postgres-operator/ui/operator_ui/cluster_discovery.py

126 lines
4.3 KiB
Python

import logging
import re
from pathlib import Path
import kubernetes.client
import kubernetes.config
import tokens
from requests.auth import AuthBase
# default URL points to kubectl proxy
DEFAULT_CLUSTERS = 'http://localhost:8001/'
CLUSTER_ID_INVALID_CHARS = re.compile('[^a-z0-9:-]')
logger = logging.getLogger(__name__)
tokens.configure(from_file_only=True)
def generate_cluster_id(url: str):
'''Generate some "cluster ID" from given API server URL'''
for prefix in ('https://', 'http://'):
if url.startswith(prefix):
url = url[len(prefix):]
return CLUSTER_ID_INVALID_CHARS.sub('-', url.lower()).strip('-')
class StaticAuthorizationHeaderAuth(AuthBase):
'''Static authentication with given "Authorization" header'''
def __init__(self, authorization):
self.authorization = authorization
def __call__(self, request):
request.headers['Authorization'] = self.authorization
return request
class OAuthTokenAuth(AuthBase):
'''Dynamic authentication using the "tokens" library to load OAuth tokens from file
(potentially mounted from a Kubernetes secret)'''
def __init__(self, token_name):
self.token_name = token_name
tokens.manage(token_name)
def __call__(self, request):
token = tokens.get(self.token_name)
request.headers['Authorization'] = 'Bearer {}'.format(token)
return request
class Cluster:
def __init__(self, id, api_server_url, ssl_ca_cert=None, auth=None, cert_file=None, key_file=None):
self.id = id
self.api_server_url = api_server_url
self.ssl_ca_cert = ssl_ca_cert
self.auth = auth
self.cert_file = cert_file
self.key_file = key_file
class StaticClusterDiscoverer:
def __init__(self, api_server_urls: list):
self._clusters = []
if not api_server_urls:
try:
kubernetes.config.load_incluster_config()
except kubernetes.config.ConfigException:
# we are not running inside a cluster
# => assume default kubectl proxy URL
cluster = Cluster(generate_cluster_id(DEFAULT_CLUSTERS), DEFAULT_CLUSTERS)
else:
logger.info("in cluster configuration failed")
config = kubernetes.client.Configuration()
cluster = Cluster(
generate_cluster_id(config.host),
config.host,
ssl_ca_cert=config.ssl_ca_cert,
auth=StaticAuthorizationHeaderAuth(config.api_key['authorization']))
self._clusters.append(cluster)
else:
for api_server_url in api_server_urls:
logger.info("api server url: {}".format(api_server_url))
if 'localhost' not in api_server_url:
# TODO: hacky way of detecting whether we need a token or not
auth = OAuthTokenAuth('read-only')
else:
auth = None
self._clusters.append(Cluster(generate_cluster_id(api_server_url), api_server_url, auth=auth))
def get_clusters(self):
return self._clusters
class KubeconfigDiscoverer:
def __init__(self, kubeconfig_path: Path, contexts: set):
self._path = kubeconfig_path
self._contexts = contexts
def get_clusters(self):
# Kubernetes Python client expects "vintage" string path
config_file = str(self._path)
contexts, current_context = kubernetes.config.list_kube_config_contexts(config_file)
for context in contexts:
if self._contexts and context['name'] not in self._contexts:
# filter out
continue
config = kubernetes.client.ConfigurationObject()
kubernetes.config.load_kube_config(config_file, context=context['name'], client_configuration=config)
authorization = config.api_key.get('authorization')
if authorization:
auth = StaticAuthorizationHeaderAuth(authorization)
else:
auth = None
cluster = Cluster(
context['name'],
config.host,
ssl_ca_cert=config.ssl_ca_cert,
cert_file=config.cert_file,
key_file=config.key_file,
auth=auth)
yield cluster