WEBVTT

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In this lecture,

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we will see the different ways
we can use provisioners in Terraform.

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In the previous lecture,

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the remote exec and the
local-exec provisioners we used,

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run tasks when a resource is created.

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This is the default behavior

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and is known as the
creation-time provisioner.

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Let's use the same example
of the local-exec provisioner

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that we used in the previous lecture.

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When applied,

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the provisioner will record the
public IP address of the webserver

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on the local machine.

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We can also make the provisioner run
before a resource is destroyed.

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This is called
a destroy-time provisioner.

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This can be specifically set

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by making use of the event argument

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as specifying its value as destroy,

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like this.

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Another default behavior
of a provisional block

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is to cause a Terraform apply to fail

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if the tasks specified in it
fails for any reason.

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For example,

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if the creation-time provisioner,
that we used earlier,

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makes use of an incorrect path
in the command,

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the default behavior would be

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for the Terraform apply to fail
with an error, like this.

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Here,

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there is no /temp directory
located in the local machine,

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and this results in a failure.

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The same behavior can be specified

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by adding an on_failure argument
in the provisional block

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with a value of fail,

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like this.

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This is the default value,

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so it's not really required
to be set.

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Please note, that when this happens,

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Terraform marks the resource
as tainted.

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We have a lecture on resource taint
in the following section.

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We may not always want
the apply step to fail

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if the provisioner fails.

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For example,

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let's say,
the provisioner script is optional

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and we don't care if it fails,

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we want the apply step
to ignore this error and proceed.

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To override the default behavior

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and for apply to go through
successfully,

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use the on_failure argument
with "continue" as the value.

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When we run Terraform apply now,

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the resource will be provisioned
successfully.

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Well, yhat brings us
to the end of this lecture.

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Head over to the Hands-On Labs

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and practice working
with Terraform provisioners.