Injecting environment_vars does not work when overriding execute_command

[tobiassoppa]

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Overview of the Issue

When executing a shell with admin rights and overwriting the execute_command to do so, the defined environment_vars are no longer getting injected into the shell, even though {{ .Vars }} are passed.

Reproduction Steps

Execute packer build . in a directory in which a Packer file similar to the simplified one below is present, together with the provided shell script.

Packer version

$ packer version
Packer v1.9.4

Simplified Packer Template

#!/bin/bash

# ./scripts/hello_world.sh

if [ "$(id -u)" -ne 0 ]; then
    echo "Must run as root"
    exit 1
fi

echo "Hello, $WORLD!"

# Expected output: Hello, World!
# Actual output: Hello, !

packer {
  required_plugins {
    amazon = {
      source  = "github.com/hashicorp/amazon"
      version = "~> 1"
    }
  }
}

source "amazon-ebs" "example" {
  ami_name      = "ami_which_uses_amazon_linux_2"
  instance_type = "t2.micro"
  region        = "us-west-2"
  source_ami_filter {
    filters = {
      "tag_key" = "unique_tag_value"
    }
    most_recent = true
    owners      = ["self"]
  }
  ssh_interface        = "session_manager"
  iam_instance_profile = "a_profile_that_we_use"
  ssh_username         = "ec2-user"
}

build {
  name = "packer-example"
  sources = [
    "source.amazon-ebs.example"
  ]

  provisioner "shell" {
    environment_vars  = [
        "WORLD=World"
    ]
    script            = "./scripts/hello_world.sh"
    execute_command   = "{{ .Vars }} sudo bash {{ .Path }}"
  }
}

Operating system and Environment details

OSX Sonoma 14.1

$ aws --version
aws-cli/2.11.6 Python/3.11.2 Darwin/23.1.0 exe/x86_64 prompt/off

$ session-manager-plugin --version                                       
1.2.497.0

[nywilken]

Hi @tobiassoppa it looks like you are passing in the environment variables but they are being set before you sudo so the root user will not see the environment variables. What you want to do is update the execute_command so that the sudo user is the one setting the environment variables.

    execute_command   = "sudo {{ .Vars }}  bash {{ .Path }}"

I believe the script has the executable flag set after it gets uploaded so you can make the execute_command a bit clearer by updating it to

    execute_command   = "sudo bash -c '{{ .Vars }} {{ .Path }}'"

I'm going to close this issue as it appears to be a user configuration issue. If you find that you are still running into issues after making the update or believe that this is still a bug please feel free to drop a comment.

[github-actions]

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