mshafiee

# Problem Description:
How to resolve scheduler and controller-manager unhealthy state in Kubernetes

# Symptom:
$ kubectl get cs / kubectl get componentstatuses
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS      MESSAGE                                                              ERROR
controller-manager   Unhealthy   Get "http://127.0.0.1:10252/healthz": dial tcp 127.0.0.1:10252: connect: connection refused
scheduler            Unhealthy   Get "http://127.0.0.1:10251/healthz": dial tcp 127.0.0.1:10251: connect: connection refused
etcd-0               Healthy     {"health":"true"}

mshafiee

(
NAMESPACE=your-rogue-namespace
kubectl proxy &
kubectl get namespace $NAMESPACE -o json |jq '.spec = {"finalizers":[]}' >temp.json
curl -k -H "Content-Type: application/json" -X PUT --data-binary @temp.json 127.0.0.1:8001/api/v1/namespaces/$NAMESPACE/finalize
)

mshafiee

[client]
user=backup
password=ffgf43rger43gtregrt43hr23
[mysqld]
socket=/var/run/mysqld/mysqld.sock
datadir=/var/lib/mysql
innodb_log_group_home_dir=/var/lib/mysql

mshafiee

DRBD (Distributed Replicated Block Device) is a really cool cluster solution to have radundant data on two or more nodes. Everybody know RAID, DRBD is like RAID 1 over network.

Install DRBD virtual package (This will work on Debian and Ubuntu):

apt-get install drbd-utils
I my case DRBD is running under control of my cluster-software, that means DRBD will be managed by corosync. I remove DRBD from upstart:


insserv -v -r drbd remove
We need to start the driver and tell Linux to load it the next time when it boots:

mshafiee

### KERNEL TUNING ###

# Increase size of file handles and inode cache
fs.file-max = 2097152

# Do less swapping
vm.swappiness = 10
vm.dirty_ratio = 60
vm.dirty_background_ratio = 2

mshafiee

sudo apt update && sudo apt upgrade -y 
sudo apt install strongswan -y
sudo vi /etc/sysctl.conf
	net.ipv4.ip_forward = 1
	net.ipv4.conf.all.accept_redirects = 0
	net.ipv4.conf.all.send_redirects = 0

sudo sysctl -p /etc/sysctl.conf

openssl rand -base64 64

mshafiee

##
# nginx server with http + ssl/https (Front)
# /etc/nginx/sites-available/example.com
server {
  listen 80;
  server_name     example.com;

  location / {
    proxy_pass      http://no-ssl:8080;
    proxy_set_header  Host $host;

mshafiee

#!/bin/bash
while IFS='' read -r line || [[ -n "$line" ]]; do
    echo '' | db2struct --host localhost -d farayad --package farayad -p --user root --struct=$line -t $line --gorm --guregu
done < "$1"


usage:
1-show tables;
2-store table name in tablename.txt file.
3- run: bash mysql2go.sh tablename.txt

mshafiee

[mysqld]
# Path to Galera library
wsrep_provider=/usr/lib/galera3/libgalera_smm.so

# Cluster connection URL contains IPs of nodes
#If no IP is found, this implies that a new cluster needs to be created,
#in order to do that you need to bootstrap this node
wsrep_cluster_address=gcomm://172.16.10.20,172.16.20.20,172.16.30.20

# In order for Galera to work correctly binlog format should be ROW

mshafiee

# Template my.cnf for PXC
# Edit to your requirements.
[mysqld]
server-id=1
datadir=/var/lib/mysql
socket=/var/run/mysqld/mysqld.sock
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
log-bin
log_slave_updates