Firstly you'll need to install docker, after dockers installed then you can run the following to pull the oracle

To download the Oracle instant client tools you need to regisger with docker on their website, after you've registered you can login via the bash command line with:

docker login

Provide the username and password you used to register with docker, after you've logged in you can the pull the oracle instant tools down using:

docker pull store/oracle/database-instantclient:12.2.0.1

You should see something like this:

12.2.0.1: Pulling from store/oracle/database-instantclient
497341ef9d71: Pull complete
598d27c2564a: Pull complete
Digest: sha256:e83a2a223a14f24e6e433847d15d817ff7799a3a1a2dd2e4b224437358e996a0
Status: Downloaded newer image for store/oracle/database-instantclient:12.2.0.1

Next you'll want to connect to your database using your connection details, in this example the client details are specified in the docker command:

sudo docker run -ti --rm store/oracle/database-instantclient:12.2.0.1 sqlplus username@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=server_ip_address)(PORT=1522)))(CONNECT_DATA=(SERVICE_NAME=your_service_name)))

Should result in the following provided all config and credentials are correct:

SQL*Plus: Release 12.2.0.1.0 Production on Fri Aug 2 08:54:33 2019
Copyright (c) 1982, 2016, Oracle.  All rights reserved.
Enter password:
Connected to:Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options