44/45. Env / ConfigMaps

44. Env variables

ENV variables can be defined under ENV 

Other ways to define ENV variables

• config-map - Value is taken from outside
• Secrets - Value is taken from outside.

ConfigMaps

When there are too many ENV files then it is better to define all variables in a seperate file in KEY/VALUE format.

How to create config-maps ( 2 ways ) 

- imperative and declarative.

Imperative way to create config-map

Declarative way for config-map

View Configmap

Config map in yaml file

Different ways of config-map

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37/38/40. Container Images

37. Define, Build and Modify Container Images.

Why ?

Created one application and we want to dockerize the application.

What are the steps if we have to deploy our application manually ?

- Deploy OS

- Update apt repo

- Install dependency using apt

- Install python dependency using pip

- Copy source folder to /opt

- Run web server using flask command.

Docker file with file name = <file-name>

FROM Ubuntu   [FROM -> Instruction, Ubuntu->Argument] <---- Install OS

RUN apt-get update                                   <------------ Install Dependencies

RUN apt-get install python

RUN pip install flask

RUN pip install flask-mysql

COPY . /opt/source-code                         <--- Copy source Code.

ENTRYPOINT FLASK_APP=/opt/source-code/app.py flask run   <-- Specify Entry Point.

Build docker

docker build <docker-file> -t <TAG>

PUSH Docker

docker push <TAG>

38. Command and Arguments in Docker ( CMD, ENTRYPOINT )

40. Command and Argument in K8

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