Category: Ubuntu – ServerOK

Easy Kubernetes setup on Ubuntu with microk8s

Posted on April 8, 2021 (April 8, 2021) by ServerOk

To install microk8s, run

sudo snap install microk8s --classic

1	sudo snap install microk8s --classic

Enable rules in firewall

sudo ufw allow in on cni0
sudo ufw allow out on cni0
sudo ufw default allow routed

sudo ufw allow in on cni0

sudo ufw allow out on cni0

sudo ufw default allow routed

Enable addons

microk8s enable dns dashboard storage

1	microk8s enable dns dashboard storage

To see status of current addons, run

microk8s status

1	microk8s status

Here is status for a defaul install

root@ip-172-26-0-217:~# microk8s status
microk8s is running
high-availability: no
  datastore master nodes: 127.0.0.1:19001
  datastore standby nodes: none
addons:
  enabled:
    ha-cluster           # Configure high availability on the current node
  disabled:
    ambassador           # Ambassador API Gateway and Ingress
    cilium               # SDN, fast with full network policy
    dashboard            # The Kubernetes dashboard
    dns                  # CoreDNS
    fluentd              # Elasticsearch-Fluentd-Kibana logging and monitoring
    gpu                  # Automatic enablement of Nvidia CUDA
    helm                 # Helm 2 - the package manager for Kubernetes
    helm3                # Helm 3 - Kubernetes package manager
    host-access          # Allow Pods connecting to Host services smoothly
    ingress              # Ingress controller for external access
    istio                # Core Istio service mesh services
    jaeger               # Kubernetes Jaeger operator with its simple config
    keda                 # Kubernetes-based Event Driven Autoscaling
    knative              # The Knative framework on Kubernetes.
    kubeflow             # Kubeflow for easy ML deployments
    linkerd              # Linkerd is a service mesh for Kubernetes and other frameworks
    metallb              # Loadbalancer for your Kubernetes cluster
    metrics-server       # K8s Metrics Server for API access to service metrics
    multus               # Multus CNI enables attaching multiple network interfaces to pods
    portainer            # Portainer UI for your Kubernetes cluster
    prometheus           # Prometheus operator for monitoring and logging
    rbac                 # Role-Based Access Control for authorisation
    registry             # Private image registry exposed on localhost:32000
    storage              # Storage class; allocates storage from host directory
    traefik              # traefik Ingress controller for external access
root@ip-172-26-0-217:~#

root@ip-172-26-0-217:~# microk8s status

microk8s is running

high-availability: no

datastore master nodes: 127.0.0.1:19001

datastore standby nodes: none

addons:

enabled:

ha-cluster # Configure high availability on the current node

disabled:

ambassador # Ambassador API Gateway and Ingress

cilium # SDN, fast with full network policy

dashboard # The Kubernetes dashboard

dns # CoreDNS

fluentd # Elasticsearch-Fluentd-Kibana logging and monitoring

gpu # Automatic enablement of Nvidia CUDA

helm # Helm 2 - the package manager for Kubernetes

helm3 # Helm 3 - Kubernetes package manager

host-access # Allow Pods connecting to Host services smoothly

ingress # Ingress controller for external access

istio # Core Istio service mesh services

jaeger # Kubernetes Jaeger operator with its simple config

keda # Kubernetes-based Event Driven Autoscaling

knative # The Knative framework on Kubernetes.

kubeflow # Kubeflow for easy ML deployments

linkerd # Linkerd is a service mesh for Kubernetes and other frameworks

metallb # Loadbalancer for your Kubernetes cluster

metrics-server # K8s Metrics Server for API access to service metrics

multus # Multus CNI enables attaching multiple network interfaces to pods

portainer # Portainer UI for your Kubernetes cluster

prometheus # Prometheus operator for monitoring and logging

rbac # Role-Based Access Control for authorisation

registry # Private image registry exposed on localhost:32000

storage # Storage class; allocates storage from host directory

traefik # traefik Ingress controller for external access

root@ip-172-26-0-217:~#

To see all pods/services/deploymens, run

microk8s kubectl get all --all-namespaces

1	microk8s kubectl get all --all-namespaces

To avoid typing microk8s before kubectl, run

alias kubectl="microk8s kubectl"

1	alias kubectl="microk8s kubectl"

You can add this to .bashrc to make it permanent. To run […]

Install dnsmasq on Ubuntu

Posted on March 6, 2021 by ServerOk

dnsmasq is a very powerful tool that can provide basic dns services/caching, act as dhcp server and also as tftp server. To install dnsmasq, run

apt install dnsmasq

1	apt install dnsmasq

When you start dnsmasq, if it complain about port 53 alreay in use

dnsmasq: failed to create listening socket for port 53: Address already in use

1	dnsmasq: failed to create listening socket for port 53: Address already in use

This is because some other service is running on port 53. To find what service […]

Ant Media Server Ubuntu firewall configuration

Posted on January 25, 2021 by ServerOk

To enable firewal for Ant Media Server on Ubnuntu server, use following rules

ufw allow ssh
ufw allow http
ufw allow https
ufw allow 1935/tcp
ufw allow 5080/tcp
ufw allow 5443/tcp
ufw allow 5000:65000/udp
enable ufw

ufw allow ssh

ufw allow http

ufw allow https

ufw allow 1935/tcp

ufw allow 5080/tcp

ufw allow 5443/tcp

ufw allow 5000:65000/udp

enable ufw

After enabling, you will have following status

root@server:~# ufw status
Status: active

To                         Action      From
--                         ------      ----
22/tcp                     ALLOW       Anywhere                  
80/tcp                     ALLOW       Anywhere                  
443/tcp                    ALLOW       Anywhere                  
1935/tcp                   ALLOW       Anywhere                  
5080/tcp                   ALLOW       Anywhere                  
5443/tcp                   ALLOW       Anywhere                  
5000:65000/udp             ALLOW       Anywhere                  
22/tcp (v6)                ALLOW       Anywhere (v6)             
80/tcp (v6)                ALLOW       Anywhere (v6)             
443/tcp (v6)               ALLOW       Anywhere (v6)             
1935/tcp (v6)              ALLOW       Anywhere (v6)             
5080/tcp (v6)              ALLOW       Anywhere (v6)             
5443/tcp (v6)              ALLOW       Anywhere (v6)             
5000:65000/udp (v6)        ALLOW       Anywhere (v6)             

root@server:~#

root@server:~# ufw status

Status: active

To Action From

-- ------ ----

22/tcp ALLOW Anywhere

80/tcp ALLOW Anywhere

443/tcp ALLOW Anywhere

1935/tcp ALLOW Anywhere

5080/tcp ALLOW Anywhere

5443/tcp ALLOW Anywhere

5000:65000/udp ALLOW Anywhere

22/tcp (v6) ALLOW Anywhere (v6)

80/tcp (v6) ALLOW Anywhere (v6)

443/tcp (v6) ALLOW Anywhere (v6)

1935/tcp (v6) ALLOW Anywhere (v6)

5080/tcp (v6) ALLOW Anywhere (v6)

5443/tcp (v6) ALLOW Anywhere (v6)

5000:65000/udp (v6) ALLOW Anywhere (v6)

root@server:~#

Port forwarding You can forward port 80 and 443 to Ant Media Server, so you don’t have to use ports. You can use following iptables commands

sudo iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 5080
sudo iptables -t nat -A PREROUTING -p tcp --dport 443 -j REDIRECT --to-port 5443

1 2	sudo iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 5080 sudo iptables -t nat -A PREROUTING -p tcp --dport 443 -j REDIRECT --to-port 5443

To make it permanent, edit

vi /etc/ufw/before.rules

1	vi /etc/ufw/before.rules

[…]

Reinstall Kernel in Ubuntu/Debian

Posted on January 13, 2021 (January 13, 2021) by ServerOk

To reinstall Kernel in Ubunru, you need to find the version of kernal installed, for this run

dpkg -l | grep linux-image

1	dpkg -l \| grep linux-image

Or you can use command, find the kernel version you need to install

apt-cache search linux-image

1	apt-cache search linux-image

Once you have the name of linux-image package you need to install, you can run

apt-get install --reinstall PKG_NAME_HERE

1	apt-get install --reinstall PKG_NAME_HERE

Example See apt, Ubuntu, Debian […]

install Shotcut Video Editor in ubuntu

Posted on December 25, 2020 (December 25, 2020) by ServerOk

Shotcut is an free open source video editor for Ubuntu. You can find more info at https://shotcut.org Latest version of Shotcut video editor can be installed on Ubuntu using command

sudo snap install shotcut --classic

1	sudo snap install shotcut --classic

shotcut is also available to be installed from apt, but this is slightly older version than snap. To install from apt, use command

sudo apt install shotcut

1	sudo apt install shotcut

[…]

Ubuntu Server 20.04 configure OVH failover IP

Posted on December 21, 2020 (January 16, 2021) by ServerOk

To configure IP in Ubuntu 20.04 guest, create file

vi /etc/netplan/50-cloud-init.yaml

1	vi /etc/netplan/50-cloud-init.yaml

add following content

network:
    version: 2
    ethernets:
        eth0:
            addresses:
                - YOUR_FO_IP_HERE/32
            nameservers:
                addresses:
                    - 1.1.1.1
                search: []
            optional: true
            routes:
                - to: 0.0.0.0/0
                  via: YOUR_GW_IP_HERE
                  on-link: true

network:

version: 2

ethernets:

eth0:

addresses:

- YOUR_FO_IP_HERE/32

nameservers:

addresses:

- 1.1.1.1

search: []

optional: true

routes:

- to: 0.0.0.0/0

via: YOUR_GW_IP_HERE

on-link: true

example

root@easyengine:~# cat /etc/netplan/50-cloud-init.yaml
network:
    version: 2
    ethernets:
        eth0:
            addresses:
                - 164.132.150.95/32
            nameservers:
                addresses:
                    - 1.1.1.1
                search: []
            optional: true
            routes:
                - to: 0.0.0.0/0
                  via: 51.255.79.254
                  on-link: true
root@easyengine:~#

root@easyengine:~# cat /etc/netplan/50-cloud-init.yaml

network:

version: 2

ethernets:

eth0:

addresses:

- 164.132.150.95/32

nameservers:

addresses:

- 1.1.1.1

search: []

optional: true

routes:

- to: 0.0.0.0/0

via: 51.255.79.254

on-link: true

root@easyengine:~#

Test network config using

netplan try

1	netplan try

If everything works fine, you can apply the changes with

netplan apply

1	netplan apply

See OVH, netplan […]

Ubuntu Remap keys in the keyboard

Posted on December 21, 2020 (December 21, 2020) by ServerOk

Left Shift key on my keyboard started acting up. It some times work, some times it won’t. I never use the caps lock key on my kayboard, this is just above the shift key. So i decided to use this key as left shift key. To re-assign key, you need to edit file /usr/share/X11/xkb/symbols/pc Lets […]

Ubuntu Server 20.04 set static IP with netplan

Posted on December 15, 2020 (December 15, 2020) by ServerOk

First check if you have file

/etc/cloud/cloud.cfg.d/subiquity-disable-cloudinit-networking.cfg

1	/etc/cloud/cloud.cfg.d/subiquity-disable-cloudinit-networking.cfg

If the file exists, make sure, you have following content in it.

root@ubuntu:~# cat /etc/cloud/cloud.cfg.d/subiquity-disable-cloudinit-networking.cfg
network: {config: disabled}
root@ubuntu:~#

root@ubuntu:~# cat /etc/cloud/cloud.cfg.d/subiquity-disable-cloudinit-networking.cfg

network: {config: disabled}

root@ubuntu:~#

Edit

vi /etc/netplan/00-installer-config.yaml

1	vi /etc/netplan/00-installer-config.yaml

Replace all content with

network:
    version: 2
    ethernets:
        eth0:
            addresses: [192.168.1.100/24]
            gateway4: 192.168.1.1
            nameservers:
                addresses: [1.1.1.1, 8.8.8.8]

network:

version: 2

ethernets:

eth0:

addresses: [192.168.1.100/24]

gateway4: 192.168.1.1

nameservers:

addresses: [1.1.1.1, 8.8.8.8]

In above cause 192.168.1.100 is your static IP address. 192.168.1.1 is the gateway. eth0 is network interface name. Now try the chnages with

netplan try

1	netplan try

If all good, you […]

Ubuntu 20.04 settings won’t open

Posted on December 4, 2020 (December 4, 2020) by ServerOk

On Ubuntu 20.04 settins won’t open. This may be caused by some software install/update. I tried to run

gnome-control-center

1	gnome-control-center

From terminal, i get error

boby@sok-01:~$ gnome-control-center

Command 'gnome-control-center' not found, but can be installed with:

sudo apt install gnome-control-center

boby@sok-01:~$

boby@sok-01:~$ gnome-control-center

Command 'gnome-control-center' not found, but can be installed with:

sudo apt install gnome-control-center

boby@sok-01:~$

To fix the error, i installed gnome-control-center package as the error suggests.

sudo apt install gnome-control-center

1	sudo apt install gnome-control-center

See Ubuntu […]

gsettings

Posted on December 1, 2020 by ServerOk

Ubuntu Screen Recorder […]