245 lines
9.3 KiB
Python
245 lines
9.3 KiB
Python
"""Generates Kubernetes secrets based on a provided app name.
|
|
|
|
If the `templates` directory contains a secret called `stackspin-{app}-variables`, it
|
|
will check if that secret already exists in the cluster, and if not: generate
|
|
it. It does the same for an `stackspin-{app}-basic-auth` secret that will contain a
|
|
password as well as a htpasswd encoded version of it.
|
|
|
|
See https://open.greenhost.net/stackspin/stackspin/-/issues/891 for the
|
|
context why we use this script and not a helm chart to generate secrets.
|
|
|
|
usage: `python generate_secrets.py $appName`
|
|
|
|
As a special case, `python generate_secrets.py stackspin` will check that the
|
|
`stackspin-cluster-variables` secret exists and that its values do not contain
|
|
problematic characters.
|
|
"""
|
|
|
|
import base64
|
|
import crypt
|
|
import os
|
|
import secrets
|
|
import string
|
|
import sys
|
|
|
|
import jinja2
|
|
import yaml
|
|
from kubernetes import client, config
|
|
from kubernetes.client import api_client
|
|
from kubernetes.client.exceptions import ApiException
|
|
from kubernetes.utils import create_from_yaml
|
|
from kubernetes.utils.create_from_yaml import FailToCreateError
|
|
|
|
# This script gets called with an app name as argument. Most of them need an
|
|
# oauth client in Hydra, but some don't. This list contains the ones that
|
|
# don't.
|
|
APPS_WITHOUT_OAUTH = [
|
|
"single-sign-on",
|
|
"prometheus",
|
|
"alertmanager",
|
|
]
|
|
|
|
|
|
def main():
|
|
"""Run everything."""
|
|
# Add jinja filters we want to use
|
|
env = jinja2.Environment(
|
|
extensions=["jinja2_base64_filters.Base64Filters"])
|
|
env.filters["generate_password"] = generate_password
|
|
|
|
if len(sys.argv) < 2:
|
|
print("Please provide an app name as an argument")
|
|
sys.exit(1)
|
|
app_name = sys.argv[1]
|
|
|
|
if app_name == "stackspin":
|
|
# This is a special case: we don't generate new secrets, but verify the
|
|
# validity of the cluster variables (populated from .flux.env).
|
|
verify_cluster_variables()
|
|
else:
|
|
# Create app variables secret
|
|
create_variables_secret(
|
|
app_name, f"stackspin-{app_name}-variables.yaml.jinja", env)
|
|
# Create a secret that contains the oauth variables for Hydra Maester
|
|
if app_name not in APPS_WITHOUT_OAUTH:
|
|
create_variables_secret(
|
|
app_name, "stackspin-oauth-variables.yaml.jinja", env)
|
|
create_basic_auth_secret(app_name, env)
|
|
|
|
|
|
def verify_cluster_variables():
|
|
data = get_kubernetes_secret_data("stackspin-cluster-variables", "flux-system")
|
|
if data is None:
|
|
raise Exception("Secret stackspin-cluster-variables was not found.")
|
|
message = "In secret stackspin-cluster-variables, key {}, the character {}" \
|
|
" was used which will probably lead to problems, so aborting." \
|
|
" You can update the value by using `kubectl edit secret -n" \
|
|
" flux-system stackspin-cluster-variables`."
|
|
for key, value in data.items():
|
|
decoded_value = base64.b64decode(value).decode("ascii")
|
|
for character in ["\"", "$"]:
|
|
if character in decoded_value:
|
|
raise Exception(message.format(key, character))
|
|
|
|
|
|
def get_templates_dir():
|
|
"""Returns directory that contains the Jinja templates used to create app secrets."""
|
|
return os.path.join(os.path.dirname(os.path.realpath(__file__)), "templates")
|
|
|
|
|
|
def create_variables_secret(app_name, variables_filename, env):
|
|
"""Checks if a variables secret for app_name already exists, generates it if necessary."""
|
|
variables_filepath = os.path.join(get_templates_dir(), variables_filename)
|
|
if os.path.exists(variables_filepath):
|
|
# Check if k8s secret already exists, if not, generate it
|
|
with open(variables_filepath, encoding="UTF-8") as template_file:
|
|
lines = template_file.read()
|
|
secret_name, secret_namespace = get_secret_metadata(lines)
|
|
new_secret_dict = yaml.safe_load(
|
|
env.from_string(lines, globals={"app": app_name}).render()
|
|
)
|
|
current_secret_data = get_kubernetes_secret_data(
|
|
secret_name, secret_namespace
|
|
)
|
|
if current_secret_data is None:
|
|
# Create new secret
|
|
update_secret = False
|
|
elif current_secret_data.keys() != new_secret_dict["data"].keys():
|
|
# Update current secret with new keys
|
|
update_secret = True
|
|
print(
|
|
f"Secret {secret_name} in namespace {secret_namespace}"
|
|
" already exists. Merging..."
|
|
)
|
|
# Merge dicts. Values from current_secret_data take precedence
|
|
new_secret_dict["data"] |= current_secret_data
|
|
else:
|
|
# Do Nothing
|
|
print(
|
|
f"Secret {secret_name} in namespace {secret_namespace}"
|
|
" is already in a good state, doing nothing."
|
|
)
|
|
return
|
|
print(
|
|
f"Storing secret {secret_name} in namespace"
|
|
f" {secret_namespace} in cluster."
|
|
)
|
|
store_kubernetes_secret(
|
|
new_secret_dict, secret_namespace, update=update_secret
|
|
)
|
|
else:
|
|
print(
|
|
f"Template {variables_filename} does not exist, no action needed")
|
|
|
|
|
|
def create_basic_auth_secret(app_name, env):
|
|
"""Checks if a basic auth secret for app_name already exists, generates it if necessary."""
|
|
basic_auth_filename = os.path.join(
|
|
get_templates_dir(), f"stackspin-{app_name}-basic-auth.yaml.jinja"
|
|
)
|
|
if os.path.exists(basic_auth_filename):
|
|
with open(basic_auth_filename, encoding="UTF-8") as template_file:
|
|
lines = template_file.read()
|
|
secret_name, secret_namespace = get_secret_metadata(lines)
|
|
|
|
if get_kubernetes_secret_data(secret_name, secret_namespace) is None:
|
|
basic_auth_username = "admin"
|
|
basic_auth_password = generate_password(32)
|
|
basic_auth_htpasswd = gen_htpasswd(
|
|
basic_auth_username, basic_auth_password
|
|
)
|
|
print(
|
|
f"Adding secret {secret_name} in namespace"
|
|
f" {secret_namespace} to cluster."
|
|
)
|
|
template = env.from_string(
|
|
lines,
|
|
globals={
|
|
"pass": basic_auth_password,
|
|
"htpasswd": basic_auth_htpasswd,
|
|
},
|
|
)
|
|
secret_dict = yaml.safe_load(template.render())
|
|
store_kubernetes_secret(secret_dict, secret_namespace)
|
|
else:
|
|
print(
|
|
f"Secret {secret_name} in namespace {secret_namespace}"
|
|
" already exists. Not generating new secrets."
|
|
)
|
|
else:
|
|
print(f"File {basic_auth_filename} does not exist, no action needed")
|
|
|
|
|
|
def get_secret_metadata(yaml_string):
|
|
"""Returns secret name and namespace from metadata field in a yaml string."""
|
|
secret_dict = yaml.safe_load(yaml_string)
|
|
secret_name = secret_dict["metadata"]["name"]
|
|
# default namespace is flux-system, but other namespace can be
|
|
# provided in secret metadata
|
|
if "namespace" in secret_dict["metadata"]:
|
|
secret_namespace = secret_dict["metadata"]["namespace"]
|
|
else:
|
|
secret_namespace = "flux-system"
|
|
return secret_name, secret_namespace
|
|
|
|
|
|
def get_kubernetes_secret_data(secret_name, namespace):
|
|
"""Returns the contents of a kubernetes secret or None if the secret does not exist."""
|
|
try:
|
|
secret = API.read_namespaced_secret(secret_name, namespace).data
|
|
except ApiException as ex:
|
|
# 404 is expected when the optional secret does not exist.
|
|
if ex.status != 404:
|
|
raise ex
|
|
return None
|
|
return secret
|
|
|
|
|
|
def store_kubernetes_secret(secret_dict, namespace, update=False):
|
|
"""Stores either a new secret in the cluster, or updates an existing one."""
|
|
api_client_instance = api_client.ApiClient()
|
|
if update:
|
|
verb = "updated"
|
|
api_response = patch_kubernetes_secret(secret_dict, namespace)
|
|
else:
|
|
verb = "created"
|
|
try:
|
|
api_response = create_from_yaml(
|
|
api_client_instance,
|
|
yaml_objects=[secret_dict],
|
|
namespace=namespace
|
|
)
|
|
except FailToCreateError as ex:
|
|
print(f"Secret not {verb} because of exception {ex}")
|
|
return
|
|
print(f"Secret {verb} with api response: {api_response}")
|
|
|
|
|
|
def patch_kubernetes_secret(secret_dict, namespace):
|
|
"""Patches secret in the cluster with new data."""
|
|
api_client_instance = api_client.ApiClient()
|
|
api_instance = client.CoreV1Api(api_client_instance)
|
|
name = secret_dict["metadata"]["name"]
|
|
body = {}
|
|
body["data"] = secret_dict["data"]
|
|
return api_instance.patch_namespaced_secret(name, namespace, body)
|
|
|
|
|
|
def generate_password(length):
|
|
"""Generates a password of "length" characters."""
|
|
length = int(length)
|
|
password = "".join((secrets.choice(string.ascii_letters)
|
|
for i in range(length)))
|
|
return password
|
|
|
|
|
|
def gen_htpasswd(user, password):
|
|
"""Generate htpasswd entry for user with password."""
|
|
return f"{user}:{crypt.crypt(password, crypt.mksalt(crypt.METHOD_SHA512))}"
|
|
|
|
|
|
if __name__ == "__main__":
|
|
config.load_kube_config()
|
|
API = client.CoreV1Api()
|
|
main()
|