How to install git on a docker ubuntu image?

Question

I have a simple docker file of

FROM ubuntu:18.04 COPY . /usr/src/app/ COPY docker_files/.bash_aliases /root/  $ docker build -t dock . Sending build context to Docker daemon  146.9kB Step 1/3 : FROM ubuntu:18.04  ---> 94e814e2efa8 Step 2/3 : COPY . /usr/src/app/  ---> bf79eb6c42c1 Step 3/3 : COPY docker_files/.bash_aliases /root/  ---> aedc97d5ee8b Successfully built aedc97d5ee8b Successfully tagged dock:latest 

I can use it:

$ docker run -it dock bash: git: command not found root@6a6bec871690:/# ls usr/src/app/ Dockerfile  Gemfile  Gemfile.lock  README.md  docker_files  go  ... root@6a6bec871690:/#  

and as you see my files were copied and aliases created for root. However git was not found (hence the err msg) and not installed.
How do I install it given my attempt below failed?

root@753b573271d5:/# git bash: git: command not found root@753b573271d5:/# apt-get install git Reading package lists... Done Building dependency tree        Reading state information... Done E: Unable to locate package git root@753b573271d5:/# sudo apt-get install git  bash: sudo: command not found 

Answer 1

This Dockerfile works for me

FROM ubuntu:18.04 RUN apt update RUN apt install -y git 

Inside the container

$ which git /usr/bin/git