Read-command in bash script

I'm trying to start using read -r, but no luck so far.
The following script (added below) should make a list of SSH servers from /etc/hosts, and then execute the command. I use it for simple administration things, adding users, etc.

I normally use sshservers=($(, but I ran my script through Shellcheck last week, and it said I should use read -r in stead.
So I added that, but now my script gets stuck when I run it.

Is someone able to help me out how I should properly use read -r in stead?
(And if you have any further tips or notes, please let me know, I'm still learning Bash, as you might see by looking at my script hehe).

Thanks in advance!

#!/bin/bash
serverlist=/home/demo/serverlist.txt

: > "$serverlist"
sed -e '/^#/d' /etc/hosts | awk '{print $2}' >> "$serverlist"
sed -i -- '/^localhost/ d' "$serverlist"
#sshservers=($(sshservers=$(read serverlist)
for sshserver in "${sshservers[@]}"
        do
        ssh -t demo@"$sshserver" "hostname && sudo ls /root/"
done
echo "done"

EDIT: /home/demo/serverlist.txt contains IP's with the following format, not sure if it helps:

192.168.1.1
192.168.1.2
192.168.1.3 

Answer

With older versions of bash (if you want the lines in an array):

sshservers=()
while read -r servername; do
    sshservers+=("$servername")
done < "$serverlist" 

In bash 4+ you can use readarray:

sshservers=()

readarray sshservers < "$serverlist"

Or in this case if you don't really need the servernames in a file, you could just loop over the results for the commands like so:

while read -r sshserver: do
    ssh -t "demo@$sshserver" "hostname && sudo ls /root/"
done < <(sed -e '/^#/d' /etc/hosts | awk '{print $2}' | grep -vE '^$|^localhost')