echo "$REPOS" | jq '.[].repositoryName' | while read -r repo; do echo "do something with $repo"; done

Output:

do something with "repo_a"
do something with "repo_b"
do something with "repo_c"
do something with "repo_d"

Or without quotes:

echo "$REPOS" | jq -r '.[].repositoryName' | while read -r repo; do echo "do something with $repo"; done

Output:

do something with repo_a
do something with repo_b
do something with repo_c
do something with repo_d

It's generally a good idea to avoid looping over the result of a command substitution. It's inelegant as the command in the substitution must finish executing before the loop can even start running, it's inefficient as the full result of the command in the substitution must be stored in memory, and it's prone to errors since the shell must be allowed to split the output of the command on whitespace and subject the resulting words to filename globbing.

It's better to use read in a while loop:

#!/bin/sh

curl -s 'localhost:14002/api/sno' |
jq -r '.satellites[].id' |
while IFS= read -r id; do
        curl -s 'localhost:14002/api/sno/satellite/'"$id"
done |
jq -r \
        --argjson auditScore 1 \
        --argjson suspensionScore 1 \
        --argjson onlineScore 0.9 \
        '.audits as a.satelliteName as $name |
        reduce ($ARGS.named|keys[]) as a[ARGS.named[$key] then (
                        . + ["\($key) below threshold: \(key]) for \($name)"]
                ) else . end
        ) | .[]'

This script assumes that you can contact your REST endpoints on localhost:14002 (the Docker container might be made to expose that port, for example). If you need to use the docker exec command to access the API, then replace the plain calls to curl with, e.g.

docker exec -i curl -s 'localhost:14002/api/sno'

For the updated question, using the api/sno/satellites endpoint:

#!/bin/sh

curl -s 'localhost:14002/api/sno/satellites' |
jq -r \
        --argjson auditScore 1 \
        --argjson suspensionScore 1 \
        --argjson onlineScore 0.9 \
        '.audits[] as a.satelliteName as $name |
        reduce ($ARGS.named|keys[]) as a[ARGS.named[$key] then (
                        . + ["\($key) below threshold: \(key]) for \($name)"]
                ) else . end
        ) | .[]'

Apart from a minor adjustment to the jq expression, this is essentially the same code as above, but bypassing the first curl call to fetch all the IDs, and the loop.

The command-line tool jq writes to STDOUT and/or STDERR. If you want to write the .AssetId information to STDOUT, then one possibility would be as follows:

jq -r ".[] | .AssetId" input.json

Output:

14462955
114385498
29715011
98253651

A more robust incantation would be: .[] | .AssetId? but your choice will depend on what you want if there is no key named "AssetId".

You are trying to invoke myfile.js as a command. You need this:

output=$(cat myfile.js)

instead of this:

output=$(myfile.js)

But even then, your current approach isn't going to work well if the data has whitespace in it (which it does, based on the sample you posted). I suggest the following alternative:

jq -c '.[]' < myfile.js |
while read -r row
do
  echo "$row"
done

Output:

{"id":1,"name":"blah blah"}
{"id":2,"name":"xxx"}

Edit: If your data is arising from a previous process invocation, such as mongo in your case, you can pipe it directly to jq (to remain portable), like this:

mongo myfile.js |
jq -c '.[]' |
while read -r row
do
  echo "$row"
done

$ cat test.jq
# Iterate over "items"

.items[] |

# Place each extracted element into an array

[
    # Select elements

    .metadata.name,

    # Use parentheses to group
    ( .spec.containers[] | .name, .resources.limits["cpu","memory"] )
]

# Join the array together

| join(", ")

$ <input jq -r -f test.jq
kafka-0, kafka, 16, 16Gi, filebeat, 2, 256Mi