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---
title: "你的服务器很好,现在是我的啦。"
description: "如何把你的数算课公共服务器“占为己有”(仅供娱乐)"
date: 2026-05-28T10:18:38+08:00
image:
math:
license:
hidden: true
slug: "00J"
---
### 阅前须知
请自觉维护公共资源的可用性,不要大规模和他人传播此用法,不要通过此方法在服务器上运行多核重负载,更不要尝试fork炸弹。
### 背景
2026年春季学期,我加入了谢正茂老师的“数据结构与算法(B)”课程。
这个课程有一个[课程主页 ](https://dsa2026.zhengmao.ltd/README.md ),在上面我发现老师贴心地为我们提供了[公用JupyterHub ](https://jupyter.zhengmao.ltd/ )以供我们学习课程。老师在上面发布每节课的讲义`.md` 文件,上课时也直接借助JupyterHub授课。
JupyterHub界面,左上角`File` -`New` -`Terminal` ,即可打开一个Bash样式的终端窗口。
这让我很意外。因为这意味着我可以直接登录后端服务器。
### 查成分
``` bash
cat /etc/redhat-release
cat /etc/os-release
uname -r
uname -a
lscpu
free -h
df -h
```
分别返回
```
Fedora release 41 (Forty One)
```
```
NAME="Fedora Linux"
VERSION="41 (Cloud Edition)"
RELEASE_TYPE=stable
ID=fedora
VERSION_ID=41
VERSION_CODENAME=""
PLATFORM_ID="platform:f41"
PRETTY_NAME="Fedora Linux 41 (Cloud Edition)"
ANSI_COLOR="0;38;2;60;110;180"
LOGO=fedora-logo-icon
CPE_NAME="cpe:/o:fedoraproject:fedora:41"
HOME_URL="https://fedoraproject.org/"
DOCUMENTATION_URL="https://docs.fedoraproject.org/en-US/fedora/f41/"
SUPPORT_URL="https://ask.fedoraproject.org/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"
REDHAT_BUGZILLA_PRODUCT="Fedora"
REDHAT_BUGZILLA_PRODUCT_VERSION=41
REDHAT_SUPPORT_PRODUCT="Fedora"
REDHAT_SUPPORT_PRODUCT_VERSION=41
SUPPORT_END=2025-12-15
VARIANT="Cloud Edition"
VARIANT_ID=cloud
```
```
6.16.7-100.fc41.x86_64
```
```
Linux nanjing.instance.cloud.lcpu.dev 6.16.7-100.fc41.x86_64 #1 SMP PREEMPT_DYNAMIC Thu Sep 11 16:41:15 UTC 2025 x86_64 GNU/Linux
```
```
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Address sizes: 48 bits physical, 48 bits virtual
Byte Order: Little Endian
CPU(s): 16
On-line CPU(s) list: 0-15
Vendor ID: AuthenticAMD
Model name: AMD EPYC 7773X 64-Core Processor
CPU family: 25
Model: 1
Thread(s) per core: 1
Core(s) per socket: 1
Socket(s): 16
Stepping: 2
BogoMIPS: 4391.74
Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx mmxext
fxsr_opt pdpe1gb rdtscp lm rep_good nopl cpuid extd_apicid tsc_known_freq pni pclmulqdq ssse3 fma cx16 pcid sse4_1
sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm cmp_legacy svm cr8_lega
cy abm sse4a misalignsse 3dnowprefetch osvw perfctr_core ssbd ibrs ibpb stibp vmmcall fsgsbase tsc_adjust bmi1 avx2
smep bmi2 erms invpcid rdseed adx smap clflushopt clwb sha_ni xsaveopt xsavec xgetbv1 xsaves clzero xsaveerptr wbn
oinvd arat npt lbrv nrip_save tsc_scale vmcb_clean flushbyasid pausefilter pfthreshold v_vmsave_vmload vgif umip pk
u ospke vaes vpclmulqdq rdpid fsrm arch_capabilities
Virtualization features:
Virtualization: AMD-V
Hypervisor vendor: KVM
Virtualization type: full
Caches (sum of all):
L1d: 1 MiB (16 instances)
L1i: 1 MiB (16 instances)
L2: 8 MiB (16 instances)
L3: 256 MiB (16 instances)
NUMA:
NUMA node(s): 1
NUMA node0 CPU(s): 0-15
Vulnerabilities:
Gather data sampling: Not affected
Ghostwrite: Not affected
Indirect target selection: Not affected
Itlb multihit: Not affected
L1tf: Not affected
Mds: Not affected
Meltdown: Not affected
Mmio stale data: Not affected
Old microcode: Not affected
Reg file data sampling: Not affected
Retbleed: Not affected
Spec rstack overflow: Vulnerable: Safe RET, no microcode
Spec store bypass: Mitigation; Speculative Store Bypass disabled via prctl
Spectre v1: Mitigation; usercopy/swapgs barriers and __user pointer sanitization
Spectre v2: Mitigation; Retpolines; IBPB conditional; IBRS_FW; STIBP disabled; RSB filling; PBRSB-eIBRS Not affected; BHI Not a
ffected
Srbds: Not affected
Tsa: Vulnerable: No microcode
Tsx async abort: Not affected
Vmscape: Not affected
```
```
total used free shared buff/cache available
Mem: 15Gi 2.0Gi 12Gi 5.1Mi 1.2Gi 13Gi
Swap: 8.0Gi 0B 8.0Gi
```
```
Filesystem Size Used Avail Use% Mounted on
/dev/sda4 29G 5.5G 23G 20% /
devtmpfs 7.8G 0 7.8G 0% /dev
tmpfs 7.8G 0 7.8G 0% /dev/shm
efivarfs 256K 17K 235K 7% /sys/firmware/efi/efivars
tmpfs 3.2G 836K 3.2G 1% /run
tmpfs 1.0M 0 1.0M 0% /run/credentials/systemd-journald.service
tmpfs 1.0M 0 1.0M 0% /run/credentials/systemd-network-generator.service
tmpfs 1.0M 0 1.0M 0% /run/credentials/systemd-udev-load-credentials.service
tmpfs 1.0M 0 1.0M 0% /run/credentials/systemd-sysctl.service
tmpfs 1.0M 0 1.0M 0% /run/credentials/systemd-tmpfiles-setup-dev-early.service
tmpfs 1.0M 0 1.0M 0% /run/credentials/systemd-tmpfiles-setup-dev.service
/dev/sda4 29G 5.5G 23G 20% /home
/dev/sda4 29G 5.5G 23G 20% /var
tmpfs 7.8G 424K 7.8G 1% /tmp
tmpfs 1.0M 0 1.0M 0% /run/credentials/systemd-vconsole-setup.service
/dev/sda3 966M 159M 742M 18% /boot
/dev/sda2 100M 18M 83M 18% /boot/efi
tmpfs 1.0M 0 1.0M 0% /run/credentials/systemd-tmpfiles-setup.service
tmpfs 1.0M 0 1.0M 0% /run/credentials/systemd-resolved.service
tmpfs 1.0M 0 1.0M 0% /run/credentials/serial-getty@ttyS0.service
tmpfs 1.0M 0 1.0M 0% /run/credentials/getty@tty1.service
```
很明显啦,这是一个来自LCPU的Fedora 41系统的Linux服务器(而且是“Cloud Edition”,这很可能意味着只有命令行环境,而没有桌面环境),运行在CLab的一个南京节点上。
配置是基于AMD EPYC 7773X的16个vCPU,以及16GiB内存,根目录有约29GiB的存储空间。这和CLab官网的`labs_and_courses` -`l8` 实例配置相吻合(一般用户可没有这么多配额捏)。
### SSH连接
这么好的服务器,当然要试试能不能SSH进来啦。首先可以肯定的是,`sshd` 服务一定是有的(不然咋管理云服务器捏)。检查一下:
``` bash
systemctl status sshd
```
返回:
```
● sshd.service - OpenSSH server daemon
Loaded: loaded (/usr/lib/systemd/system/sshd.service; enabled; preset: enabled)
Drop-In: /usr/lib/systemd/system/service.d
└─10-timeout-abort.conf, 50-keep-warm.conf
Active: active (running) since Thu 2026-05-28 01:31:57 CST; 10h ago
Invocation: 776d2e3a056b4249bf701cb7353af275
Docs: man:sshd(8)
man:sshd_config(5)
Main PID: 1181 (sshd)
Tasks: 1 (limit: 19053)
Memory: 6.3M (peak: 9.6M)
CPU: 140ms
CGroup: /system.slice/sshd.service
└─1181 "sshd: /usr/sbin/sshd -D [listener] 0 of 10-100 startups"
Warning: some journal files were not opened due to insufficient permissions.
```
没问题的话,那就直接查IP😋
``` bash
ip addr show
```
返回:
```
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host noprefixroute
valid_lft forever preferred_lft forever
2: enp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether fa:16:3e:d0:7e:b6 brd ff:ff:ff:ff:ff:ff
inet 10.129.83.107/22 brd 10.129.83.255 scope global dynamic noprefixroute enp3s0
valid_lft 50260sec preferred_lft 50260sec
inet6 2001:da8:201:2782:f816:3eff:fed0:7eb6/64 scope global dynamic noprefixroute
valid_lft 2591999sec preferred_lft 604799sec
inet6 fe80::f816:3eff:fed0:7eb6/64 scope link noprefixroute
valid_lft forever preferred_lft forever
```
这样我们就得到了IPv4和IPv6地址:分别是`10.129.83.107` 和`2001:da8:201:2782:f816:3eff:fed0:7eb6` 。
直接SSH:在Mac上执行:(注意占位符)
``` zsh
ssh <我的用户名>@2001:da8:201:2782:f816:3eff:fed0:7eb6
```
意外地没有报错(22端口竟然没有访问IP限制……),输入我的用户密码,就可以轻松地连上啦。
### 设置密钥登录和VSCode Remote SSH
在Mac上输入:
``` zsh
ssh-keygen -t ed25519
```
直接按3次回车,会生成私钥文件`~/.ssh/id_ed25519` 和公钥文件`~/.ssh/id_ed25519.pub` 。
接下来,在Mac上输入:(注意占位符)
``` zsh
ssh-copy-id -i ~/.ssh/id_ed25519.pub <我的用户名>@2001:da8:201:2782:f816:3eff:fed0:7eb6
```
根据提示输入一次我的密码,公钥就上传好啦。
在Mac的`~/.ssh/config` 上添加:
```
Host EPYC
HostName 2001:da8:201:2782:f816:3eff:fed0:7eb6
Port 22
User chenyichen
IdentityFile ~/.ssh/id_ed25519
AddKeysToAgent yes
UseKeychain yes
```
在VSCode的“远程资源管理器”就会出现“EPYC”,连接。
连接完成之后,这个服务器就可以用作你的远程工作区啦。不过安装VSCode扩展前,可以设置`"remote.downloadExtensionsLocally": true` ,以提升安装速度。(这个服务器访问GitHub好慢诶……我也开不了代理)
### 安装命令行工具,进行C++开发
服务器上默认有`python` 指令(那当然啦,JupyterHub咋不用Python……),但Clang编译器等都没有。
Fedora 41系统使用的包管理器是DNF。常用指令:
- 安装软件:`sudo dnf install <包名>`
- 更新软件:`sudo dnf update` `sudo dnf upgrade`
- 卸载软件:`sudo dnf remove <包名>`
- 清理缓存:`sudo dnf clean all`
不幸的是,其所有命令都需要`sudo` 执行,而:
``` bash
sudo whoami
```
返回
```
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.
For security reasons, the password you type will not be visible.
[sudo] password for <我的用户名>:
```
输入密码后,返回:
```
<我的用户名> is not in the sudoers file.
```
我并没有`sudo` 权限,也就无法使用DNF包管理器。
幸运的是,我们有一个用户态包管理器:Miniconda。
``` bash
curl -L https://repo.anaconda.com/miniconda/Miniconda3-latest-Linux-x86_64.sh -o ~/Miniconda3.sh
bash ~/Miniconda3.sh -b -p ~/miniconda3
~/miniconda3/bin/conda init bash
source ~/.bashrc
conda tos accept --override-channels --channel https://repo.anaconda.com/pkgs/main
conda tos accept --override-channels --channel https://repo.anaconda.com/pkgs/r
conda config --add channels conda-forge
conda config --set channel_priority strict
```
然后就可以尽情安装软件啦。(conda-forge包生态还挺丰富的捏)
``` bash
conda install git htop clang = 21 clangxx = 21 gcc gxx llvm libcxx-devel= 21
```
(注意`libcxx-devel` 是使用Clang编译器时必须额外安装的,顺便会自动安装意`libcxx-headers` ,否则Clang会因为找不到libc++头文件而无法使用。这和macOS的Homebrew不一样。)
编译C++文件时,指令需加几个参数:
``` bash
clang++ -stdlib= libc++ -L$HOME /miniconda3/lib -Wl,-rpath,$HOME /miniconda3/lib cpp1.cpp -o program.out
```
因为libc++是安装到用户态的,头文件和动态链接库都不在默认查找路径,需要显式指定。
### 提供Web服务
我打算把这个服务器用作Uptime Kuma监控节点,检测我自己的服务器的运行状态。
``` bash
conda install nodejs nginx
```
因为服务器上不去GitHub,在本地有代理的Mac上执行:
``` zsh
git clone https://github.com/louislam/uptime-kuma.git
wget -c https://github.com/louislam/uptime-kuma/releases/download/2.3.2/dist.tar.gz
```
把下载的`dist.tar.gz` 放在`uptime-kuma` 文件夹下,再把整个文件夹`scp` 到服务器上,再在服务器上执行:
``` bash
cd uptime-kuma
npm run setup
```
显示`Downloading dist https://github.com/louislam/uptime-kuma/releases/download/2.3.2/dist.tar.gz` 时按Control+C取消,然后:
``` bash
tar -xzf dist.tar.gz
node server/server.js
```
就可以成功启动Uptime Kuma啦。通过`10.129.83.107:3001` 访问,并进行管理员初次设置。
在我的域名控制台上把我的域名解析到这个地址后,需要通过Nginx反向代理,才能通过域名访问。
``` bash
cd ~/miniconda3/etc/nginx
mkdir -p sites.d
```
随后在`~/miniconda3/etc/nginx/sites.d/sucrose_proxy.conf` 里面设置反向代理配置,在`~/miniconda3/etc/nginx/nginx.conf` 设置SSL证书。
注意:`~/miniconda3/etc/nginx/nginx.conf` 里面默认的80和443端口已经被JupyterHub占用啦……我们可以改成其他端口。
再启动Nginx:
``` bash
nginx
```
就好啦。
(注意,conda安装的软件并不支持注册为系统Daemon,都是以用户身份运行在Shell窗口中,关闭Shell进程即会终止。可以配合`nohup` 命令使用。)
### 总结
很好玩捏。但需要注意:不要影响公共资源的可用性,运行重负载/大量用户部署服务可能会导致JupyterHub变卡,影响同学们的正常学习。因此不建议依赖此方法。