Comment for_each à travers une liste (d'objets) dans Terraform 0.12

Question

Je dois déployer une liste d'instances de calcul GCP. Comment puis-je boucler for_each à travers les "vms" dans une liste d'objets comme ceci :

    "gcp_zone": "us-central1-a",
    "image_name": "centos-cloud/centos-7",
    "vms": [
      {
        "hostname": "test1-srfe",
        "cpu": 1,
        "ram": 4,
        "hdd": 15,
        "log_drive": 300,
        "template": "Template-New",
        "service_types": [
          "sql",
          "db01",
          "db02"
        ]
      },
      {
        "hostname": "test1-second",
        "cpu": 1,
        "ram": 4,
        "hdd": 15,
        "template": "APPs-Template",
        "service_types": [
          "configs"
        ]
      }
    ]    
}

Answer 1

On dirait que j'ai trouvé ce qu'il faut faire. Si vous passez non pas les cartes des cartes mais la liste des cartes, vous pouvez utiliser ce code

resource "google_compute_instance" "node" {
    for_each = {for vm in var.vms:  vm.hostname => vm}

    name         = "${each.value.hostname}"
    machine_type = "custom-${each.value.cpu}-${each.value.ram*1024}"
    zone         = "${var.gcp_zone}"

    boot_disk {
        initialize_params {
        image = "${var.image_name}"
        size = "${each.value.hdd}"
        }
    }

    network_interface {
        network = "${var.network}"
    }

    metadata = {
        env_id = "${var.env_id}"
        service_types = "${join(",",each.value.service_types)}"
  }
}

Il créera le nombre réel d'instances et lorsque vous supprimez par exemple celle du milieu sur trois (si vous en créez trois :)), terraform supprimera ce que nous avons demandé.

Answer 2

À partir de Terraform 0.12, vous pouvez utiliser le for_each avec des modules comme les suivants :

modules/google_compute_instance/variables.tf

variable "hosts" {
    type = map(object({
        hostname        = string
        cpu             = number
        ram             = number
        hdd             = number
        log_drive       = number
        template        = string 
        service_types   = list(string)
      }))
    }

modules/google_compute_instance/main.tf

resource "google_compute_instance" "gcp_instance" {
  for_each = var.hosts

  hostname      = each.value.repository_name
  cpu           = each.value.cpu
  ram           = each.value.ram
  hdd           = each.value.hdd
  log_drive     = each.value.log_drive
  template      = each.value.template
  service_types = each.value.service_types
}

serveurs.tf

module "gcp_instances" {
    source = ./modules/google_compute_instance"

    hosts = {
        "test1-srfe" = {
            hostname        = "test1-srfe",
            cpu             = 1,
            ram             = 4,
            hdd             = 15,
            log_drive       = 300,
            template        = "Template-New",
            service_types   = ["sql", "db01", "db02"]
        },
        "test1-second" = {
            hostname        = "test1-second",
            cpu             = 1,
            ram             = 4,
            hdd             = 15,
            log_drive       = 300,
            template        = "APPs-Template",
            service_types   = ["configs"]
        },
    }
}

Bien entendu, vous pouvez ajouter autant de variables que nécessaire et les utiliser dans le module.

Answer 3

Utilisation de la for_each Le bloc est assez récent et il n'y a pas beaucoup de documentation. Certaines des meilleures informations proviennent de l'article du blogue d'annonce : https://www.hashicorp.com/blog/hashicorp-terraform-0-12-preview-for-and-for-each/

Veillez également à consulter la section Blocs dynamiques de leur documentation : https://www.terraform.io/docs/configuration/expressions.html#dynamic-blocks

D'après votre exemple, vous devez disposer d'un ensemble de valeurs pour chaque instance créée, de sorte que vous aurez une carte de cartes :

Vous trouverez ci-dessous un exemple que j'ai créé en utilisant Terraform 0.12.12 :

variable "hostnames" {
    default = {
        "one" = {
            "name" = "one",
            "machine" = "n1-standard-1",
            "os" = "projects/coreos-cloud/global/images/coreos-stable-2247-5-0-v20191016",
            "zone" = "us-central1-a"
        },
        "two" = {
            "name" = "two",
            "machine" = "n1-standard-2",
            "os" = "projects/centos-cloud/global/images/centos-8-v20191018",
            "zone" = "us-central1-b"
        }
    }
}

resource "google_compute_instance" "default" {
    for_each = var.hostnames
    name         = each.value.name
    machine_type = each.value.machine
    zone         = each.value.zone

    boot_disk {
        initialize_params {
            image = each.value.os
        }
    }

    scratch_disk {
    }

    network_interface {
        network = "default"
    }
}

Sortie du plan Terraform :

Terraform will perform the following actions:

  # google_compute_instance.default["one"] will be created
  + resource "google_compute_instance" "default" {
      + can_ip_forward       = false
      + cpu_platform         = (known after apply)
      + deletion_protection  = false
      + guest_accelerator    = (known after apply)
      + id                   = (known after apply)
      + instance_id          = (known after apply)
      + label_fingerprint    = (known after apply)
      + machine_type         = "n1-standard-1"
      + metadata_fingerprint = (known after apply)
      + name                 = "one"
      + project              = (known after apply)
      + self_link            = (known after apply)
      + tags_fingerprint     = (known after apply)
      + zone                 = "us-central1-a"

      + boot_disk {
          + auto_delete                = true
          + device_name                = (known after apply)
          + disk_encryption_key_sha256 = (known after apply)
          + kms_key_self_link          = (known after apply)
          + mode                       = "READ_WRITE"
          + source                     = (known after apply)

          + initialize_params {
              + image  = "projects/coreos-cloud/global/images/coreos-stable-2247-5-0-v20191016"
              + labels = (known after apply)
              + size   = (known after apply)
              + type   = (known after apply)
            }
        }

      + network_interface {
          + address            = (known after apply)
          + name               = (known after apply)
          + network            = "default"
          + network_ip         = (known after apply)
          + subnetwork         = (known after apply)
          + subnetwork_project = (known after apply)
        }

      + scheduling {
          + automatic_restart   = (known after apply)
          + on_host_maintenance = (known after apply)
          + preemptible         = (known after apply)

          + node_affinities {
              + key      = (known after apply)
              + operator = (known after apply)
              + values   = (known after apply)
            }
        }

      + scratch_disk {
          + interface = "SCSI"
        }
    }

  # google_compute_instance.default["two"] will be created
  + resource "google_compute_instance" "default" {
      + can_ip_forward       = false
      + cpu_platform         = (known after apply)
      + deletion_protection  = false
      + guest_accelerator    = (known after apply)
      + id                   = (known after apply)
      + instance_id          = (known after apply)
      + label_fingerprint    = (known after apply)
      + machine_type         = "n1-standard-2"
      + metadata_fingerprint = (known after apply)
      + name                 = "two"
      + project              = (known after apply)
      + self_link            = (known after apply)
      + tags_fingerprint     = (known after apply)
      + zone                 = "us-central1-b"

      + boot_disk {
          + auto_delete                = true
          + device_name                = (known after apply)
          + disk_encryption_key_sha256 = (known after apply)
          + kms_key_self_link          = (known after apply)
          + mode                       = "READ_WRITE"
          + source                     = (known after apply)

          + initialize_params {
              + image  = "projects/centos-cloud/global/images/centos-8-v20191018"
              + labels = (known after apply)
              + size   = (known after apply)
              + type   = (known after apply)
            }
        }

      + network_interface {
          + address            = (known after apply)
          + name               = (known after apply)
          + network            = "default"
          + network_ip         = (known after apply)
          + subnetwork         = (known after apply)
          + subnetwork_project = (known after apply)
        }

      + scheduling {
          + automatic_restart   = (known after apply)
          + on_host_maintenance = (known after apply)
          + preemptible         = (known after apply)

          + node_affinities {
              + key      = (known after apply)
              + operator = (known after apply)
              + values   = (known after apply)
            }
        }

      + scratch_disk {
          + interface = "SCSI"
        }
    }

Plan: 2 to add, 0 to change, 0 to destroy.

Answer 4

Vous pouvez procéder comme suit :

for_each = toset(keys({for i, r in var.vms:  i => r}))
cpu = var.vms[each.value]["cpu"]

En supposant que vous ayez les éléments suivants :

variable "vms" {
    type = list(object({
        hostname        = string
        cpu             = number
        ram             = number
        hdd             = number
        log_drive       = number
        template        = string 
        service_types   = list(string)
    }))
    default = [
        {
            cpu: 1
            ...
        }
    ]
}

Answer 5

Je travaille beaucoup avec des listes de chaînes de caractères et des listes d'objets dans Terraform. Cela m'a toujours donné des maux de tête. J'ai donc identifié deux des modèles les plus courants, à savoir une liste de chaînes de caractères et une liste d'objets. Pour une liste de chaînes de caractères, vous pouvez toujours utiliser toset() et de boucler dessus avec for_each . Lorsque vous travaillez avec une liste d'objets, vous devez la convertir en une carte où la clé est une valeur unique. Pour cette valeur unique, vous pouvez utiliser un index, un hachage ou simplement une valeur unique pour tous les objets de la liste.

Liste des cordes :

locals {
  ip_addresses = ["10.0.0.1", "10.0.0.2"]
}

resource "example" "example" {
  for_each   = toset(local.ip_addresses)
  ip_address = each.key
}

Liste d'objets :

locals {
  virtual_machines = [
    {
      ip_address = "10.0.0.1"
      name       = "vm-1"
    },
    {
      ip_address = "10.0.0.1"
      name       = "vm-1"
    }
  ]
}    

resource "example" "example" {
  for_each   = {
    for index, vm in local.virtual_machines:
    index => vm
    # OR: vm.name => vm (not always unique if names are the same)
    # OR: sha1(vm.name) vm => (not always unique if names are the same)
    # NOT: uuid() => vm (gets recreated everytime)
  }
  name       = each.value.name
  ip_address = each.value.ip_address
}