05. Remote Access - some exercises for ssh and parallel-ssh

Chapter 5 gives some examples for ssh and parallel-ssh (pssh...). As a note, in Debian/Ubuntu etc. pssh etc. has been renamed to:
parallel-ssh
parallel-scp
parallel-slurp
etc.
I have 5 VMs running on my PC - master, worker1...worker4. The workers are Ubuntu 18.04 servers, so they use the /etc/netplan/...yaml file for network configuration. I had already manually configured all of them, except for the ~/.ssh/config file.
I created a ~/.ssh/config file on the host with the following content:
Host master HostName 192.168.0.130 User student Host worker1 HostName 192.168.0.131 User student Host worker2 HostName 192.168.0.132 User student Host worker3 HostName 192.168.0.133 User student Host worker4 HostName 192.168.0.134 User student
I then ran the following script as an exercise:
#!/bin/bash # Exercise using parallel-scp and parallel-ssh # # ips.txt contains the IP addresses of the hosts, one per line # -h hostfile -- provides list of hosts (IP addresses) # -i inline -- print output inline on localhost # # This script does the following: # 1. Copies the ~.ssh/config file on LOCALHOST to the remote hosts # specified in ips.txt. # 2. Shows the remote config files using cat. # 3. Deletes the remote config files. # 4. Shows the remote config files using cat - this gives an error. # 5. Copies again the ~.ssh/config file on LOCALHOST to the remote hosts. # 6. Shows the remote config files using cat. parallel-scp -h ips.txt ~/.ssh/config /home/heiko/.ssh/ parallel-ssh -ih ips.txt cat ~/.ssh/config parallel-ssh -ih ips.txt rm ~/.ssh/config parallel-ssh -ih ips.txt cat ~/.ssh/config parallel-scp -h ips.txt ~/.ssh/config /home/heiko/.ssh/ parallel-ssh -ih ips.txt cat ~/.ssh/config
Since I already defined aliases for all my VMs, I could also use the aliases inside ips.txt:
worker1 worker2 worker3 worker4
The following is an exercise using parallel-slurp to copy remote files to the local host under ~/outdir:
#!/bin/bash # # Copy /etc/netplan/0....yaml files on remote hosts to local host: parallel-slurp -L ~/outdir -h remhosts.txt /etc/netplan/0* . # Copy the /etc/hosts and /etc/hostname files to local host: parallel-slurp -L ~/outdir -h remhosts.txt /etc/hosts . parallel-slurp -L ~/outdir -h remhosts.txt /etc/hostname .
Using the aliases, these files are then neatly stored in folders worker1...worker4.
I wonder if I could use pscp / parallel-scp to copy configuration stanzas to remote hosts and then manually change e.g. the IP. I'm talking specifically about the /etc/netplan/...yaml config file where I would have to change just the IP.
If I understand correctly, the IP would only change with the "netplan apply" command?
Comments
-
Thank you for the suggestion !
1 -
Just as a footnote, the text already says names may be different, and I just checked on RHEL-8:
c8:/home/coop/Desktop>rpm -qil pssh | grep bin /usr/bin/pnuke /usr/bin/prsync /usr/bin/pscp.pssh /usr/bin/pslurp /usr/bin/pssh c8:/home/coop/Desktop>
1 -
Thanks for the response. I was trying to find out if pssh etc. were actually used for sysadmin tasks and tried to figure out a practical use case. As my experience = inexperience, I probably come up with all kinds of strange ideas on how to use commands.
My post was by no means a critique, just my way of thinking and the hope that someone sets me straight, or confirms the possible use case.
0
Categories
- All Categories
- 229 LFX Mentorship
- 229 LFX Mentorship: Linux Kernel
- 810 Linux Foundation IT Professional Programs
- 363 Cloud Engineer IT Professional Program
- 183 Advanced Cloud Engineer IT Professional Program
- 82 DevOps Engineer IT Professional Program
- 151 Cloud Native Developer IT Professional Program
- 138 Express Training Courses & Microlearning
- 138 Express Courses - Discussion Forum
- Microlearning - Discussion Forum
- 6.3K Training Courses
- 48 LFC110 Class Forum - Discontinued
- 71 LFC131 Class Forum
- 44 LFD102 Class Forum
- 228 LFD103 Class Forum
- 19 LFD110 Class Forum
- 41 LFD121 Class Forum
- 18 LFD133 Class Forum
- 8 LFD134 Class Forum
- 18 LFD137 Class Forum
- 71 LFD201 Class Forum
- 5 LFD210 Class Forum
- 5 LFD210-CN Class Forum
- 2 LFD213 Class Forum - Discontinued
- 128 LFD232 Class Forum - Discontinued
- 2 LFD233 Class Forum
- 4 LFD237 Class Forum
- 24 LFD254 Class Forum
- 701 LFD259 Class Forum
- 111 LFD272 Class Forum - Discontinued
- 4 LFD272-JP クラス フォーラム
- 13 LFD273 Class Forum
- 179 LFS101 Class Forum
- 1 LFS111 Class Forum
- 3 LFS112 Class Forum
- 3 LFS116 Class Forum
- 7 LFS118 Class Forum
- LFS120 Class Forum
- 9 LFS142 Class Forum
- 8 LFS144 Class Forum
- 4 LFS145 Class Forum
- 3 LFS146 Class Forum
- 2 LFS148 Class Forum
- 15 LFS151 Class Forum
- 4 LFS157 Class Forum
- 44 LFS158 Class Forum
- LFS158-JP クラス フォーラム
- 10 LFS162 Class Forum
- 2 LFS166 Class Forum
- 4 LFS167 Class Forum
- 3 LFS170 Class Forum
- 2 LFS171 Class Forum
- 3 LFS178 Class Forum
- 3 LFS180 Class Forum
- 2 LFS182 Class Forum
- 5 LFS183 Class Forum
- 32 LFS200 Class Forum
- 737 LFS201 Class Forum - Discontinued
- 3 LFS201-JP クラス フォーラム - Discontinued
- 19 LFS203 Class Forum
- 135 LFS207 Class Forum
- 2 LFS207-DE-Klassenforum
- 1 LFS207-JP クラス フォーラム
- 302 LFS211 Class Forum
- 56 LFS216 Class Forum
- 52 LFS241 Class Forum
- 48 LFS242 Class Forum
- 38 LFS243 Class Forum
- 15 LFS244 Class Forum
- 5 LFS245 Class Forum
- LFS246 Class Forum
- LFS248 Class Forum
- 52 LFS250 Class Forum
- 2 LFS250-JP クラス フォーラム
- 1 LFS251 Class Forum
- 156 LFS253 Class Forum
- 1 LFS254 Class Forum
- 1 LFS255 Class Forum
- 9 LFS256 Class Forum
- 1 LFS257 Class Forum
- 1.3K LFS258 Class Forum
- 10 LFS258-JP クラス フォーラム
- 129 LFS260 Class Forum
- 160 LFS261 Class Forum
- 43 LFS262 Class Forum
- 82 LFS263 Class Forum - Discontinued
- 15 LFS264 Class Forum - Discontinued
- 11 LFS266 Class Forum - Discontinued
- 24 LFS267 Class Forum
- 25 LFS268 Class Forum
- 32 LFS269 Class Forum
- 6 LFS270 Class Forum
- 202 LFS272 Class Forum - Discontinued
- 2 LFS272-JP クラス フォーラム
- 4 LFS147 Class Forum
- 1 LFS274 Class Forum
- 4 LFS281 Class Forum
- 12 LFW111 Class Forum
- 262 LFW211 Class Forum
- 184 LFW212 Class Forum
- 15 SKF100 Class Forum
- 1 SKF200 Class Forum
- 1 SKF201 Class Forum
- 797 Hardware
- 199 Drivers
- 68 I/O Devices
- 37 Monitors
- 104 Multimedia
- 174 Networking
- 91 Printers & Scanners
- 85 Storage
- 759 Linux Distributions
- 82 Debian
- 67 Fedora
- 17 Linux Mint
- 13 Mageia
- 23 openSUSE
- 148 Red Hat Enterprise
- 31 Slackware
- 13 SUSE Enterprise
- 354 Ubuntu
- 470 Linux System Administration
- 39 Cloud Computing
- 71 Command Line/Scripting
- Github systems admin projects
- 95 Linux Security
- 78 Network Management
- 102 System Management
- 47 Web Management
- 69 Mobile Computing
- 18 Android
- 38 Development
- 1.2K New to Linux
- 1K Getting Started with Linux
- 374 Off Topic
- 115 Introductions
- 174 Small Talk
- 24 Study Material
- 807 Programming and Development
- 304 Kernel Development
- 485 Software Development
- 1.8K Software
- 263 Applications
- 183 Command Line
- 3 Compiling/Installing
- 987 Games
- 317 Installation
- 102 All In Program
- 102 All In Forum
Upcoming Training
-
August 20, 2018
Kubernetes Administration (LFS458)
-
August 20, 2018
Linux System Administration (LFS301)
-
August 27, 2018
Open Source Virtualization (LFS462)
-
August 27, 2018
Linux Kernel Debugging and Security (LFD440)