How to set up 3 master nodes in kubernetes?

Question

Docker

Greetings, there are 3 machines on which it is planned to raise kubernetes 1.16
Now we have a docker swarm cluster, also on 3 nodes, each of which is a manager and balancer. Only one node has a VIP address, when the machine dies, the VIP moves and everything works as it should.
I am just learning Kubernetes, mainly due to the fact that many projects already have ready-made pod.yml for their applications, and I want to learn a new technology.
Well, I decided to make the logic the same as the current docker swarm, that is, a VIP address and 3 master nodes.

~ kubectl get node
NAME            STATUS   ROLES    AGE   VERSION
tech-app01   Ready    master   21d   v1.16.2
tech-app02   Ready    master   21d   v1.16.2
tech-app03   Ready    master   21d   v1.16.2

~ kubectl get pod -n kube-system
NAME                                    READY   STATUS    RESTARTS   AGE
coredns-5644d7b6d9-9xzcj                1/1     Running   1          21d
coredns-5644d7b6d9-wtkwm                1/1     Running   1          21d
etcd-tech-cl-app01                      1/1     Running   1          21d
etcd-tech-cl-app02                      1/1     Running   1          21d
etcd-tech-cl-app03                      1/1     Running   1          21d
kube-apiserver-tech-cl-app01            1/1     Running   1          21d
kube-apiserver-tech-cl-app02            1/1     Running   1          21d
kube-apiserver-tech-cl-app03            1/1     Running   1          21d
kube-controller-manager-tech-cl-app01   1/1     Running   2          21d
kube-controller-manager-tech-cl-app02   1/1     Running   1          21d
kube-controller-manager-tech-cl-app03   1/1     Running   1          21d
kube-proxy-knvfk                        1/1     Running   1          21d
kube-proxy-rz27m                        1/1     Running   1          21d
kube-proxy-wwtfq                        1/1     Running   1          21d
kube-scheduler-tech-cl-app01            1/1     Running   2          21d
kube-scheduler-tech-cl-app02            1/1     Running   1          21d
kube-scheduler-tech-cl-app03            1/1     Running   1          21d
weave-net-jkd5f                         2/2     Running   3          21d
weave-net-nm4qn                         2/2     Running   3          21d
weave-net-strqt                         2/2     Running   3          21d

But when I try to run some application on 3 nodes, an error pops up:
I'm doing such an example from the office. docks:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80

kubectl get pods
NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-64599f457f-dhjc7   0/1     Pending   0          4m48s
nginx-deployment-64599f457f-qdbh7   0/1     Pending   0          4m48s
nginx-deployment-64599f457f-zqn7b   0/1     Pending   0          4m48s

All containers are in Pending status.
Looking at events:

tech-app01:/opt/kuber-apps/test:~$ kubectl get events
LAST SEEN   TYPE      REASON              OBJECT                                   MESSAGE
<unknown>   Warning   FailedScheduling    pod/nginx-deployment-64599f457f-dhjc7    0/3 nodes are available: 3 node(s) had taints that the pod didn't tolerate.
<unknown>   Warning   FailedScheduling    pod/nginx-deployment-64599f457f-dhjc7    0/3 nodes are available: 3 node(s) had taints that the pod didn't tolerate.
<unknown>   Warning   FailedScheduling    pod/nginx-deployment-64599f457f-qdbh7    0/3 nodes are available: 3 node(s) had taints that the pod didn't tolerate.
<unknown>   Warning   FailedScheduling    pod/nginx-deployment-64599f457f-qdbh7    0/3 nodes are available: 3 node(s) had taints that the pod didn't tolerate.
<unknown>   Warning   FailedScheduling    pod/nginx-deployment-64599f457f-zqn7b    0/3 nodes are available: 3 node(s) had taints that the pod didn't tolerate.
<unknown>   Warning   FailedScheduling    pod/nginx-deployment-64599f457f-zqn7b    0/3 nodes are available: 3 node(s) had taints that the pod didn't tolerate.
7m52s       Normal    SuccessfulCreate    replicaset/nginx-deployment-64599f457f   Created pod: nginx-deployment-64599f457f-dhjc7
7m51s       Normal    SuccessfulCreate    replicaset/nginx-deployment-64599f457f   Created pod: nginx-deployment-64599f457f-qdbh7
7m51s       Normal    SuccessfulCreate    replicaset/nginx-deployment-64599f457f   Created pod: nginx-deployment-64599f457f-zqn7b
7m52s       Normal    ScalingReplicaSet   deployment/nginx-deployment              Scaled up replica set nginx-deployment-64599f457f to 3

I understand that he cannot run 3 containers, because he does not see 3 worker nodes? So?
Is there any way to raise both master and worker on the same node? After all, minikube somehow works on one machine ...

Answer 1

Try allowing the master to run containers:
from here: https://blog.alexellis.io/kubernetes-in-10-minutes/