As of your listing - where its from? ES presents sth different.
Just paste the commands I shown:
wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.5.0.tar.gz
tar xvf elasticsearch-5.5.0.tar.gz
cd elasticsearch-5.5.0
ls -l
And tell me what you have.
Learn about GZ (and tar.gz)
Actually, TAR means: Tape ARchiver. See https://en.wikipedia.org/wiki/Tar_(computing)
In computing, tar is a computer software utility for collecting many files into one archive file, often referred to as a tarball, for distribution or backup purposes.
GZ stands for GZIP: See https://en.wikipedia.org/wiki/Gzip:
gzip is a file format and a software application used for file compression and decompression.
as name says, its designed to store sources.
I don't think so. But may be you'd like to fix Wikipedia definitions?
Reason? Just because Im confused - you have two (or even more - I dont know) starting guidelines instead of one solid.
On the start page, I read:
Download package for your platform.
wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.5.0.tar.gz
Extract .zip or tar.gz file
tar xvf elasticsearch-5.5.0.tar.gz
cd into extracted folder
cd elasticsearch-5.5.0
Nothing more. I don't know where you saw that you have to compile anything.
On the other end, if you have clicked on "Or install with a package manager or Windows MSI." link, you have read then:
https://www.elastic.co/guide/en/elasticsearch/reference/current/install-elasticsearch.html#install-elasticsearch
Where you have documentation for whatever package you can get officially from elastic.
I'd encourage you reading the following one as you stated that you want to deploy elasticsearch on Ubuntu.
This links to the page I already pasted:
https://www.elastic.co/guide/en/elasticsearch/reference/current/deb.html
So I believe that everything from the start page is there.
Now, coming back to your problem:
Can you follow the very first advice I gave you and follow all the steps mentioned at https://www.elastic.co/guide/en/elasticsearch/reference/current/deb.html?
If you have any issue by running this guide, please feel free to open a question in #elasticsearch forum as it could help other community members. Please provide there all details (commands and outputs).
In case you want to offer to your customers a production ready elasticsearch cluster which is pre-installed, managed by elastic and is providing out of the box security, backups... you should give a look at https://cloud.elastic.co/.