Set up Google Analytics 4

[chalin]

This as part of a CNCF-wide effort to upgrade project websites to GA4. For context, see:

• Migrate CNCF websites to GA4 cncf/techdocs#108

Tasks (stage 1):

• Create a GA4 tag (measurement ID) --> G-QZHM7YEG07. For details see comments below
  • Note: the UA and GA4 tags are now connected
• Google analytics: switch from Netlify injection to Hugo config #1517
• Add config gtag() call to GA4 tag by doing either of the following:
  • (Option 1, preferred) Update: doesn't work - Switch to using GA4 tag as an argument to gtag(), and see if the fact that the UA tag is connected back propagates the events - Analytics: explicitly config GA4 #1523, Analytics: revert and use UA id #1524
  • (Option 2, plan B) Add a separate gtag() config call for the GA4 tag -- probably first. Analytics: configure both GA4 and UA IDs explicitly #1525
    • Followup: Analytics: use YAML list for GA IDs #1544
  • (Option 3) Stick with connected tags without the need for any other code modifications. This would imply a code change (to explicitly use the GA4 id) at some point in the future. Not my preferred option.

If Option 1 doesn't work, and we have to fall back on Option 2, see if we can upstream a change to the Hugo internal template in support of more than one GA tag.

Followup: stages 2 & 3

• Analytics: use GA4 site tag only #1554

Resources:

• https://support.google.com/analytics/answer/11091026

[chalin]

Steps:

• Select Admin (bottom of left-nav)
• Select GA4 Setup Assistant
• Select I want to create a new Google Analytics 4 property > Get started

Here is the resulting web-stream measurement ID: G-QZHM7YEG07

No code changes were required since the tags are connected.

[chalin]

I confirm, as of this morning (2022/07/06) that analytics data is appearing in both the UA and GA4 consoles.

[chalin]

Option 1 isn't working, sadly:

The drop in page views corresponds to about the time when #1523 was merged. I'll revert it now so that we get back to a steady state.

#1524 reverted option 1. I'll wait for the analytics data to stabilize before trying something else.

Events are back to normal levels:

[chalin]

I confirm that option 2 (#1525) works:

The part of the histogram in the green box shows activity after #1525 was merged.