This example shows how you can backup and restore the application that is deployed using DeploymentConfig, OpenShift's resource on an OpenShift cluster. Like Deployment, Statefulset in Kubernetes, OpenShift has another controller named DeploymentConfig, it is almost like Deployment but has some significant differences.
DeploymentConfig is not standard Kubernetes resource but OpenShift resource and creates a new ReplicationController and let's it start up Pods.
This example can be followed if your application is deployed on OpenShift cluster's DeploymentConfig resources.
- Setup OpenShift, you can follow steps mentioned below
- PV provisioner support in the underlying infrastructure
- Kanister controller version 0.106.0 installed in your cluster in namespace
kanister - Kanctl CLI installed (https://docs.kanister.io/tooling.html#kanctl)
To test the applications that are deployed on OpenShift using DeploymentConfig, we will first have to setup OpenShift cluster. To setup the OpenShift cluster in our local environment we are going to use minishift. To install and setup minishift please follow this guide.
Once we have minishift setup we will go ahead and deploy PostgreSQL application on the minishift cluster using DeploymentConfig and try to backup and restore the data from the application.
Note
Once you have setup minishift by following the steps mentioned above, you can interact with the cluster using oc command line tool. By default
you are logged in as developer user, that will prevent us from creating some of the resources so please make sure you login as admin by
the following command
oc login -u system:admin
and you are all set to go through rest of this example.
We will use the JSON templates, as described here, provided by OpenShift to deploy the PostgreSQL database on the minishift cluster that we have just setup.
To install the PostgreSQL on your cluster please run below command
# Create the namespaces
~ oc create ns postgres-test
namespace/postgres-test created
# Install the database
~ oc new-app https://raw.githubusercontent.com/openshift/origin/master/examples/db-templates/postgresql-persistent-template.json -n postgres-test \
-e POSTGRESQL_ADMIN_PASSWORD=secretpasswordWe can use the environment variable POSTGRESQL_ADMIN_PASSWORD to set the ADMIN password for our PostgreSQL installation. Once the database is installed, fetch all the pods from the namespace to make sure all the pods are in Running status.
~ oc get pods -n postgres-test
NAME READY STATUS RESTARTS AGE
postgresql-1-72k8g 1/1 Running 0 2mNote
The secret that gets created after installation of PostgreSQL doesn't have the ADMIN password that we have just specified and this password gets used by the blueprint to connect to the PostgreSQL instance and perform the activities.
To address above issue, we will have to manually create a secret that will have this ADMIN password for the key postgresql_admin_password. Please use below command to create the secret
~ oc create secret generic postgresql-postgres-test -n postgres-test --from-literal=postgresql_admin_password=secretpassword
secret/postgresql-postgres-test createdWhen we say integrating with Kanister, we actually mean creating some Kanister resources to support backup and restore
actions.
Create Profile Kanister resource using below command
~ kanctl create profile s3compliant --access-key <ACCESS-KEY> \
--secret-key <SECRET-KEY> \
--bucket <BUKET-NAME> --region <AWS-REGION> \
--namespace postgres-test
secret 's3-secret-htzs2i' created
profile 's3-profile-2rzmc' createdNOTE:
The command will configure a location where artifacts resulting from Kanister
data operations such as backup should go. This is stored as a profiles.cr.kanister.io
CustomResource (CR) which is then referenced in Kanister ActionSets. Every ActionSet
requires a Profile reference to complete the action. This CR (profiles.cr.kanister.io)
can be shared between Kanister-enabled application instances.
Create Blueprint in the same namespace as the controller (kanister)
~ oc create -f postgres-dep-config-blueprint.yaml -n kanister
blueprint.cr.kanister.io/postgres-bp created
Now that we have created the Profile and Blueprint Kanister resources we will insert some data into
PostgreSQL database that we will take backup of.
To insert the data into the PostgreSQL database we will exec into the PostgreSQL pod, please follow below commands
to do so
# Get the PostgreSQL pod
~ oc get pods -n postgres-test
NAME READY STATUS RESTARTS AGE
postgresql-1-72k8g 1/1 Running 0 17m
# Exec into the PostgreSQL pod
~ oc exec -it -n postgres-test postgresql-1-72k8g bash
## use psql cli to add entries in postgresql database
bash-4.2$ PGPASSWORD=${POSTGRESQL_ADMIN_PASSWORD} psql -U ${PGUSER}
psql (10.6)
Type "help" for help.
postgres=# CREATE DATABASE test;
postgres=# \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+----------+----------+------------+------------+-----------------------
postgres | postgres | UTF8 | en_US.utf8 | en_US.utf8 |
sampledb | userC3S | UTF8 | en_US.utf8 | en_US.utf8 |
template0 | postgres | UTF8 | en_US.utf8 | en_US.utf8 | =c/postgres +
| | | | | postgres=CTc/postgres
template1 | postgres | UTF8 | en_US.utf8 | en_US.utf8 | =c/postgres +
| | | | | postgres=CTc/postgres
test | postgres | UTF8 | en_US.utf8 | en_US.utf8 |
(5 rows)
# Connect to test database1
postgres=# \c test
You are now connected to database "test" as user "postgres".
# Create company table in the test database
test=# CREATE TABLE COMPANY(
test(# ID INT PRIMARY KEY NOT NULL,
test(# NAME TEXT NOT NULL,
test(# AGE INT NOT NULL,
test(# ADDRESS CHAR(50),
test(# SALARY REAL,
test(# CREATED_AT TIMESTAMP
test(# );
CREATE TABLE
# Insert some data into the table
test=# INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY,CREATED_AT) VALUES (10, 'Paul', 32, 'California', 20000.00, now());
INSERT 0 1
test=# INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY,CREATED_AT) VALUES (11, 'John', 31, 'NY', 20100.00, now());
INSERT 0 1
test=# INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY,CREATED_AT) VALUES (12, 'Robert', 28, 'Wash. DC', 21100.00, now());
INSERT 0 1
# list all the data from the company table in the test database
test=# select * from company;
id | name | age | address | salary | created_at
----+--------+-----+----------------------------------------------------+--------+----------------------------
10 | Paul | 32 | California | 20000 | 2020-03-02 12:03:28.919661
11 | John | 31 | NY | 20100 | 2020-03-02 12:04:03.766175
12 | Robert | 28 | Wash. DC | 21100 | 2020-03-02 12:05:18.345847
(3 rows)
Now that we have inserted some data into the database let's try to create Actionset Kanister resource to take backup
of the data that we have inserted. Create an Actionset in the same namespace where your Kanister controller is
# get the name of the profile resource
~ oc get profile -n postgres-test
NAME AGE
s3-profile-2rzmc 33m
# Create backup Actionset
~ kanctl create actionset --action backup --namespace kanister --blueprint postgres-bp \
--profile postgres-test/s3-profile-2rzmc \
--deploymentconfig postgres-test/postgresql
actionset backup-tnf2d created
# check the status of the Actionset
~ oc describe actionset -n kanister backup-tnf2dOnce we have made sure that the backup action is complete, we can go ahead and delete the data from the database to imitate the disaster.
Let's say someone accidentally deleted the test database using the following command:
# Get the PostgreSQL pod name
~ oc get pods -n postgres-test
NAME READY STATUS RESTARTS AGE
postgresql-1-72k8g 1/1 Running 0 56m
# Exec into the POD
~ oc exec -it -n postgres-test postgresql-1-72k8g bash
bash-4.2$ PGPASSWORD=${POSTGRESQL_ADMIN_PASSWORD} psql -U ${PGUSER}
psql (10.6)
Type "help" for help.
# list all the databases
postgres=# \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+----------+----------+------------+------------+-----------------------
postgres | postgres | UTF8 | en_US.utf8 | en_US.utf8 |
sampledb | userC3S | UTF8 | en_US.utf8 | en_US.utf8 |
template0 | postgres | UTF8 | en_US.utf8 | en_US.utf8 | =c/postgres +
| | | | | postgres=CTc/postgres
template1 | postgres | UTF8 | en_US.utf8 | en_US.utf8 | =c/postgres +
| | | | | postgres=CTc/postgres
test | postgres | UTF8 | en_US.utf8 | en_US.utf8 |
(5 rows)
# Drop the test database
postgres=# drop database test ;
DROP DATABASE
postgres=# \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+----------+----------+------------+------------+-----------------------
postgres | postgres | UTF8 | en_US.utf8 | en_US.utf8 |
sampledb | userC3S | UTF8 | en_US.utf8 | en_US.utf8 |
template0 | postgres | UTF8 | en_US.utf8 | en_US.utf8 | =c/postgres +
| | | | | postgres=CTc/postgres
template1 | postgres | UTF8 | en_US.utf8 | en_US.utf8 | =c/postgres +
| | | | | postgres=CTc/postgres
(4 rows)
After dropping the test database as you can see we are only able to see 4 databases.
To restore the missing data, you should use the backup that you created before. An easy way to do this is to leverage kanctl, a command-line tool that helps create ActionSets that depend on other ActionSets:
# Get the backup Actionset name
~ oc get actionset -n kanister
NAME AGE
backup-tnf2d 7m
# Create restore Actionset
~ kanctl --namespace kanister create actionset --action restore --from backup-tnf2d
actionset restore-backup-tnf2d-jhnt7 created
# Check the status of the restore Actionset to make sure the actionset is completed
~ oc describe actionset -n kanister restore-backup-tnf2d-jhnt7
# and you will be able to see, in events section, that the Actionset is completed.Once the status of the Actionset is completed, exec into the PostgreSQL pod once again and make sure the test database and all of it's records have
been restored successfully.
~ oc exec -it -n postgres-test postgresql-1-72k8g bash
bash-4.2$ PGPASSWORD=${POSTGRESQL_ADMIN_PASSWORD} psql -U ${PGUSER}
psql (10.6)
Type "help" for help.
# list all the databases
postgres=# \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+----------+----------+------------+------------+-----------------------
postgres | postgres | UTF8 | en_US.utf8 | en_US.utf8 |
sampledb | userC3S | UTF8 | en_US.utf8 | en_US.utf8 |
template0 | postgres | UTF8 | en_US.utf8 | en_US.utf8 | =c/postgres +
| | | | | postgres=CTc/postgres
template1 | postgres | UTF8 | en_US.utf8 | en_US.utf8 | postgres=CTc/postgres+
| | | | | =c/postgres
test | postgres | UTF8 | en_US.utf8 | en_US.utf8 |
(5 rows)
# As you can see we have restored the test database
# connect to the test database
postgres=# \c test
You are now connected to database "test" as user "postgres".
test=# select * from company;
id | name | age | address | salary | created_at
----+--------+-----+----------------------------------------------------+--------+----------------------------
10 | Paul | 32 | California | 20000 | 2020-03-02 12:03:28.919661
11 | John | 31 | NY | 20100 | 2020-03-02 12:04:03.766175
12 | Robert | 28 | Wash. DC | 21100 | 2020-03-02 12:05:18.345847
(3 rows)
As you can see we have successfully restored the data into the PostgreSQL database using the backup that we had already created.
The artifacts created by the backup action can be cleaned up using the following command:
~ kanctl --namespace kanister create actionset --action delete --from backup-tnf2d
actionset delete-backup-tnf2d-qxl6k created
# View the status of the ActionSet
$ kubectl --namespace kanister describe actionset delete-backup-tnf2d-qxl6kIf you run into any issues with the above commands, you can check the logs of the controller using:
$ kubectl --namespace kanister logs -l app=kanister-operatoryou can also check events of the actionset
$ kubectl describe actionset <actionset-name> -n kanisterWhen we install a application using oc new-app a label of format app=<name>, gets added to all the resources that get created. To get that label execute below command
~ oc get pods -n postgres-test --show-labels
NAME READY STATUS RESTARTS AGE LABELS
postgresql-1-72k8g 1/1 Running 0 1h app=postgresql-persistent,deployment=postgresql-1,deploymentconfig=postgresql,name=postgresql
As you can see the label that was added is app=postgresql-persistent to delete all the resources with this label, use below command
~ oc delete all -n postgres-test -l app=postgresql-persistentRemove Blueprint and Profile CR
$ kubectl delete blueprints.cr.kanister.io <blueprint-name> -n kanister
$ kubectl delete profiles.cr.kanister.io <profile-name> -n postgres-test