CODEWITHSUNDEEP
amazon-web-servicesaws-cloudformation
shantanuo
shantanuo

Reputation: 32316

Change variables in user data

Here is a cloudformation template that works as expected.

https://github.com/shantanuo/cloudformation/blob/master/updated/so2.tpl.txt

But when I change the last line to something like this...

/home/ec2-user/mysecret.txt`'' --valid-ips  !Ref MyIpAddress >

It silently ignores the command. Is there any other way to substitute the MyIpAddress variable?

Upvotes: 1

Views: 365

Answers (2)

shantanuo
shantanuo

Reputation: 32316

I do not know how and why does it work. But this is what I was looking for.

              - >-
                /usr/local/bin/aws-ec2-assign-elastic-ip --access-key ''`cat
                /home/ec2-user/myaccesskey.txt`''  --secret-key ''`cat
                /home/ec2-user/mysecret.txt`'' --valid-ips '
              - !Ref MyIpAddress
              - |
                '

Thanks to Pat's comment!

Upvotes: 1

Haider Ali
Haider Ali

Reputation: 481

Instead of using 'Fn::Join' you can use 'Fn::Sub'. This will make your template more readable as won't have to break your script inot multiple lines and you can reference MyIpAddress as ${MyIpAddress}.

Upvotes: 1

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