Can elsastic search a logfile and pull users from that file


I'm new to Elastic/Logstash/kibana. I was wondering if I could actually do a search of a log file and pull out particular information and then output it to kibana graphically or within a table.

Here is the message that I'm trying to parse:

"logmessage": "Accepted a login request from a client. Client =, Username = xxxxx"

I'm actually trying to display any time someone logs in but I just need the "Username = xxxx", portion.

Is that possible?

I'm trying to think if I can do this with grok, but I cant find any examples.

Here is my example to work of what I came up with:

if "Accepted a login request from a client" in [logmessage] {
grok {
match => ["logmessage", "Username = "]