insert variable output of script in multiple lines using sed - variables

Question

test file contains
$ cat test
i-d119c118,vol-37905322,,,2015-07-29T03:50:32.511Z,General Purpose SSD,15
i-2278b42e,vol-c90539cc,,,2014-11-12T04:27:22.618Z,General Purpose SSD,10
script output:
$ for instance_id in $(cut -d"," -f1 test); do python getattrib.py get $instance_id | cut -d"'" -f2; done
10.10.0.68
10.10.0.96
inserting variable using sed yields following result, note the same IP address
$ insert=( `for instance_id in $(cut -d"," -f1 test); do python getattrib.py get $instance_id | cut -d"'" -f2; done` )
$ sed "s|$|,${insert}|" test
i-d119c118,vol-37905322,,,2015-07-29T03:50:32.511Z,General Purpose SSD,15,10.10.0.68
i-2278b42e,vol-c90539cc,,,2014-11-12T04:27:22.618Z,General Purpose SSD,10,10.10.0.68
but i am looking for output as below:
10.10.0.68,i-d119c118,vol-37905322,,,2015-07-29T03:50:32.511Z,General Purpose SSD,15
10.10.0.96,i-2278b42e,vol-c90539cc,,,2014-11-12T04:27:22.618Z,General Purpose SSD,10

Answer 1

use start delimiter ^ instead of end $ and adapt the ,
sed "s/^/${insert},/" test
but your sed and value retreiving need to be into the loop, not after or taking all result as value
example in loop:
for instance_id in $(cut -d"," -f1 test)
do
insert="$( python getattrib.py get ${instance_id} | cut -d"'" -f2 )"
sed -e "/^${instance_id}/ !d" -e "s|$|,${insert}|" test
done

Answer 2

insert=( `for instance_id in $(cut -d"," -f1 test); do python getattrib.py get $instance_id | cut -d"'" -f2; done` )
the insert variable is an array holding 2 elements
sed "s|$|,${insert}|" test
${insert} only retrieves the first element -- it is implicitly ${insert[0]}
I would rewrite that like this, to read the file line-by-line:
while IFS=, read -ra fields; do
ip=$( python getattrib.py get "${fields[0]}" | cut -d"'" -f2 )
printf "%s" "$ip"
printf ",%s" "${fields[#]}"
echo
done < test