Output - Terragrunt — ContextQMD

Executing terragrunt stack output in a stack directory produces an aggregated output from all units within the stack:

bash

$ terragrunt stack output
service.output1 = "output1"
service.output2 = "output2"
db.output1 = "output1"
db.output2 = "output2"

Indexing outputs

To retrieve outputs for a specific unit, specify the unit name:

bash

$ terragrunt stack output project1_app1
project1_app1 = {
  complex = {
    delta     = 0.02
    id        = 2
    name      = "name1"
    timestamp = "2025-02-07T21:05:51Z"
  }
  complex_list = [{
    delta     = 0.02
    id        = 10
    name      = "name1"
    timestamp = "2025-02-07T21:05:51Z"
    }, {
    delta     = 0.03
    id        = 20
    name      = "name10"
    timestamp = "2025-02-07T21:05:51Z"
  }]
  custom_value1 = "value1"
  data          = "app1"
  list          = ["1", "2", "3"]
}

You can also retrieve a specific output from a unit:

bash

$ terragrunt stack output project1_app1.custom_value1
project1_app1.custom_value1 = "value1"

Output formats

Terragrunt provides multiple output formats for easier parsing and integration with other tools. The desired format can be specified using the --format CLI flag.

Format	Description
`default`	Format output as HCL.
`json`	Format output as JSON. This can be useful for integrations with other tools.
`raw`	Format output as a simple raw string. Useful for integration into bash scripts.

To retrieve outputs in structured JSON format:

bash

$ terragrunt stack output --format json project1_app2
{
  "project1_app2": {
    "complex": {
      "delta": 0.02,
      "id": 2,
      "name": "name2",
      "timestamp": "2025-02-07T21:05:51Z"
    },
    "complex_list": [
      {
        "delta": 0.02,
        "id": 2,
        "name": "name2",
        "timestamp": "2025-02-07T21:05:51Z"
      },
      {
        "delta": 0.03,
        "id": 2,
        "name": "name3",
        "timestamp": "2025-02-07T21:05:51Z"
      }
    ],
    "custom_value2": "value2",
    "data": "app2",
    "list": [
      "a",
      "b",
      "c"
    ]
  }
}

json format

Accessing a specific list inside JSON format:

bash

$ terragrunt stack output --format json project1_app2.complex_list
{
  "project1_app2.complex_list": [
    {
      "delta": 0.02,
      "id": 2,
      "name": "name2",
      "timestamp": "2025-02-07T21:05:51Z"
    },
    {
      "delta": 0.03,
      "id": 2,
      "name": "name3",
      "timestamp": "2025-02-07T21:05:51Z"
    }
  ]
}

raw format

The raw format returns outputs as plain values without additional structure. When accessing lists or structured outputs, indexes are required to extract values.

Retrieving a simple value:

bash

$ terragrunt stack output --format raw project1_app2.data
app2