website: outputs

website/source/intro/getting-started/outputs.html.md

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+---
+layout: "intro"
+page_title: "Output Variables"
+sidebar_current: "gettingstarted-outputs"
+---
+
+# Output Variables
+
+In the previous section, we introduced input variables as a way
+to parameterize Terraform configurations. In this page, we
+introduce output variables as a way to organize data to be
+easily queried and shown back to the Terraform user.
+
+When building potentially complex infrastructure, Terraform
+stores hundreds or thousands of attribute values for all your
+resources. But as a user of Terraform, you may only be interested
+in a few values of importance, such as a load balancer IP,
+VPN address, etc.
+
+Outputs are a way to tell Terraform what data is important.
+This data is outputted when `apply` is called, and can be
+queried using the `terraform output` command.
+
+## Defining Outputs
+
+Let's define an output to show us the public IP address of the
+elastic IP address that we create. Add this to any of your
+`*.tf` files:
+
+```
+output "ip" {
+	value = "${aws_eip.ip.public_ip}"
+}
+```
+
+This defines an output variables named "ip". The `value` field
+specifies what the value will be, and almost always contains
+one or more interpolations, since the output data is typically
+dynamic in some form. In this case, we're outputting the
+`public_ip` attribute of the elastic IP address.
+
+Multiple `output` blocks can be defined to specify multiple
+output variables.
+
+## Viewing Outputs
+
+Run `terraform apply` to populate the output. This only needs
+to be done once after the output is defined. The apply output
+should change slightly. At the end you should see this:
+
+```
+$ terraform apply
+...
+
+Apply complete! Resources: 0 added, 0 changed, 0 destroyed.
+
+Outputs:
+
+  ip = 50.17.232.209
+```
+
+`apply` highlights the outputs. You can also query the outputs
+after apply-time using `terraform output`:
+
+```
+$ terraform output ip
+50.17.232.209
+```
+
+This command is useful for scripts to extract outputs.
+
+## Next
+
+You now know how to parameterize configurations with input
+variables, and extract important data using output variables.
+
+Next, we're going to use provisioners to install some software
+on the instances created on top of the base AMI used.