af3f78975e
The local-exec provisioner documentation includes an example which refers to an attribute of the current resource using its full traversal path, rather than using "self" as we typically expect. Due to some coincidences in how Terraform builds the dependency graph, referring to the resource in this way happens to work when the resource has only a single instance (the graph builder just skips that self-referential dependency edge), but it fails if the user later tries to add "count" or "for_each" to the resource, because at that point all of the instances become dependent on one another, which creates a dependency cycle. Using "self" to access the current instance attributes is the usual approach, so I've updated the documentation to show that.
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layout, page_title, sidebar_current, description
| layout | page_title | sidebar_current | description |
|---|---|---|---|
| language | Provisioner: local-exec | docs-provisioners-local | The `local-exec` provisioner invokes a local executable after a resource is created. This invokes a process on the machine running Terraform, not on the resource. See the `remote-exec` provisioner to run commands on the resource. |
local-exec Provisioner
The local-exec provisioner invokes a local executable after a resource is
created. This invokes a process on the machine running Terraform, not on the
resource. See the remote-exec
provisioner to run commands on the
resource.
Note that even though the resource will be fully created when the provisioner is
run, there is no guarantee that it will be in an operable state - for example
system services such as sshd may not be started yet on compute resources.
-> Note: Provisioners should only be used as a last resort. For most common situations there are better alternatives. For more information, see the main Provisioners page.
Example usage
resource "aws_instance" "web" {
# ...
provisioner "local-exec" {
command = "echo ${self.private_ip} >> private_ips.txt"
}
}
Argument Reference
The following arguments are supported:
-
command- (Required) This is the command to execute. It can be provided as a relative path to the current working directory or as an absolute path. It is evaluated in a shell, and can use environment variables or Terraform variables. -
working_dir- (Optional) If provided, specifies the working directory wherecommandwill be executed. It can be provided as as a relative path to the current working directory or as an absolute path. The directory must exist. -
interpreter- (Optional) If provided, this is a list of interpreter arguments used to execute the command. The first argument is the interpreter itself. It can be provided as a relative path to the current working directory or as an absolute path. The remaining arguments are appended prior to the command. This allows building command lines of the form "/bin/bash", "-c", "echo foo". Ifinterpreteris unspecified, sensible defaults will be chosen based on the system OS. -
environment- (Optional) block of key value pairs representing the environment of the executed command. inherits the current process environment.
Interpreter Examples
resource "null_resource" "example1" {
provisioner "local-exec" {
command = "open WFH, '>completed.txt' and print WFH scalar localtime"
interpreter = ["perl", "-e"]
}
}
resource "null_resource" "example2" {
provisioner "local-exec" {
command = "Get-Date > completed.txt"
interpreter = ["PowerShell", "-Command"]
}
}
resource "aws_instance" "web" {
# ...
provisioner "local-exec" {
command = "echo $FOO $BAR $BAZ >> env_vars.txt"
environment = {
FOO = "bar"
BAR = 1
BAZ = "true"
}
}
}