Changed documentation to store cluster name in ENV-variable for more flexibility

[smoell]

Issue #, if available (include keywords to close issue as applicable, e.g. "fixes <##>"):

Description of changes:

• Changed documentation
• Changed shell scripts which get downloaded from S3

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[dalbhanj]

Hi @smoell
I'd rather store EKS environment variables used throughout the workshop in bashrc via Build script (lab-ide-build.sh). Do you want to update this build script and resend the PR?

[buzzsurfr]

Let's update the build script to set EKS_CLUSTER_NAME by default, but also provide instructions in the README about how to overwrite.

[smoell]

Sounds good, I'll do this. Additional question: why are the shell-scripts pulled from S3 and not part of the repo, I want to change this as well if you agree.

[buzzsurfr]

The scripts are hosted in S3 since the CloudFormation templates also must be in S3. The logic was to have everything you need before cloning the repository in the S3 bucket.

The scripts are kept in the repository, and the goal was to incorporate a CI process that would automatically validate the template/scripts and export to the S3 bucket.

The script also clones the repository, so it’s also a “chicken and egg” scenario.

I would prefer to pull the script from S3, but it won’t make a difference.

[smoell]

I see ok, so I'll provide the changed shell scripts directly.

[dalbhanj]

LGTM. @buzzsurfr if you are good with this PR, let's merge it

[buzzsurfr]

LGTM (Sorry for delay, was OOO)