Terraform templatefile

Question

The code below is working. I would like the template content to be in a separate file and not within main.tf. I tried using the templatefile method but without success. At the end I show what I tried. Maybe it's the way I set up the metric_info variable, or it's necessary to reformulate the template after I implement the templatefile function.

main.tf:

locals {
  # Base variables 
  base_vars = yamldecode(file("env/${var.working_env}/vars.yaml")) # TF_VAR_working_env

  # Metrics subfolder names
  metrics = distinct([
    for dir_path in fileset("../metrics-table/", "*/*/") :
    basename(dirname(dir_path))
  ])

  # Metrics configuration 
  metrics_config = flatten([
    for subfolder in local.metrics :
    [
      for file in fileset("../metrics-table/${subfolder}", "metrics.yaml") :
      merge(yamldecode(file("../metrics-table/${subfolder}/${file}")), { subfolder = subfolder })
    ]
  ])

  # Metrics info
  metric_info = [
    {
      metrics = merge([
        for metric_config in local.metrics_config :
        {
          for metric_name, metric_data in metric_config.metrics :
          metric_name => {
            name          = metric_data.name
            metric_table  = metric_config.metric_table
            numerator     = metric_data.numerator
            denominator   = metric_data.denominator
          }
        }
        ]...)
    }
  ]

}

#  TEMPLATE ALL_METRICS.SQL

data "template_file" "all_metrics_sql" {
  template = <<EOT
# Parte 1 do arquivo SQL
-- BEGIN Parte 1 do arquivo SQL
WITH
%{ for metric_info in local.metric_info }
  %{ for metric_name, metric_data in metric_info.metrics }
    ${metric_name} AS (
      SELECT
        date,
        '${metric_name}' AS metric_name,
        experiment,
        alternative,
        context_id,
        control,
        CASE
          WHEN version IS NULL THEN 'v1'
          ELSE version
        END AS version,
        device_group,
        platform,
        SUM(${metric_data.denominator}) AS denominator,
        SUM(${metric_data.numerator}) AS numerator,
        SAFE_DIVIDE(SUM(${metric_data.numerator}), SUM(${metric_data.denominator})) AS metric_value
      FROM `${local.base_vars.project}.ab_experiment_metrics.${metric_data.metric_table}`
      WHERE outlier = FALSE
      GROUP BY
        date,
        experiment,
        alternative,
        context_id,
        control,
        version,
        device_group,
        platform,
        metric_name
    ),
      
  %{ endfor }
%{ endfor }

-- END Parte 1 do arquivo SQL

# Parte 2 do arquivo SQL
-- BEGIN Parte 2 do arquivo SQL
all_metrics AS (
    SELECT * FROM conversion_rate
    %{ for metric_info in local.metric_info }
        %{ for metric_name, _ in metric_info.metrics }
            UNION ALL
            SELECT * FROM ${metric_name}
        %{ endfor }
    %{ endfor }
),
all_metrics_final as
(
    SELECT
        date,
        metric_name,
        all_metrics.experiment,
        alternative,
        control,
        version,
        device_group,
        platform,
        denominator,
        SUM(denominator) OVER (PARTITION BY metric_name, all_metrics.experiment, alternative, version, device_group, platform ORDER BY date ASC ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS denominator_cumsum,
        numerator,
        SUM(numerator) OVER (PARTITION BY metric_name, all_metrics.experiment, alternative, version, device_group, platform ORDER BY date ASC ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS numerator_cumsum,
        metric_value
    FROM all_metrics
)

SELECT *
FROM all_metrics_final
-- END Parte 2 do arquivo SQL
EOT
}

# CREATE ALL_METRICS.SQL

resource "local_file" "all_metrics_sql" {
  filename = "all_metrics.sql"
  content  = data.template_file.all_metrics_sql.rendered
}



#   OUTPUTS
output "metrics_config" {
  value = local.metrics_config
}

output "metric_info" {
  value = local.metric_info
}

output "all_metrics_sql_content" {
  value = data.template_file.all_metrics_sql.rendered
}

Changes to Outputs:
  + metric_info    = [
      + {
          + metrics = {
              + time_to_first_play_per_login    = {
                  + denominator  = "experiment_login_count"
                  + metric_table = "time_to_first_play"
                  + name         = "time_to_first_play_per_login"
                  + numerator    = "total_time_to_first_play"
                }
              + time_to_first_play_per_session  = {
                  + denominator  = "experiment_session_count"
                  + metric_table = "time_to_first_play"
                  + name         = "time_to_first_play_per_session"
                  + numerator    = "total_time_to_first_play"
                }
              + time_to_first_play_per_user     = {
                  + denominator  = "experiment_user_count"
                  + metric_table = "time_to_first_play"
                  + name         = "time_to_first_play_per_user"
                  + numerator    = "total_time_to_first_play"
                }
              + time_to_second_play_per_creator = {
                  + denominator  = "experiment_user_count"
                  + metric_table = "time_to_second_play"
                  + name         = "time_to_second_play_per_user"
                  + numerator    = "total_time_to_second_play"
                }
              + time_to_second_play_per_login   = {
                  + denominator  = "experiment_user_count"
                  + metric_table = "time_to_second_play"
                  + name         = "time_to_second_play_per_user"
                  + numerator    = "total_time_to_second_play"
                }
              + time_to_second_play_per_name    = {
                  + denominator  = "experiment_session_count"
                  + metric_table = "time_to_second_play"
                  + name         = "time_to_second_play_per_session"
                  + numerator    = "total_time_to_second_play"
                }
            }
        },
    ]
  + metrics_config = [
      + {
          + metric_table = "time_to_first_play"
          + metrics      = {
              + time_to_first_play_per_login   = {
                  + active         = 1
                  + category       = "Métrica de vídeo"
                  + denominator    = "experiment_login_count"
                  + description    = "Tempo médio que cada usuário leva para dar o primeiro play em algum vídeo"
                  + metric_title   = "Tempo para o Primeiro Play por Usuário"
                  + metric_type_id = 2
                  + name           = "time_to_first_play_per_login"
                  + numerator      = "total_time_to_first_play"
                }
              + time_to_first_play_per_session = {
                  + active         = 1
                  + category       = "Métrica de vídeo"
                  + denominator    = "experiment_session_count"
                  + description    = "Tempo médio que cada sessão leva para dar o primeiro play em algum vídeo"
                  + metric_title   = "Tempo para o Primeiro Play por Sessão"
                  + metric_type_id = 2
                  + name           = "time_to_first_play_per_session"
                  + numerator      = "total_time_to_first_play"
                }
              + time_to_first_play_per_user    = {
                  + active         = 1
                  + category       = "Métrica de vídeo"
                  + denominator    = "experiment_user_count"
                  + description    = "Tempo médio que cada usuário leva para dar o primeiro play em algum vídeo"
                  + metric_title   = "Tempo para o Primeiro Play por Usuário"
                  + metric_type_id = 2
                  + name           = "time_to_first_play_per_user"
                  + numerator      = "total_time_to_first_play"
                }
            }
          + subfolder    = "time_to_first_play"
        },
      + {
          + metric_table = "time_to_second_play"
          + metrics      = {
              + time_to_second_play_per_creator = {
                  + active         = 1
                  + category       = "Métrica de vídeo"
                  + denominator    = "experiment_user_count"
                  + description    = "Tempo médio que cada usuário leva para dar o primeiro play em algum vídeo"
                  + metric_title   = "Tempo para o Primeiro Play por Usuário"
                  + metric_type_id = 2
                  + name           = "time_to_second_play_per_user"
                  + numerator      = "total_time_to_second_play"
                }
              + time_to_second_play_per_login   = {
                  + active         = 1
                  + category       = "Métrica de vídeo"
                  + denominator    = "experiment_user_count"
                  + description    = "Tempo médio que cada usuário leva para dar o primeiro play em algum vídeo"
                  + metric_title   = "Tempo para o Primeiro Play por Usuário"
                  + metric_type_id = 2
                  + name           = "time_to_second_play_per_user"
                  + numerator      = "total_time_to_second_play"
                }
              + time_to_second_play_per_name    = {
                  + active         = 1
                  + category       = "Métrica de vídeo"
                  + denominator    = "experiment_session_count"
                  + description    = "Tempo médio que cada sessão leva para dar o primeiro play em algum vídeo"
                  + metric_title   = "Tempo para o Primeiro Play por Sessão"
                  + metric_type_id = 2
                  + name           = "time_to_second_play_per_session"
                  + numerator      = "total_time_to_second_play"
                }
            }
          + subfolder    = "time_to_second_play"
        },
    ]

I tried to use the method below but return erros.

data "template_file" "all_metrics_sql" {
  template = templatefile("${path.module}/template.tftpl", {
    metric_info = local.metric_info.metrics
  })
}

╷
│ Error: Not enough function arguments
│ 
│   on main.tf line 69, in data "template_file" "all_metrics_sql":
│   69:   template = templatefile("arquivo_template.tpl")
│ 
│ Function "templatefile" expects 2 argument(s). Missing value for
│ "vars".
╵
╷
│ Error: Unsupported attribute
│ 
│   on main.tf line 72, in data "template_file" "all_metrics_sql":
│   72:     metric_info = local.metric_info.metrics
│     ├────────────────
│     │ local.metric_info is tuple with 1 element
│ 
│ This value does not have any attributes.

Answer 1

You are using both the deprecated template_file data source and the templatefile function at the same time. These both perform the same operation, so it is incorrect to use them together.

You can use the templatefile function alone. You should never need to use the template_file data source in modern Terraform; it exists to support very old versions of Terraform that didn't have the templatefile function yet.

resource "local_file" "all_metrics_sql" {
  filename = "all_metrics.sql"
  content = templatefile("${path.module}/template.tftpl", {
    metric_info = local.metric_info.metrics
  })
}

The above assigns the result of template rendering directly to a resource argument, which is a concise way to write it when you only need the template result in one part of your configuration. If you want to reuse that template result in multiple locations then you can optionally assign its result to a local value:

locals {
  all_metrics_sql = templatefile("${path.module}/template.tftpl", {
    metric_info = local.metric_info.metrics
  })
}

resource "local_file" "all_metrics_sql" {
  filename = "all_metrics.sql"
  content  = local.all_metrics_sql
}