How does KeepAlive work in net.Dialer?

Question

go

Hey!
The standard http.Client in Go looks something like this:

http.Client{
  Transport: &http.Transport{
    Dial: (&net.Dialer{
      Timeout:   30 * time.Second,
      KeepAlive: 30 * time.Second,
      DualStack: true,
    }).DialContext,
  MaxIdleConns:          100,
  IdleConnTimeout:       90 * time.Second,
  TLSHandshakeTimeout:   10 * time.Second,
  ExpectContinueTimeout: 1 * time.Second,
  },
}

As I understand it:
MaxIdleConns - the maximum number of connections that can be in the pool of free connections for ALL hosts.
IdleConnTimeout - The maximum time idle connections can be kept in the pool.
There is also
MaxIdleConnsPerHost - which by default is equal to DefaultMaxIdleConnsPerHost ... i.e. 2
So if I establish 10 connections with one host, then only 2 free connections will be stored in the MaxIdleConns pool ... and not 100.
And there is also KeepAlive : 30 sec. How does it interact with IdleConnTimeout ?
If I establish a connection, make a request, then it will fall into the pool. So will it die in 30s or 90s as specified by IdleConnTimeout ? And if the request took 15 seconds, then the connection fell into the pool, lay there for 25 seconds, and again I make a request for 15 seconds. Connection will die during request? It's just that Client.Timeout works that way.