get subnet id AWS - bash

Question

i am trying to get the subnet ids within a particular VPC and store them in variables
so I can use them in a bash script
aws ec2 describe-subnets --filter "Name=vpc-id,Values=VPCid" --region $REGION --query "Subnets[*].SubnetId" --output text
and this gives something like this
subnet-12345 subnet-78910
(END)
I wonder how I can store them into a variable.
I tried with
SBnet=$(aws ec2 describe-subnets --filter "Name=vpc-id,Values=VPCid" --region $REGION --query "Subnets[*].SubnetId" --output text)
but then I do not know I can access the array/list created.
I tried with
echo $(SBnet[0])
but does not work
I am on MACos usin zsh

Answer 1

You can do this as follows (add your VPC and the region):
#!/bin/bash
SUBNET_IDS=$(aws ec2 describe-subnets --filter "Name=vpc-id,Values=vpc-1234" --query "Subnets[*].SubnetId" --output text)
for SUBNET_ID in $SUBNET_IDS;
do
echo $SUBNET_ID
done
To split the list of subnet IDs into variables, you can do this:
#!/bin/bash
SUBNET_IDS=$(aws ec2 describe-subnets --filter "Name=vpc-id,Values=vpc-1234" --query "Subnets[*].SubnetId" --output text)
IFS=$'\t ' read -r -a subnet_ids <<< $SUBNET_IDS
echo "${subnet_ids[0]}"
echo "${subnet_ids[1]}"
And the individual subnet IDs will be in the subnet_ids array.

Answer 2

you can do as #jarmod suggested and you could also write a query to extract all the subnets tied to all the VPC's in your system in a comma separated output and use it further like this
aws ec2 describe-subnets --query "Subnets[].[SubnetId,VpcId,CidrBlock,AvailabilityZone]" --output text|sed 's/\t/,/g'