If you see logs to a kube-apiserver logs similar to below, it may be due to incorrect or invalid etcd Certificate Authority certificate file configured in the kube-apiserver.
W0715 12:46:09.529643 1 logging.go:55] [core] [Channel #1 SubChannel #2]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "transport: authentication handshake failed: tls: failed to verify certificate: x509: certificate signed by unknown authority"
W0715 12:46:10.502578 1 logging.go:55] [core] [Channel #3 SubChannel #4]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "transport: authentication handshake failed: tls: failed to verify certificate: x509: certificate signed by unknown authority"
W0715 12:46:10.635518 1 logging.go:55] [core] [Channel #5 SubChannel #6]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "transport: authentication handshake failed: tls: failed to verify certificate: x509: certificate signed by unknown authority"
W0715 12:46:15.763732 1 logging.go:55] [core] [Channel #1 SubChannel #2]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "transport: authentication handshake failed: tls: failed to verify certificate: x509: certificate signed by unknown authority"
W0715 12:46:16.952953 1 logging.go:55] [core] [Channel #5 SubChannel #6]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "transport: authentication handshake failed: tls: failed to verify certificate: x509: certificate signed by unknown authority"
W0715 12:46:17.090479 1 logging.go:55] [core] [Channel #3 SubChannel #4]grpc: addrConn.createTransport failed to connect to {Addr: "127.0.0.1:2379", ServerName: "127.0.0.1:2379", }. Err: connection error: desc = "transport: authentication handshake failed: tls: failed to verify certificate: x509: certificate signed by unknown authority"
F0715 12:46:20.789804 1 instance.go:226] Error creating leases: error creating storage factory: context deadline exceeded