You are looking at the documentation of a prior release. To read the documentation of the latest release, please
visit here.
New to KubeDB? Please start here.
This is an Enterprise-only feature. Please install KubeDB Enterprise Edition to try this feature.
Reconfigure ProxySQL TLS/SSL (Transport Encryption)
KubeDB supports reconfigure i.e. add, remove, update and rotation of TLS/SSL certificates for existing ProxySQL via a ProxySQLOpsRequest. This tutorial will show you how to use KubeDB to reconfigure TLS/SSL encryption.
ReconfigureTLS is a very useful ops-request when it comes to reconfiguring TLS settings for proxysql server without entering the admin panel. With this type of ops-request you can add, remove and update TLS configuration for the proxysql server. You can rotate the certificates as well.
Below, we are providing some examples for the ops-request.
Before You Begin
At first, you need to have a Kubernetes Cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using kind.
Install
cert-mangerv1.6.0 or later to your cluster to manage your SSL/TLS certificates.Now, install KubeDB cli on your workstation and KubeDB operator in your cluster following the steps here.
To keep things isolated, this tutorial uses a separate namespace called
demothroughout this tutorial.$ kubectl create ns demo namespace/demo created
Prepare MySQL Backend
To test any proxysql functionality we need to have a mysql backend .
Below, here is the yaml for the KubeDB MySQL backend.
apiVersion: kubedb.com/v1alpha2
kind: MySQL
metadata:
name: mysql-server
namespace: demo
spec:
version: "5.7.36"
replicas: 3
topology:
mode: GroupReplication
storageType: Durable
storage:
storageClassName: "standard"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
terminationPolicy: WipeOut
Let’s apply the yaml,
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2023.10.9/docs/guides/proxysql/reconfigure-tls/cluster/examples/sample-mysql.yaml
mysql.kubedb.com/mysql-server created
Let’s now wait for the mysql instance to be ready,
$ kubectl get mysql -n demo
NAME VERSION STATUS AGE
mysql-server 5.7.36 Ready 3m16s
$ kubectl get pods -n demo
NAME READY STATUS RESTARTS AGE
mysql-server-0 2/2 Running 0 3m11s
mysql-server-1 2/2 Running 0 113s
mysql-server-2 2/2 Running 0 109s
We need a user to test all the ssl functionalities. So let’s create one user inside the mysql servers,
~ $ kubectl exec -it -n demo mysql-server-0 -- bash
Defaulted container "mysql" out of: mysql, mysql-coordinator, mysql-init (init)
root@mysql-server-0:/# mysql -uroot -p$MYSQL_ROOT_PASSWORD
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 106
Server version: 5.7.36-log MySQL Community Server (GPL)
Copyright (c) 2000, 2021, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> create user 'test'@'%' identified by 'pass';
Query OK, 0 rows affected (0.00 sec)
mysql> create database testdb;
Query OK, 1 row affected (0.00 sec)
mysql> grant all privileges on testdb.* to 'test'@'%';
Query OK, 0 rows affected (0.01 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
mysql> exit
Bye
Deploy ProxySQL without TLS
We are now all set with our backend. Now let’s create a KubeDB ProxySQL server. Lets keep the syncUser field true so that we don’t need to create the user again.
apiVersion: kubedb.com/v1alpha2
kind: ProxySQL
metadata:
name: proxy-server
namespace: demo
spec:
version: "2.3.2-debian"
replicas: 3
backend:
name: mysql-server
syncUsers: true
terminationPolicy: WipeOut
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2023.10.9/docs/guides/proxysql/reconfigure-tls/cluster/examples/sample-proxysql.yaml
proxysql.kubedb.com/proxy-server created
Check User and current TLS status
Let’s exec into the proxysql pod and see the current status.
$ kubectl exec -it -n demo proxy-server-0 -- bash
root@proxy-server-0:/# mysql -uadmin -padmin -h127.0.0.1 -P6032
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MySQL connection id is 18
Server version: 8.0.27 (ProxySQL Admin Module)
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MySQL [(none)]> select username, use_ssl from mysql_users;
+----------+---------+
| username | use_ssl |
+----------+---------+
| root | 0 |
| test | 0 |
+----------+---------+
2 rows in set (0.000 sec)
MySQL [(none)]> show variables like '%have_ssl%';
+----------------+-------+
| Variable_name | Value |
+----------------+-------+
| mysql-have_ssl | false |
+----------------+-------+
1 row in set (0.001 sec)
MySQL [(none)]> exit
Bye
We can see that the users have been fetched. Also the mysql-have_ssl variables is set to false. The use_ssl column is also set to 0 which means that there is no need for ssl-ca or cert for connect.
Let’s check it with the follwing command.
root@proxy-server-0:/# mysql -utest -ppass -h127.0.0.1 -P6033
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MySQL connection id is 914
Server version: 8.0.27 (ProxySQL)
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MySQL [(none)]> \s
--------------
mysql Ver 15.1 Distrib 10.5.15-MariaDB, for debian-linux-gnu (x86_64) using EditLine wrapper
Connection id: 914
Current database: information_schema
Current user: [email protected]
SSL: Not in use
Current pager: stdout
Using outfile: ''
Using delimiter: ;
Server: MySQL
Server version: 8.0.27 (ProxySQL)
Protocol version: 10
Connection: 127.0.0.1 via TCP/IP
Server characterset: latin1
Db characterset: utf8
Client characterset: latin1
Conn. characterset: latin1
TCP port: 6033
Uptime: 1 hour 27 min 36 sec
Threads: 1 Questions: 3 Slow queries: 3
--------------
MySQL [(none)]> exit
Bye
Add TLS with RreconfigureTLS Ops-Request
Now we want to add TLS to our proxysql server and we want the frontend connections to be tls-secured.
Create Issuer
First we need an issuer for this. We can create one with the following command. Make sure that you have cert-manager running in your cluster and openssl installed.
$ openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout ./ca.key -out ./ca.crt -subj "/CN=mysql/O=kubedb"
Generating a RSA private key
.......................................+++++
...........................+++++
writing new private key to './ca.key'
Let’s create the ca-secret with the above created ca.crt and ca.key by using the following command,
$ kubectl create secret tls proxy-ca \
--cert=ca.crt \
--key=ca.key \
--namespace=demo
secret/proxy-ca created
Now create issuer with the following yaml,
apiVersion: cert-manager.io/v1
kind: Issuer
metadata:
name: proxy-issuer
namespace: demo
spec:
ca:
secretName: proxy-ca
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2023.10.9/docs/guides/proxysql/reconfigure-tls/cluster/examples/issuer.yaml
issuer.cert-manager.io/proxy-issuer created
Apply ops-request to add TLS
We are all set to go! now lets create an ReconfigureTLS ops-request like below. We have set a desired configuration under the .spec.tls section here as you can see. You can checkout the api documentation of this field here.
apiVersion: ops.kubedb.com/v1alpha1
kind: ProxySQLOpsRequest
metadata:
name: recon-tls-add
namespace: demo
spec:
type: ReconfigureTLS
proxyRef:
name: proxy-server
tls:
issuerRef:
apiGroup: cert-manager.io
kind: Issuer
name: proxy-issuer
certificates:
- alias: server
subject:
organizations:
- kubedb:server
dnsNames:
- localhost
ipAddresses:
- "127.0.0.1"
emailAddresses:
- "[email protected]"
Let’s apply and wait for the ops-request to be succeeded.
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2023.10.9/docs/guides/proxysql/reconfigure-tls/cluster/examples/proxyops-add-tls.yaml
proxysqlopsrequest.ops.kubedb.com/recon-tls-add created
$ kubectl get proxysqlopsrequest -n demo
NAME TYPE STATUS AGE
recon-tls-add ReconfigureTLS Successful 5m
Check ops-request effects
Following secrets should be created
$ kubectl get secrets -n demo | grep cert
proxy-server-server-cert kubernetes.io/tls 3 4m53s
proxy-server-client-cert kubernetes.io/tls 3 4m53s
The directory /var/lib/frontend/ should carry the certificates and other files within the directories as seen below.
root@proxy-server-0:/# ls /var/lib/frontend/
client server
root@proxy-server-0:/# ls /var/lib/frontend/client
ca.crt tls.crt tls.key
root@proxy-server-0:/# ls /var/lib/frontend/server
ca.crt tls.crt tls.key
The mysql-have_ssl variables should be true by this time.
root@proxy-server-0:/# mysql -uadmin -padmin -h127.0.0.1 -P6032
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MySQL connection id is 22
Server version: 8.0.27 (ProxySQL Admin Module)
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MySQL [(none)]> show variables like '%have_ssl%';
+----------------+-------+
| Variable_name | Value |
+----------------+-------+
| mysql-have_ssl | true |
+----------------+-------+
1 row in set (0.001 sec)
Activate use_ssl field for the test user
Now our ProxySQL server is ready to serve tls-secured connections. Let’s modify our test user to use ssl with an ops-request. You can do this task from the admin panel also. But we like to do it in KubeDB way.
apiVersion: ops.kubedb.com/v1alpha1
kind: ProxySQLOpsRequest
metadata:
name: activate-ssl
namespace: demo
spec:
type: Reconfigure
proxyRef:
name: proxy-server
configuration:
mysqlUsers:
users:
- username: test
use_ssl: 1
reqType: update
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2023.10.9/docs/guides/proxysql/reconfigure-tls/cluster/examples/proxyops-activate-ssl.yaml
proxysqlopsrequest.ops.kubedb.com/activate-ssl created
Let’s check the effect from the admin panel.
MySQL [(none)]> select username,use_ssl from mysql_users;
+----------+---------+
| username | use_ssl |
+----------+---------+
| root | 0 |
| test | 1 |
+----------+---------+
2 rows in set (0.001 sec)
Check TLS secured connections
Now our user is also modified to accept only tls-secured requests. Let’s try to connect without TLS.
root@proxy-server-0:/# mysql -utest -ppass -h127.0.0.01 -P6033
ERROR 1045 (28000): ProxySQL Error: Access denied for user 'test' (using password: YES). SSL is required
We can see that the connection is refused. Now try with the tls certificates.
root@proxy-server-0:/# mysql -utest -ppass -h127.0.0.01 -P6033 --ssl-ca=/var/lib/frontend/client/ca.crt --ssl-cert=/var/lib/frontend/client/tls.crt --ssl-key=/var/lib/frontend/client/tls.key
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MySQL connection id is 107
Server version: 8.0.27 (ProxySQL)
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MySQL [testdb]> \s
--------------
mysql Ver 15.1 Distrib 10.5.15-MariaDB, for debian-linux-gnu (x86_64) using EditLine wrapper
Connection id: 107
Current database: testdb
Current user: [email protected]
SSL: Cipher in use is TLS_AES_256_GCM_SHA384
Current pager: stdout
Using outfile: ''
Using delimiter: ;
Server: MySQL
Server version: 8.0.27 (ProxySQL)
Protocol version: 10
Connection: 127.0.0.01 via TCP/IP
Server characterset: latin1
Db characterset: latin1
Client characterset: latin1
Conn. characterset: latin1
TCP port: 6033
Uptime: 8 min 3 sec
Threads: 1 Questions: 7 Slow queries: 7
--------------
We can see that the user is successfuly logged in with the tls informations. Also in the \s query result , the SSL field has got a cipher name, which means the connection is tls-secured.
Rotate Certificate
Now we are going to rotate the certificate for this proxysql. First let’s check the current expiration date for current certificate.
root@proxy-server-0:/# openssl x509 -in /var/lib/frontend/client/tls.crt -inform PEM -enddate -nameopt RFC2253 -noout
notAfter=Feb 6 08:44:01 2023 GMT
Let’s look into the server certificate crd.
~ $ kubectl describe certificate -n demo proxy-server-server-cert
Name: proxy-server-server-cert
Namespace: demo
Labels: app.kubernetes.io/component=database
app.kubernetes.io/instance=proxy-server
app.kubernetes.io/managed-by=kubedb.com
app.kubernetes.io/name=proxysqls.kubedb.com
proxysql.kubedb.com/load-balance=GroupReplication
Annotations: <none>
API Version: cert-manager.io/v1
Kind: Certificate
Metadata:
Creation Timestamp: 2022-11-08T08:44:01Z
Generation: 1
...
Owner References:
API Version: kubedb.com/v1alpha2
Block Owner Deletion: true
Controller: true
Kind: ProxySQL
Name: proxy-server
UID: b4fa48bc-b6cc-4ce7-beaf-c91987f4e0b5
Resource Version: 29102
UID: aa69c146-1581-4fce-a160-ad85b4296e4d
Spec:
Common Name: proxy-server
Dns Names:
*.proxy-server-pods.demo.svc
*.proxy-server-pods.demo.svc.cluster.local
*.proxy-server.demo.svc
localhost
proxy-server
proxy-server.demo.svc
Email Addresses:
[email protected]
Ip Addresses:
127.0.0.1
Issuer Ref:
Group: cert-manager.io
Kind: Issuer
Name: proxy-issuer
Secret Name: proxy-server-server-cert
Subject:
Organizations:
kubedb:server
Usages:
digital signature
key encipherment
server auth
client auth
Status:
Conditions:
Last Transition Time: 2022-11-08T08:44:01Z
Message: Certificate is up to date and has not expired
Observed Generation: 1
Reason: Ready
Status: True
Type: Ready
Not After: 2023-02-06T08:44:01Z
Not Before: 2022-11-08T08:44:01Z
Renewal Time: 2023-01-07T08:44:01Z
Revision: 1
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Issuing 17m cert-manager Issuing certificate as Secret does not exist
Normal Generated 17m cert-manager Stored new private key in temporary Secret resource "proxy-server-server-cert-ksk6g"
Normal Requested 17m cert-manager Created new CertificateRequest resource "proxy-server-server-cert-9mqjf"
Normal Issuing 17m cert-manager The certificate has been successfully issued
Apply ops-request to rotate certificate
Now lets apply the follwoing yaml and rotate the certificate of our proxysql server.
apiVersion: ops.kubedb.com/v1alpha1
kind: ProxySQLOpsRequest
metadata:
name: recon-tls-rotate
namespace: demo
spec:
type: ReconfigureTLS
proxyRef:
name: proxy-server
tls:
rotateCertificates: true
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2023.10.9/docs/guides/proxysql/reconfigure-tls/cluster/examples/proxyops-rotate-tls.yaml
proxysqlopsrequest.ops.kubedb.com/recon-tls-rotate created
$ kubectl get proxysqlopsrequest -n demo
NAME TYPE STATUS AGE
recon-tls-add ReconfigureTLS Successful 15m
recon-tls-rotate ReconfigureTLS Successful 5m
Check ops-request effect
Let’s check if the expiration time has been updated or not.
root@proxy-server-0:/# openssl x509 -in /var/lib/frontend/client/tls.crt -inform PEM -enddate -nameopt RFC2253 -noout
notAfter=Feb 6 09:05:54 2023 GMT
The expiration time has been updated. Now lets check the certificate crd.
$ kubectl describe certificate -n demo proxy-server-server-cert
Name: proxy-server-server-cert
Namespace: demo
Labels: app.kubernetes.io/component=database
app.kubernetes.io/instance=proxy-server
app.kubernetes.io/managed-by=kubedb.com
app.kubernetes.io/name=proxysqls.kubedb.com
proxysql.kubedb.com/load-balance=GroupReplication
Annotations: <none>
API Version: cert-manager.io/v1
Kind: Certificate
Metadata:
Creation Timestamp: 2022-11-08T08:44:01Z
Generation: 1
...
Owner References:
API Version: kubedb.com/v1alpha2
Block Owner Deletion: true
Controller: true
Kind: ProxySQL
Name: proxy-server
UID: b4fa48bc-b6cc-4ce7-beaf-c91987f4e0b5
Resource Version: 32254
UID: aa69c146-1581-4fce-a160-ad85b4296e4d
Spec:
Common Name: proxy-server
Dns Names:
*.proxy-server-pods.demo.svc
*.proxy-server-pods.demo.svc.cluster.local
*.proxy-server.demo.svc
localhost
proxy-server
proxy-server.demo.svc
Email Addresses:
[email protected]
Ip Addresses:
127.0.0.1
Issuer Ref:
Group: cert-manager.io
Kind: Issuer
Name: proxy-issuer
Secret Name: proxy-server-server-cert
Subject:
Organizations:
kubedb:server
Usages:
digital signature
key encipherment
server auth
client auth
Status:
Conditions:
Last Transition Time: 2022-11-08T08:44:01Z
Message: Certificate is up to date and has not expired
Observed Generation: 1
Reason: Ready
Status: True
Type: Ready
Not After: 2023-02-06T09:05:54Z
Not Before: 2022-11-08T09:05:54Z
Renewal Time: 2023-01-07T09:05:54Z
Revision: 6
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Issuing 23m cert-manager Issuing certificate as Secret does not exist
Normal Generated 23m cert-manager Stored new private key in temporary Secret resource "proxy-server-server-cert-ksk6g"
Normal Requested 23m cert-manager Created new CertificateRequest resource "proxy-server-server-cert-9mqjf"
Normal Requested 4m22s cert-manager Created new CertificateRequest resource "proxy-server-server-cert-s7d6r"
Normal Requested 4m22s cert-manager Created new CertificateRequest resource "proxy-server-server-cert-cd5sg"
Normal Requested 4m17s cert-manager Created new CertificateRequest resource "proxy-server-server-cert-pbm8q"
Normal Requested 2m9s cert-manager Created new CertificateRequest resource "proxy-server-server-cert-4qm6l"
Normal Requested 2m2s cert-manager Created new CertificateRequest resource "proxy-server-server-cert-l2xgk"
Normal Reused 2m2s (x5 over 4m22s) cert-manager Reusing private key stored in existing Secret resource "proxy-server-server-cert"
Normal Issuing 2m1s (x6 over 23m) cert-manager The certificate has been successfully issued
This has also been updated.
So from the above ovservation we can say that the TLS certificate rotation has been succeeded.
Update TLS Configuration
Now lets update the certificate information.
Let’s check the current info first.
root@proxy-server-0:/# openssl x509 -in /var/lib/proxysql/proxysql-cert.pem -inform PEM -subject -email -nameopt RFC2253 -noout
subject=CN=proxy-server,O=kubedb:server
[email protected]
Apply ops-request to update TLS
We can see the informations. Suppose we want to update the email address . We want to change it to [email protected]. Let’s create a ops-request for that in the following manner.
apiVersion: ops.kubedb.com/v1alpha1
kind: ProxySQLOpsRequest
metadata:
name: recon-tls-update
namespace: demo
spec:
type: ReconfigureTLS
proxyRef:
name: proxy-server
tls:
certificates:
- alias: server
subject:
organizations:
- kubedb:server
dnsNames:
- localhost
ipAddresses:
- "127.0.0.1"
emailAddresses:
- "[email protected]"
certificates:
- alias: client
subject:
organizations:
- kubedb:server
dnsNames:
- localhost
ipAddresses:
- "127.0.0.1"
emailAddresses:
- "[email protected]"
Let’s apply and then wait for it to be succeed.
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2023.10.9/docs/guides/proxysql/reconfigure-tls/cluster/examples/proxyops-update-tls.yaml
proxysqlopsrequest.ops.kubedb.com/recon-tls-update created
$ kubectl get proxysqlopsrequest -n demo
NAME TYPE STATUS AGE
recon-tls-update ReconfigureTLS Successful 5m
recon-tls-add ReconfigureTLS Successful 15m
recon-tls-rotate ReconfigureTLS Successful 10m
Let’s check the info now.
root@proxy-server-1:/# openssl x509 -in /var/lib/frontend/server/tls.crt -inform PEM -subject -email -nameopt RFC2253 -noout
subject=CN=proxy-server,O=kubedb:server
[email protected]
We can see the email has been successfuly updated. You can configure other field as well. To know more about the .spec.tls field refer to the link here .
Remove TLS
To remove TLS from a KubeDB ProxySQL instance, all you need to do is apply a similar yaml like below. Just change the .spec.proxyRef.name field with your own ProxySQL instance name.
apiVersion: ops.kubedb.com/v1alpha1
kind: ProxySQLOpsRequest
metadata:
name: recon-tls-remove
namespace: demo
spec:
type: ReconfigureTLS
proxyRef:
name: proxy-server
tls:
remove: true
Let’s apply and check the effects.
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2023.10.9/docs/guides/proxysql/reconfigure-tls/cluster/examples/proxyops-remove-tls.yaml
proxysqlopsrequest.ops.kubedb.com/recon-tls-remove created
$ kubectl get proxysqlopsrequest -n demo
NAME TYPE STATUS AGE
recon-tls-remove ReconfigureTLS Successful 3m
recon-tls-update ReconfigureTLS Successful 7m
recon-tls-add ReconfigureTLS Successful 17m
recon-tls-rotate ReconfigureTLS Successful 12m
Check ops-request effect
Let’s check the effect.
root@proxy-server-1:/# mysql -uadmin -padmin -h127.0.0.1 -P6032
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MySQL connection id is 25
Server version: 8.0.27 (ProxySQL Admin Module)
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MySQL [(none)]> show variables like '%have_ssl%';
+----------------+-------+
| Variable_name | Value |
+----------------+-------+
| mysql-have_ssl | false |
+----------------+-------+
1 row in set (0.001 sec)
The mysql-have_ssl has been set to false by the ops-request. So no more tls-secured frontend connections will be created.
Let’s update the user configuration to use_ssl=0 . Otherwise the user won’t be able to connect.
MySQL [(none)]> update mysql_users set use_ssl=0 where username='test';
Query OK, 1 row affected (0.001 sec)
MySQL [(none)]> LOAD MYSQL USERS TO RUNTIME;
Query OK, 0 rows affected (0.001 sec)
MySQL [(none)]> ^DBye
root@proxy-server-1:/# mysql -utest -ppass -h127.0.0.1 -P6033
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MySQL connection id is 267
Server version: 8.0.27 (ProxySQL)
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MySQL [(none)]>
We can see the user has been successfuly connected without the tls information.
Cleaning up
To cleanup the Kubernetes resources created by this tutorial, run:
$ kubectl delete proxysql -n demo --all
$ kubectl delete issuer -n demo --all
$ kubectl delete proxysqlopsrequest -n demo --all
$ kubectl delete ns demo