在 Kubernetes 上创建副本数据库
如何使用 Database Controller 创建和自动化数据库副本
| 适用于 Kubernetes 的 Redis Enterprise |
|---|
您可以通过在
这replicaSources部分。
必须使用stringData部分，如下所示：
使用副本源 URI 创建一个密钥，该 URI 列在stringData字段，如下所示：
apiVersion: v1
kind: Secret
metadata:
name: my-replica-source
stringData:
uri: <replica-source-uri-goes-here>
The replica source URL can be retrieved by going to "UI > database > configuration > Press the button Get Replica of source URL"
in the administrative UI. But, this information can also be retrieved directly from
the REST API as well.
A replica of database CR simply uses the secret in the replicaSources section:
apiVersion: app.redislabs.com/v1alpha1
kind: RedisEnterpriseDatabase
metadata:
name: name-of-replica
spec:
redisEnterpriseCluster:
name: name-of-cluster
replicaSources:
- replicaSourceType: SECRET
replicaSourceName: my-replica-source
In the above, name-of-replica database will be created as a replica of the
source database as long as the source database exists on the source cluster
and the secret contains the correct replica source URL for that database.
Retrieving the replica source URL via kubectl
You will need kubectl, curl, and jq installed for this procedure.
-
Set your metadata:
CLUSTER_NAME=test
SOURCE_DB=db1
TARGET_DB=db2
TARGET_CLUSTER_NAME=test
-
Retrieve the cluster authentication:
CLUSTER_USER=`kubectl get secret/${CLUSTER_NAME} -o json | jq -r .data.username | base64 -d`
CLUSTER_PASSWORD=`kubectl get secret/${CLUSTER_NAME} -o json | jq -r .data.password | base64 -d`
-
Forward the port of the REST API service for your source cluster:
kubectl port-forward pod/${CLUSTER_NAME}-0 9443
-
Request the information from the REST API:
JQ='.[] | select(.name=="'
JQ+="${SOURCE_DB}"
JQ+='") | ("redis://admin:" + .authentication_admin_pass + "@"+.name+":"+(.endpoints[0].port|tostring))'
URI=`curl -sf -k -u "$CLUSTER_USER:$CLUSTER_PASSWORD" "https://localhost:9443/v1/bdbs?fields=uid,name,endpoints,authentication_admin_pass" | jq "$JQ" | sed 's/"//g'`
Note: URI now contains the replica source URI.
-
Construct the secret for the replica:
cat << EOF > secret.yaml
apiVersion: v1
kind: Secret
metadata:
name: ${SOURCE_DB}-url
stringData:
uri: ${URI}
EOF
kubectl apply -f secret.yaml
-
Create the replica database:
cat << EOF > target.yaml
apiVersion: app.redislabs.com/v1alpha1
kind: RedisEnterpriseDatabase
metadata:
name: ${TARGET_DB}
spec:
redisEnterpriseCluster:
name: ${TARGET_CLUSTER_NAME}
replicaSources:
- replicaSourceType: SECRET
replicaSourceName: ${SOURCE_DB}-url
EOF
kubectl apply -f target.yaml
Automating the creation via a job
The following procedure uses a ConfigMap and a Job to construct the replica
source URL secret from the source database and configure the target database.
There are four parameters:
source - the name of the source databasecluster - the name of the cluster for the source databasetarget - the name of the target databasetargetCluster - the name of the cluster for the target database
These parameters can be set by:
kubectl create configmap replica-of-database-parameters \
--from-literal=source=name-of-source \
--from-literal=cluster=name-of-cluster \
--from-literal=target=name-of-target \
--from-literal=targetCluster=name-of-cluster
where "name-of-..." is replaced with the database source, source cluster,
database target, and target cluster names.
The Job and ConfigMap below, when submitted, will create the secret and
replica database:
apiVersion: batch/v1
kind: Job
metadata:
name: replica-of-database
spec:
backoffLimit: 4
template:
spec:
serviceAccountName: redis-enterprise-operator
restartPolicy: Never
volumes:
- name: scripts
configMap:
name: replica-of-database
containers:
- name: createdb
image: debian:stable-slim
env:
- name: MY_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
- name: SCRIPT
value: create.sh
- name: SOURCE_DB
valueFrom:
configMapKeyRef:
name: replica-of-database-parameters
key: source
- name: TARGET_DB
valueFrom:
configMapKeyRef:
name: replica-of-database-parameters
key: target
- name: CLUSTER_SERVICE
value: .svc.cluster.local
- name: CLUSTER_NAME
valueFrom:
configMapKeyRef:
name: replica-of-database-parameters
key: cluster
- name: CLUSTER_PORT
value: "9443"
- name: TARGET_CLUSTER_NAME
valueFrom:
configMapKeyRef:
name: replica-of-database-parameters
key: targetCluster
volumeMounts:
- mountPath: /opt/scripts/
name: scripts
command:
- /bin/bash
- -c
- |
apt-get update; apt-get install -y curl jq apt-transport-https gnupg2
apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 6A030B21BA07F4FB
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
echo "deb https://apt.kubernetes.io/ kubernetes-xenial main" | tee -a /etc/apt/sources.list.d/kubernetes.list
apt-get update
apt-get install -y kubectl
bash /opt/scripts/$SCRIPT
---
apiVersion: v1
kind: ConfigMap
metadata:
name: replica-of-database
data:
create.sh: |
CLUSTER_USER=`kubectl get secret/${CLUSTER_NAME} -o json | jq -r .data.username | base64 -d`
CLUSTER_PASSWORD=`kubectl get secret/${CLUSTER_NAME} -o json | jq -r .data.password | base64 -d`
CLUSTER_HOST=${CLUSTER_NAME}.${MY_NAMESPACE}${CLUSTER_SERVICE}
JQ='.[] | select(.name=="'
JQ+="${SOURCE_DB}"
JQ+='") | ("redis://admin:" + .authentication_admin_pass + "@"+.endpoints[0].dns_name+":"+(.endpoints[0].port|tostring))'
URI=`curl -sf -k -u "$CLUSTER_USER:$CLUSTER_PASSWORD" "https://${CLUSTER_HOST}:${CLUSTER_PORT}/v1/bdbs?fields=uid,name,endpoints,authentication_admin_pass" | jq "$JQ" | sed 's/"//g'`
echo "URL: ${URL}"
echo ""
cat << EOF > /tmp/secret.yaml
apiVersion: v1
kind: Secret
metadata:
name: ${SOURCE_DB}-url
stringData:
uri: ${URI}
EOF
cat /tmp/secret.yaml
cat << EOF > /tmp/target.yaml
apiVersion: app.redislabs.com/v1alpha1
kind: RedisEnterpriseDatabase
metadata:
name: ${TARGET_DB}
spec:
redisEnterpriseCluster:
name: ${TARGET_CLUSTER_NAME}
replicaSources:
- replicaSourceType: SECRET
replicaSourceName: ${SOURCE_DB}-url
EOF
echo "---"
cat /tmp/target.yaml
echo ""
kubectl -n ${MY_NAMESPACE} apply -f /tmp/secret.yaml
kubectl -n ${MY_NAMESPACE} apply -f /tmp/target.yaml
On this page