github.com/pdecat/terraform@v0.11.9-beta1/website/docs/configuration/outputs.html.md (about)

     1  ---
     2  layout: "docs"
     3  page_title: "Configuring Outputs"
     4  sidebar_current: "docs-config-outputs"
     5  description: |-
     6    Outputs define values that will be highlighted to the user when Terraform applies, and can be queried easily using the output command. Output usage is covered in more detail in the getting started guide. This page covers configuration syntax for outputs.
     7  ---
     8  
     9  # Output Configuration
    10  
    11  Outputs define values that will be highlighted to the user
    12  when Terraform applies, and can be queried easily using the
    13  [output command](/docs/commands/output.html). Output usage
    14  is covered in more detail in the
    15  [getting started guide](/intro/getting-started/outputs.html).
    16  This page covers configuration syntax for outputs.
    17  
    18  Terraform knows a lot about the infrastructure it manages.
    19  Most resources have attributes associated with them, and
    20  outputs are a way to easily extract and query that information.
    21  
    22  This page assumes you are familiar with the
    23  [configuration syntax](/docs/configuration/syntax.html)
    24  already.
    25  
    26  ## Example
    27  
    28  A simple output configuration looks like the following:
    29  
    30  ```hcl
    31  output "address" {
    32    value = "${aws_instance.db.public_dns}"
    33  }
    34  ```
    35  
    36  This will output a string value corresponding to the public
    37  DNS address of the Terraform-defined AWS instance named "db". It
    38  is possible to export complex data types like maps and lists as
    39  well:
    40  
    41  ```hcl
    42  output "addresses" {
    43    value = ["${aws_instance.web.*.public_dns}"]
    44  }
    45  ```
    46  
    47  ## Description
    48  
    49  The `output` block configures a single output variable. Multiple
    50  output variables can be configured with multiple output blocks.
    51  The `NAME` given to the output block is the name used to reference
    52  the output variable. It must conform to Terraform variable naming
    53  conventions if it is to be used as an input to other modules.
    54  
    55  Within the block (the `{ }`) is configuration for the output.
    56  These are the parameters that can be set:
    57  
    58  - `value` (required) - The value of the output. This can be a string, list, or
    59    map. This usually includes an interpolation since outputs that are static
    60    aren't usually useful.
    61  
    62  - `description` (optional) - A human-friendly description for the output. This
    63    is primarily for documentation for users using your Terraform configuration. A
    64    future version of Terraform will expose these descriptions as part of some
    65    Terraform CLI command.
    66  
    67  - `depends_on` (list of strings) - Explicit dependencies that this output has.
    68    These dependencies will be created before this output value is processed. The
    69    dependencies are in the format of `TYPE.NAME`, for example `aws_instance.web`.
    70  
    71  - `sensitive` (optional, boolean) - See below.
    72  
    73  ## Syntax
    74  
    75  The full syntax is:
    76  
    77  ```text
    78  output NAME {
    79    value = VALUE
    80  }
    81  ```
    82  
    83  ## Sensitive Outputs
    84  
    85  Outputs can be marked as containing sensitive material by setting the
    86  `sensitive` attribute to `true`, like this:
    87  
    88  ```hcl
    89  output "sensitive" {
    90    sensitive = true
    91    value     = VALUE
    92  }
    93  ```
    94  
    95  When outputs are displayed on-screen following a `terraform apply` or
    96  `terraform refresh`, sensitive outputs are redacted, with `<sensitive>`
    97  displayed in place of their value.
    98  
    99  ### Limitations of Sensitive Outputs
   100  
   101  - The values of sensitive outputs are still stored in the Terraform state, and
   102    available using the `terraform output` command, so cannot be relied on as a
   103    sole means of protecting values.
   104  
   105  - Sensitivity is not tracked internally, so if the output is interpolated in
   106    another module into a resource, the value will be displayed.