Answers

Here are possible answers to this chapter’s questions:

1. The Dockerfile could look like this:

   FROM ubuntu:22.04RUN apt-get update && \apt-get install -y iputils-pingCMD ping 127.0.0.1

Note that in Ubuntu, the ping tool is part of the iputils-ping package. You can build the image called pinger – for example – with the following command:

$ docker image build -t mypinger .

2. The Dockerfile could look like this:

   FROM alpine:latestRUN apk update && \apk add curl

Build the image with the following command:

$ docker image build -t my-alpine:1.0 .

3. The Dockerfile for a Go application could look like this:

   FROM golang:alpineWORKDIR /appADD . /appRUN go env -w GO111MODULE=offRUN cd /app && go build -o goappENTRYPOINT ./goapp

You can find the full solution in the ~/The-Ultimate-Docker-Container-Book/sample-solutions/ch04/answer03 folder.

4. A Docker image has the following characteristics:
   • It is immutable...