Why did Russia invade Ukraine now, in 2022? [duplicate]

Are there any indications why Russia decided to threaten and then invade Ukraine at the time it did?

In particular:

• The two countries were already at war with each other since 2014. Have there been any changes in the situation which could explain the timing of the invasion?
• Could it be related to some domestic factors in Russia which provided the Russian government with some kind of political opportunity?

To explain the context of my question: potentially the Russian government could have started their attack at any time in the past 8 years, for example in the middle of the Covid pandemic or during the Taliban takeover of Afghanistan. It could also have waited longer. There is certainly a reason why Putin chose this particular time, but of course I'm aware that this reason might be unknown.