Deploy Multiple Stacks

Terraspace allows you to deploy multiple stacks with a single command:

terraspace all up

How to Configure Dependencies

To configure dependencies, you simply wire stack outputs to inputs variables of another stack. Here is an example of an instance stack that depends on a vpc stack.

app/stacks/vpc/outputs.tf

output "vpc_id" {
  description = "VPC ID"
  value       = aws_vpc.this.id
}

app/stacks/instance/variables.tf

variable "vpc_id" {
  description = "VPC to launch instance in"
  type        = string
  default     = null
}

Wire them together with the output helper in the instance tfvars file.

app/stacks/instance/tfvars/base.tfvars

vpc_id = <%= output('vpc.vpc_id') %>

Terraspace infers the dependency from this wiring and will deploy the vpc before the instance. It’s that simple.

Deploying

When you run the terraspace all up command, Terraspace will deploy the resources in batches:

$ terraspace all up
Will run:
    terraspace up vpc # batch 1
    terraspace up instance # batch 2
Are you sure? (y/N) y
Batch Run 1:
Running: terraspace up vpc Logs: log/up/vpc.log
terraspace up vpc:  Apply complete! Resources: 2 added, 0 changed, 0 destroyed.
Batch Run 2:
Running: terraspace up instance Logs: log/up/instance.log
terraspace up instance:  Apply complete! Resources: 2 added, 0 changed, 0 destroyed.
Time took: 7s
$

Terraspace provides a reduced-noise summary of the runs. The full logs are also written for further inspection and debugging. The terraspace logs command is useful for viewing the logs.

Dependency Graph & Parallelism

Terraspace builds the dependency graph and runs the commands in parallel as much as possible. Let’s say you have this dependency graph:

Terraspace will deploy resources in this order:

1. vpc - deployed first
2. redis and mysql - deployed together
3. instance - deployed last

Configuring Concurrency

By default, terraspace runs up to 5 concurrency processes. If you hit cloud provider rate limits, you may want to configure the rate of concurrency. To configure concurrency:

config/app.rb:

Terraspace.configure do |config|
  config.all.concurrency = 2
  # ...
end

More docs: Config Reference

Filtering Subgraphs

You can filter for subtrees or subgraphs to deploy:

terraspace all up mysql # will deploy vpc and then mysql

More info: Subgraphs Docs

You can also configure Terraspace to completely ignore stacks with the all.exclude_stacks option. This can be useful if you have test stacks that you don’t want to be considered as part of the graph yet.

config/app.rb

Terraspace.configure do |config|
  # ...
  config.all.exclude_stacks = ["stack1"]
end

More Docs: Excluding Stacks.

Best of Both Worlds

Terraspace allows you to deploy all stacks with a single command. Instead of having to run terraspace up on each individual stack. You can run:

terraspace all up

Additionally, you can target subtrees or subgraphs to deploy:

terraspace all up mysql # will deploy vpc and then mysql

Lastly, you can always drop down and run the individual stack to debug. Example:

terraspace up vpc
terraspace up redis
terraspace up mysql
terraspace up instance

Terraspace gives you the best of both worlds.