Creating Route53 Record Sets via Shell Script

Question

As a part of my shell script, I am trying to create record sets in AWS Route53. However, using variables in the aws cli within my shell script to create those records set, my variables exported in the Shell scripted are not being passed to the aws cli command.

AWS CLI command provided by AWS:

$ aws route53 change-resource-record-sets --hosted-zone-id 1234567890ABC \
  --change-batch file:///path/to/record.json

I do not want to create a separate json file on my computer for simplicity purpose, I want to have all my commands and variables within the shell script.

#!/bin/bash

export TARGET_ENVIRONMENT=uat 
export BASE_ENVIRONMENT_DNS=abcd-External-9982627718-1916763929.us-west-1.elb.amazonaws.com

# Creates route 53 records based on env name

aws route53 change-resource-record-sets --hosted-zone-id 1234567890ABC  
--change-batch '{ "Comment": "Testing creating a record set", 
"Changes": [ { "Action": "CREATE", "ResourceRecordSet": { "Name": 
"$(TARGET_ENVIRONMENT).company.com", "Type": "CNAME", "TTL": 
120, "ResourceRecords": [ { "Value": "$(BASE_ENVIRONMENT_DNS)" } ] } } ] }'

This last command is creating a record set on the AWS Route53 as:

$(TARGET_ENVIRONMENT).company.com

with CNAME as

$(BASE_ENVIRONMENT_DNS)

and NOT really as I want it to be, which is:

uat.company.com

with the CNAME:

abcd-External-9982627718-1916763929.us-west-1.elb.amazonaws.com

How can I pass the environment variables into my aws cli command within the script?

Any help will be highly appreciated.

Thanks!

score 25 · Answer 1 · edited Oct 25 '21 at 10:47

25

Variables do not expand within single quotes.

If you close the single quotes before your variable expansion, and then open them again immediately after, it should produce the desired effect. You may or may not need to wrap the variable in double quotes for it to expand.

#!/bin/bash

ENV=uat 
DNS=abcd-External-9982627718-1916763929.us-west-1.elb.amazonaws.com

# Creates route 53 records based on env name

aws route53 change-resource-record-sets \
  --hosted-zone-id 1234567890ABC \
  --change-batch '
  {
    "Comment": "Testing creating a record set"
    ,"Changes": [{
      "Action"              : "CREATE"
      ,"ResourceRecordSet"  : {
        "Name"              : "'" $ENV "'.company.com"
        ,"Type"             : "CNAME"
        ,"TTL"              : 120
        ,"ResourceRecords"  : [{
            "Value"         : "'" $DNS "'"
        }]
      }
    }]
  }
  '

edited Oct 25 '21 at 10:47

weinerk

472
6
12

answered Mar 12 '18 at 05:38

nicholas.hauschild

42,483
9
127
120

13

For those who may scratch their heads trying to understand why this works, the shell does not require a concatenation operator for adjacent quoted literals (which are expanded when double quotes are used). `echo 'a'"b"'c'` illustrates this. (Result: `abc` with no spaces in between.) – Michael - sqlbot Mar 12 '18 at 11:23
Thank you @nicholas.hauschild, that worked. Appreciate the help. – arfat619 Mar 12 '18 at 15:27
1

I hate that this works. But I'm also glad. – jorfus Feb 05 '21 at 23:49

score 3 · Answer 2 · edited Jan 04 '23 at 07:50

You could also leverage process substitution to keep the JSON formatted:

#!/bin/bash

export TARGET_ENVIRONMENT=uat 
export BASE_ENVIRONMENT_DNS=abcd-External-9982627718-1916763929.us-west-1.elb.amazonaws.com

# Creates route 53 records based on env name

aws route53 change-resource-record-sets --hosted-zone-id 1234567890ABC --change-batch file://<(cat << EOF
{
  "Comment": "Testing creating a record set",
  "Changes": [
    {
      "Action": "CREATE",
      "ResourceRecordSet": {
        "Name": "${TARGET_ENVIRONMENT}.company.com",
        "Type": "CNAME",
        "TTL": 120,
        "ResourceRecords": [
          {
            "Value": "${BASE_ENVIRONMENT_DNS}"
          }
        ]
      }
    }
  ]
}
EOF
)

CAUTION! This does not work if your record is too long!! – Chau Giang May 31 '22 at 08:49 — Chau Giang, May 31 '22 at 08:49

score 3 · Answer 3 · answered Nov 24 '22 at 10:38

This worked for me!

#!/bin/bash
zoneid=xxxxyyyyyzzzzz
recordname=mycname
recordvalue=myendpoint

aws route53 change-resource-record-sets \
  --hosted-zone-id $zoneid \
  --change-batch '
  {
    "Comment": "Creating a record set for cognito endpoint"
    ,"Changes": [{
      "Action"              : "CREATE"
      ,"ResourceRecordSet"  : {
        "Name"              : "'$recordname'.mydomain.com"
        ,"Type"             : "CNAME"
        ,"TTL"              : 120
        ,"ResourceRecords"  : [{
            "Value"         : "'$recordvalue'"
        }]
      }
    }]
  }

This works with `GNU bash, version 4.2.46(2)-release (x86_64-koji-linux-gnu)` — sgargel, Nov 28 '22 at 13:57

Toni Arantegui · Answer 4 · 2023-02-20T10:41:52.563

You need to close the single quotation mark. Here is the fixed snippet.

#!/bin/bash
zoneid=xxxxyyyyyzzzzz
recordname=mycname
recordvalue=myendpoint

aws route53 change-resource-record-sets \
  --hosted-zone-id $zoneid \
  --change-batch '
  {
    "Comment": "Creating a record set for cognito endpoint"
    ,"Changes": [{
      "Action"              : "CREATE"
      ,"ResourceRecordSet"  : {
        "Name"              : "'$recordname'.mydomain.com"
        ,"Type"             : "CNAME"
        ,"TTL"              : 120
        ,"ResourceRecords"  : [{
            "Value"         : "'$recordvalue'"
        }]
      }
    }]
  }'

Creating Route53 Record Sets via Shell Script

4 Answers4

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