Terraform不支持shell括号中的变量？

Question

I am using Terraform v0.13.1. I am trying to use provisioner local-exec to run some shell commands on an EC2 instance:

provisioner "local-exec" {
  command = <<EOF
    AWS_PROFILE=test ssh centos@<EC2 instance ID> "filename=test && touch \$filename && mv \$filename \$\{filename//t/a\}"
    EOF
}

I got the following error message after running terraform apply:

null_resource.test (local-exec): Executing: ["/bin/sh" "-c" "      AWS_PROFILE=test ssh centos@<instance ID> \"filename=test && touch \\$filename && mv \\$filename \\$\\{filename//t/a\\}\"\n"]
null_resource.test (local-exec): mv: cannot move 'test' to '${filename//t/a}' : No such file or directory


Error: Error running command '      AWS_PROFILE=test ssh centos@<instance ID> "filename=test && touch \$filename && mv \$filename \$\{filename//t/a\}"
': exit status 1. Output: mv: cannot move 'test' to '${filename//t/a}' : No such file or directory

It looks like Terraform was able to parse $filename variable after adding escape to the dollar sign. However, shell variables in brackets (${filename}) are not parsed properly in my case even though I added escape to the dollar sign.

I also tried $$ and %${ but neither worked. I am lost on this. Can someone please advise whether this is supported in Terraform and what I did wrong?

Answer 1

The below code worked for me:

provisioner "local-exec" {
    interpreter = ["/bin/bash", "-c"]
    command = <<EOF
        AWS_PROFILE=test ssh centos@<instance ID> "filename=test && touch \$filename && mv \$filename \$${filename//t/a}"
      EOF
    }

Basically need to double up the initial marker and escape dollar signs.