# Using a single workspace:
terraform {
backend "remote" {
hostname = "app.terraform.io"
organization = "company"
workspaces {
name = "my-app-prod"
}
}
}
For Terraform remote backend, would there be a way to use variable to specify the organization / workspace name instead of the hardcoded values there?
The Terraform documentation
didn't seem to mention anything related either.
The backend configuration documentation goes into this in some detail. The main point to note is this:
Only one backend may be specified and the configuration may not contain interpolations. Terraform will validate this.
If you want to make this easily configurable then you can use partial configuration for the static parts (eg the type of backend such as S3) and then provide config at run time interactively, via environment variables or via command line flags.
I personally wrap Terraform actions in a small shell script that runs terraform init with command line flags that uses an appropriate S3 bucket (eg a different one for each project and AWS account) and makes sure the state file location matches the path to the directory I am working on.
I had the same problems and was very disappointed with the need of additional init/wrapper scripts. Some time ago I started to use Terragrunt.
It's worth taking a look at Terragrunt because it closes the gap between Terraform and the lack of using variables at some points, e.g. for the remote backend configuration:
https://terragrunt.gruntwork.io/docs/getting-started/quick-start/#keep-your-backend-configuration-dry
Related
I have a Terraform (1.0+) script that generates a local config file from a template based on some inputs, e.g:
locals {
config_tpl = templatefile("${path.module}/config.tpl", {
foo = "bar"
})
}
resource "local_file" "config" {
content = local._config_tpl
filename = "${path.module}/config.yaml"
}
This file is then used by a subsequent command run from a local-exec block, which in turn also generates local config files:
resource "null_resource" "my_command" {
provisioner "local-exec" {
when = create
command = "../scripts/my_command.sh"
working_dir = "${path.module}"
}
depends_on = [
local_file.config,
]
}
my_command.sh generates infrastructure for which there is no Terraform provider currently available.
All of the generated files should form part of the configuration state, as they are required later during upgrades and ultimately to destroy the environment.
I also would like to run these scripts from a CI/CD pipeline, so naturally you would expect the workspace to be clean on each run, which means the generated files won't be present.
Is there a pattern for managing files such as these? My initial though is to create cloud storage bucket, zip the files up, and store them there before pulling them back down whenever they're needed. However, this feels even more dirty than what is already happening, and it seems like there is the possibility to run into dependency issues.
Or, am I missing something completely different to solve issues such as this?
The problem you've encountered here is what the warning in the hashicorp/local provider's documentation is discussing:
Terraform primarily deals with remote resources which are able to outlive a single Terraform run, and so local resources can sometimes violate its assumptions. The resources here are best used with care, since depending on local state can make it hard to apply the same Terraform configuration on many different local systems where the local resources may not be universally available. See specific notes in each resource for more information.
The short and unfortunate answer is that what you are trying to do here is not a problem Terraform is designed to address: its purpose is to manage long-lived objects in remote systems, not artifacts on your local workstation where you are running Terraform.
In the case of your config.yaml file you may find it a suitable alternative to use a cloud storage object resource type instead of local_file, so that Terraform will just write the file directly to that remote storage and not affect the local system at all. Of course, that will help only if whatever you intend to have read this file is also able to read from the same cloud storage, or if you can write a separate glue script to fetch the object after terraform apply is finished.
There is no straightforward path to treating the result of a provisioner as persistent data in the state. If you use provisioners then they are always, by definition, one-shot actions taken only during creation of a resource.
# Using a single workspace:
terraform {
backend "remote" {
hostname = "app.terraform.io"
organization = "company"
workspaces {
name = "my-app-prod"
}
}
}
For Terraform remote backend, would there be a way to use variable to specify the organization / workspace name instead of the hardcoded values there?
The Terraform documentation
didn't seem to mention anything related either.
The backend configuration documentation goes into this in some detail. The main point to note is this:
Only one backend may be specified and the configuration may not contain interpolations. Terraform will validate this.
If you want to make this easily configurable then you can use partial configuration for the static parts (eg the type of backend such as S3) and then provide config at run time interactively, via environment variables or via command line flags.
I personally wrap Terraform actions in a small shell script that runs terraform init with command line flags that uses an appropriate S3 bucket (eg a different one for each project and AWS account) and makes sure the state file location matches the path to the directory I am working on.
I had the same problems and was very disappointed with the need of additional init/wrapper scripts. Some time ago I started to use Terragrunt.
It's worth taking a look at Terragrunt because it closes the gap between Terraform and the lack of using variables at some points, e.g. for the remote backend configuration:
https://terragrunt.gruntwork.io/docs/getting-started/quick-start/#keep-your-backend-configuration-dry
I have 3 questions here:
I have created terraform form scripts in Oracle Cloud Infrastructure to build the instance and other resources. But I am not able to get any script for route table configuration and service in network script. So i have made them manual. my current table has only the resource name, rest all configuration is blank. So i need help in getting a properly supported script for OCI to create route table with configuration.
As i did such things manually, i am not able to give terraform apply after doing some changes in the script, as terraform apply will delete all the rules which i created manually. So is it mandatory to give terraform apply every time when i change the script? or can i enter the config manually and simultaneously match that in the terraform script so that everything is intact?
After every terraform changes i could see 2 files is getting enlarge (terraform.tfstate, terraform.tfstate.backup) what are these two files? if that is a backup file, then how will it help me to restore if i mess up in my configuration?
In Terraform, the configuration script is always the source of truth. When you apply a configuration; Terraform will favor the settings of that configuration and override any changes that were manually done outside of Terraform.
To make sure your manual changes are not overwritten, you should make sure the configuration always matches the manual changes. One way to import manual resources into your configuration is using "terraform import" (see https://www.terraform.io/docs/import/index.html).
The terraform.tfstate and terraform.tfstate.backup files are used by Terraform to keep track of the latest state of the resources that Terraform has created. These files are used to help Terraform determine whether you configuration script has drifted from the state; so it knows how to apply your configuration script. To my knowledge, these state files are not intended to be backup files if you mess up your configuration. (see https://www.terraform.io/docs/state/index.html)
Hope this helps.
Here is an example for a route table resource in Terraform config file:
resource "oci_core_route_table" "webserver-rt" {
compartment_id = "${var.compartment_ocid}"
vcn_id = "${oci_core_virtual_network.oci-vcn.id}"
display_name = "webserver-rt"
route_rules = [{
destination = "0.0.0.0/0"
network_entity_id = "${oci_core_internet_gateway.internet-gateway.id}"
}]
}
You may find more details here: https://github.com/terraform-providers/terraform-provider-oci/blob/master/docs/examples/networking/route_table/route_table.tf
I have 2 repos for my project. A Static website and server. I want the website to be hosted by cloudfront and s3 and the server on elasticbeanstalk. I know these resources will need to know about a route53 resource at least to be under the same domain name for cors to work. Among other things such as vpcs and stuff.
So my question is how do I manage terraform with multiple repos.
I'm thinking I could have a seperate infrastructure repo that builds for all repos.
I could also have them seperate and pass in the arns/names/ids as variables (annoying).
You can use terraform remote_state for this. It lets you read the output variables from another terraform state file.
Lets assume you save your state files remotely on s3 and you have your website.tfstate and server.tfstate file. You could output your hosted zone ID of your route53 zone as hosted_zone_id in your website.tfstate and then reference that output variable directly in your server state terraform code.
data "terraform_remote_state" "website" {
backend = "s3"
config {
bucket = "<website_state_bucket>"
region = "<website_bucket_region>"
key = "website.tfstate"
}
}
resource "aws_route53_record" "www" {
zone_id = "${data.terraform_remote_state.website.hosted_zone_id}"
name = "www.example.com"
type = "A"
ttl = "300"
records = ["${aws_eip.lb.public_ip}"]
}
Note, that you can only read output variables from remote states. You cannot access resources directly, as terraform treats other states/modules as black boxes.
Update
As mentioned in the comments, terraform_remote_state is a simple way to share explicitly published variables across multiple states. However, it comes with 2 issues:
Close coupling between code components, i.e., producer of the variable cannot change easily.
It can only be used by terraform, i.e., you cannot easily share those variables across different layers. Configuration tools such as Ansible cannot use .tfstate natively without some additional custom plugin/wrapper.
The recommended HashiCorp way is to use a central config store such as Consul. It comes with more benefits:
Consumer is decoupled from the variable producer.
Explicit publishing of variables (like in terraform_remote_state).
Can be used by other tools.
A more detailed explanation can be found here.
An approach I've used in the past is to have a single repo for all of the Infrastructure.
An alternative is to have 2 separate tf configurations, each using remote state. Config 1 can use output variables to store any arns/ids as necessary.
Config 2 can then have a remote_state data source to query for the relevant arns/ids.
E.g.
# Declare remote state
data "terraform_remote_state" "network" {
backend = "s3"
config {
bucket = "my-terraform-state"
key = "network/terraform.tfstate"
region = "us-east-1"
}
}
You can then use output values using standard interpolation syntax
${data.terraform_remote_state.network.some_id}
How can I get Terraform 0.10.1 to support two different providers without having to run 'terraform init' every time for each provider?
I am trying to use Terraform to
1) Provision an API server with the 'DigitalOcean' provider
2) Subsequently use the 'Docker' provider to spin up my containers
Any suggestions? Do I need to write an orchestrating script that wraps Terraform?
Terraform's current design struggles with creating "multi-layer" architectures in a single configuration, due to the need to pass dynamic settings from one provider to another:
resource "digitalocean_droplet" "example" {
# (settings for a machine running docker)
}
provider "docker" {
host = "tcp://${digitalocean_droplet.example.ipv4_address_private}:2376/"
}
As you saw in the documentation, passing dynamic values into provider configuration doesn't fully work. It does actually partially work if you use it with care, so one way to get this done is to use a config like the above and then solve the "chicken-and-egg" problem by forcing Terraform to create the droplet first:
$ terraform plan -out=tfplan -target=digitalocean_droplet.example
The above will create a plan that only deals with the droplet and any of its dependencies, ignoring the docker resources. Once the Docker droplet is up and running, you can then re-run Terraform as normal to complete the setup, which should then work as expected because the Droplet's ipv4_address_private attribute will then be known. As long as the droplet is never replaced, Terraform can be used as normal after this.
Using -target is fiddly, and so the current recommendation is to split such systems up into multiple configurations, with one for each conceptual "layer". This does, however, require initializing two separate working directories, which you indicated in your question that you didn't want to do. This -target trick allows you to get it done within a single configuration, at the expense of an unconventional workflow to get it initially bootstrapped.
Maybe you can use a provider instance within your resources/module to set up various resources with various providers.
https://www.terraform.io/docs/configuration/providers.html#multiple-provider-instances
The doc talks about multiple instances of same provider but I believe the same should be doable with distinct providers as well.
A little bit late...
Well, got the same Problem. My workaround is to create modules.
First you need a module for your docker Provider with an ip variable:
# File: ./docker/main.tf
variable "ip" {}
provider "docker" {
host = "tcp://${var.ip}:2375/"
}
resource "docker_container" "www" {
provider = "docker"
name = "www"
}
Next one is to load that modul in your root configuration:
# File: .main.tf
module "docker01" {
source = "./docker"
ip = "192.169.10.12"
}
module "docker02" {
source = "./docker"
ip = "192.169.10.12"
}
True, you will create on every node the same container, but in my case that's what i wanted. I currently haven't found a way to configure the hosts with an individual configuration. Maybe nested modules, but that didn't work in the first tries.