This is a bit of a beginner's question. I'm attempting to get a simple Hello World Python flask application deployed in a kubernetes cluster on IBM Cloud. The application (main.py):
import os
from flask import Flask
app = Flask(__name__)
@app.route('/')
def welcomeToMyapp():
return 'Ciao'
port = os.getenv('PORT', '5000')
if __name__ == "__main__":
app.run(host='0.0.0.0', port=int(port))
I build my Docker image with docker build --rm -t kube-hw . and Dockerfile:
FROM ubuntu:latest
WORKDIR /app
ADD requirements.txt /app
RUN apt-get -y update
RUN apt-get -y install python3-pip
RUN pip3 install --upgrade pip
RUN pip3 install -r requirements.txt
ADD main.py /app
EXPOSE 80
CMD ["python3", "main.py"]
I run it locally with docker run --rm -p 5000:5000 kube-hw. That works fine. I can browse http://0.0.0.0:5000/.
However, when I run the same image on k8s on IBM Cloud I can't seem to access the URL endpoint. My deployment steps are (from the article mentioned in the answer below):
docker tag kube-hw registry.ng.bluemix.net/sudoku/kube-hw:latest
docker push registry.ng.bluemix.net/sudoku/kube-hw:latest
kubectl run kube-hw --image=registry.ng.bluemix.net/sudoku/kube-hw:latest --port=80
kubectl expose deployment kube-hw --port=80 --target-port=5000 --type=NodePort
I then use kubectl describe pod kube-hw to get the external IP address 10.77.223.141:
Name: kube-hw-3409617459-5bczp
Namespace: default
Node: 10.77.223.141/10.77.223.141
Start Time: Sat, 23 Dec 2017 14:52:39 -0500
Status: Running
IP: 172.30.205.113
And kubectl describe service kube-hw to get the port 30930:
Name: kube-hw
Namespace: default
Labels: run=kube-hw
Annotations: <none>
Selector: run=kube-hw
Type: NodePort
IP: 172.21.250.32
Port: <unset> 80/TCP
TargetPort: 5000/TCP
NodePort: <unset> 30930/TCP
Endpoints: 172.30.205.116:5000
Session Affinity: None
External Traffic Policy: Cluster
Events: <none>
The URL http:\\10.77.223.141:30930 doesn't resolve. I can look at the log and see the app running, but no requests are getting to it. The article uses --target-port=8888. But since I've used port 5000 in the container I changed to --target-port=5000. I'm wondering if I have a misalignment of port numbers somewhere.
The IP address that you need is the external IP address of a worker node in your cluster. The IP address that you have identified is an internal address.
To get an external IP address, run bx cs workers <cluster_name>
Then form the URL as follows: http://<external_node_ip>:<NodePort>
Here's a doc with more information on using NodePort: https://console.bluemix.net/docs/containers/cs_apps.html#cs_apps_public_nodeport