I've dockerized a Flask app, using gunicorn to serve it. The last line of my Dockerfile is:
CMD source activate my_env && gunicorn --timeout 333 --bind 0.0.0.0:5000 app:app
When running the app locally – either straight in my console, without docker, or with
docker run -dit \
--name my-app \
--publish 5000:5000 \
my-app:latest
It boots up fine. I get a log like:
[2018-12-04 19:32:30 +0000] [8] [INFO] Starting gunicorn 19.7.1
[2018-12-04 19:32:30 +0000] [8] [INFO] Listening at: http://0.0.0.0:5000 (8)
[2018-12-04 19:32:30 +0000] [8] [INFO] Using worker: sync
[2018-12-04 19:32:30 +0000] [16] [INFO] Booting worker with pid: 16
<my app's output>
When running the same image in k8s
I get
[2018-12-10 21:09:42 +0000] [5] [INFO] Starting gunicorn 19.7.1
[2018-12-10 21:09:42 +0000] [5] [INFO] Listening at: http://0.0.0.0:5000 (5)
[2018-12-10 21:09:42 +0000] [5] [INFO] Using worker: sync
[2018-12-10 21:09:42 +0000] [13] [INFO] Booting worker with pid: 13
[2018-12-10 21:10:52 +0000] [16] [INFO] Booting worker with pid: 16
[2018-12-10 21:10:53 +0000] [19] [INFO] Booting worker with pid: 19
[2018-12-10 21:14:40 +0000] [22] [INFO] Booting worker with pid: 22
[2018-12-10 21:16:14 +0000] [25] [INFO] Booting worker with pid: 25
[2018-12-10 21:16:25 +0000] [28] [INFO] Booting worker with pid: 28
<etc>
My k8s deployment yaml looks like
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: my-deployment
spec:
replicas: 1
selector:
matchLabels:
app: my-app
template:
metadata:
labels:
app: my-app
spec:
imagePullSecrets:
- name: regcred
containers:
- name: my-frontend
image: my-registry/my-frontend:latest
ports:
- containerPort: 80
- name: my-backend
image: my-registry/my-backend:latest
ports:
- containerPort: 5000
Here, the container in question is my-backend
. Any ideas why this is happening?
Update: As I wrote this, the events list that is printed with kubectl describe pods
was updated with the following:
Warning FailedMount 9m55s kubelet, minikube MountVolume.SetUp failed for volume "default-token-k2shm" : Get https://localhost:8443/api/v1/namespaces/default/secrets/default-token-k2shm: net/http: TLS handshake timeout
Warning FailedMount 9m53s (x2 over 9m54s) kubelet, minikube MountVolume.SetUp failed for volume "default-token-k2shm" : secrets "default-token-k2shm" is forbidden: User "system:node:minikube" cannot get secrets in the namespace "default": no path found to object
Normal SuccessfulMountVolume 9m50s kubelet, minikube MountVolume.SetUp succeeded for volume "default-token-k2shm"
Not sure if it's relevant to my issue
I solved this by adding resources under the container - mine needed more memory.
resources:
requests:
memory: "512Mi"
cpu: 0.1
limits:
memory: "1024Mi"
cpu: 1.0
Hope that helps.