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Nomad
Cluster Setup

Set up a Nomad cluster on GCP

  • 30min
  • |
  • Nomad
  • Terraform
  • Packer

This tutorial will guide you through deploying a Nomad cluster with access control lists (ACLs) enabled on GCP. Consider checking out the cluster setup overview first as it covers the contents of the code repository used in this tutorial.

Prerequisites

For this tutorial, you will need:

Note

This tutorial creates GCP resources that may not qualify as part of the GCP free tier. Be sure to follow the Cleanup process at the end of this tutorial so you don't incur any additional unnecessary charges.

Clone the code repository

The cluster setup code repository contains configuration files for creating a Nomad cluster on GCP. It uses Consul for the initial setup of the Nomad servers and clients and enables ACLs for both Consul and Nomad.

Clone the code repository.

$ git clone https://github.com/hashicorp/learn-nomad-cluster-setup

Navigate to the cloned repository folder.

$ cd learn-nomad-cluster-setup

Check out the v0.2 tag of the repository as a local branch named nomad-cluster.

$ git checkout v0.2 -b nomad-cluster

Navigate to the gcp folder.

$ cd gcp

Configure gcloud

Log in to GCP with gcloud and follow the prompts to complete the login process.

$ gcloud auth login
Your browser has been opened to visit:

https://accounts.google.com/o/oauth2/auth?response_type=code[...]

You are now logged in as [YOUR_GCP_ACCOUNT].
Your current project is [YOUR_CURRENT_PROJECT].  You can change this setting by running:
  $ gcloud config set project PROJECT_ID

Set the project, region, and zone configurations in gcloud.

Tip

If you already have a project in your GCP account, these configurations will be set for you as part of the login step. If not, set them with the gcloud config set command after creating a project.

First, set project to the project ID of your preferred project.

$ gcloud config set project <GCP_PROJECT_ID>

Then, set region to the associated region.

$ gcloud config set compute/region <GCP_REGION>

Finally, set zone to the associated zone. Note that the zone must be in the region set above.

$ gcloud config set compute/zone <GCP_ZONE>

Create the Nomad cluster

There are two main steps to creating the cluster: building a Google Compute Engine image with Packer and provisioning the cluster infrastructure with Terraform. Both Packer and Terraform require that some configurations be set before they run and these configuration variables are defined in the variables.hcl.example file.

Update the variables file for Packer

Rename variables.hcl.example to variables.hcl and open it in your text editor.

$ mv variables.hcl.example variables.hcl

Warning

The .gitignore file in the example repo is set to ignore variables.hcl so your configurations will not get pushed to your source code repository if you choose to do so. Do not commit sensitive data like credentials to your source code repository.

Update the project, region, and zone variables with the values from gcloud by first listing the configurations and then copying the values for project, region, and zone into variables.hcl. In this example, those would be hc-3ff63253e6a54756b207e4d4727, us-east1, and us-east1-b.

$ gcloud config list
[compute]
region = us-east1
zone = us-east1-b
[core]
account = [GCP_ACCOUNT]
disable_usage_reporting = True
project = hc-3ff63253e6a54756b207e4d4727

Update the retry_join variable with the project ID by replacing the GCP_PROJECT_ID placeholder in the value with the same project ID as the project variable above. Save the file.

gcp/variables.hcl
# Packer variables (all are required)
project                   = "hc-3ff63253e6a54756b207e4d4727"
region                    = "us-east1"
zone                      = "us-east1-b"

# Terraform variables (all are required)
retry_join = "project_name=hc-3ff63253e6a54756b207e4d4727 provider=gce tag_value=auto-join"
# ...

Build the GCE image

Initialize Packer to download the required plugins.

Tip

packer init returns no output when it finishes successfully.

$ packer init image.pkr.hcl

Then, build the image and provide the variables file with the -var-file flag.

Tip

Packer will print out a Warning: Undefined variable message notifying you that some variables were set in variables.hcl but not used, this is only a warning. The build will still complete sucessfully.

$ packer build -var-file=variables.hcl image.pkr.hcl  
googlecompute.hashistack: output will be in this color.

==> googlecompute.hashistack: Checking image does not exist...
==> googlecompute.hashistack: Creating temporary RSA SSH key for instance...
==> googlecompute.hashistack: Using image: ubuntu-minimal-1804-bionic-v20221026
==> googlecompute.hashistack: Creating instance...
    googlecompute.hashistack: Loading zone: us-east1-b

# ...

==> googlecompute.hashistack: Creating image...
==> googlecompute.hashistack: Deleting disk...
    googlecompute.hashistack: Disk has been deleted!
Build 'googlecompute.hashistack' finished after 4 minutes 31 seconds.

==> Wait completed after 4 minutes 31 seconds

==> Builds finished. The artifacts of successful builds are:
--> googlecompute.hashistack: A disk image was created: hashistack-20221121163551

Update the variables file for Terraform

Open variables.hcl in your text editor again.

Update machine_image with the value output from the Packer build. In this example, the value would be hashistack-20221121163551.

Then, open your terminal and use the built-in uuid() function of the Terraform console to generate two new UUIDs for the token's credentials.

$ terraform console
> uuid()
> "a90a52ae-bcb7-e38a-5fe9-6ac084b37078"
> uuid()
> "d14d6a73-a0f1-508d-6d64-6b0f79e5cb44"
> exit

Copy these UUIDs and update the nomad_consul_token_id and nomad_consul_token_secret variables with the UUID values. Save the file.

In this example, the value for nomad_consul_token_id would be a90a52ae-bcb7-e38a-5fe9-6ac084b37078 and the value for nomad_consul_token_secret would be d14d6a73-a0f1-508d-6d64-6b0f79e5cb44.

gcp/variables.hcl
# Packer variables (all are required)
project                   = "hc-3ff63253e6a54756b207e4d4727"
region                    = "us-east1"
zone                      = "us-east1-b"

# Terraform variables (all are required)
retry_join = "project_name=hc-3ff63253e6a54756b207e4d4727 provider=gce tag_value=auto-join"
machine_image             = "hashistack-20221121163551"
nomad_consul_token_id     = "a90a52ae-bcb7-e38a-5fe9-6ac084b37078"
nomad_consul_token_secret = "d14d6a73-a0f1-508d-6d64-6b0f79e5cb44"

# ...

The remaining variables in variables.hcl are optional.

  •  allowlist_ip is a CIDR range specifying which IP addresses are allowed to access the Consul and Nomad UIs on ports 8500 and 4646 as well as SSH on port 22. The default value of 0.0.0.0/0 will allow traffic from everywhere.

Note

We recommend that you update allowlist_ip to your machine's IP address or a range of trusted IPs.

  •  name is a prefix for naming the GCP resources.
  •  server_instance_type and client_instance_type are the virtual machine instance types for the cluster server and client nodes, respectively.
  •  server_count and client_count are the number of nodes to create for the servers and clients, respectively.

Deploy the Nomad cluster

Initialize Terraform to download required plugins and set up the workspace.

$ terraform init
Initializing the backend...

Initializing provider plugins...
- Finding latest version of hashicorp/google...
- Installing hashicorp/google v4.43.1...
- Installed hashicorp/google v4.43.1 (signed by HashiCorp)

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!

Provision the resources and provide the variables file with the -var-file flag. Respond yes to the prompt to confirm the operation. The provisioning takes several minutes. Once complete, the Consul and Nomad web interfaces will become available.

$ terraform apply -var-file=variables.hcl

# ...

Plan: 10 to add, 0 to change, 0 to destroy.

Changes to Outputs:
  + IP_Addresses                  = (known after apply)
  + consul_bootstrap_token_secret = "123e4567-e89b-12d3-a456-426614174000"
  + lb_address_consul_nomad       = (known after apply)

Do you want to perform these actions?
  Terraform will perform the actions described above.
  Only 'yes' will be accepted to approve.

  Enter a value: Yes

# ...


Apply complete! Resources: 10 added, 0 changed, 0 destroyed.

Outputs:

IP_Addresses = <<EOT

Client public IPs: 34.148.129.28, 34.139.143.190, 35.237.35.204

Server public IPs: 35.229.22.209, 34.75.31.170, 34.74.139.184

The Consul UI can be accessed at http://35.229.22.209:8500/ui
with the bootstrap token: d14d6a73-a0f1-508d-6d64-6b0f79e5cb44

EOT
consul_bootstrap_token_secret = "d14d6a73-a0f1-508d-6d64-6b0f79e5cb44"
lb_address_consul_nomad = "http://35.229.22.209"

Verify the services are in a healthy state. Navigate to the Consul UI in your web browser with the link in the Terraform output.

Consul UI Services page with login button

Click on the Log in button and use the bootstrap token secret consul_bootstrap_token_secret from the Terraform output to log in.

Consul UI with log in dialog

Click on the Nodes page from the sidebar navigation. There are six healthy nodes, including three Consul servers and three Consul clients created with Terraform.

Consul UI listing cluster nodes

Set up access to Nomad

Run the post-setup.sh script.

Warning

If the nomad.token file already exists from a previous run, the script won't work until the token file has been deleted. Delete the file manually and re-run the script or use rm nomad.token && ./post-script.sh.

Note

It may take some time for the setup scripts to complete and for the Nomad user token to become available in the Consul KV store. If the post-setup.sh script doesn't work the first time, wait a couple of minutes and try again.

$ ./post-setup.sh
The Nomad user token has been saved locally to nomad.token and deleted from the Consul KV store.

Set the following environment variables to access your Nomad cluster with the user token created during setup:

export NOMAD_ADDR=$(terraform output -raw lb_address_consul_nomad):4646
export NOMAD_TOKEN=$(cat nomad.token)


The Nomad UI can be accessed at http://nomad-server-lb-2108864054.us-east-1.elb.amazonaws.com:4646/ui
with the bootstrap token: a3376a1d-58ef-b21a-14cd-da31b2c14292

Apply the export commands from the output.

$ export NOMAD_ADDR=$(terraform output -raw lb_address_consul_nomad):4646 && \
  export NOMAD_TOKEN=$(cat nomad.token)

Finally, verify connectivity to the cluster with nomad node status

$ nomad node status
ID        DC   Name              Class   Drain  Eligibility  Status
a945787c  dc1  ip-172-31-94-155  <none>  false  eligible     ready
0582714a  dc1  ip-172-31-81-146  <none>  false  eligible     ready
c52c4f14  dc1  ip-172-31-94-66   <none>  false  eligible     ready

You can navigate to the Nomad UI in your web browser with the link in the post-setup.sh script output. From there, log in with the bootstrap token saved in the NOMAD_TOKEN environment variable by setting the Secret ID to the token's value and clicking on the Clients page from the sidebar navigation.

Nomad UI Access Control Tokens page

Nomad Clients page

Cleanup

Use terraform destroy to remove the provisioned infrastructure. Respond yes to the prompt to confirm removal.

$ terraform destroy -var-file=variables.hcl
# ...

Plan: 0 to add, 0 to change, 10 to destroy.

Changes to Outputs:
  - IP_Addresses                  = <<-EOT
        
        Client public IPs: 34.148.129.28, 34.139.143.190, 35.237.35.204
        
        Server public IPs: 35.229.22.209, 34.75.31.170, 34.74.139.184
        
        The Consul UI can be accessed at http://35.229.22.209:8500/ui
        with the bootstrap token: d14d6a73-a0f1-508d-6d64-6b0f79e5cb44
    EOT -> null
  - consul_bootstrap_token_secret = "d14d6a73-a0f1-508d-6d64-6b0f79e5cb44" -> null
  - lb_address_consul_nomad       = "http://35.229.22.209" -> null

Do you really want to destroy all resources?
  Terraform will destroy all your managed infrastructure, as shown above.
  There is no undo. Only 'yes' will be accepted to confirm.

  Enter a value: yes

# ...

google_compute_instance.server[1]: Destruction complete after 51s
google_compute_instance.client[2]: Destruction complete after 51s
google_compute_instance.server[2]: Destruction complete after 51s
google_compute_instance.client[1]: Destruction complete after 51s
google_compute_instance.server[0]: Destruction complete after 51s
google_compute_instance.client[0]: Destruction complete after 51s
google_compute_network.hashistack: Destruction complete after 52s

Destroy complete! Resources: 10 destroyed.

Next steps

In this tutorial you created a Nomad cluster on GCP with Consul and ACLs enabled. From here, you may want to:

For more information, check out the following resources.

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