The Fei's Tech Notes: October 2022

Monday, October 31, 2022

Docker Client and Containerd Behind Proxy in CentOS 8

# docker pull kubeimage/kube-apiserver:v1.15.0

Error response from daemon: Get "https://registry-1.docker.io/v2/": dial tcp: lookup registry-1.docker.io on 17.15.75.8:53: no such host

vi /usr/lib/systemd/system/docker.service with below entries

[Service]
Environment=HTTP_PROXY=http://8.8.8.8:8888
Environment=HTTPS_PROXY=http://8.8.8.8:8888

systemctl daemon-reload
systemctl restart docker

# kubeadm config images pull --v=10

I1031 22:12:20.527118   22397 version.go:187] fetching Kubernetes version from URL: https://dl.k8s.io/release/stable-1.txt
exit status 1
output: E1031 22:12:20.843791   22419 remote_image.go:242] "PullImage from image service failed" err="rpc error: code = Unknown desc = failed to pull and unpack image \"registry.k8s.io/kube-apiserver:v1.25.3\": failed to resolve reference \"registry.k8s.io/kube-apiserver:v1.25.3\": failed to do request: Head \"https://registry.k8s.io/v2/kube-apiserver/manifests/v1.25.3\": dial tcp: lookup registry.k8s.io on 137.15.210.9:53: no such host" image="registry.k8s.io/kube-apiserver:v1.25.3"
time="2022-10-31T22:12:20-04:00" level=fatal msg="pulling image: rpc error: code = Unknown desc = failed to pull and unpack image \"registry.k8s.io/kube-apiserver:v1.25.3\": failed to resolve reference \"registry.k8s.io/kube-apiserver:v1.25.3\": failed to do request: Head \"https://registry.k8s.io/v2/kube-apiserver/manifests/v1.25.3\": dial tcp: lookup registry.k8s.io on 137.15.210.9:53: no such host"
, error

Add below entries into /usr/lib/systemd/system/containerd.service under section [Service]

[Service]
Environment=HTTP_PROXY=http://8.8.8.8:8888
Environment=HTTPS_PROXY=http://8.8.8.8:8888
systemctl daemon-reload
systemctl restart containerd

Sunday, October 16, 2022

Install Minikube with Docker Engine

Install docker engine

```

yum install -y yum-utils
yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
yum remove docker
yum install docker-ce docker-ce-cli containerd.io docker-compose-plugin

Install minikube

https://minikube.sigs.k8s.io/docs/start/

```

curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
sudo install minikube-linux-amd64 /usr/local/bin/minikube

Install kubectl

https://kubernetes.io/docs/tasks/tools/install-kubectl-linux/

Set environment variables if the minikube runs behind proxy

export HTTP_PROXY=http://<proxy hostname:port>
export HTTPS_PROXY=https://<proxy hostname:port>
export NO_PROXY=localhost,127.0.0.1,192.168.49.0/24

or run below command on fly
```

export no_proxy=$no_proxy,$(minikube ip)

Open firewall rule for port 8443

```

firewall-cmd --permanent --add-port=8443/tcp

`Start minikube`

```

minikube start --driver=docker

List porfiles

```

minikube profiles list

Delete existing profile

```

minikube delete

Delete existing profile with force

```

minikube delete --purge --all

Get cluster information

```

kubectl cluster-info

Saturday, October 15, 2022

mysql-community-server-5.7 Requires: libsasl2.so.2()(64bit)

# yum install mysql-community-server

Loaded plugins: langpacks, ulninfo

Resolving Dependencies

--> Running transaction check

---> Package mysql-community-server.x86_64 0:5.7.40-1.el6 will be installed

--> Processing Dependency: mysql-community-client(x86-64) >= 5.7.9 for package: mysql-community-server-5.7.40-1.el6.x86_64

--> Processing Dependency: libsasl2.so.2()(64bit) for package: mysql-community-server-5.7.40-1.el6.x86_64

--> Running transaction check

---> Package mysql-community-client.x86_64 0:5.7.40-1.el6 will be installed

---> Package mysql-community-server.x86_64 0:5.7.40-1.el6 will be installed

--> Processing Dependency: libsasl2.so.2()(64bit) for package: mysql-community-server-5.7.40-1.el6.x86_64

--> Finished Dependency Resolution

Error: Package: mysql-community-server-5.7.40-1.el6.x86_64 (mysql57-community)

Requires: libsasl2.so.2()(64bit)

You could try using --skip-broken to work around the problem

You could try running: rpm -Va --nofiles --nodigest

Cause:

Baseurl in repo config file is mapped to old release.

Solution:

# cat /etc/yum.repos.d/mysql.repo

[mysql57-community]

name=MySQL 5.7 Community Server

## baseurl=http://repo.mysql.com/yum/mysql-5.7-community/el/6/$basearch/

baseurl=http://repo.mysql.com/yum/mysql-5.7-community/el/7/$basearch/

enabled=1

gpgcheck=0

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

https://blog.fearcat.in/a?ID=00001-3311f896-7ed9-4220-8f2f-0e7ba81f2add

Monday, October 10, 2022

Kubernetes: Setup K8s on your Local

https://matt-rickard.com/docker-desktop-alternatives

https://cri-o.io/

Releases: https://github.com/cri-o/cri-o/releases

Install cri-o

  dnf module list cri-o
  VERSION=1.18
  dnf module enable cri-o:$VERSION
  dnf install cri-o

export OS=CentOS_8
export VERSION=1.25

curl -L -o /etc/yum.repos.d/devel:kubic:libcontainers:stable.repo https://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/stable/$OS/devel:kubic:libcontainers:stable.repo
curl -L -o /etc/yum.repos.d/devel:kubic:libcontainers:stable:cri-o:$VERSION.repo https://download.opensuse.org/repositories/devel:kubic:libcontainers:stable:cri-o:$VERSION/$OS/devel:kubic:libcontainers:stable:cri-o:$VERSION.repo
yum install cri-o

https://minikube.sigs.k8s.io/docs/start/

Install kubectl

https://kubernetes.io/docs/tasks/tools/install-kubectl-linux/

Friday, October 7, 2022

Linux partition operations

Reference: https://ismailyenigul.medium.com/resize-xfs-partition-without-lvm-df3ea681c6d3

# lsblk

# dnf install cloud-utils-growpart -y

# growpart /dev/sda 3

CHANGED: partition=3 start=6293504 old: size=35649536 end=41943040 new: size=203421663 end=209715167

# df -h

Filesystem Size Used Avail Use% Mounted on

devtmpfs 1.8G 0 1.8G 0% /dev

tmpfs 1.8G 0 1.8G 0% /dev/shm

tmpfs 1.8G 8.5M 1.8G 1% /run

tmpfs 1.8G 0 1.8G 0% /sys/fs/cgroup

/dev/sda3 17G 2.4G 15G 14% /

/dev/sda1 1014M 349M 666M 35% /boot

tmpfs 364M 0 364M 0% /run/user/0

# xfs_growfs /

meta-data=/dev/sda3 isize=512 agcount=4, agsize=1114048 blks

= sectsz=512 attr=2, projid32bit=1

= crc=1 finobt=1, sparse=1, rmapbt=0

= reflink=1

data = bsize=4096 blocks=4456192, imaxpct=25

= sunit=0 swidth=0 blks

naming =version 2 bsize=4096 ascii-ci=0, ftype=1

log =internal log bsize=4096 blocks=2560, version=2

= sectsz=512 sunit=0 blks, lazy-count=1

realtime =none extsz=4096 blocks=0, rtextents=0

data blocks changed from 4456192 to 25427707