Update readme

Tasks/4.Building images/README.md

@@ -1,22 +1,20 @@
 # Practice - building images
 
-Your project utilizes microservices and Kuberenetes. On your cluster you have many containers (pods) with your services. There's a special container which runs Ubuntu and can access the other services' databases and other components. To access those components you install a few CLI tools on this special container. The problem - each time the cluster is re-deployed you must install the CLI tools again because they're not part of the container's base Ubuntu image.
+Your project utilizes microservices and Kuberenetes. On your cluster you have many containers (pods) with your services. There’s a special container **jumpbox** which runs Ubuntu and can access the other services' databases and other components. To access those components you install a few CLI tools on this special container. The problem - each time the cluster is re-deployed you must install the CLI tools again because they're not part of the container's base Ubuntu image.
 
-You want to automate this process by building a Dockerfile for this container using ubuntu:18.04 as your base image.
+You want to automate this process by building a Dockerfile for this container using **ubuntu:18.04** as your base image.
 
 To install those tools you normally use the following commands:
 
-- $ `DEBIAN_FRONTEND=noninteractive` # Env var required for postgres
+- $ `DEBIAN_FRONTEND=noninteractive` # Env var required for postgres installation
 - $ `apt-get update && apt-get install -y postgresql` # Install postgres to access dbs
 - $ `apt-get install -y wget` # Install wget for downloading software packages
 - $ `apt-get install -y curl` # Install curl for running HTTP requests
 
-:whale: HINT: Research how to set environment variables inside Dockerfiles for the DEBIAN_FRONTEND variable.
-
-To build the image, navigate to your Dockerfile path and use
- - `docker build –t "<name>:<tag>" .`
-
-Run a container from this image in interactive mode and verify the installations:
+1. Create the above Dockerfile and build an image **jumpbox** with a **1.0** tag. Run a container with interactive bash and verify the installations:
  - `psql --version` # You should see the psql version
  - `wget --version` # You should see the wget version and other info
  - `curl 'http://example.com'` # You should see some html
+2. Change **curl** to **inetutils-ping**. Build a jumpbox version **2.0** and test again:
+- `psql --version`
+- `ping 8.8.8.8`