MindMaps

Mind Map: OpenStack CLI

 

I love Mind Maps. I’ve actually been called a “Mind Map” junkie by another computer fellow (@open4storage), which I a fan of. I think Mind Maps add a new level of how to lay down a set of information. With it’s visual cues, it is, in my opinion, easier to find a snipet of information one is looking for than it is to skim throughout a notebook.

That been said, I will take this here as an opportunity to start a new section on this blog, where I will share my Mind Maps. To start, here’s a Mind Map based on the OpenStack CLI Cheat Sheet (docs.openstack.org/user-guide/cli_cheat_sheet.html).  The commands on the previous URL do not encompass all of the available CLI commands on OpenStack. As a matter of fact, I do not believe that the purpose of this cheat sheet (and of the Mind Map, by virtue of origin – that is, being a copy of the cli cheat sheet), is to have a compendium of all of the commands, flags, syntax’s and so on. The purpose of the cheat sheet is to be a quick reference guide to the most common commands used on OpenStack (this is debatable but let’s stick with the idea for now).

 

OpenStack_cli_cheat_sheet.html.png

Mind Map of the OpenStack CLI Cheat Sheet

For beginners, knowing all of these commands can be daunting, but I hope that having a visual cue to them will help you as it did help me.

If you want to try some Mind Maps, you can download here the OpenStack CLI Cheat Sheet. I’d recommend downloading the free version of XMind (http://www.xmind.net/), available for Windows, OSX and Linux.

Key takeaways:

  • Mind Maps provide a different way to display complex information in a visual diagram.
  • Learning OpenStack can be difficult. There are a lot of commands, flags and syntax’s to learn. A cheat sheet exists and provides the most common commands. This is specially beneficial to beginners.
  • A new Mind Map, presented here, aims to display the OpenStack CLI in a visual diagram.

Files:

  • OpenStack CLI Cheat Sheet Mind  Map (.png / .xmind)
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Trash dumping: Finding jewels in the sea of waste

Trash dumping. Unlikely to be your Sunday morning plan (or Saturday evening for that mater), could bring you back something of interest. In my case, my experience is a two-fold, one in the physical world and another in the digital. Although what I’m about to tell you is more of a parable, I did not literally had to dump into any trash to find anything useful, the outcome was positive: In both cases, I did get something valuable out of it.

TLDR: Two things happened here: #1 built a version of the famous hacked “Ikea Standing-Up desk” and #2 I discovered a new, awesome, podcast called Garbage, from two OpenBSD developers. Read along.

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Export OVF template failure on ESXi 6

For some reason, when trying to export a VM as an OVF file or OVA I keep getting the following error on VCSA 6:

ovf_erros

After going through the forums I found the answer here: https://communities.vmware.com/thread/518369?start=0&tstart=0

Essentially, you need to add the the VCSA IP address and hostname to the hosts file on the computer that you are connecting to the VCSA, such as your laptop or workstation. (/etc/hosts on *NIX or C:\Windows\System32\drivers\etc on Windows). Once that is done, you should be able to export the OVF or OVA file.

OVF_export_vSphere6

Hope this helps you

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Cloud Infra, Uncategorized

OpenStack Images default users

openstack-cloud-software-horizontal-small

After chasing this information too often, I’ve decided to give a break to my brain and compile a list of the most common OpenStack Images (at least for my day-to-day activities). Without further ado, here’s the list:

Distribution Default User
Ubuntu 14.04 Trusty ubuntu
CentOS 6/7 centos
Red Hat Enterprise Linux 6/7 cloud-user
CirrOS cirros
Debian admin

A complete and up to date list can be found at the OpenStack site.

You can then login into an instance with the provided SSH keys or optionally, you could also change the default user password with the following cloud-config, which will allow you to ssh into an instance but force the password to be changed on the first login:

#cloud-config
password: ChangeMe
chpasswd: { expire: True }
ssh_pwauth: True

Let’s understand the options from the above configuration.

# you can set passwords for a user or multiple users
# this is off by default.
# to set the default user's password, use the 'password' option.
# if set, to 'R' or 'RANDOM', then a random password will be
# generated and written to stdout (the console)
# password: passw0rd
#
# also note, that this will expire the password, forcing a change
# on first login. If you do not want to expire, see 'chpasswd' below.
# So, a simple working example to allow login via ssh, and not expire
# for the default user would look like:
password: passw0rd
chpasswd: { expire: False }
ssh_pwauth: True

and finally,

# in order to enable password login via ssh you must set
# 'ssh_pwauth'.
# If it is set, to 'True' or 'False', then sshd_config will be updated
# to ensure the desired function.  If not set, or set to '' or 'unchanged'
# then sshd_config will not be updated.
# ssh_pwauth: True

More examples can be found here.

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Paradox of (a computer) Choice

FullSizeRenderHow many boots can you count?

    “choose less and feel better.”
    ― Barry Schwartz, The Paradox of Choice: Why More Is Less

Yes, Dr. Schwartz could’vent said better. On his book, “The Paradox of Choice: Why More Is Less”, Dr. Schwartz dissects the minutia behind the decision making machine, our brain, and the challenges that we face today, in a time and age cluttered with information, options and choices. Making a decision has never been so difficult.

What is the Paradox of Choice? According to the definition on the Cambridge English Dictionary:

    a ​statement or ​situation that may be ​true but ​seems ​impossible or ​difficult to ​understand because it ​contains two ​opposite ​facts or characteristics

Following an example:

    It’s a ​curious paradox that ​drinking a lot of ​water can often make you ​feel ​thirsty.

Going back to the Paradox of Choice, the idea is that the fact that one has so many options actually makes the exercise of choosing (anything really) a burden, a difficult tasks, leading to a cognitive fatigue due to the information overload and anxiety. All undesirable symptoms well described by Barry Schwartz.

I’ve recently went to a famous boot store in Austin, Texas and saw this myself (the boots from picture above). I thought about getting something for my wife, a nice boot perhaps. Well, with a lot of options, various colors, shapes, ornaments, and sizes this ins’t an easy task, and here we are only talking about boots. Now imagine how things can easily get complicated when we are talking about computers. By the way, I ended up leaving the store empty handed overwhelmed by the number of possibilities.

This is actually surprisingly easy to observe and you can verify this first hand during the holidays. Working in IT means that we are usually consulted for (a) when all-things-computers break or (b) when someone needs to buy/upgrade their electronics (you should be flattered buy this, because in between the lines, people are saying that they trust your judgement and that you’re serving as a consultant for them.).

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Cloud Infra, SysAdmin, Uncategorized

smash-clp

Have you ever been in a situation where you had to go down to your home lab datacenter to reset a stubborn system? I bet you did and that’s not cool (at all). Luckily, many servers have a way to help you out with this. For me, salvation came in the form and shape of the Intel RMM (Remote Management Module) board.

According to Intel here are the key features:

  • Full remote access keyboard, video and mouse (KVM)
  • USB media redirection
  • Remote power actions
  • Proactive system health monitoring
  • Secure, embedded web server
  • Dedicated network connection

Which translates into pretty much the same experience as one would have by sitting in front of the machine (BIOS access and such). This also means that one could install an operating system remotely and even reboot/shutdown/poweron a server (again, remotely).

The access to this board is usually done through ssh. After you login you will be prompted into some form of shell (a bit more crude), specified by the Systems Management Architecture for Server Hardware Command-Line Protocol (aka SMASH CLP), specified bt the DTMF.

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Using GNU Screen (when there’s no tmux)

TLDR: using screen when tmux is not available. This isn’t a tmux vs screen post but rather how to use the tools that you have to get the job done.

It’s hard to imagine a day spent on a shell without the use of a terminal multiplexer. My favourite tool for the job is tmux, which comes handy when I’m working on or from an OpenBSD machine. tmux is installed by default on OpenBSD for quite a few releases now (circa 2009), you can see the commit log here.

It is easy to get used to something good😉 However, IT being IT, this wouldn’t be so easy. One reason that I see, is that a lot of servers out there running some sort of Unix-like OS (mainly, Linux) do not have tmux installed. Now the interesting side of this is that I often find the GNU screen installed.

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