unable to parse JSON using terraform external data

问题

USE CASE

I wanted to provision an EFS in a given region with an EC2 instance and then mount that instance with EFSand if EFS doesn't exist in that region then I need to provision an alternate of EFS.

PROBLEMS

Amazon is not offering EFS service in every region.
There is no way to identify the availability of service using aws-cli. Already asked but didn't get an answer yet link

WHAT I TRIED

This is the case where amazon provide the service, If I run this command curl -ls https://elasticfilesystem.us-east-1.amazonaws.com system returns the following output.

<MissingAuthenticationTokenException>
  <Message>Missing Authentication Token</Message>
</MissingAuthenticationTokenException>

And if I change the region to eu-west-3 (paris) and run the command system returns nothing.

So this is the WORKAROUND that I've in my mind to check the availability of service in any particular region. But If i write a bash script for this and run the same command using terraform datasource external it shows an error message that unable to parse a JSON error pasring '<'. I've no clue why bash-script considering this returned XML, though I'm checking the exit code instead.

bash script

function check_efs() {
curl -ls https://elasticfilesystem.us-east-1.amazonsaws.com
if [ $? -eq 0 ]; then
        output=1
else:
        output=0
}

function produce_output() {
value=$(output)

jq -n \
    --arg is_efs_exist "$value" \
    '{"is_efs_exist":$is_efs_exist}'
}

check_efs
produce_output

main.tf

provider external {}

data "external" "this" {
program = ["bash", "${path.module}/scripts/efschecker.sh"]
}

来源：https://stackoverflow.com/questions/52789813/unable-to-parse-json-using-terraform-external-data

标签

bash

amazon-web-services

curl

terraform

amazon-efs