = _merge_dictionaries(a[key], b[key])
else:
merged[key] = b[key]
else:
merged[key] = b[key]
return merged
def get_config(key, default=None):
"""
Find a config item of a given name & return it
Parses everything as YAML, so lists and dicts are available too
get_config("a.b.c") returns config['a']['b']['c']
"""
value = _load_config()
# resolve path in yaml
for level in key.split("."):
if not isinstance(value, dict):
# a parent is a scalar or null,
# can't resolve full path
return default
if level not in value:
return default
else:
value = value[level]
return value
def set_config_if_not_none(cparent, name, key):
"""
Find a config item of a given name, set the corresponding Jupyter
configuration item if not None
"""
data = get_config(key)
if data is not None:
setattr(cparent, name, data)