Storing the ACL Bootstrap Token in Vault

This topic describes how to configure the Consul Helm chart to use an ACL bootstrap token stored in Vault.

Overview

To use an ACL bootstrap token stored in Vault, we will follow the steps outlined in the Data Integration section:

One time setup in Vault

  1. Store the secret in Vault.
  2. Create a Vault policy that authorizes the desired level of access to the secret.

Setup per Consul datacenter

  1. Create Vault Kubernetes auth roles that link the policy to each Consul on Kubernetes service account that requires access.
  2. Update the Consul on Kubernetes helm chart.

Prerequisites

Prior to setting up the data integration between Vault and Consul on Kubernetes, you will need to have:

  1. Read and completed the steps in the Systems Integration section of Vault as a Secrets Backend.
  2. Read the Data Integration Overview section of Vault as a Secrets Backend.

One time setup in Vault

Generate and Store the Secret in Vault

First, generate and store the ACL bootstrap token in Vault:

  1. $ vault kv put secret/consul/bootstrap-token token="$(uuidgen | tr '[:upper:]' '[:lower:]')"
  1. $ vault kv put secret/consul/bootstrap-token token="$(uuidgen | tr '[:upper:]' '[:lower:]')"

Create a Vault policy that authorizes the desired level of access to the secret

Note: The secret path referenced by the Vault Policy below will be your global.acls.bootstrapToken.secretName Helm value.

Next, you will need to create a Vault policy that allows read access to this secret:

  1. path "secret/data/consul/bootstrap-token" {
  2.   capabilities = ["read"]
  3. }

Bootstrap Token - 图1

bootstrap-token-policy.hcl

  1. path "secret/data/consul/bootstrap-token" {
  2.   capabilities = ["read"]
  3. }

Apply the Vault policy by issuing the vault policy write CLI command:

  1. $ vault policy write bootstrap-token-policy bootstrap-token-policy.hcl
  1. $ vault policy write bootstrap-token-policy bootstrap-token-policy.hcl

Setup per Consul datacenter

Next, you will create Kubernetes auth roles for the Consul server-acl-init container that runs as part of the Consul server statefulset:

  1. $ vault write auth/kubernetes/role/consul-server-acl-init \
  2.     bound_service_account_names=<Consul server service account> \
  3.     bound_service_account_namespaces=<Consul installation namespace> \
  4.     policies=bootstrap-token-policy \
  5.     ttl=1h
  1. $ vault write auth/kubernetes/role/consul-server-acl-init \
  2.     bound_service_account_names=<Consul server service account> \
  3.     bound_service_account_namespaces=<Consul installation namespace> \
  4.     policies=bootstrap-token-policy \
  5.     ttl=1h

To find out the service account name of the Consul server-acl-init job (i.e. the Consul server service account name), you can run the following helm template command with your Consul on Kubernetes values file:

  1. $ helm template --release-name ${RELEASE_NAME} -s templates/server-acl-init-serviceaccount.yaml hashicorp/consul
  1. $ helm template --release-name ${RELEASE_NAME} -s templates/server-acl-init-serviceaccount.yaml hashicorp/consul

Update the Consul on Kubernetes helm chart

Now that you have configured Vault, you can configure the Consul Helm chart to use the ACL bootstrap token in Vault:

  1. global:
  2.   secretsBackend:
  3.     vault:
  4.       enabled: true
  5.       manageSystemACLsRole: consul-server-acl-init
  6.   acls:
  7.     bootstrapToken:
  8.       secretName: secret/data/consul/bootstrap-token
  9.       secretKey: token

Bootstrap Token - 图2

values.yaml

  1. global:
  2.   secretsBackend:
  3.     vault:
  4.       enabled: true
  5.       manageSystemACLsRole: consul-server-acl-init
  6.   acls:
  7.     bootstrapToken:
  8.       secretName: secret/data/consul/bootstrap-token
  9.       secretKey: token

Note that global.acls.bootstrapToken.secretName is the path of the secret in Vault. This should be the same path as the one you included in your Vault policy. global.acls.bootstrapToken.secretKey is the key inside the secret data. This should be the same as the key you passed when creating the ACL replication token secret in Vault.