consul-terraform-sync

main.tf

variable "services" {
  description = "Consul Terraform Sync creates this variable"
}

resource "local_file" "tags" {
  content = <<EOT
%{ for node in var.services ~}
${node.address}:
%{ for tag in node.tags ~}
  - ${tag}
%{ endfor ~}
%{ endfor ~}
EOT
  filename = "/tmp/tags.txt"
}

shell.sh

$ consul agent -dev > /dev/null 2>&1 &
[1] 30788

$ consul services register -name ranjit -tag=one
Registered service: ranjit

$ consul-terraform-sync -config-file tags.hcl &
[2] 30794

$ cat /tmp/tags.txt
127.0.0.1:
  - one

$ consul services register -name ranjit -tag=one -tag=two -tag=three
Registered service: ranjit

$ cat /tmp/tags.txt
127.0.0.1:
  - one
  - three
  - two

$ kill %2
$
[2]  + 30794 done       consul-terraform-sync -config-file tags.hcl

$ kill %1
$
[1]  + 30788 exit 1     consul agent -dev > /dev/null 2>&1
$

tags.hcl

task {
  name        = "write_tags"
  description = "Update a file with service tags"
  # Relative to ./sync-tasks/write_tags that is created
  source      = "../../"
  services    = ["ranjit"]
}

driver "terraform" {}