mirror of https://github.com/status-im/consul.git
242 lines
10 KiB
Plaintext
242 lines
10 KiB
Plaintext
---
|
|
layout: docs
|
|
page_title: Vault as the Webhook Certificate Provider for Consul Controller and Connect Inject on Kubernetes
|
|
description: >-
|
|
Configuring the Consul Helm chart to use TLS certificates issued by Vault for the Consul Controller and Connect Inject webhooks.
|
|
---
|
|
|
|
# Vault as the Controller and Connect Inject Webhook Certificate Provider on Kubernetes
|
|
|
|
This topic describes how to configure the Consul Helm chart to use TLS certificates issued by Vault in the Consul controller and connect inject webhooks.
|
|
|
|
## Overview
|
|
In a Consul Helm chart configuration that does not use Vault, webhook-cert-manager normally fulfills the role of ensuring that a valid certificate is updated to the `mutatingwebhookconfiguration` of either controller or connect inject to ensure that Kubernetes can communicate with each of these services.
|
|
|
|
When Vault is configured as the controller and connect inject Webhook Certificate Provider on Kubernetes:
|
|
- `webhook-cert-manager` is no longer deployed to the cluster.
|
|
- controller and connect inject each get their webhook certificates from its own Vault PKI mount via the injected Vault Agent.
|
|
- controller and connect inject each need to be configured with its own Vault Role that has necessary permissions to receive certificates from its respective PKI mount.
|
|
- controller and connect inject each locally update its own `mutatingwebhookconfiguration` so that Kubernetes can relay events.
|
|
- Vault manages certificate rotation and rotates certificates to each webhook.
|
|
|
|
To use Vault as the controller and connect inject Webhook Certificate Provider, we will need to modify the steps outlined in the [Data Integration](/docs/k8s/installation/vault/data-integration) section:
|
|
|
|
These following steps will be repeated for each datacenter:
|
|
1. Create a Vault policy that authorizes the desired level of access to the secret.
|
|
1. (Added) Create Vault PKI roles for controller and connect inject each that establish the domains that each is allowed to issue certificates for.
|
|
1. Create Vault Kubernetes auth roles that link the policy to each Consul on Kubernetes service account that requires access.
|
|
1. Configure the Vault Kubernetes auth roles in the Consul on Kubernetes helm chart.
|
|
|
|
## Prerequisites
|
|
Complete the following prerequisites prior to implementing the integration described in this topic:
|
|
1. Verify that you have completed the steps described in [Systems Integration](/docs/k8s/installation/vault/systems-integration) section of [Vault as a Secrets Backend](/docs/k8s/installation/vault).
|
|
1. You should be familiar with the [Data Integration Overview](/docs/k8s/installation/vault/data-integration) section of [Vault as a Secrets Backend](/docs/k8s/installation/vault).
|
|
1. Configure [Vault as the Server TLS Certificate Provider on Kubernetes](/docs/k8s/installation/vault/data-integration/server-tls)
|
|
1. Configure [Vault as the Service Mesh Certificate Provider on Kubernetes](/docs/k8s/installation/vault/data-integration/connect-ca)
|
|
|
|
## Bootstrapping the PKI Engines
|
|
Issue the following commands to enable and configure the PKI Secrets Engine to serve TLS certificates for the controller and connect inject webhooks:
|
|
|
|
* Mount the PKI Secrets Engine for each:
|
|
|
|
```shell-session
|
|
$ vault secrets enable -path=controller pki
|
|
```
|
|
|
|
```shell-session
|
|
$ vault secrets enable -path=connect-inject pki
|
|
```
|
|
|
|
* Tune the engine mounts to enable longer TTL:
|
|
|
|
```shell-session
|
|
$ vault secrets tune -max-lease-ttl=87600h controller
|
|
```
|
|
|
|
```shell-session
|
|
$ vault secrets tune -max-lease-ttl=87600h connect-inject
|
|
```
|
|
|
|
* Generate the root CA for each:
|
|
|
|
```shell-session
|
|
$ vault write -field=certificate controller/root/generate/internal \
|
|
common_name="<helm release name>-controller-webhook" \
|
|
ttl=87600h
|
|
```
|
|
|
|
```shell-session
|
|
$ vault write -field=certificate connect-inject/root/generate/internal \
|
|
common_name="<helm release name>-connect-injector" \
|
|
ttl=87600h
|
|
```
|
|
## Create Vault Policies
|
|
1. Create a policy that allows `["create", "update"]` access to the
|
|
[certificate issuing URL](https://www.vaultproject.io/api-docs/secret/pki) so Consul controller and connect inject can fetch a new certificate/key pair and provide it to the Kubernetes `mutatingwebhookconfiguration`.
|
|
|
|
The path to the secret referenced in the `path` resource is the same value that you will configure in the `global.secretsBackend.vault.controller.tlsCert.secretName` and `global.secretsBackend.vault.connectInject.tlsCert.secretName` Helm configuration (refer to [Update Consul on Kubernetes Helm chart](#update-consul-on-kubernetes-helm-chart)).
|
|
|
|
```shell-session
|
|
$ vault policy write controller-tls-policy - <<EOF
|
|
path controller/issue/controller-role {
|
|
capabilities = ["create", "update"]
|
|
}
|
|
EOF
|
|
```
|
|
|
|
```shell-session
|
|
$ vault policy write connect-inject-policy - <<EOF
|
|
path connect-inject/issue/connect-inject-role {
|
|
capabilities = ["create", "update"]
|
|
}
|
|
EOF
|
|
```
|
|
|
|
1. Create a policy that allows `["read"]` access to the [CA URL](https://www.vaultproject.io/api/secret/pki#read-certificate),
|
|
this is required for the Consul components to communicate with the Consul servers in order to fetch their auto-encryption certificates.
|
|
|
|
The path to the secret referenced in the `path` resource is the same values that you will configure in the `global.secretsBackend.vault.controller.caCert.secretName` and `global.secretsBackend.vault.connectInject.caCert.secretName` Helm configuration (refer to [Update Consul on Kubernetes Helm chart](#update-consul-on-kubernetes-helm-chart)).
|
|
|
|
```shell-session
|
|
$ vault policy write controller-ca-policy - <<EOF
|
|
path controller/cert/ca {
|
|
capabilities = ["read"]
|
|
}
|
|
EOF
|
|
```
|
|
|
|
```shell-session
|
|
$ vault policy write connect-inject-ca-policy - <<EOF
|
|
path connect-inject/cert/ca {
|
|
capabilities = ["read"]
|
|
}
|
|
EOF
|
|
```
|
|
1. Configure allowed domains for PKI certificates.
|
|
|
|
```shell-session
|
|
$ vault write controller/roles/controller-role \
|
|
allowed_domains="<Allowed-domains-string>" \
|
|
allow_subdomains=true \
|
|
allow_bare_domains=true \
|
|
allow_localhost=true \
|
|
generate_lease=true \
|
|
max_ttl="720h"
|
|
```
|
|
|
|
```shell-session
|
|
$ vault write connect-inject/roles/connect-inject-role \
|
|
allowed_domains="<Allowed-domains-string>" \
|
|
allow_subdomains=true \
|
|
allow_bare_domains=true \
|
|
allow_localhost=true \
|
|
generate_lease=true \
|
|
max_ttl="720h"
|
|
```
|
|
|
|
To generate the `<Allowed-domains-string>` for each use the following script as a template:
|
|
|
|
```shell-session
|
|
#!/bin/sh
|
|
|
|
# NAME is set to either the value from `global.name` from your Consul K8s value file, or your $HELM_RELEASE_NAME-consul
|
|
export NAME=consulk8s
|
|
# NAMESPACE is where the Consul on Kubernetes is installed
|
|
export NAMESPACE=consul
|
|
# DATACENTER is the value of `global.datacenter` from your Helm values config file
|
|
export DATACENTER=dc1
|
|
|
|
echo allowed_domains_controller=\"${NAME}-controller-webhook,${NAME}-controller-webhook.${NAMESPACE},${NAME}-controller-webhook.${NAMESPACE}.svc,${NAME}-controller-webhook.${NAMESPACE}.svc.cluster.local\""
|
|
|
|
echo allowed_domains_connect_inject=\"${NAME}-connect-injector,${NAME}-connect-injector.${NAMESPACE},${NAME}-connect-injector.${NAMESPACE}.svc,${NAME}-connect-injector.${NAMESPACE}.svc.cluster.local\""
|
|
```
|
|
|
|
1. Finally, Kubernetes auth roles need to be created for controller and connect inject webhooks.
|
|
|
|
|
|
The path to the secret referenced in the `path` resource is the same values that you will configure in the `global.secretsBackend.vault.controllerRole` and `global.secretsBackend.vault.connectInjectRole` Helm configuration (refer to [Update Consul on Kubernetes Helm chart](#update-consul-on-kubernetes-helm-chart)).
|
|
|
|
Role for Consul controller webhooks:
|
|
```shell-session
|
|
$ vault write auth/kubernetes/role/controller-role \
|
|
bound_service_account_names=<Consul controller service account> \
|
|
bound_service_account_namespaces=<Consul installation namespace> \
|
|
policies=controller-ca-policy \
|
|
ttl=1h
|
|
```
|
|
|
|
To find out the service account name of the Consul controller,
|
|
you can run:
|
|
|
|
```shell-session
|
|
$ helm template --release-name ${RELEASE_NAME} --show-only templates/controller-serviceaccount.yaml hashicorp/consul
|
|
```
|
|
|
|
Role for Consul connect inject webhooks:
|
|
|
|
```shell-session
|
|
$ vault write auth/kubernetes/role/connect-inject-role \
|
|
bound_service_account_names=<Consul connect inject service account> \
|
|
bound_service_account_namespaces=<Consul installation namespace> \
|
|
policies=connect-inject-ca-policy \
|
|
ttl=1h
|
|
```
|
|
|
|
To find out the service account name of the Consul connect inject, use the command below.
|
|
```shell-session
|
|
$ helm template --release-name ${RELEASE_NAME} --show-only templates/connect-inject-serviceaccount.yaml hashicorp/consul
|
|
```
|
|
|
|
## Update Consul on Kubernetes Helm chart
|
|
|
|
Now that we've configured Vault, you can configure the Consul Helm chart to
|
|
use the Server TLS certificates from Vault:
|
|
|
|
<CodeBlockConfig filename="values.yaml" linenumbers highlight="8,9,10,11,12,13,14,15,16,17,18,19">
|
|
|
|
```yaml
|
|
global:
|
|
secretsBackend:
|
|
vault:
|
|
enabled: true
|
|
consulServerRole: "consul-server"
|
|
consulClientRole: "consul-client"
|
|
consulCARole: "consul-ca"
|
|
controllerRole: "controller-role"
|
|
connectInjectRole: "connect-inject-role"
|
|
controller:
|
|
caCert:
|
|
secretName: "controller/cert/ca"
|
|
tlsCert:
|
|
secretName: "controller/issue/controller-role"
|
|
connectInject:
|
|
caCert:
|
|
secretName: "connect-inject/cert/ca"
|
|
tlsCert:
|
|
secretName: "connect-inject/issue/connect-inject-role"
|
|
tls:
|
|
enabled: true
|
|
enableAutoEncrypt: true
|
|
caCert:
|
|
secretName: "pki/cert/ca"
|
|
server:
|
|
serverCert:
|
|
secretName: "pki/issue/consul-server"
|
|
extraVolumes:
|
|
- type: "secret"
|
|
name: <vaultCASecret>
|
|
load: "false"
|
|
connectInject:
|
|
enabled: true
|
|
controller:
|
|
enabled: true
|
|
```
|
|
|
|
</CodeBlockConfig>
|
|
|
|
The `vaultCASecret` is the Kubernetes secret that stores the CA Certificate that is used for Vault communication. To provide a CA, you first need to create a Kubernetes secret containing the CA. For example, you may create a secret with the Vault CA like so:
|
|
|
|
```shell-session
|
|
$ kubectl create secret generic vault-ca --from-file vault.ca=/path/to/your/vault/
|
|
```
|