etcd
etcd is an object-relational database management system (ORDBMS) with an emphasis on extensibility and on standards-compliance.
TL;DR
$ helm repo add bitnami https://charts.bitnami.com/bitnami
$ helm install my-release bitnami/etcd
Introduction
This chart bootstraps a etcd deployment on a Kubernetes cluster using the Helm package manager.
Bitnami charts can be used with Kubeapps for deployment and management of Helm Charts in clusters. This Helm chart has been tested on top of Bitnami Kubernetes Production Runtime (BKPR). Deploy BKPR to get automated TLS certificates, logging and monitoring for your applications.
Prerequisites
- Kubernetes 1.12+
- Helm 3.1.0
- PV provisioner support in the underlying infrastructure
Installing the Chart
To install the chart with the release name my-release:
$ helm repo add bitnami https://charts.bitnami.com/bitnami
$ helm install my-release bitnami/etcd
These commands deploy etcd on the Kubernetes cluster in the default configuration. The Parameters section lists the parameters that can be configured during installation.
Tip
: List all releases using
helm list
Uninstalling the Chart
To uninstall/delete the my-release deployment:
$ helm delete my-release
The command removes all the Kubernetes components associated with the chart and deletes the release.
Parameters
The following tables lists the configurable parameters of the etcd chart and their default values.
| Parameter | Description | Default |
|---|---|---|
global.imageRegistry |
Global Docker image registry | nil |
global.imagePullSecrets |
Global Docker registry secret names as an array | [] (does not add image pull secrets to deployed pods) |
global.storageClass |
Global storage class for dynamic provisioning | nil |
image.registry |
etcd image registry | docker.io |
image.repository |
etcd image name | bitnami/etcd |
image.tag |
etcd image tag | {TAG_NAME} |
image.pullPolicy |
etcd image pull policy | IfNotPresent |
image.pullSecrets |
Specify docker-registry secret names as an array | [] (does not add image pull secrets to deployed pods) |
image.debug |
Specify if debug values should be set | false |
nameOverride |
String to partially override etcd.fullname template with a string (will prepend the release name) | nil |
fullnameOverride |
String to fully override etcd.fullname template with a string | nil |
volumePermissions.enabled |
Enable init container that changes volume permissions in the data directory (for cases where the default k8s runAsUser and fsUser values do not work) |
false |
volumePermissions.image.registry |
Init container volume-permissions image registry | docker.io |
volumePermissions.image.repository |
Init container volume-permissions image name | bitnami/minideb |
volumePermissions.image.tag |
Init container volume-permissions image tag | buster |
volumePermissions.image.pullPolicy |
Init container volume-permissions image pull policy | Always |
volumePermissions.resources |
Init container resource requests/limit | nil |
statefulset.updateStrategy |
Update strategy for the stateful set | RollingUpdate |
statefulset.rollingUpdatePartition |
Partition for Rolling Update strategy | nil |
statefulset.podManagementPolicy |
Pod management policy for the stateful set | OrderedReady |
statefulset.replicaCount |
Number of etcd nodes | 1 |
configFileConfigMap |
ConfigMap that contains a etcd.conf.yaml to be mounted | nil |
envVarsConfigMap |
ConfigMap that contains environment variables to be set in the container | nil |
allowNoneAuthentication |
Allow to use etcd without configuring RBAC authentication | true |
maxProcs |
Set GOMAXPROCS environment variable to limit the number of CPUs | nil |
etcd.initialClusterState |
Initial cluster state. Allowed values: 'new' or 'existing' | nil |
auth.rbac.enabled |
Switch to enable the etcd authentication. | true |
auth.rbac.rootPassword |
Password for the root user | nil |
auth.rbac.existingSecret |
Name of the existing secret containing the root password | nil |
auth.client.secureTransport |
Switch to encrypt client communication using TLS certificates | false |
auth.client.useAutoTLS |
Switch to automatically create the TLS certificates | false |
auth.client.enableAuthentication |
Switch to enable host authentication using TLS certificates. Requires existing secret. | secret |
auth.client.existingSecret |
Name of the existing secret containing cert files for client communication. | nil |
auth.client.certFilename |
Name of the file containing the client certificate. | cert.pem |
auth.client.certKeyFilename |
Name of the file containing the client certificate private key. | key.pem |
auth.client.caFilename |
Name of the file containing the client CA certificate. If not specified and enableAuthentication or rbac.enabled is true, the default is is ca.crt. |
"" |
auth.peer.secureTransport |
Switch to encrypt peer communication using TLS certificates | false |
auth.peer.useAutoTLS |
Switch to automatically create the TLS certificates | false |
auth.peer.enableAuthentication |
Switch to enable host authentication using TLS certificates. Requires existing secret. | false |
auth.peer.existingSecret |
Name of the existing secret containing cert files for peer communication. | nil |
auth.peer.certFilename |
Name of the file containing the peer certificate. | cert.pem |
auth.peer.certKeyFilename |
Name of the file containing the peer certificate private key. | key.pem |
auth.peer.caFilename |
Name of the file containing the peer CA certificate. If not specified and enableAuthentication or rbac.enabled is true, the default is is ca.crt. |
"" |
securityContext.enabled |
Enable security context | true |
securityContext.fsGroup |
Group ID for the container | 1001 |
securityContext.runAsUser |
User ID for the container | 1001 |
clusterDomain |
Default Kubernetes cluster domain | cluster.local |
service.type |
Kubernetes Service type | ClusterIP |
service.port |
etcd client port | 2379 |
service.clientPortNameOverride |
etcd client port name override | "" |
service.peerPort |
etcd peer port | 2380 |
service.peerPortNameOverride |
etcd peer port name override | "" |
service.nodePorts.clientPort |
Kubernetes etcd client node port | "" |
service.nodePorts.peerPort |
Kubernetes etcd peer node port | "" |
service.annotations |
Annotations for etcd service | {} |
service.loadBalancerIP |
loadBalancerIP if etcd service type is LoadBalancer |
nil |
service.loadBalancerSourceRanges |
loadBalancerSourceRanges if etcd service type is LoadBalancer |
nil |
service.externalIPs |
externalIPs for if etcd service | nil |
persistence.enabled |
Enable persistence using PVC | true |
persistence.storageClass |
PVC Storage Class for etcd volume | nil |
persistence.accessMode |
PVC Access Mode for etcd volume | ReadWriteOnce |
persistence.selector |
PVC label selector for etcd volume | {} |
persistence.size |
PVC Storage Request for etcd volume | 8Gi |
persistence.annotations |
Annotations for the PVC | {} |
pdb.enabled |
Pod Disruption Budget toggle | false |
pdb.minAvailable |
Minimum available pods | nil |
pdb.maxUnavailable |
Maximum unavailable pods | nil |
resources |
CPU/Memory resource requests/limits | Memory: 256Mi, CPU: 250m |
livenessProbe.enabled |
Turn on and off liveness probe | true |
livenessProbe.initialDelaySeconds |
Delay before liveness probe is initiated | 10 |
livenessProbe.periodSeconds |
How often to perform the probe | 10 |
livenessProbe.timeoutSeconds |
When the probe times out | 5 |
livenessProbe.failureThreshold |
Minimum consecutive failures for the probe to be considered failed after having succeeded. | 2 |
livenessProbe.successThreshold |
Minimum consecutive successes for the probe to be considered successful after having failed | 1 |
readinessProbe.enabled |
Turn on and off readiness probe | true |
readinessProbe.initialDelaySeconds |
Delay before liveness probe is initiated | 15 |
readinessProbe.periodSeconds |
How often to perform the probe | 10 |
readinessProbe.timeoutSeconds |
When the probe times out | 5 |
readinessProbe.failureThreshold |
Minimum consecutive failures for the probe to be considered failed after having succeeded. | 6 |
readinessProbe.successThreshold |
Minimum consecutive successes for the probe to be considered successful after having failed | 1 |
statefulsetLabels |
Extra statefulset labels | {} (evaluated as a template) |
podAnnotations |
Annotations to be added to pods | {} |
podLabels |
Extra pod labels | {} (evaluated as a template) |
podAffinityPreset |
Pod affinity preset. Ignored if affinity is set. Allowed values: soft or hard |
"" |
podAntiAffinityPreset |
Pod anti-affinity preset. Ignored if affinity is set. Allowed values: soft or hard |
soft |
nodeAffinityPreset.type |
Node affinity preset type. Ignored if affinity is set. Allowed values: soft or hard |
"" |
nodeAffinityPreset.key |
Node label key to match Ignored if affinity is set. |
"" |
nodeAffinityPreset.values |
Node label values to match. Ignored if affinity is set. |
[] |
affinity |
Affinity for pod assignment | {} (evaluated as a template) |
nodeSelector |
Node labels for pod assignment | {} (evaluated as a template) |
tolerations |
Tolerations for pod assignment | [] (evaluated as a template) |
priorityClassName |
Name of the existing priority class to be used by etcd pods. | "" |
metrics.enabled |
Enable Prometheus exporter to expose etcd metrics | false |
metrics.podAnnotations |
Annotations for enabling prometheus to access the metrics endpoint | {prometheus.io/scrape: "true",prometheus.io/port: "2379"} |
metrics.serviceMonitor.enabled |
if true, creates a Prometheus Operator ServiceMonitor (also requires metrics.enabled to be true) |
false |
metrics.serviceMonitor.namespace |
Namespace in which Prometheus is running | nil |
metrics.serviceMonitor.interval |
Interval at which metrics should be scraped. | nil (Prometheus Operator default value) |
metrics.serviceMonitor.metricRelabelings |
MetricRelabelConfigs to apply to samples before ingestion scraping | [] |
metrics.serviceMonitor.relabelings |
RelabelConfigs to apply to samples before ingestion | [] |
metrics.serviceMonitor.scheme |
HTTP scheme to use for scraping | "" (Prometheus Operator default value) |
metrics.serviceMonitor.scrapeTimeout |
Timeout after which the scrape is ended | nil (Prometheus Operator default value) |
metrics.serviceMonitor.selector |
Prometheus instance selector labels | nil |
metrics.serviceMonitor.tlsConfig |
TLS configuration used for scrape endpoints used by Prometheus | nil |
startFromSnapshot.enabled |
Initialize new cluster recovering an existing snapshot | false |
startFromSnapshot.existingClaim |
PVC containing the existing snapshot | nil |
startFromSnapshot.snapshotFilename |
Snapshot filename | nil |
disasterRecovery.enabled |
Enable auto disaster recovery by periodically snapshotting the keyspace | false |
disasterRecovery.debug |
Enable debug logging for snapshots | false |
disasterRecovery.cronjob.schedule |
Schedule in Cron format to save snapshots | */30 * * * * |
disasterRecovery.cronjob.historyLimit |
Number of successful finished jobs to retain | 1 |
disasterRecovery.cronjob.snapshotHistoryLimit |
Number of etcd snapshots to retain, tagged by date | 1 |
disasterRecovery.cronjob.podAnnotations |
Pod annotations for cronjob pods | {} |
disasterRecovery.pvc.existingClaim |
Provide an existing PersistentVolumeClaim, the value is evaluated as a template. |
nil |
disasterRecovery.pvc.size |
PVC Storage Request | 2Gi |
disasterRecovery.pvc.storageClassName |
Storage Class for snapshots volume | nfs |
Specify each parameter using the --set key=value[,key=value] argument to helm install. For example,
$ helm install my-release \
--set auth.rbac.rootPassword=secretpassword bitnami/etcd
The above command sets the etcd root account password to secretpassword.
Alternatively, a YAML file that specifies the values for the parameters can be provided while installing the chart. For example,
$ helm install my-release -f values.yaml bitnami/etcd
Tip
: You can use the default values.yaml
Configuration and installation details
Rolling VS Immutable tags
It is strongly recommended to use immutable tags in a production environment. This ensures your deployment does not change automatically if the same tag is updated with a different image.
Bitnami will release a new chart updating its containers if a new version of the main container, significant changes, or critical vulnerabilities exist.
Using custom configuration
In order to use custom configuration parameters, two options are available:
- Using environment variables: etcd allows setting environment variables that map to configuration settings. In order to set extra environment variables, use the
envVarsConfigMapvalue to point to a ConfigMap (shown in the below example) that contains them. This ConfigMap can be created with the-f /tmp/configurationEnvVars.yamlflag. Then deploy the chart with theenvVarsConfigMap=etcd-env-varsparameter:
$ cat << EOF > /tmp/configurationEnvVars.yaml
apiVersion: v1
kind: ConfigMap
metadata:
name: etcd-env-vars
namespace: default
data:
ETCD_AUTO_COMPACTION_RETENTION: "0"
ETCD_HEARTBEAT_INTERVAL: "150"
EOF
- Using a custom
etcd.conf.yml: The etcd chart allows mounting a custom etcd.conf.yml file as ConfigMap (named, for example, etcd-conf) and deploy it using theconfigFileConfigMap=etcd-confparameter.
Enable security for etcd
Configure RBAC
In order to enable Role-based access control for etcd you can set the following parameters:
auth.rbac.enabled=true
auth.rbac.rootPassword=YOUR-PASSWORD
The previous command will deploy etcd creating a root user with its associate root role with access to everything. The rest of users will use the guest role and won't have permissions to do anything.
Configure certificated for peer communication
In order to enable secure transport between peer nodes deploy the helm chart with these options:
auth.peer.secureTransport=true
auth.peer.useAutoTLS=true
Configure certificates for client communication
In order to enable secure transport between client and server you have to create a secret containing the cert and key files and the CA used to sign those client certificates.
You can create that secret and deploy the helm chart with these options:
auth.client.secureTransport=true
auth.client.enableAuthentication=true
auth.client.existingSecret=etcd-client-certs
Ref: etcd security model
Disaster recovery
You can enable auto disaster recovery by periodically snapshotting the keyspace. If the cluster permanently loses more than (N-1)/2 members, it tries to recover the cluster from a previous snapshot. You can enable it using the following parameters:
persistence.enabled=true
disasterRecovery.enabled=true
disasterRecovery.pvc.size=2Gi
disasterRecovery.pvc.storageClassName=nfs
If startFromSnapshot is enabled at the same time than disasterRecovery, the PVC provided via startFromSnapshot.existingClaim will be used to store the periodical snapshots.
Note
: Disaster recovery feature requires using volumes with ReadWriteMany access mode. For instance, you can use the stable/nfs-server-provisioner chart to provide NFS PVCs.
Setting Pod's affinity
This chart allows you to set your custom affinity using the affinity parameter. Find more information about Pod's affinity in the kubernetes documentation.
As an alternative, you can use of the preset configurations for pod affinity, pod anti-affinity, and node affinity available at the bitnami/common chart. To do so, set the podAffinityPreset, podAntiAffinityPreset, or nodeAffinityPreset parameters.
Persistence
The Bitnami etcd image stores the etcd data at the /bitnami/etcd path of the container. Persistent Volume Claims are used to keep the data across statefulsets.
By default, the chart mounts a Persistent Volume at this location. The volume is created using dynamic volume provisioning. See the Parameters section to configure the PVC.
Adjust permissions of persistent volume mountpoint
As the image run as non-root by default, it is necessary to adjust the ownership of the persistent volume so that the container can write data into it.
By default, the chart is configured to use Kubernetes Security Context to automatically change the ownership of the volume. However, this feature does not work in all Kubernetes distributions. As an alternative, this chart supports using an initContainer to change the ownership of the volume before mounting it in the final destination.
You can enable this initContainer by setting volumePermissions.enabled to true.
Troubleshooting
Find more information about how to deal with common errors related to Bitnami’s Helm charts in this troubleshooting guide.
Upgrading
5.2.0
This version also introduces bitnami/common, a library chart as a dependency. More documentation about this new utility could be found here. Please, make sure that you have updated the chart dependencies before executing any upgrade.
To 5.0.0
On November 13, 2020, Helm v2 support was formally finished, this major version is the result of the required changes applied to the Helm Chart to be able to incorporate the different features added in Helm v3 and to be consistent with the Helm project itself regarding the Helm v2 EOL.
What changes were introduced in this major version?
- Previous versions of this Helm Chart use
apiVersion: v1(installable by both Helm 2 and 3), this Helm Chart was updated toapiVersion: v2(installable by Helm 3 only). Here you can find more information about theapiVersionfield. - The different fields present in the Chart.yaml file has been ordered alphabetically in a homogeneous way for all the Bitnami Helm Charts
Considerations when upgrading to this version
- If you want to upgrade to this version from a previous one installed with Helm v3, you shouldn't face any issues
- If you want to upgrade to this version using Helm v2, this scenario is not supported as this version doesn't support Helm v2 anymore
- If you installed the previous version with Helm v2 and wants to upgrade to this version with Helm v3, please refer to the official Helm documentation about migrating from Helm v2 to v3
Useful links
- https://docs.bitnami.com/tutorials/resolve-helm2-helm3-post-migration-issues/
- https://helm.sh/docs/topics/v2_v3_migration/
- https://helm.sh/blog/migrate-from-helm-v2-to-helm-v3/
To 4.4.14
In this release we addressed a vulnerability that showed the ETCD_ROOT_PASSWORD environment variable in the application logs. Users are advised to update immediately. More information in this issue.
To 3.0.0
Backwards compatibility is not guaranteed. The following notables changes were included:
- etcdctl uses v3 API.
- Adds support for auto disaster recovery.
- Labels are adapted to follow the Helm charts best practices.
To upgrade from previous charts versions, create a snapshot of the keyspace and restore it in a new etcd cluster. Only v3 API data can be restored. You can use the command below to upgrade your chart by starting a new cluster using an existing snapshot, available in an existing PVC, to initialize the members:
$ helm install new-release bitnami/etcd \
--set statefulset.replicaCount=3 \
--set persistence.enabled=true \
--set persistence.size=8Gi \
--set startFromSnapshot.enabled=true \
--set startFromSnapshot.existingClaim=my-claim \
--set startFromSnapshot.snapshotFilename=my-snapshot.db
To 1.0.0
Backwards compatibility is not guaranteed unless you modify the labels used on the chart's deployments. Use the workaround below to upgrade from versions previous to 1.0.0. The following example assumes that the release name is etcd:
$ kubectl delete statefulset etcd --cascade=false