notes

#This is a demo.

#create a demo 

#remove a env

conda remove --name=demo --all

#create demo env

conda create -n demo

conda activate demo

#install packages

conda install pip

conda install flask

conda install -c conda-forge uwsgi

#run flask by uwsgi

uwsgi --http 127.0.0.1:3031 --wsgi-file main.py --callable app --processes 4 --threads 2 --stats 127.0.0.1:9191

#create requirements.txt

conda list -e > requirements.txt

#pip freeze > requirements.txt

################################################
#Create a conda environment
conda create --name <environment-name> python=<version:2.7/3.5>

#To create a requirements.txt file:
conda list #Gives you list of packages used for the environment

conda list -e > requirements.txt #Save all the info about packages to your folder

#To export environment file
activate <environment-name>
conda env export > <environment-name>.yml

#For other person to use the environment
conda env create -f <environment-name>.yml
##############################################                           

#create Dockerfile


#when flask with built-in wsgi server flask

app.run()   not work

app.run(host='0.0.0.0') # works! run app.run(host='0.0.0.0') make the server publicly available.

#when use uwsgi as wsgi server
in the .ini,

http = 0.0.0.0

#build image

docker build -t johnzhu999/demo .

#run to make sure it work

docker run -d --name demo -p 4041:3031 johnzhu999/demo

access http://127.0.0.1:4041   

returns "Hello from Python!" works!

#push to docker hub

login to docker hub

create repo demo

in local machine

docker login

docker push johnzhu999/demo 

#deploy to minikube

#create a deployment
kubectl create deployment demo --image=johnzhu999/demo
#expose port
kubectl expose deployment demo --type=LoadBalancer --port=5000  #5000 is the port that docker container is listening to. it is decided by demo.ini or simply decided by app.run(host='0.0.0.0', port='5000')

#batch deploy docker

inside deplyment.yaml

 ports:
  - protocol: TCP
    port: 5000
    targetPort: 5000
  type: NodePort


      containers:
      - name: demo
        image: johnzhu999/demo
        imagePullPolicy: Never
        ports:
        - containerPort: 5000

kubectl apply -f deployment.yaml

#test if loadBalancer work
#
kubectl apply -f deployment.loadbalancer.yaml

works!


#use asf jenkins and rancher

create a view Data Services

New Item

job name: cicd-demo

type: pipeline

Pipeline script from SCM

SCM git

Repository URL: https://github.com/cirrusasf/cicd_demo.git
credentials: jenkins
branch specifer: */master


problem:
 docker push <VIC_Appliance_FQDN_IP>/default-project/some-image-name:latest
    The push refers to repository [<VIC_Appliance_FQDN_IP>/default-project/some-image-name]
    An image does not exist locally with the tag: <VIC_Appliance_FQDN_IP>/default-roject/some-image-name
 Cause
The container image needs to be tag locally for the new registry before it can be pushed. 
 Resolution
To resolve this issue we must Tag the image using the "docker tag" command.

For example:
docker tag some-image-name:latest <VIC_Appliance_FQDN_IP>/default-project/some-image-name:latest

#rancher

create project data_services

create namespace "cicd-demo" in project "data_services"


#kubectl check rancher

#copy content of the kubeconfig from rancher to local host ~/.kube/config

kubectl get -n cicd-demo pod

#in order for dockerized api work in kubernets, you need define the port and host='0.0.0.0' in app

if __name__ == "__main__":
    app.run(port=8080, host='0.0.0.0')

if you do not define port, it will not work.

we use uwsgi as wsgi server to communicate with flask, in the *.ini also need define http = 0.0.0.0:8080

That is to say we must define the same port and host in the two place. 

In k8s.yaml, also need define the same port (8080) as it defined in app. 

service port 8080

containerPort 8080