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Resource hierarchy
This stage performs two important tasks:
- create the top-level hierarchy of folders, and the associated resources used later on to automate each part of the hierarchy (eg. Networking)
- set organization policies on the organization, and any exception required on specific folders
The code is intentionally simple, as it's intended to provide a generic initial setup (Networking, Security, etc.), and then allow easy customizations to complete the implementation of the intended hierarchy design.
The following diagram is a high level reference of the resources created and managed here:
Design overview and choices
Despite its simplicity, this stage implements the basics of a design that we've seen working well for a variety of customers, where the hierarchy is laid out following two conceptually different approaches:
- core or shared resources are grouped in hierarchy branches that map to their type or purpose (e.g. Networking)
- team or application resources are grouped in lower level hierarchy branches that map to management or operational considerations (e.g. which team manages a set of applications, or owns a subset of company data, etc.)
This split approach usually represents well functional and operational patterns, where core resources are centrally managed by individual teams (e.g. networking, security, fleets of similar VMS, etc.), while teams need more granularity to access managed services used by the applications they maintain.
The approach also adapts to different high level requirements:
- it can be used either for single organizations containing multiple environments, or with multiple organizations dedicated to specific environments (e.g. prod/nonprod), as the environment split is implemented at the project or lower folder level
- it adapts to complex scenarios, with different countries or corporate entities using the same GCP organization, as core services are typically shared, and/or an extra layer on top can be used as a drop-in to implement the country/entity separation
Additionally, a few critical benefits are directly provided by this design:
- core services are clearly separated, with very few touchpoints where IAM and security policies need to be applied (typically their top-level folder)
- adding a new set of core services (e.g. shared GKE clusters) is a trivial operation that does not break the existing design
- grouping application resources and services using teams or business logic is a flexible approach, which maps well to typical operational or budget requirements
- automation stages (e.g. Networking) can be segregated in a simple and effective way, by creating the required service accounts and buckets for each stage here, and applying a handful of IAM roles to the relevant folder
For a discussion on naming, please refer to the Bootstrap stage documentation, as the same approach is shared by all stages.
Workload Identity Federation and CI/CD
This stage also implements optional support for CI/CD, much in the same way as the bootstrap stage. The only difference is on Workload Identity Federation, which is only configured in bootstrap and made available here via stage interface variables (the automatically generated .tfvars
files).
For details on how to configure CI/CD please refer to the relevant section in the bootstrap stage documentation.
How to run this stage
This stage is meant to be executed after the bootstrap stage has run, as it leverages the automation service account and bucket created there. The relevant user groups must also exist, but that's one of the requirements for the previous stage too, so if you ran that successfully, you're good to go.
It's of course possible to run this stage in isolation, but that's outside the scope of this document, and you would need to refer to the code for the bootstrap stage for the actual roles needed.
Before running this stage, you need to make sure you have the correct credentials and permissions, and localize variables by assigning values that match your configuration.
Providers configuration
The default way of making sure you have the right permissions, is to use the identity of the service account pre-created for this stage during bootstrap, and that you are a member of the group that can impersonate it via provider-level configuration (gcp-devops
or organization-admins
).
To simplify setup, the previous stage pre-configures a valid providers file in its output, and optionally writes it to a local file if the outputs_location
variable is set to a valid path.
If you have set a valid value for outputs_location
in the bootstrap stage (see the bootstrap stage README for more details), simply link the relevant providers.tf
file from this stage's folder in the path you specified:
# `outputs_location` is set to `~/fast-config`
ln -s ~/fast-config/providers/01-resman-providers.tf .
If you have not configured outputs_location
in bootstrap, you can derive the providers file from that stage's outputs:
cd ../00-bootstrap
terraform output -json providers | jq -r '.["01-resman"]' \
> ../01-resman/providers.tf
If you want to continue to rely on outputs_location
logic, create a terraform.tfvars
file and configure it as described here.
Variable configuration
There are two broad sets of variables you will need to fill in:
- variables shared by other stages (org id, billing account id, etc.), or derived from a resource managed by a different stage (folder id, automation project id, etc.)
- variables specific to resources managed by this stage
To avoid the tedious job of filling in the first group of variable with values derived from other stages' outputs, the same mechanism used above for the provider configuration can be used to leverage pre-configured .tfvars
files.
If you configured a valid path for outputs_location
in the bootstrap stage, simply link the relevant terraform-*.auto.tfvars.json
files from the outputs folder. For this stage, you need the .tfvars
file compiled manually for the bootstrap stage, and the one generated by it:
# `outputs_location` is set to `~/fast-config`
ln -s ~/fast-config/tfvars/00-bootstrap.auto.tfvars.json .
# also copy the tfvars file used for the bootstrap stage
cp ../00-bootstrap/terraform.tfvars .
A second set of variables is specific to this stage, they are all optional so if you need to customize them, create an extra terraform.tfvars
file or add them to the file copied from bootstrap.
Refer to the Variables table at the bottom of this document, for a full list of variables, their origin (e.g. a stage or specific to this one), and descriptions explaining their meaning. The sections below also describe some of the possible customizations. For billing configurations, refer to the Bootstrap documentation on billing as the billing_account
variable is identical across all stages.
Once done, you can run this stage:
terraform init
terraform apply
Customizations
Team folders
This stage provides a single built-in customization that offers a minimal (but usable) implementation of the "application" or "business" grouping for resources discussed above. The team_folders
variable allows you to specify a map of team name and groups, that will result in folders, automation service accounts, and IAM policies applied.
Consider the following example in a tfvars
file:
team_folders = {
team-a = {
descriptive_name = "Team A"
group_iam = {
"team-a@gcp-pso-italy.net" = [
"roles/viewer"
]
}
impersonation_groups = ["team-a-admins@gcp-pso-italy.net"]
}
}
This will result in
- a "Team A" folder under the "Teams" folder
- one GCS bucket in the automation project
- one service account in the automation project with the correct IAM policies on the folder and bucket
- a IAM policy on the folder that assigns
roles/viewer
to theteam-a
group - a IAM policy on the service account that allows
team-a
to impersonate it
This allows to centralize the minimum set of resources to delegate control of each team's folder to a pipeline, and/or to the team group. This can be used as a starting point for scenarios that implement more complex requirements (e.g. environment folders per team, etc.).
Organization policies
Organization policies are laid out in an explicit manner in the organization.tf
file, so it's fairly easy to add or remove specific policies.
For policies where additional data is needed, a root-level organization_policy_configs
variable allows passing in specific data. Its built-in use to add additional organizations to the Domain Restricted Sharing policy, can be taken as an example on how to leverage it for additional customizations.
IAM
IAM roles can be easily edited in the relevant branch-xxx.tf
file, following the best practice outlined in the bootstrap stage documentation of separating user-level and service-account level IAM policies in modules' iam_groups
, iam
, and iam_additive
variables.
A full reference of IAM roles managed by this stage is available here.
Additional folders
Due to its simplicity, this stage lends itself easily to customizations: adding a new top-level branch (e.g. for shared GKE clusters) is as easy as cloning one of the branch-xxx.tf
files, and changing names.
Files
name | description | modules | resources |
---|---|---|---|
billing.tf | Billing resources for external billing use cases. | organization |
google_billing_account_iam_member |
branch-data-platform.tf | Data Platform stages resources. | folder · gcs · iam-service-account |
|
branch-networking.tf | Networking stage resources. | folder · gcs · iam-service-account |
|
branch-sandbox.tf | Sandbox stage resources. | folder · gcs · iam-service-account |
|
branch-security.tf | Security stage resources. | folder · gcs · iam-service-account |
|
branch-teams.tf | Team stage resources. | folder · gcs · iam-service-account |
|
cicd-data-platform.tf | CI/CD resources for the data platform branch. | iam-service-account · source-repository |
|
cicd-networking.tf | CI/CD resources for the networking branch. | iam-service-account · source-repository |
|
cicd-security.tf | CI/CD resources for the security branch. | iam-service-account · source-repository |
|
cicd-teams.tf | CI/CD resources for the teams branch. | iam-service-account · source-repository |
|
main.tf | Module-level locals and resources. | ||
organization.tf | Organization policies. | organization |
google_organization_iam_member |
outputs-files.tf | Output files persistence to local filesystem. | local_file |
|
outputs-gcs.tf | Output files persistence to automation GCS bucket. | google_storage_bucket_object |
|
outputs.tf | Module outputs. | ||
variables.tf | Module variables. |
Variables
name | description | type | required | default | producer |
---|---|---|---|---|---|
automation | Automation resources created by the bootstrap stage. | object({…}) |
✓ | 00-bootstrap |
|
billing_account | Billing account id and organization id ('nnnnnnnn' or null). | object({…}) |
✓ | 00-bootstrap |
|
organization | Organization details. | object({…}) |
✓ | 00-bootstrap |
|
prefix | Prefix used for resources that need unique names. Use 9 characters or less. | string |
✓ | 00-bootstrap |
|
cicd_repositories | CI/CD repository configuration. Identity providers reference keys in the automation.federated_identity_providers variable. Set to null to disable, or set individual repositories to null if not needed. |
object({…}) |
null |
||
custom_roles | Custom roles defined at the org level, in key => id format. | object({…}) |
null |
00-bootstrap |
|
groups | Group names to grant organization-level permissions. | map(string) |
{…} |
00-bootstrap |
|
organization_policy_configs | Organization policies customization. | object({…}) |
null |
||
outputs_location | Enable writing provider, tfvars and CI/CD workflow files to local filesystem. Leave null to disable | string |
null |
||
tag_names | Customized names for resource management tags. | object({…}) |
{…} |
||
team_folders | Team folders to be created. Format is described in a code comment. | map(object({…})) |
null |
Outputs
name | description | sensitive | consumers |
---|---|---|---|
cicd_repositories | WIF configuration for CI/CD repositories. | ||
dataplatform | Data for the Data Platform stage. | ||
networking | Data for the networking stage. | ||
project_factories | Data for the project factories stage. | ||
providers | Terraform provider files for this stage and dependent stages. | ✓ | 02-networking · 02-security · 03-dataplatform · xx-sandbox · xx-teams |
sandbox | Data for the sandbox stage. | xx-sandbox |
|
security | Data for the networking stage. | 02-security |
|
teams | Data for the teams stage. | ||
tfvars | Terraform variable files for the following stages. | ✓ |