mirror of https://github.com/status-im/consul.git
315 lines
11 KiB
Plaintext
315 lines
11 KiB
Plaintext
---
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layout: docs
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page_title: Install with Helm Chart - Kubernetes
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description: >-
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Consul can run directly on Kubernetes, both in server or client mode. For
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pure-Kubernetes workloads, this enables Consul to also exist purely within
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Kubernetes. For heterogeneous workloads, Consul agents can join a server
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running inside or outside of Kubernetes.
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---
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# Installing Consul on Kubernetes
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Consul can run directly on Kubernetes, both in server or client mode.
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For pure-Kubernetes workloads, this enables Consul to also exist purely
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within Kubernetes. For heterogeneous workloads, Consul agents can join
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a server running inside or outside of Kubernetes.
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You can install Consul on Kubernetes using the following methods:
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1. [Helm chart install](#helm-chart-installation)
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1. [Consul K8s CLI install <sup>BETA</sup>.](#consul-k8s-cli-installation)
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Refer to the [architecture](/docs/k8s/installation/install#architecture) section to learn more about the general architecture of Consul on Kubernetes.
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For a hands-on experience with Consul as a service mesh
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for Kubernetes, follow the [Getting Started with Consul service
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mesh](https://learn.hashicorp.com/tutorials/consul/service-mesh-deploy?utm_source=WEBSITE&utm_medium=WEB_IO&utm_offer=ARTICLE_PAGE&utm_content=DOCS) tutorial.
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## Helm Chart Installation
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The recommended way to run Consul on Kubernetes is via the
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[Helm chart](/docs/k8s/helm). This will install and configure
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all the necessary components to run Consul. The configuration enables you
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to run a server cluster, a client cluster, or both.
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Step-by-step tutorials for how to deploy Consul to Kubernetes, please see
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our [Deploy to Kubernetes](https://learn.hashicorp.com/collections/consul/kubernetes-deploy)
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collection. This collection includes configuration caveats for single-node deployments.
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The Helm chart exposes several useful configurations and automatically
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sets up complex resources, but it **does not automatically operate Consul.**
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You must still become familiar with how to monitor, backup,
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upgrade, etc. the Consul cluster.
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The Helm chart has no required configuration and will install a Consul
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cluster with default configurations. We strongly recommend [learning about the configuration options](/docs/k8s/helm#configuration-values) prior to going to production.
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~> **Security Warning:** By default, the chart will install an insecure configuration
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of Consul. This provides a less complicated out-of-box experience for new users,
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but is not appropriate for a production setup. We strongly recommend using
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a properly-secured Kubernetes cluster or making sure that you understand and enable
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the [recommended security features](/docs/internals/security). Currently,
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some of these features are not supported in the Helm chart and require additional
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manual configuration.
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### Prerequisites
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The Consul Helm only supports Helm 3.2+. Install the latest version of the Helm CLI here:
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[Installing Helm](https://helm.sh/docs/intro/install/).
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### Installing Consul
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1. Add the HashiCorp Helm Repository:
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```shell-session
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$ helm repo add hashicorp https://helm.releases.hashicorp.com
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"hashicorp" has been added to your repositories
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```
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1. Verify that you have access to the consul chart:
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```shell-session
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$ helm search repo hashicorp/consul
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NAME CHART VERSION APP VERSION DESCRIPTION
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hashicorp/consul 0.35.0 1.10.3 Official HashiCorp Consul Chart
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```
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1. Prior to installing via Helm, ensure that the `consul` Kubernetes namespace does not exist, as installing on a dedicated namespace
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is recommended.
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```shell-session
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$ kubectl get namespace
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NAME STATUS AGE
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default Active 18h
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kube-node-lease Active 18h
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kube-public Active 18h
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kube-system Active 18h
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```
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1. Issue the following command to install Consul with the default configuration using Helm. You could also install Consul on a dedicated
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namespace of your choosing by modifying the value of the `-n` flag for the Helm install.
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```shell-session
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$ helm install consul hashicorp/consul --set global.name=consul --create-namespace -n consul
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NAME: consul
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...
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```
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The Helm chart does everything to set up a recommended Consul-on-Kubernetes deployment.
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After installation, a Consul cluster will be formed, a leader will be elected, and every node will have a running Consul agent.
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### Customizing Your Installation
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If you want to customize your installation,
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create a `config.yaml` file to override the default settings.
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You can learn what settings are available by running `helm inspect values hashicorp/consul`
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or by reading the [Helm Chart Reference](/docs/k8s/helm).
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For example, if you want to enable the [Consul Connect](/docs/k8s/connect) feature,
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use the following config file:
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<CodeBlockConfig filename="config.yaml">
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```yaml
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global:
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name: consul
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connectInject:
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enabled: true
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controller:
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enabled: true
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```
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</CodeBlockConfig>
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Once you've created your `config.yaml` file, run `helm install` with the `-f` flag:
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```shell-session
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$ helm install consul hashicorp/consul --create-namespace -n consul -f config.yaml
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NAME: consul
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...
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```
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If you've already installed Consul and want to make changes, you'll need to run
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`helm upgrade`. See [Upgrading](/docs/k8s/operations/upgrading) for more details.
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## Consul K8s CLI Installation
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You can install Consul on Kubernetes using the Consul K8s CLI tool.
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The tool is currently availabe as an alpha release and is not recommended for production environments.
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1. Download and build the CLI as described in the [Consul K8s CLI reference](/docs/k8s/k8s-cli).
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1. Issue the `install` subcommand to install Consul on Kubernetes:
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```shell-session
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consul-k8s install <OPTIONS>
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```
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Refer to the [Consul K8s CLI reference](/docs/k8s/k8s-cli) for details about all commands and available options.
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If you did not set the `-auto-approve` option to `true`, you will be prompted to proceed with the installation if the pre-install checks pass.
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```shell-session
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==> Pre-Install Checks
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✓ No existing installations found
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✓ No previous persistent volume claims found
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✓ No previous secrets found
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==> Consul Installation Summary
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Installation name: consul
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Namespace: myns
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Overrides:
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connectInject:
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enabled: true
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global:
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name: consul
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server:
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bootstrapExpect: 1
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replicas: 1
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Proceed with installation? (y/n)
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```
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1. Enter `y` to proceed. The pre-install checks may fail if existing `PersistentVolumeClaims` (PVC) are detected. Refer to the [uninstall instructions](/docs/k8s/operations/uninstall#uninstall-consul) for information about removing PVCs.
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## Viewing the Consul UI
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The Consul UI is enabled by default when using the Helm chart.
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For security reasons, it isn't exposed via a `LoadBalancer` Service by default so you must
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use `kubectl port-forward` to visit the UI.
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#### TLS Disabled
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If running with TLS disabled, the Consul UI will be accessible via http on port 8500:
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```shell-session
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$ kubectl port-forward service/consul-server 8500:8500
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...
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```
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Once the port is forwarded navigate to [http://localhost:8500](http://localhost:8500).
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#### TLS Enabled
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If running with TLS enabled, the Consul UI will be accessible via https on port 8501:
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```shell-session
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$ kubectl port-forward service/consul-server 8501:8501
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...
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```
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Once the port is forwarded navigate to [https://localhost:8501](https://localhost:8501).
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~> You'll need to click through an SSL warning from your browser because the
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Consul certificate authority is self-signed and not in the browser's trust store.
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#### ACLs Enabled
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If ACLs are enabled, you will need to input an ACL token into the UI in order
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to see all resources and make modifications.
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To retrieve the bootstrap token that has full permissions, run:
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```shell-session
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$ kubectl get secrets/consul-bootstrap-acl-token --template='{{.data.token | base64decode }}'
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e7924dd1-dc3f-f644-da54-81a73ba0a178%
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```
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Then paste the token into the UI under the ACLs tab (without the `%`).
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~> NOTE: If using multi-cluster federation, your kubectl context must be in the primary datacenter
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to retrieve the bootstrap token since secondary datacenters use a separate token
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with less permissions.
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### Exposing the UI via a service
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If you want to expose the UI via a Kubernetes Service, configure
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the [`ui.service` chart values](/docs/k8s/helm#v-ui-service).
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This service will allow requests to the Consul servers so it should
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not be open to the world.
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## Accessing the Consul HTTP API
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The Consul HTTP API should be accessed by communicating to the local agent
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running on the same node. While technically any listening agent (client or
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server) can respond to the HTTP API, communicating with the local agent
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has important caching behavior, and allows you to use the simpler
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[`/agent` endpoints for services and checks](/api/agent).
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For Consul installed via the Helm chart, a client agent is installed on
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each Kubernetes node. This is explained in the [architecture](/docs/k8s/installation/install#client-agents)
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section. To access the agent, you may use the
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[downward API](https://kubernetes.io/docs/tasks/inject-data-application/downward-api-volume-expose-pod-information/).
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An example pod specification is shown below. In addition to pods, anything
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with a pod template can also access the downward API and can therefore also
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access Consul: StatefulSets, Deployments, Jobs, etc.
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```yaml
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apiVersion: v1
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kind: Pod
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metadata:
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name: consul-example
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spec:
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containers:
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- name: example
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image: 'consul:latest'
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env:
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- name: HOST_IP
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valueFrom:
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fieldRef:
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fieldPath: status.hostIP
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command:
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- '/bin/sh'
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- '-ec'
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- |
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export CONSUL_HTTP_ADDR="${HOST_IP}:8500"
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consul kv put hello world
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restartPolicy: Never
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```
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An example `Deployment` is also shown below to show how the host IP can
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be accessed from nested pod specifications:
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<CodeBlockConfig highlight="18-28">
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```yaml
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apiVersion: apps/v1
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kind: Deployment
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metadata:
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name: consul-example-deployment
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spec:
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replicas: 1
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selector:
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matchLabels:
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app: consul-example
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template:
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metadata:
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labels:
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app: consul-example
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spec:
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containers:
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- name: example
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image: 'consul:latest'
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env:
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- name: HOST_IP
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valueFrom:
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fieldRef:
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fieldPath: status.hostIP
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command:
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- '/bin/sh'
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- '-ec'
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- |
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export CONSUL_HTTP_ADDR="${HOST_IP}:8500"
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consul kv put hello world
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```
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</CodeBlockConfig>
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## Next Steps
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If you are still considering a move to Kubernetes, or to Consul on Kubernetes specifically, our [Migrate to Microservices with Consul Service Mesh on Kubernetes](https://learn.hashicorp.com/collections/consul/microservices?utm_source=WEBSITE&utm_medium=WEB_IO&utm_offer=ARTICLE_PAGE&utm_content=DOCS)
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collection uses an example application written by a fictional company to illustrate why and how organizations can
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migrate from monolith to microservices using Consul service mesh on Kubernetes. The case study in this collection
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should provide information valuable for understanding how to develop services that leverage Consul during any stage
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of your microservices journey.
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