OpenShift 4 - Fedora CoreOS (5) - CoreOS的常规操作

《OpenShift 4.x HOL教程汇总》

常规操作

查看CoreOS操作系统信息

[core@tutorial ~]$ cat /etc/redhat-release
Fedora release 32 (Thirty Two)
[core@tutorial ~]$ cat /etc/os-release
NAME=Fedora
VERSION="32.20200923.3.0 (CoreOS)"
ID=fedora
VERSION_ID=32
VERSION_CODENAME=""
PLATFORM_ID="platform:f32"
PRETTY_NAME="Fedora CoreOS 32.20200923.3.0"
ANSI_COLOR="0;34"
LOGO=fedora-logo-icon
CPE_NAME="cpe:/o:fedoraproject:fedora:32"
HOME_URL="https://getfedora.org/coreos/"
DOCUMENTATION_URL="https://docs.fedoraproject.org/en-US/fedora-coreos/"
SUPPORT_URL="https://github.com/coreos/fedora-coreos-tracker/"
BUG_REPORT_URL="https://github.com/coreos/fedora-coreos-tracker/"
REDHAT_BUGZILLA_PRODUCT="Fedora"
REDHAT_BUGZILLA_PRODUCT_VERSION=32
REDHAT_SUPPORT_PRODUCT="Fedora"
REDHAT_SUPPORT_PRODUCT_VERSION=32
PRIVACY_POLICY_URL="https://fedoraproject.org/wiki/Legal:PrivacyPolicy"
VARIANT="CoreOS"
VARIANT_ID=coreos
OSTREE_VERSION='32.20200923.3.0'

查看网络配置

[core@tutorial ~]$ nmcli con show
NAME              UUID                                  TYPE      DEVICE
Wired Connection  e1fb8b00-3905-4e08-aecb-fdd212690515  ethernet  enp0s3
$ ll /etc/sysconfig/network-scripts/
total 0

修改IP

1. 执行命令

$ ip a | grep 192.168.1
    inet 192.168.1.18/24 brd 192.168.1.255 scope global dynamic noprefixroute enp0s3 
 
$ nmcli connection show 'Wired Connection' | grep ipv4.addresses
 ipv4.addresses:                         192.168.1.18/24 
 
$ sudo nmcli connection mod 'Wired Connection' \
  ipv4.method manual \
  ipv4.addresses 192.168.1.20/24 \
  ipv4.gateway 192.168.1.1 \
  ipv4.dns 192.168.1.1 \
  connection.autoconnect yes
$ nmcli connection show 'Wired Connection' | grep ipv4.addresses
ipv4.addresses:                         192.168.1.18/24

2. 重启后验证

$ nmcli connection show 'Wired Connection' | grep ipv4.addresses
ipv4.addresses:                         192.168.1.20/24

Docker 环境

1. 启动docker环境

$ systemctl status docker
● docker.service - Docker Application Container Engine
     Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)
     Active: inactive (dead)
TriggeredBy: ● docker.socket
       Docs: https://docs.docker.com
$ sudo systemctl start docker
$ systemctl status docker
● docker.service - Docker Application Container Engine
     Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled; vendor preset: disabled)
     Active: active (running) since Wed 2020-10-07 03:50:03 UTC; 3s ago
TriggeredBy: ● docker.socket
       Docs: https://docs.docker.com
   Main PID: 2398 (dockerd)
      Tasks: 16 (limit: 1076)
     Memory: 175.1M
     CGroup: /system.slice/docker.service
             ├─2398 /usr/bin/dockerd --host=fd:// --exec-opt native.cgroupdriver=systemd --selinux-enabled --log-driver=journald --storage-driver=overlay2 --live-restore --d>
             └─2403 containerd --config /var/run/docker/containerd/containerd.toml --log-level info

2. 运行容器

$ sudo docker run -it busybox
Unable to find image 'busybox:latest' locally
latest: Pulling from library/busybox
df8698476c65: Pull complete
Digest: sha256:d366a4665ab44f0648d7a00ae3fae139d55e32f9712c67accd604bb55df9d05a
Status: Downloaded newer image for busybox:latest
/ # hostname
c970dc6c1f75
/ # exit
 
$ sudo docker image ls
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
busybox             latest              6858809bf669        4 weeks ago         1.23MB

podman

1. 运行容器

$ podman run -it busybox
Trying to pull registry.fedoraproject.org/busybox...
  manifest unknown: manifest unknown
Trying to pull registry.access.redhat.com/busybox...
  name unknown: Repo not found
Trying to pull registry.centos.org/busybox...
  manifest unknown: manifest unknown
Trying to pull docker.io/library/busybox...
Getting image source signatures
Copying blob df8698476c65 done
Copying config 6858809bf6 done
Writing manifest to image destination
Storing signatures
/ # exit
  
$ podman images
REPOSITORY                 TAG     IMAGE ID      CREATED      SIZE
docker.io/library/busybox  latest  6858809bf669  4 weeks ago  1.45 MB

使用toolbox

什么是toolbox

在CoreOS中只提供了最基础的系统级命令，其它功能都建议通过Container运行，而不是直接安装运行在CoreOS系统中。为此CoreOS提供了名为toolbox的命令，它会根据CoreOS环境参数（通常）下载并运行对应的toolbox容器镜像（RedHat CoreOS和Fedora CoreOS的默认toolbox镜像不同）。toolbox容器在运行起来后会自动将宿主CoreOS的分区挂载到toolbox容器中，这样我们就可以在toolbox容器中访问宿主CoreOS的目录和文件了。我们可以在toolbox容器中使用yum安装CoreOS中没有的命令或工具，以提高可操作性。

安装toolbox容器

CoreOS缺省提供了toolbox命令，但是没包括toolbox对应的容器。在第一次运行toolbox命令的时候，CoreOS会自动下载由缺省参数指定的toolbox容器镜像。

1. 在CoreOS中创建toolbox环境，然后通过命令进入toolbox容器。

[core@tutorial ~]$ /bin/toolbox create
Image required to create toolbox container.
Download registry.fedoraproject.org/f32/fedora-toolbox:32 (500MB)? [y/N]: y
Created container: fedora-toolbox-32
Enter with: toolbox enter
[core@tutorial ~]$ toolbox enter
/usr/bin/id: cannot find name for group ID 1000
 
Welcome to the Toolbox; a container where you can install and run
all your tools.
 
 -- Use DNF in the usual manner to install command line tools.
 -- To create a new tools container, run 'toolbox create'.
 
For more information, see the documentation.

软件安装

1. 安装wget工具。

⬢[core@toolbox tmp]$ sudo yum install -y wget
We trust you have received the usual lecture from the local System
Administrator. It usually boils down to these three things:
 
    #1) Respect the privacy of others.
    #2) Think before you type.
    #3) With great power comes great responsibility.
 
Fedora 32 openh264 (From Cisco) - x86_64                                               903  B/s | 2.5 kB     00:02
Fedora Modular 32 - x86_64                                                             1.1 MB/s | 4.9 MB     00:04
Fedora Modular 32 - x86_64 - Updates                                                   1.3 MB/s | 3.7 MB     00:02
Fedora 32 - x86_64 - Updates                                                            13 kB/s |  26 MB     33:42
Fedora 32 - x86_64                                                                     1.1 MB/s |  70 MB     01:01
Package wget-1.20.3-4.fc32.x86_64 is already installed.
Dependencies resolved.
Nothing to do.
Complete!

2. 使用wget下载文件。

⬢[core@toolbox tmp]$ wget http://www.baidu.com

文件操作

2. 在toolbox 中查看文件系统，确认CoreOS宿主机的目录是挂载到toolbox容器中的“/run/host”目录下，例如下面的“/run/host/tmp”、“/run/host/var”等。

⬢[core@toolbox ~]$ df -h
Filesystem      Size  Used Avail Use% Mounted on
fuse-overlayfs  3.1G  696M  2.2G  24% /
tmpfs           487M     0  487M   0% /sys/fs/cgroup
devtmpfs        448M     0  448M   0% /dev
tmpfs           487M   84K  487M   1% /dev/shm
tmpfs            98M   76K   98M   1% /etc/hostname
tmpfs           487M  6.8M  481M   2% /run/media
/dev/sda4       4.4G  1.9G  2.5G  43% /run/host/etc
tmpfs           487M     0  487M   0% /run/host/tmp
/dev/sda5       3.1G  696M  2.2G  24% /run/host/var
tmpfs           487M     0  487M   0% /tmp

3. 在/run/host/tmp中创建一个test文件。

⬢[core@toolbox ~]$ echo aaa > /run/host/tmp/test

4. 从toolbox容器中退出来，查看CoreOS的/tmp目录，确认有在toolbox中创建的test文件。

⬢[core@toolbox ~]$ exit
logout
[core@tutorial ~]$ df -h
Filesystem      Size  Used Avail Use% Mounted on
devtmpfs        448M     0  448M   0% /dev
tmpfs           487M   84K  487M   1% /dev/shm
tmpfs           487M  6.8M  481M   2% /run
tmpfs           487M     0  487M   0% /sys/fs/cgroup
/dev/sda4       4.4G  1.9G  2.5G  43% /sysroot
tmpfs           487M     0  487M   0% /tmp
/dev/sda5       3.1G  696M  2.2G  24% /var
/dev/sda1       364M  169M  173M  50% /boot
/dev/sda2       127M  8.5M  119M   7% /boot/efi
tmpfs            98M   68K   98M   1% /run/user/1000
[core@tutorial tmp]$ cat /tmp/test
aaa

参考

https://www.katacoda.com/courses/coreos/playground