Golang regular expression for parsing key value pair into a string map

I'm looking to parse the following string into a map[string]string using a regular expression:

time="2017-05-30T19:02:08-05:00" level=info msg="some log message" app=sample size=10

I'm trying to create a map that would have

m["time"] = "2017-05-30T19:02:08-05:00"
m["level"] = "info"

etc

I have tried using regex.FindAllStringIndex but can't quite come up with an appropriate regex? Is this the correct way to go?