aws cloudformation userdata: how to use local variable in script

Question

I'm writing the cloudformation template that includes ec2 instance. In userdata block, I want to create a file with some content. In the file, I'm initializing local variable MY_MESSAGE, but next, after the template is deployed this variable is not shown in the file.

original temlate:

EC2Instance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: ami-03368e982f317ae48
      InstanceType: t2.micro
      KeyName: ec2
      UserData:
        !Base64 |
        #!/bin/bash
        cat <<EOF > /etc/aws-kinesis/start.sh
        #!/bin/sh
        MY_MESSAGE="Hello World"
        echo $MY_MESSAGE

output file in ec2 instance:

#!/bin/sh
MY_MESSAGE="Hello World"
echo

As you can see variable MY_MESSAGE does not exist in echo block.

Marcin · Accepted Answer · 2020-08-13 08:24:54Z

2

You can put EOF in quotes: "EOF":

      UserData:
        !Base64 |
          #!/bin/bash
          cat <<"EOF" > /etc/aws-kinesis/start.sh
          #!/bin/sh
          MY_MESSAGE="Hello World"
          echo $MY_MESSAGE
          EOF

edited Aug 13, 2020 at 8:24

answered Aug 13, 2020 at 7:48

Marcin

241k16 gold badges315 silver badges368 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

aws cloudformation userdata: how to use local variable in script

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related