Docker Images

Creating a Dockerfile is a  declarative way to define the steps for building a docker image. A Dockerfile is a simple text-based script that contains the instructions for building a docker image, making it a reproducible and shareable artifact.

How to Create Docker Images?

1. Create application directory:

   • Begin by creating a dedicated directory for the application. This Directory will contain both the app and Dockerfile.

2. Create an empty Docker file:

   • In this directory, create an empty Dockerfile using a text/code editor.

     sudo nano Dockerfile

3. Add instruction to the Dockerfile:

   • Define the steps for building the Docker image in the Dockerfile. For example:

     #Set parent image 
     FROM ubuntu:22.04 as build 
     
     #Set working directory in the container 
     WORKDIR /app
     
     #Copy the local scripts and file to the container 
     COPY lyrics.sh .
     
     # Install any needed packages 
     RUN apt-get update && apt-get install -y \
         curl && \
         apt-get clean   
         
     #Make scripts executable and run the script
     RUN chmod +x lyrics.sh && ./lyrics.sh

4. Build and Tag Docker image:

   • Build the Docker image in the same directory (“.”) as the Dockerfile. Tagging the image helps organize it, especially if you plan to push it to a Docker repository. Use meaningful names or version numbers as tags.

     docker build -t imagename:youtag .
     docker tag imagename:youtag imagename:image1

5. Log into docker account and push image to docker repository

   • Log into docker account:

     docker login

   • Push image to a docker repo. This will make it accessible to others:

     docker push tagname