Bash script - AWS SSM export variables in parallel

Question

My original script loads SSM variables from AWS and works fine but each variables takes about 1 second

#!/bin/bash

getEnvironmentVariable() {
  SECRET=$1
  ssm_value=$(aws ssm get-parameter --name "/TEST_PREFIX/${SECRET}" --with-decryption --query 'Parameter.Value' --output text)
  export "${SECRET}"="${ssm_value}"
}

getEnvironmentVariable "TEST_SECRET_1"
getEnvironmentVariable "TEST_SECRET_2"

Instead I would love to pull environment variables in parallel and export them.

My attempt at parallelizing them.

#!/bin/bash

getEnvironmentVariable() {
  SECRET=$1
  ssm_value=$(aws ssm get-parameter --name "/TEST_PREFIX/${SECRET}" --with-decryption --query 'Parameter.Value' --output text)
  echo "${SECRET}"="${ssm_value}"
}

export $(getEnvironmentVariable "TEST_SECRET_1") &
export $(getEnvironmentVariable "TEST_SECRET_2") &
wait

env | grep "TEST_SECRET_2"

I'm getting a little stuck on how to run things in parallel with a subshell and still be able to export them.

Is it possible to fetch and export the values in parallel?

Answer 1

You are looking for parset (Introduced in 20170422, but has seen heavy development in the past year):

#!/bin/bash

. `which env_parallel.bash`

getEnvironmentVariable() {
  SECRET=$1
  aws ssm get-parameter --name "/TEST_PREFIX/${SECRET}" --with-decryption --query 'Parameter.Value' --output text
}
export -f getEnvironmentVariable

parset TEST_SECRET_1,TEST_SECRET_2 getEnvironmentVariable ::: TEST_SECRET_1 TEST_SECRET_2
echo $TEST_SECRET1

# And if you need it exported:
export TEST_SECRET_1
export TEST_SECRET_2
bash -c 'echo $TEST_SECRET2'