# Day 2 - 90daysofDevOps

For installing docker in ubuntu machine and a few more basic commands are as bellow

```plaintext
sudo apt-get update                //updating latest packages in the server
sudo apt-get install docker.io     //installing docker 
sudo usermod -aG docker $USER      //adding docker user to the group file
cat /etc/group | grep -i docker    //checking if user is added or not
docker ps                          //to check if the docker container are working
docker run mysql:5.7               //creating docker container of mysql
docker exec -it <container_id> bash   //running the container in iteractive bash mode
 
```

Things to remember :

***Docker File -&gt; Docker Image -&gt; Docker Container***

Always, first the file is prepared (Dockerfile) , then using Dockerfile, image is created using Docker build command, and then Container is created from that image using Docker run command.

# **Dockerfile**

Docker builds images by reading the instructions from a Dockerfile. A Dockerfile is a text file containing instructions for building your source code.

example of Dockerfile of a java application

```plaintext
 #Toget the base image from Dockerhub
FROM openjdk:11

#Create a wprking dorectory to compile java app
WORKDIR /app

#Copy code from local machine to the container(assuming we are in java app dir)
COPY Hello.java . 

#Compile the code
RUN javac Hello.java

#Run the java app
CMD["java","Hello"]
```

### **Charting Our Docker Adventure 🗺️**

Today's Docker tasks were like unlocking the hidden treasures of containerization. Sail through the sea of containers, and let's share our Docker stories on this #DevOpsJourney! ⚓🌐

Join me tomorrow for another thrilling DevOps challenge. Until then, keep Dockerizing! 🐳🚀

Happy Containerizing! 🌟👨‍💻