I'm having trouble accessing a Kubernetes environment variable in my python app's init.py file. It appears to be available in other files, however.
My init.py file includes this code app.config.from_object(os.environ['APP_SETTINGS'])
. The value of APP_SETTINGS
depends on my environment with values being config.DevelopmentConfig
, config.StagingConfig
or config.ProductionConfig
. From here, my app pulls configs from my config.py file, which looks like this:
import os
basedir = os.path.abspath(os.path.dirname(__file__))
class Config(object):
WTF_CSRF_ENABLED = True
SECRET_KEY = 'you-will-never-guess'
APP_SETTINGS = os.environ['APP_SETTINGS'] # For debug purposes
class DevelopmentConfig(Config):
TEMPLATES_AUTO_RELOAD = True
DEBUG = True
class StagingConfig(Config):
DEBUG = True
class ProductionConfig(Config):
DEBUG = False
When I set APP_SETTINGS locally in my dev environment in my docker-compose, like so...
environment:
- APP_SETTINGS=config.DevelopmentConfig
everything works just fine. When I deploy to my Staging pod in Kubernetes with APP_SETTINGS=config.StagingConfig
set in my Secrets file, I'm greeted with the following error:
Traceback (most recent call last):
File "/usr/local/lib/python3.6/site-packages/werkzeug/utils.py", line 434, in import_string
return getattr(module, obj_name)
AttributeError: module 'config' has no attribute 'StagingConfig
'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/local/lib/python3.6/site-packages/werkzeug/utils.py", line 436, in import_string
raise ImportError(e)
ImportError: module 'config' has no attribute 'StagingConfig
'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "manage.py", line 3, in <module>
from app import app
File "/root/app/__init__.py", line 11, in <module>
app.config.from_object(os.environ['APP_SETTINGS'])
File "/usr/local/lib/python3.6/site-packages/flask/config.py", line 168, in from_object
obj = import_string(obj)
File "/usr/local/lib/python3.6/site-packages/werkzeug/utils.py", line 443, in import_string
sys.exc_info()[2])
File "/usr/local/lib/python3.6/site-packages/werkzeug/_compat.py", line 137, in reraise
raise value.with_traceback(tb)
File "/usr/local/lib/python3.6/site-packages/werkzeug/utils.py", line 436, in import_string
raise ImportError(e)
werkzeug.utils.ImportStringError: import_string() failed for 'config.StagingConfig\n'. Possible reasons are:
- missing __init__.py in a package;
- package or module path not included in sys.path;
- duplicated package or module name taking precedence in sys.path;
- missing module, class, function or variable;
Debugged import:
- 'config' found in '/root/config.py'.
- 'config.StagingConfig\n' not found.
Original exception:
ImportError: module 'config' has no attribute 'StagingConfig
'
upgrading database schema...
Traceback (most recent call last):
File "/usr/local/lib/python3.6/site-packages/werkzeug/utils.py", line 434, in import_string
return getattr(module, obj_name)
AttributeError: module 'config' has no attribute 'StagingConfig
'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/local/lib/python3.6/site-packages/werkzeug/utils.py", line 436, in import_string
raise ImportError(e)
ImportError: module 'config' has no attribute 'StagingConfig
'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "manage.py", line 3, in <module>
from app import app
File "/root/app/__init__.py", line 11, in <module>
app.config.from_object(os.environ['APP_SETTINGS'])
File "/usr/local/lib/python3.6/site-packages/flask/config.py", line 168, in from_object
obj = import_string(obj)
File "/usr/local/lib/python3.6/site-packages/werkzeug/utils.py", line 443, in import_string
sys.exc_info()[2])
File "/usr/local/lib/python3.6/site-packages/werkzeug/_compat.py", line 137, in reraise
raise value.with_traceback(tb)
File "/usr/local/lib/python3.6/site-packages/werkzeug/utils.py", line 436, in import_string
raise ImportError(e)
werkzeug.utils.ImportStringError: import_string() failed for 'config.StagingConfig\n'. Possible reasons are:
- missing __init__.py in a package;
- package or module path not included in sys.path;
- duplicated package or module name taking precedence in sys.path;
- missing module, class, function or variable;
Debugged import:
- 'config' found in '/root/config.py'.
- 'config.StagingConfig\n' not found.
Original exception:
ImportError: module 'config' has no attribute 'StagingConfig
'
starting metriculous web server...
Traceback (most recent call last):
File "/usr/local/lib/python3.6/site-packages/werkzeug/utils.py", line 434, in import_string
return getattr(module, obj_name)
AttributeError: module 'config' has no attribute 'StagingConfig
'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/local/lib/python3.6/site-packages/werkzeug/utils.py", line 436, in import_string
raise ImportError(e)
ImportError: module 'config' has no attribute 'StagingConfig
'
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "manage.py", line 3, in <module>
from app import app
File "/root/app/__init__.py", line 11, in <module>
app.config.from_object(os.environ['APP_SETTINGS'])
File "/usr/local/lib/python3.6/site-packages/flask/config.py", line 168, in from_object
obj = import_string(obj)
File "/usr/local/lib/python3.6/site-packages/werkzeug/utils.py", line 443, in import_string
sys.exc_info()[2])
File "/usr/local/lib/python3.6/site-packages/werkzeug/_compat.py", line 137, in reraise
raise value.with_traceback(tb)
File "/usr/local/lib/python3.6/site-packages/werkzeug/utils.py", line 436, in import_string
raise ImportError(e)
werkzeug.utils.ImportStringError: import_string() failed for 'config.StagingConfig\n'. Possible reasons are:
- missing __init__.py in a package;
- package or module path not included in sys.path;
- duplicated package or module name taking precedence in sys.path;
- missing module, class, function or variable;
Debugged import:
- 'config' found in '/root/config.py'.
- 'config.StagingConfig\n' not found.
Original exception:
ImportError: module 'config' has no attribute 'StagingConfig
However, when I hard code the APP_SETTINGS value in my init.py file like so app.config.from_object('config.StagingConfig')
and deploy to Kubernetes, it works fine. When I do it this way, I can even confirm that my APP_SETTINGS env var declared in my Settings in Kubernetes exists by logging into my pod and running echo $APP_SETTINGS
.
Any thoughts about what I'm doing wrong?
EDIT #1 - Adding my deployment.yaml file
kind: Deployment
apiVersion: apps/v1beta2
metadata:
annotations:
deployment.kubernetes.io/revision: '4'
selfLink: /apis/apps/v1beta2/namespaces/tools/deployments/met-staging-myapp
resourceVersion: '51731234'
name: met-staging-myapp
uid: g1fce905-1234-56y4-9c15-12de61100d0a
creationTimestamp: '2018-01-29T17:22:14Z'
generation: 6
namespace: tools
labels:
app: myapp
chart: myapp-1.0.1
heritage: Tiller
release: met-staging
spec:
replicas: 1
selector:
matchLabels:
app: myapp
release: met-staging
template:
metadata:
creationTimestamp: null
labels:
app: myapp
release: met-staging
spec:
containers:
- name: myapp-web
image: 'gitlab.ourdomain.com:4567/ourspace/myapp:web-latest'
ports:
- containerPort: 80
protocol: TCP
env:
- name: APP_SETTINGS
valueFrom:
secretKeyRef:
name: myapp-creds
key: APP_SETTINGS
- name: AWS_ACCESS_KEY_ID
valueFrom:
secretKeyRef:
name: myapp-creds
key: AWS_ACCESS_KEY_ID
- name: AWS_SECRET_ACCESS_KEY
valueFrom:
secretKeyRef:
name: myapp-creds
key: AWS_SECRET_ACCESS_KEY
resources: {}
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
imagePullPolicy: Always
- name: myapp-celery
image: 'gitlab.ourdomain.com:4567/ourspace/myapp:celery-latest'
env:
- name: APP_SETTINGS
valueFrom:
secretKeyRef:
name: myapp-creds
key: APP_SETTINGS
- name: AWS_ACCESS_KEY_ID
valueFrom:
secretKeyRef:
name: myapp-creds
key: AWS_ACCESS_KEY_ID
- name: AWS_SECRET_ACCESS_KEY
valueFrom:
secretKeyRef:
name: myapp-creds
key: AWS_SECRET_ACCESS_KEY
resources: {}
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
imagePullPolicy: Always
- name: rabbit
image: 'rabbitmq:alpine'
env:
- name: RABBITMQ_DEFAULT_USER
value: rabbit_user
- name: RABBITMQ_DEFAULT_PASS
value: fake_pw
resources: {}
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
imagePullPolicy: IfNotPresent
restartPolicy: Always
terminationGracePeriodSeconds: 30
dnsPolicy: ClusterFirst
securityContext: {}
imagePullSecrets:
- name: gitlab-registry
schedulerName: default-scheduler
strategy:
type: RollingUpdate
rollingUpdate:
maxUnavailable: 1
maxSurge: 1
revisionHistoryLimit: 10
progressDeadlineSeconds: 600
status:
observedGeneration: 6
replicas: 1
updatedReplicas: 1
readyReplicas: 1
availableReplicas: 1
conditions:
- type: Available
status: 'True'
lastUpdateTime: '2018-01-29T17:22:14Z'
lastTransitionTime: '2018-01-29T17:22:14Z'
reason: MinimumReplicasAvailable
message: Deployment has minimum availability.
- type: Progressing
status: 'True'
lastUpdateTime: '2018-05-25T10:20:49Z'
lastTransitionTime: '2018-02-16T20:29:45Z'
reason: NewReplicaSetAvailable
message: >-
ReplicaSet "met-staging-myapp-2615c4545f" has successfully
progressed.
werkzeug.utils.ImportStringError: import_string() failed for 'config.StagingConfig\n'. Possible reasons are:
It very clearly shows you that the module name has a trailing newline character, which is a very, very, very common error for people who try to echo something | base64
and put that value into a kubernetes Secret
. The correct way of doing that is either via kubectl create secret generic myapp-creds --from-literal=APP_SETTINGS=config.StagingConfig
, or printf '%s' config.StagingConfig | base64
. Or, of course, stop putting non-Secret text into a Secret and using either a ConfigMap
or just a traditional environment value: config.StagingConfig
setting, and reserve the Secret
construct for Secret
values.