Cannot install packages inside docker Ubuntu image

Question

I installed Ubuntu 14.04 image on docker. After that, when I try to install packages inside the ubuntu image, I\'m getting unable to locate package error:

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Answer 1

From the docs in May 2017 2018 2019 2020

Always combine RUN apt-get update with apt-get install in the same RUN statement, for example

RUN apt-get update && apt-get install -y package-bar

(...)

Using apt-get update alone in a RUN statement causes caching issues and subsequent apt-get install instructions fail.

(...)

Using RUN apt-get update && apt-get install -y ensures your Dockerfile installs the latest package versions with no further coding or manual intervention. This technique is known as “cache busting”.