2015-10-27 21:28:37 +01:00
|
|
|
---
|
|
|
|
layout: "docs"
|
|
|
|
page_title: "Provisioners: null_resource"
|
|
|
|
sidebar_current: "docs-provisioners-null-resource"
|
|
|
|
description: |-
|
|
|
|
The `null_resource` is a resource allows you to configure provisioners that
|
2019-03-21 21:31:00 +01:00
|
|
|
are not directly associated with a single existing resource.
|
2015-10-27 21:28:37 +01:00
|
|
|
---
|
|
|
|
|
|
|
|
# null\_resource
|
|
|
|
|
|
|
|
The `null_resource` is a resource that allows you to configure provisioners
|
|
|
|
that are not directly associated with a single existing resource.
|
|
|
|
|
|
|
|
A `null_resource` behaves exactly like any other resource, so you configure
|
|
|
|
[provisioners](/docs/provisioners/index.html), [connection
|
|
|
|
details](/docs/provisioners/connection.html), and other meta-parameters in the
|
|
|
|
same way you would on any other resource.
|
|
|
|
|
|
|
|
This allows fine-grained control over when provisioners run in the dependency
|
|
|
|
graph.
|
|
|
|
|
|
|
|
## Example usage
|
|
|
|
|
2017-04-05 17:29:27 +02:00
|
|
|
```hcl
|
2015-10-27 21:28:37 +01:00
|
|
|
resource "aws_instance" "cluster" {
|
|
|
|
count = 3
|
2017-02-18 23:48:50 +01:00
|
|
|
|
2017-04-05 17:29:27 +02:00
|
|
|
# ...
|
2015-10-27 21:28:37 +01:00
|
|
|
}
|
|
|
|
|
|
|
|
resource "null_resource" "cluster" {
|
|
|
|
# Changes to any instance of the cluster requires re-provisioning
|
|
|
|
triggers {
|
|
|
|
cluster_instance_ids = "${join(",", aws_instance.cluster.*.id)}"
|
|
|
|
}
|
|
|
|
|
|
|
|
# Bootstrap script can run on any instance of the cluster
|
|
|
|
# So we just choose the first in this case
|
|
|
|
connection {
|
|
|
|
host = "${element(aws_instance.cluster.*.public_ip, 0)}"
|
|
|
|
}
|
|
|
|
|
|
|
|
provisioner "remote-exec" {
|
2019-03-25 19:16:14 +01:00
|
|
|
# Bootstrap script called with private_ip of each node in the cluster
|
2015-10-27 21:28:37 +01:00
|
|
|
inline = [
|
2017-02-18 23:48:50 +01:00
|
|
|
"bootstrap-cluster.sh ${join(" ", aws_instance.cluster.*.private_ip)}",
|
2015-10-27 21:28:37 +01:00
|
|
|
]
|
|
|
|
}
|
|
|
|
}
|
|
|
|
```
|
|
|
|
|
|
|
|
## Argument Reference
|
|
|
|
|
|
|
|
In addition to all the resource configuration available, `null_resource` supports the following specific configuration options:
|
|
|
|
|
|
|
|
* `triggers` - A mapping of values which should trigger a rerun of this set of
|
|
|
|
provisioners. Values are meant to be interpolated references to variables or
|
|
|
|
attributes of other resources.
|