How to use dependency's output

[ares-b]

I have two terraform modules :

• docker_server: provisions a VM on Oracle Cloud and configures docker on it
• docker_service: needs to take the provisioned VM ip to provision container on it using ssh

I'm also managing multiple Oracle Cloud Account (Provisioned VMs are within the always free tier).

Here's my directory hierarchy :

└── terraform
    └── docker_servers
        └── account_1
            └── docker_server.yaml
            └── terragrunt.hcl
        └── account_2
            └── docker_server.yaml
            └── terragrunt.hcl
        └── terragrunt.hcl
        └── common.hcl
    └── docker_services
        └── influxdb
            └── docker_service.yaml
            └── terragrunt.hcl
        └── terragrunt.hcl
        └── common.hcl
    └── modules
        └── docker_server
        └── docker_service

On docker_services/common.hcl I have the following dependency to docker_servers:

dependency "docker_server" {
    config_path = "${get_terragrunt_dir()}/../../docker_servers/${local.docker_service.server}"
}

When I run terragrunt run-all plan I get this error :

* /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_servers/account_1/terragrunt.hcl is a dependency of /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_services/influxdb/terragrunt.hcl but detected no outputs. Either the target module has not been applied yet, or the module has no outputs. If this is expected, set the skip_outputs flag to true on the dependency block.

And When I add the following to the dependency:

mock_outputs = {
        ip          = "127.0.0.1"
        privatekey  = "not so private"
    }

It tries to ping the docker server, so I get this error:

│ Error: Error pinging Docker server: error during connect: Get "http://docker.example.com/_ping": command [ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -i not so private -- 127.0.0.1 docker system dial-stdio] has exited with exit status 255, please make sure the URL is valid, and Docker 18.09 or later is installed on the remote host: stderr=Warning: Identity file not so private not accessible: No such file or directory.
│ ssh: connect to host 127.0.0.1 port 22: Connection refused
│ 
│ 
│   with provider["registry.terraform.io/kreuzwerker/docker"],
│   on provider.tf line 11, in provider "docker":
│   11: provider "docker" {
│ 
╵

Is there any way to achieve what I'm trying to do ?

Do I need to have something that orchestrate the order in which terragrunt executes my modules ? Like something that tells him run what's in docker_servers and then what's in docker_services.

[denis256]

Hi,

Without the source code, troubleshooting is challenging, but here are a few suggestions:

1. The error message "the module has no outputs" indicates that the module may not have "output" variables or the output variables might have different names than expected.
2. Check the log messages of run-all plan; it should display the paths to applied dependencies and the order in which they were applied.
3. Based on your description, I created a sample repository at https://github.com/denis256/terragrunt-tests/tree/master/discussion-834. This repository has a similar structure and works fine with run-all.
4. If there are no explicit dependencies between modules, you can use the dependencies block to specify explicit dependencies.

https://terragrunt.gruntwork.io/docs/reference/config-blocks-and-attributes/#dependency

https://terragrunt.gruntwork.io/docs/reference/config-blocks-and-attributes/#dependencies

[ares-b]

Hi,

You're right, it's kinda hard to help me without the code :D I've just uploaded it in this repository: https://github.com/ares-b/terragrunt_oracle.

The error message "the module has no outputs" indicates that the module may not have "output" variables or the output variables might have different names than expected.

Correct me If I'm wrong but terraform and terragrunt get output data from the terraform state. So what would happen if I run run-all plan on the top-level directory while the state is non-existant ?

If there are no explicit dependencies between modules, you can use the dependencies block to specify explicit dependencies.

In fact, there's explicit dependencies, docker_services must wait until docker_servers are provisioned, so they can use the IPs fixed by oracle to know where to provision the docker services.

Here's the complete log of terragrunt run-all plan :

INFO[0000] The stack at /home/ares/dev/rust/profit_prophet/infrastructure/terraform will be processed in the following order for command plan:
Group 1
- Module /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_servers/account_1
- Module /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_servers/account_2

Group 2
- Module /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_services/influxdb
 
INFO[0000] Downloading Terraform configurations from file:///home/ares/dev/rust/profit_prophet/infrastructure/terraform/modules/docker_server into /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_servers/account_2/.terragrunt-cache/UC7g_mbIOJrup6MbVnTWMZtHSQg/wDv2CAJIERc6793miieXN-ahOEI  prefix=[/home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_servers/account_2] 
INFO[0000] Downloading Terraform configurations from file:///home/ares/dev/rust/profit_prophet/infrastructure/terraform/modules/docker_server into /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_servers/account_1/.terragrunt-cache/FB6PXWmS5hbIpIw_-Vf5vQwqLi8/wDv2CAJIERc6793miieXN-ahOEI  prefix=[/home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_servers/account_1] 

Initializing the backend...

Initializing the backend...
Initializing modules...
Initializing modules...
- oracle_alwaysfree in oracle_alwaysfree
- oracle_alwaysfree in oracle_alwaysfree

Initializing provider plugins...
- Finding latest version of hashicorp/null...

Initializing provider plugins...
- Finding oracle/oci versions matching "5.46.0"...
- Finding latest version of hashicorp/tls...
- Finding latest version of hashicorp/null...
- Finding oracle/oci versions matching "5.46.0"...
- Finding latest version of hashicorp/tls...
- Installing hashicorp/null v3.2.2...
- Installing hashicorp/null v3.2.2...
- Installed hashicorp/null v3.2.2 (signed by HashiCorp)
- Installing hashicorp/tls v4.0.5...
- Installed hashicorp/null v3.2.2 (signed by HashiCorp)
- Installing hashicorp/tls v4.0.5...
- Installed hashicorp/tls v4.0.5 (signed by HashiCorp)
- Installed hashicorp/tls v4.0.5 (signed by HashiCorp)
- Installing oracle/oci v5.46.0...
- Installing oracle/oci v5.46.0...
- Installed oracle/oci v5.46.0 (signed by a HashiCorp partner, key ID 1533A49284137CEB)

Partner and community providers are signed by their developers.
If you'd like to know more about provider signing, you can read about it here:
https://www.terraform.io/docs/cli/plugins/signing.html

Terraform has created a lock file .terraform.lock.hcl to record the provider
selections it made above. Include this file in your version control repository
so that Terraform can guarantee to make the same selections by default when
you run "terraform init" in the future.

Terraform has been successfully initialized!

You may now begin working with Terraform. Try running "terraform plan" to see
any changes that are required for your infrastructure. All Terraform commands
should now work.

If you ever set or change modules or backend configuration for Terraform,
rerun this command to reinitialize your working directory. If you forget, other
commands will detect it and remind you to do so if necessary.

Terraform used the selected providers to generate the following execution
plan. Resource actions are indicated with the following symbols:
  + create
 <= read (data resources)

Terraform will perform the following actions:

  # null_resource.ansible_provisioner will be created
  + resource "null_resource" "ansible_provisioner" {
      + id = (known after apply)
    }

  # module.oracle_alwaysfree.data.oci_core_images.ubuntu will be read during apply
  # (config refers to values not yet known)
 <= data "oci_core_images" "ubuntu" {
      + compartment_id           = (known after apply)
      + id                       = (known after apply)
      + images                   = (known after apply)
      + operating_system         = "Canonical Ubuntu"
      + operating_system_version = "22.04"
      + shape                    = "VM.Standard.A1.Flex"
    }

  # module.oracle_alwaysfree.data.oci_identity_availability_domains.ads will be read during apply
  # (config refers to values not yet known)
 <= data "oci_identity_availability_domains" "ads" {
      + availability_domains = (known after apply)
      + compartment_id       = (known after apply)
      + id                   = (known after apply)
    }

  # module.oracle_alwaysfree.oci_core_instance.alwaysfree_instance will be created
  + resource "oci_core_instance" "alwaysfree_instance" {
      + availability_domain                 = (known after apply)
      + boot_volume_id                      = (known after apply)
      + capacity_reservation_id             = (known after apply)
      + compartment_id                      = (known after apply)
      + compute_cluster_id                  = (known after apply)
      + dedicated_vm_host_id                = (known after apply)
      + defined_tags                        = (known after apply)
      + display_name                        = (known after apply)
      + extended_metadata                   = (known after apply)
      + fault_domain                        = (known after apply)
      + freeform_tags                       = (known after apply)
      + hostname_label                      = (known after apply)
      + id                                  = (known after apply)
      + image                               = (known after apply)
      + instance_configuration_id           = (known after apply)
      + ipxe_script                         = (known after apply)
      + is_cross_numa_node                  = (known after apply)
      + is_pv_encryption_in_transit_enabled = (known after apply)
      + launch_mode                         = (known after apply)
      + metadata                            = (known after apply)
      + private_ip                          = (known after apply)
      + public_ip                           = (known after apply)
      + region                              = (known after apply)
      + shape                               = "VM.Standard.A1.Flex"
      + state                               = (known after apply)
      + subnet_id                           = (known after apply)
      + system_tags                         = (known after apply)
      + time_created                        = (known after apply)
      + time_maintenance_reboot_due         = (known after apply)

      + create_vnic_details {
          + assign_ipv6ip          = (known after apply)
          + assign_public_ip       = "true"
          + defined_tags           = (known after apply)
          + display_name           = (known after apply)
          + freeform_tags          = (known after apply)
          + hostname_label         = (known after apply)
          + nsg_ids                = (known after apply)
          + private_ip             = (known after apply)
          + skip_source_dest_check = (known after apply)
          + subnet_id              = (known after apply)
          + vlan_id                = (known after apply)
        }

      + shape_config {
          + baseline_ocpu_utilization     = (known after apply)
          + gpu_description               = (known after apply)
          + gpus                          = (known after apply)
          + local_disk_description        = (known after apply)
          + local_disks                   = (known after apply)
          + local_disks_total_size_in_gbs = (known after apply)
          + max_vnic_attachments          = (known after apply)
          + memory_in_gbs                 = 24
          + networking_bandwidth_in_gbps  = (known after apply)
          + nvmes                         = (known after apply)
          + ocpus                         = 4
          + processor_description         = (known after apply)
          + vcpus                         = (known after apply)
        }

      + source_details {
          + boot_volume_size_in_gbs = "200"
          + boot_volume_vpus_per_gb = (known after apply)
          + source_id               = (known after apply)
          + source_type             = "image"
        }
    }

  # module.oracle_alwaysfree.oci_core_internet_gateway.alwaysfree_igw will be created
  + resource "oci_core_internet_gateway" "alwaysfree_igw" {
      + compartment_id = (known after apply)
      + defined_tags   = (known after apply)
      + display_name   = "alwaysfree_igw"
      + enabled        = true
      + freeform_tags  = (known after apply)
      + id             = (known after apply)
      + route_table_id = (known after apply)
      + state          = (known after apply)
      + time_created   = (known after apply)
      + vcn_id         = (known after apply)
    }

  # module.oracle_alwaysfree.oci_core_route_table.alwaysfree_route_table will be created
  + resource "oci_core_route_table" "alwaysfree_route_table" {
      + compartment_id = (known after apply)
      + defined_tags   = (known after apply)
      + display_name   = (known after apply)
      + freeform_tags  = (known after apply)
      + id             = (known after apply)
      + state          = (known after apply)
      + time_created   = (known after apply)
      + vcn_id         = (known after apply)

      + route_rules {
          + cidr_block        = (known after apply)
          + description       = (known after apply)
          + destination       = "0.0.0.0/0"
          + destination_type  = (known after apply)
          + network_entity_id = (known after apply)
          + route_type        = (known after apply)
        }
    }

  # module.oracle_alwaysfree.oci_core_security_list.alwaysfree_security_list will be created
  + resource "oci_core_security_list" "alwaysfree_security_list" {
      + compartment_id = (known after apply)
      + defined_tags   = (known after apply)
      + display_name   = "alwaysfree_security_list"
      + freeform_tags  = (known after apply)
      + id             = (known after apply)
      + state          = (known after apply)
      + time_created   = (known after apply)
      + vcn_id         = (known after apply)

      + egress_security_rules {
          + description      = (known after apply)
          + destination      = "0.0.0.0/0"
          + destination_type = (known after apply)
          + protocol         = "all"
          + stateless        = (known after apply)
        }

      + ingress_security_rules {
          + description = (known after apply)
          + protocol    = "6"
          + source      = "0.0.0.0/0"
          + source_type = (known after apply)
          + stateless   = false

          + tcp_options {
              + max = 22
              + min = 22
            }
        }
      + ingress_security_rules {
          + description = (known after apply)
          + protocol    = "6"
          + source      = "0.0.0.0/0"
          + source_type = (known after apply)
          + stateless   = false

          + tcp_options {
              + max = 8086
              + min = 8086
            }
        }
    }

  # module.oracle_alwaysfree.oci_core_subnet.alwaysfree_subnet will be created
  + resource "oci_core_subnet" "alwaysfree_subnet" {
      + availability_domain        = (known after apply)
      + cidr_block                 = "10.0.0.0/24"
      + compartment_id             = (known after apply)
      + defined_tags               = (known after apply)
      + dhcp_options_id            = (known after apply)
      + display_name               = "alwaysfree_subnet"
      + dns_label                  = (known after apply)
      + freeform_tags              = (known after apply)
      + id                         = (known after apply)
      + ipv6cidr_block             = (known after apply)
      + ipv6cidr_blocks            = (known after apply)
      + ipv6virtual_router_ip      = (known after apply)
      + prohibit_internet_ingress  = (known after apply)
      + prohibit_public_ip_on_vnic = false
      + route_table_id             = (known after apply)
      + security_list_ids          = (known after apply)
      + state                      = (known after apply)
      + subnet_domain_name         = (known after apply)
      + time_created               = (known after apply)
      + vcn_id                     = (known after apply)
      + virtual_router_ip          = (known after apply)
      + virtual_router_mac         = (known after apply)
    }

  # module.oracle_alwaysfree.oci_core_vcn.alwaysfree_vcn will be created
  + resource "oci_core_vcn" "alwaysfree_vcn" {
      + byoipv6cidr_blocks               = (known after apply)
      + cidr_block                       = "10.0.0.0/16"
      + cidr_blocks                      = (known after apply)
      + compartment_id                   = (known after apply)
      + default_dhcp_options_id          = (known after apply)
      + default_route_table_id           = (known after apply)
      + default_security_list_id         = (known after apply)
      + defined_tags                     = (known after apply)
      + display_name                     = "alwaysfree_vcn"
      + dns_label                        = (known after apply)
      + freeform_tags                    = (known after apply)
      + id                               = (known after apply)
      + ipv6cidr_blocks                  = (known after apply)
      + ipv6private_cidr_blocks          = (known after apply)
      + is_ipv6enabled                   = (known after apply)
      + is_oracle_gua_allocation_enabled = (known after apply)
      + state                            = (known after apply)
      + time_created                     = (known after apply)
      + vcn_domain_name                  = (known after apply)
    }

  # module.oracle_alwaysfree.oci_identity_compartment.alwaysfree_compartment will be created
  + resource "oci_identity_compartment" "alwaysfree_compartment" {
      + compartment_id = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
      + defined_tags   = (known after apply)
      + description    = "Compartment for Always Free Resources"
      + freeform_tags  = (known after apply)
      + id             = (known after apply)
      + inactive_state = (known after apply)
      + is_accessible  = (known after apply)
      + name           = "alwaysfree"
      + state          = (known after apply)
      + time_created   = (known after apply)
    }

  # module.oracle_alwaysfree.tls_private_key.ssh_key will be created
  + resource "tls_private_key" "ssh_key" {
      + algorithm                     = "RSA"
      + ecdsa_curve                   = "P224"
      + id                            = (known after apply)
      + private_key_openssh           = (sensitive value)
      + private_key_pem               = (sensitive value)
      + private_key_pem_pkcs8         = (sensitive value)
      + public_key_fingerprint_md5    = (known after apply)
      + public_key_fingerprint_sha256 = (known after apply)
      + public_key_openssh            = (known after apply)
      + public_key_pem                = (known after apply)
      + rsa_bits                      = 4096
    }

Plan: 9 to add, 0 to change, 0 to destroy.

Changes to Outputs:
  + ip         = (known after apply)
  + privatekey = (sensitive value)

─────────────────────────────────────────────────────────────────────────────

Note: You didn't use the -out option to save this plan, so Terraform can't
guarantee to take exactly these actions if you run "terraform apply" now.
ERRO[0008] Module /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_services/influxdb has finished with an error: /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_servers/account_1/terragrunt.hcl is a dependency of /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_services/influxdb/terragrunt.hcl but detected no outputs. Either the target module has not been applied yet, or the module has no outputs. If this is expected, set the skip_outputs flag to true on the dependency block.  prefix=[/home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_services/influxdb] 
- Installed oracle/oci v5.46.0 (signed by a HashiCorp partner, key ID 1533A49284137CEB)

Partner and community providers are signed by their developers.
If you'd like to know more about provider signing, you can read about it here:
https://www.terraform.io/docs/cli/plugins/signing.html

Terraform has created a lock file .terraform.lock.hcl to record the provider
selections it made above. Include this file in your version control repository
so that Terraform can guarantee to make the same selections by default when
you run "terraform init" in the future.

Terraform has been successfully initialized!

You may now begin working with Terraform. Try running "terraform plan" to see
any changes that are required for your infrastructure. All Terraform commands
should now work.

If you ever set or change modules or backend configuration for Terraform,
rerun this command to reinitialize your working directory. If you forget, other
commands will detect it and remind you to do so if necessary.

Terraform used the selected providers to generate the following execution
plan. Resource actions are indicated with the following symbols:
  + create
 <= read (data resources)

Terraform will perform the following actions:

  # null_resource.ansible_provisioner will be created
  + resource "null_resource" "ansible_provisioner" {
      + id = (known after apply)
    }

  # module.oracle_alwaysfree.data.oci_core_images.ubuntu will be read during apply
  # (config refers to values not yet known)
 <= data "oci_core_images" "ubuntu" {
      + compartment_id           = (known after apply)
      + id                       = (known after apply)
      + images                   = (known after apply)
      + operating_system         = "Canonical Ubuntu"
      + operating_system_version = "22.04"
      + shape                    = "VM.Standard.A1.Flex"
    }

  # module.oracle_alwaysfree.data.oci_identity_availability_domains.ads will be read during apply
  # (config refers to values not yet known)
 <= data "oci_identity_availability_domains" "ads" {
      + availability_domains = (known after apply)
      + compartment_id       = (known after apply)
      + id                   = (known after apply)
    }

  # module.oracle_alwaysfree.oci_core_instance.alwaysfree_instance will be created
  + resource "oci_core_instance" "alwaysfree_instance" {
      + availability_domain                 = (known after apply)
      + boot_volume_id                      = (known after apply)
      + capacity_reservation_id             = (known after apply)
      + compartment_id                      = (known after apply)
      + compute_cluster_id                  = (known after apply)
      + dedicated_vm_host_id                = (known after apply)
      + defined_tags                        = (known after apply)
      + display_name                        = (known after apply)
      + extended_metadata                   = (known after apply)
      + fault_domain                        = (known after apply)
      + freeform_tags                       = (known after apply)
      + hostname_label                      = (known after apply)
      + id                                  = (known after apply)
      + image                               = (known after apply)
      + instance_configuration_id           = (known after apply)
      + ipxe_script                         = (known after apply)
      + is_cross_numa_node                  = (known after apply)
      + is_pv_encryption_in_transit_enabled = (known after apply)
      + launch_mode                         = (known after apply)
      + metadata                            = (known after apply)
      + private_ip                          = (known after apply)
      + public_ip                           = (known after apply)
      + region                              = (known after apply)
      + shape                               = "VM.Standard.A1.Flex"
      + state                               = (known after apply)
      + subnet_id                           = (known after apply)
      + system_tags                         = (known after apply)
      + time_created                        = (known after apply)
      + time_maintenance_reboot_due         = (known after apply)

      + create_vnic_details {
          + assign_ipv6ip          = (known after apply)
          + assign_public_ip       = "true"
          + defined_tags           = (known after apply)
          + display_name           = (known after apply)
          + freeform_tags          = (known after apply)
          + hostname_label         = (known after apply)
          + nsg_ids                = (known after apply)
          + private_ip             = (known after apply)
          + skip_source_dest_check = (known after apply)
          + subnet_id              = (known after apply)
          + vlan_id                = (known after apply)
        }

      + shape_config {
          + baseline_ocpu_utilization     = (known after apply)
          + gpu_description               = (known after apply)
          + gpus                          = (known after apply)
          + local_disk_description        = (known after apply)
          + local_disks                   = (known after apply)
          + local_disks_total_size_in_gbs = (known after apply)
          + max_vnic_attachments          = (known after apply)
          + memory_in_gbs                 = 24
          + networking_bandwidth_in_gbps  = (known after apply)
          + nvmes                         = (known after apply)
          + ocpus                         = 4
          + processor_description         = (known after apply)
          + vcpus                         = (known after apply)
        }

      + source_details {
          + boot_volume_size_in_gbs = "200"
          + boot_volume_vpus_per_gb = (known after apply)
          + source_id               = (known after apply)
          + source_type             = "image"
        }
    }

  # module.oracle_alwaysfree.oci_core_internet_gateway.alwaysfree_igw will be created
  + resource "oci_core_internet_gateway" "alwaysfree_igw" {
      + compartment_id = (known after apply)
      + defined_tags   = (known after apply)
      + display_name   = "alwaysfree_igw"
      + enabled        = true
      + freeform_tags  = (known after apply)
      + id             = (known after apply)
      + route_table_id = (known after apply)
      + state          = (known after apply)
      + time_created   = (known after apply)
      + vcn_id         = (known after apply)
    }

  # module.oracle_alwaysfree.oci_core_route_table.alwaysfree_route_table will be created
  + resource "oci_core_route_table" "alwaysfree_route_table" {
      + compartment_id = (known after apply)
      + defined_tags   = (known after apply)
      + display_name   = (known after apply)
      + freeform_tags  = (known after apply)
      + id             = (known after apply)
      + state          = (known after apply)
      + time_created   = (known after apply)
      + vcn_id         = (known after apply)

      + route_rules {
          + cidr_block        = (known after apply)
          + description       = (known after apply)
          + destination       = "0.0.0.0/0"
          + destination_type  = (known after apply)
          + network_entity_id = (known after apply)
          + route_type        = (known after apply)
        }
    }

  # module.oracle_alwaysfree.oci_core_security_list.alwaysfree_security_list will be created
  + resource "oci_core_security_list" "alwaysfree_security_list" {
      + compartment_id = (known after apply)
      + defined_tags   = (known after apply)
      + display_name   = "alwaysfree_security_list"
      + freeform_tags  = (known after apply)
      + id             = (known after apply)
      + state          = (known after apply)
      + time_created   = (known after apply)
      + vcn_id         = (known after apply)

      + egress_security_rules {
          + description      = (known after apply)
          + destination      = "0.0.0.0/0"
          + destination_type = (known after apply)
          + protocol         = "all"
          + stateless        = (known after apply)
        }
    }

  # module.oracle_alwaysfree.oci_core_subnet.alwaysfree_subnet will be created
  + resource "oci_core_subnet" "alwaysfree_subnet" {
      + availability_domain        = (known after apply)
      + cidr_block                 = "10.0.0.0/24"
      + compartment_id             = (known after apply)
      + defined_tags               = (known after apply)
      + dhcp_options_id            = (known after apply)
      + display_name               = "alwaysfree_subnet"
      + dns_label                  = (known after apply)
      + freeform_tags              = (known after apply)
      + id                         = (known after apply)
      + ipv6cidr_block             = (known after apply)
      + ipv6cidr_blocks            = (known after apply)
      + ipv6virtual_router_ip      = (known after apply)
      + prohibit_internet_ingress  = (known after apply)
      + prohibit_public_ip_on_vnic = false
      + route_table_id             = (known after apply)
      + security_list_ids          = (known after apply)
      + state                      = (known after apply)
      + subnet_domain_name         = (known after apply)
      + time_created               = (known after apply)
      + vcn_id                     = (known after apply)
      + virtual_router_ip          = (known after apply)
      + virtual_router_mac         = (known after apply)
    }

  # module.oracle_alwaysfree.oci_core_vcn.alwaysfree_vcn will be created
  + resource "oci_core_vcn" "alwaysfree_vcn" {
      + byoipv6cidr_blocks               = (known after apply)
      + cidr_block                       = "10.0.0.0/16"
      + cidr_blocks                      = (known after apply)
      + compartment_id                   = (known after apply)
      + default_dhcp_options_id          = (known after apply)
      + default_route_table_id           = (known after apply)
      + default_security_list_id         = (known after apply)
      + defined_tags                     = (known after apply)
      + display_name                     = "alwaysfree_vcn"
      + dns_label                        = (known after apply)
      + freeform_tags                    = (known after apply)
      + id                               = (known after apply)
      + ipv6cidr_blocks                  = (known after apply)
      + ipv6private_cidr_blocks          = (known after apply)
      + is_ipv6enabled                   = (known after apply)
      + is_oracle_gua_allocation_enabled = (known after apply)
      + state                            = (known after apply)
      + time_created                     = (known after apply)
      + vcn_domain_name                  = (known after apply)
    }

  # module.oracle_alwaysfree.oci_identity_compartment.alwaysfree_compartment will be created
  + resource "oci_identity_compartment" "alwaysfree_compartment" {
      + compartment_id = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
      + defined_tags   = (known after apply)
      + description    = "Compartment for Always Free Resources"
      + freeform_tags  = (known after apply)
      + id             = (known after apply)
      + inactive_state = (known after apply)
      + is_accessible  = (known after apply)
      + name           = "alwaysfree"
      + state          = (known after apply)
      + time_created   = (known after apply)
    }

  # module.oracle_alwaysfree.tls_private_key.ssh_key will be created
  + resource "tls_private_key" "ssh_key" {
      + algorithm                     = "RSA"
      + ecdsa_curve                   = "P224"
      + id                            = (known after apply)
      + private_key_openssh           = (sensitive value)
      + private_key_pem               = (sensitive value)
      + private_key_pem_pkcs8         = (sensitive value)
      + public_key_fingerprint_md5    = (known after apply)
      + public_key_fingerprint_sha256 = (known after apply)
      + public_key_openssh            = (known after apply)
      + public_key_pem                = (known after apply)
      + rsa_bits                      = 4096
    }

Plan: 9 to add, 0 to change, 0 to destroy.

Changes to Outputs:
  + ip         = (known after apply)
  + privatekey = (sensitive value)

─────────────────────────────────────────────────────────────────────────────

Note: You didn't use the -out option to save this plan, so Terraform can't
guarantee to take exactly these actions if you run "terraform apply" now.
ERRO[0009] 1 error occurred:
        * /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_servers/account_1/terragrunt.hcl is a dependency of /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_services/influxdb/terragrunt.hcl but detected no outputs. Either the target module has not been applied yet, or the module has no outputs. If this is expected, set the skip_outputs flag to true on the dependency block.
 
ERRO[0009] Unable to determine underlying exit code, so Terragrunt will exit with error code 1 

[denis256]

By default, Terragrunt is using terraform output to read outputs

Error mentions that influxdb/terragrunt.hcl doesn't have any outputs

/home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_servers/account_1/terragrunt.hcl is a dependency of /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_services/influxdb/terragrunt.hcl but detected no outputs

Checking how docker_services is configured:

# docker_services/common.hcl
terraform {
  source = "${get_terragrunt_dir()}/../../modules/docker_service"
}

Modules define outputs only in docker_server, not in docker_service

$ pwd
/projects/gruntwork/tests/terragrunt_oracle/terraform/modules

$ ls
docker_server  docker_service

$ grep -irn "output" .
./docker_server/outputs.tf:1:output "ip" {
./docker_server/outputs.tf:5:output "privatekey" {
./docker_server/oracle_alwaysfree/outputs.tf:1:output "alwaysfree_user" {
./docker_server/oracle_alwaysfree/outputs.tf:5:output "alwaysfree_instance_ip" {
./docker_server/oracle_alwaysfree/outputs.tf:9:output "alwaysfree_instance_privatekey" {
./docker_server/oracle_alwaysfree/outputs.tf:14:output "alwaysfree_instance_publickey" {

[ares-b]

Modules define outputs only in docker_server, not in docker_service

That's right I don't have any output in docker_service. But I need to use docker_server outputs to generate docker_service's provider.

# docker_services/common.hcl
dependency "docker_server" {
    config_path = "${get_terragrunt_dir()}/../../docker_servers/${local.docker_service.server}"
}

generate "provider" {
    path        = "provider.tf"
    if_exists   = "overwrite"
    contents    = templatefile("${get_terragrunt_dir()}/../../terragrunt_templates/docker_ssh_provider.tpl", {
        docker_server    = dependency.docker_server.outputs.ip
        private_key      = dependency.docker_server.outputs.privatekey
    })
}

[denis256]

Hello,
explicit dependencies can be defined using the dependencies block.
Additionally, if a dependency is not expected to produce outputs, the skip_outputs option can be set.

https://terragrunt.gruntwork.io/docs/reference/config-blocks-and-attributes/#dependencies

[ares-b]

Hello, explicit dependencies can be defined using the dependencies block. Additionally, if a dependency is not expected to produce outputs, the skip_outputs option can be set.

https://terragrunt.gruntwork.io/docs/reference/config-blocks-and-attributes/#dependencies

My dependency (docker_server) do have outputs, it has ip and privatekey.

# https://github.com/ares-b/terragrunt_oracle/blob/main/terraform/docker_servers/common.hcl
terraform {
  source = "${get_terragrunt_dir()}/../../modules/docker_server"
}

# https://github.com/ares-b/terragrunt_oracle/blob/main/terraform/modules/docker_server/outputs.tf 
output "ip" {
  value = module.oracle_alwaysfree.alwaysfree_instance_ip
}

output "privatekey" {
  value = module.oracle_alwaysfree.alwaysfree_instance_privatekey
  sensitive = true
}

I've set docker_services to have docker_server as a dependency. Then I'm using ip and privatekey from docker_server to generate a docker provider for docker_services.

# https://github.com/ares-b/terragrunt_oracle/blob/main/terraform/docker_services/common.hcl
dependency "docker_server" {
    config_path = "${get_terragrunt_dir()}/../../docker_servers/${local.docker_service.server}"
}

generate "provider" {
    path        = "provider.tf"
    if_exists   = "overwrite"
    contents    = templatefile("${get_terragrunt_dir()}/../../terragrunt_templates/docker_ssh_provider.tpl", {
        docker_server    = dependency.docker_server.outputs.ip
        private_key      = dependency.docker_server.outputs.privatekey
    })
}

So my dependency (docker_server) IS producing an output.
Dependency graphis :

ares@ares:~/dev/rust/profit_prophet/infrastructure/terraform$ terragrunt graph-dependencies 
digraph {
        "docker_servers/account_1" ;
        "docker_servers/account_2" ;
        "docker_services/influxdb" ;
        "docker_services/influxdb" -> "docker_servers/account_1";
}

So docker_services/influxdb runs AFTER docker_servers/account_1 and uses its outputs. Yet I'm stil having this error :

ERRO[0001] Module /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_services/influxdb has finished with an error: /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_servers/account_1/terragrunt.hcl is a dependency of /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_services/influxdb/terragrunt.hcl but detected no outputs. Either the target module has not been applied yet, or the module has no outputs. If this is expected, set the skip_outputs flag to true on the dependency block.  prefix=[/home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_services/influxdb] 
ERRO[0001] 1 error occurred:
        * /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_servers/account_1/terragrunt.hcl is a dependency of /home/ares/dev/rust/profit_prophet/infrastructure/terraform/docker_services/influxdb/terragrunt.hcl but detected no outputs. Either the target module has not been applied yet, or the module has no outputs. If this is expected, set the skip_outputs flag to true on the dependency block.

I'd be happy to provide more information if needed