Deploying a New Greenplum Cluster

This section describes how to use the Greenplum Operator deploy a Greenplum cluster to your Kubernetes system. You can use these instructions either to deploy a brand new cluster (provisioning new, empty Persistent Volume Claims in Kubernetes), or to re-deploy an earlier cluster, re-using existing Persistent Volumes if available.

Prerequisites

This procedure requires that you first install the Greenplum for Kubernetes docker images and create the Greenplum Operator in your Kubernetes system. See Installing Greenplum for Kubernetes for more information.

Verify that the Greenplum Operator is installed and running in your system before you continue:

$ helm list

NAME                REVISION    UPDATED                     STATUS      CHART           APP VERSION     NAMESPACE
greenplum-operator  1           Thu Oct 11 15:38:54 2018    DEPLOYED    operator-0.1.0  1.0             default

Procedure

Go to the workspace subdirectory where you unpacked the Greenplum for Kubernetes distribution:
```
$ cd ./greenplum-for-kubernetes-*/workspace
```
If necessary, create a Kubernetes manifest file to specify the configuration of your Greenplum cluster. A sample file is provided in workspace/my-gp-instance.yaml. my-gp-instance.yaml contains the minimal set of instructions necessary to create a demonstration cluster named “my-greenplum” with a single segment (a single primary and mirror segment) and default storage, memory, and CPU settings:
```
apiVersion: "greenplum.pivotal.io/v1"
kind: "GreenplumCluster"
metadata:
  name: my-greenplum
spec:
  masterAndStandby:
    hostBasedAuthentication: |
      # host   all   gpadmin   1.2.3.4/32   trust
      # host   all   gpuser    0.0.0.0/0   md5
    memory: "800Mi"
    cpu: "0.5"
    storageClassName: standard
    storage: 1G
  segments:
    primarySegmentCount: 1
    memory: "800Mi"
    cpu: "0.5"
    storageClassName: standard
    storage: 2G
```
Most non-trivial clusters will require configuration changes to specify additional segments, cpu, memory, pg_hba.conf entries, and Storage Class resources. See Greenplum Operator Manifest File for information about these configuration parameters and change them as necessary before you continue.

If you want to re-deploy a Greenplum cluster that you previously deployed, simply locate the existing configuration file.
Use kubectl apply command and specify your manifest file to send the deployment request to the Greenplum Operator. For example, to use the sample my-gp-instance.yaml file:
```
$ kubectl apply -f ./my-gp-instance.yaml 
```
```
greenplumcluster.greenplum.pivotal.io/my-greenplum created
```
The Greenplum Operator deploys the necessary Greenplum resources according to your specification, and also populates a gpinitsystem configuration file necessary to initialize the Greenplum cluster. If there are no existing Persistent Volume Claims for the cluster, new PVCs are created and used for the deployment. If PVCs for the cluster already exist, they are used as-is with the available data.

Use watch kubectl get all and wait until all Greenplum cluster pods have the status Running:

$ watch kubectl get all

NAME                                      READY     STATUS    RESTARTS   AGE
pod/greenplum-operator-58dd68b9c5-frrbz   1/1       Running   3          3h
pod/master-0                              1/1       Running   0          1m
pod/master-1                              1/1       Running   0          1m
pod/segment-a-0                           1/1       Running   0          1m
pod/segment-b-0                           1/1       Running   0          1m

NAME                 TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
service/agent        ClusterIP      None            <none>        22/TCP           1m
service/greenplum    LoadBalancer   10.110.26.184   <pending>     5432:32686/TCP   1m
service/kubernetes   ClusterIP      10.96.0.1       <none>        443/TCP          22h

NAME                                 DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/greenplum-operator   1         1         1            1           3h

NAME                                            DESIRED   CURRENT   READY     AGE
replicaset.apps/greenplum-operator-58dd68b9c5   1         1         1         3h

NAME                         DESIRED   CURRENT   AGE
statefulset.apps/master      2         2         1m
statefulset.apps/segment-a   1         1         1m
statefulset.apps/segment-b   1         1         1m

Describe your Greenplum cluster to verify that it was created successfully:

$ kubectl describe greenplumClusters/my-greenplum

Name:         my-greenplum
Namespace:    default
Labels:       <none>
Annotations:  kubectl.kubernetes.io/last-applied-configuration:
                {"apiVersion":"greenplum.pivotal.io/v1","kind":"GreenplumCluster", "metadata":{"annotations":{},"name":"my-greenplum", "namespace":"default"...
API Version:  greenplum.pivotal.io/v1
Kind:         GreenplumCluster
Metadata:
  Creation Timestamp:  2019-01-10T22:15:40Z
  Generation:          1
  Resource Version:    28403
  Self Link:           /apis/greenplum.pivotal.io/v1/namespaces/default/ greenplumclusters/my-greenplum
  UID:                 43842f53-1525-11e9-941d-080027530600
Spec:
  Master And Standby:
    Cpu:                        0.5
    Host Based Authentication:  # host   all   gpadmin   1.2.3.4/32   trust
# host   all   gpuser    0.0.0.0/0   md5

    Memory:              800Mi
    Storage:             1G
    Storage Class Name:  standard
    Worker Selector:
  Segments:
    Cpu:                    0.5
    Memory:                 800Mi
    Primary Segment Count:  1
    Storage:                2G
    Storage Class Name:     standard
    Worker Selector:
Status:
  Instance Image:  greenplum-for-kubernetes:latest
  Phase:           Running
Events:
  Type    Reason   Age   From               Message
  ----    ------   ----  ----               -------
  Normal  created  12s   greenplumOperator  greenplumCluster created
  Normal  updated  12s   greenplumOperator  greenplumCluster updated successfully

The Phase should be Running and the Events should match the output above.

If you redeployed a previously-deployed Greenplum cluster, it uses any Persistent Volume Claims that were available. In this case, the master and segment data directories will already exist in their former state, and you can skip this step.

If you are deploying a brand new cluster, wait until all Greenplum pods show the status Running and then execute the wrap_initialize_cluster.bash script on the master-0 pod to initialize all Greenplum cluster segments:

$ kubectl exec -it master-0 /home/gpadmin/tools/wrap_initialize_cluster.bash

Key scanning started
*******************************
Initializing Greenplum for Kubernetes Cluster
*******************************
*******************************
SSH KeyScan started
*******************************
*******************************
Generating gpinitsystem_config
*******************************
Sub Domain for the cluster is: agent.default.svc.cluster.local
*******************************
Running gpinitsystem
*******************************
20181005:23:30:45:000101 gpinitsystem:master-0:gpadmin-[INFO]:-Environment variable $LOGNAME unset, will set to gpadmin
20181005:23:30:45:000101 gpinitsystem:master-0:gpadmin-[INFO]:-Checking configuration parameters, please wait...
...
*******************************
Running createdb
*******************************

At this point, you can work with the deployed Greenplum cluster by executing Greenplum utilities from within Kubernetes, or by using a locally-installed tool, such as psql, to access the Greenplum instance running in Kubernetes. For example, to run the psql utility on the master-0 pod:

$ kubectl exec -it master-0 bash -- -c "source /opt/gpdb/greenplum_path.sh; psql"

psql (8.3.23)
Type "help" for help.

gpadmin=# select * from gp_segment_configuration;

 dbid | content | role | preferred_role | mode | status | port  |               
  hostname                 |                   address                   | repli
cation_port 
------+---------+------+----------------+------+--------+-------+---------------
---------------------------+---------------------------------------------+------
------------
    1 |      -1 | p    | p              | s    | u      |  5432 | master-0      
                           | master-0.agent.default.svc.cluster.local    |      

    2 |       0 | p    | p              | s    | u      | 40000 | segment-a-0   
                           | segment-a-0.agent.default.svc.cluster.local |      
       6000
    3 |       0 | m    | m              | s    | u      | 50000 | segment-b-0   
                           | segment-b-0.agent.default.svc.cluster.local |      
       6001
    4 |      -1 | m    | m              | s    | u      |  5432 | master-1.agent
.default.svc.cluster.local | master-1.agent.default.svc.cluster.local    |      

(4 rows)

(Enter \q to exit the psql utility.)