How to pipe multiple results into a command?

Question

I have a piece of code which works, something like this (note this is inside CloudFormation Template for AWS auto deployment):

EFS_SERVER_IPS_ARRAY=( $(aws efs describe-mount-targets --file-system-id ${SharedFileSystem} | jq '.MountTargets[].IpAddress' -r) )
echo "IPs in EFS_SERVER_IPS_ARRAY:"
for element in "${EFS_SERVER_IPS_ARRAY[@]}"
do
    echo "$element"
    echo "$element $MOUNT_SOURCE" >> /etc/hosts
done

This works but looks ugly. I want to avoid the array variable and the for loop (basically I don't care about the first echo command).

Can I somehow use the output ($element, which is 1 or more, currently 2 lines of IPs) and funnel it into two executions of something like:

long AWS command >> echo $element $MOUNT_SOURCE  >> /etc/hosts

with echo executing as many times as there are variables in the array, in current implementation? How would I rewrite this?

The output of the AWS command is like this:

10.10.10.10
10.22.22.22

Then, the added lines in /etc/hosts look like:

10.10.10.10  unique-id.efs.us-east-1.amazonaws.com
10.22.22.22  unique-id.efs.us-east-1.amazonaws.com

Answer 1

aws efs describe-mount-targets --file-system-id ${SharedFileSystem} \
    | jq --arg mntsrc "$MOUNT_SOURCE" '.MountTargets[].IpAddress | . + $mntsrc' -r >> /etc/hosts

or, if you prefer,

aws efs describe-mount-targets --file-system-id ${SharedFileSystem} \
    | jq '.MountTargets[].IpAddress' -r | sed -e "s~\$~$MOUNT_SOURCE~" >> /etc/hosts

All that's happening is adding some extra fixed text to the end of each line, which can happen either in jq (top) or in various ways outside (bottom). There's not really any array context here or anything being repeated, so you don't need a loop.