Inform users about telemetry and how to opt-out

[cakrit]

Indicate in all installers before the Enter/yes-no: "Anonymous statistics will be [enabled/disabled]", according to the provided option. Provide information on the option relevant to the specific installer, to opt-out:

• netdata-installer.sh
• kickstart.sh
• kickstart-static64.sh
• binary packages (not sure about this one)

For docker images:

• Add a DO_NOT_TRACK env var which when set will disable the anonymous stat pings.
• Document the env var

Related: #7404 (comment)

[ncmans]

@cakrit I see you wrote:

We will plan the implementation of the suggested measures (other than opting-in) as soon as possible.

in #7366 (comment)

Does that make this high priority? cc @cosmix

[sneak]

The statistics collected are not and can not be anonymous, so by claiming this, you would be making a false statement to your users. I suggest making the copy clear about the fact that the software will not use an anonymous method to submit the data.

[amoss]

@sneak the information provided by Google describing their anonymous IP collection is here: https://support.google.com/analytics/answer/2763052?hl=en.

[sneak]

What Google does or does not do with the data is irrelevant. The data that is transmitted is not anonymous nor is it transmitted anonymously. To claim otherwise, regardless of what Google or any other party does or does not do, is false.

It is also received by many more parties than just Google.

[cakrit]

@cakrit I see you wrote:

We will plan the implementation of the suggested measures (other than opting-in) as soon as possible.

in #7366 (comment)

Does that make this high priority? cc @cosmix

Yes, this is high priority. We did fill the next sprint with critical priority items, but if there's any capacity from anyone, we want to progress the other items as well.

[ncmans]

@cakrit kickstart scripts already prompt dozen times for installing various OS packages if --dont-wait or --non-interactive options aren't set. Should stat collection be another question we ask interactively when running kickstarts?

EDIT: never mind — since kickstart calls into netdata-installer.sh anyway, they don't need any changes.