Friday, 28 January 2022

Git is well-named - again

 I was trying to push a newly created branch to a GitHub repository earlier, and kept seeing: -

To github.com:Foobar/documentation.git

 ! [rejected]        snafu-branch -> snafu-branch (non-fast-forward)

error: failed to push some refs to 'github.com:Foobar/documentation.git'

hint: Updates were rejected because the tip of your current branch is behind

hint: its remote counterpart. Integrate the remote changes (e.g.

hint: 'git pull ...') before pushing again.

hint: See the 'Note about fast-forwards' in 'git push --help' for details.

After much tinkering and fiddling and cursing, I realised the problem.

I was trying to push a new branch to the GH project, without deleting a previously created branch OF THE SAME NAME.

I'd done some work last evening, and opened a PR - for various boring reasons, the PR didn't play nice, so I decided to close BUT forgot to delete the branch.

So, when I started again on my local machine, re-cloning the repo, rebasing on the main branch, creating my new branch, making the requisite changes etc. ....

Yes, I was trying to push a new branch of the same name over an existing branch

Once I deleted the branch in the repo ( it's my branch, I can do what I want ), all was good.

Tuesday, 25 January 2022

Today I Learned - useful keyboard shortcut for macOS

Last night, I chose to charge my Apple Magic Mouse - which, you might say, seems like a reasonable thing to do.

The thing is that, anyone who "knows" the most recent generation of Magic Mice is aware of the limitation: -


Source:  iPad Pro 11 - Magic Mouse 2 Pairing issue 

Try using the mouse whilst it's being charged, and you'll get the point ...

Why Apple chose to put the Lightning port there, and not on the "top" of the mouse, like most other rechargeable wireless mouse vendors do .....

Anyway, on the occasion that I want to be able to drive my Mac whilst the mouse is getting it's mouse juice, there're keyboard shortcuts.

The first is super-useful, but does require three key presses: -

[shift] + [command] + /

which takes focus to the Help -> Search menu: -


and the shorter: -

[control] + [f2]

which takes focus to the Apple menu: -


Both are super-useful !

Thanks to IBM friends for both

Monday, 24 January 2022

Today I learned how to use the QUOTIENT function in Excel ...

So, being the world's laziest person, I wanted to have Excel do some very very simple division and return the whole number portion, without the remainder.

I've got a cell that contains a total amount e.g. 1,234  and a few rows that contain "exchange rates".

For each row, I wanted to divide the total e.g. cell C1 by the exchange rate, and return the whole number.

This: -

QUOTIENT function

gave me what I needed i.e. the QUOTIENT() function.

For each row, I "anchored" cell C1 as the first argument to the function ( the numerator, the number "on top" of the division ) and the exchange rate cell as the second argument ( the denominator ) e.g.


I then used the value of the QUOTIENT() function to calculate the total i.e. voucher face value vs. the quotient.

Yeah, I know, dividing 342 into 1234 ain't that hard but ... automation is everything ....

Monday, 17 January 2022

SSH keys and variables

Leaving this here to remind my future self ...

I wanted to generate a variable containing my SSH public key ..

I tried to simply copy the key to my clipboard and paste it into the variable: -

export MY_PUB_KEY="ssh-rsa ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE foo@bar.com"

which is somewhat unwieldy.

However, given that my public key is in a file: -

id_rsa_04012022.pub

why didn't I simply do this ?

export MY_PUB_KEY=$(cat ~/.ssh/id_rsa_04012022.pub)

Now isn't that simpler ?

Friday, 14 January 2022

In other news, upgrading Bash

Following on from my earlier post: -

TIL: Suppressing Apple's "nagware" about ZSH 

reflecting the fact that macOS 12.1 Monterey still includes Bash 3.X: -

bash --version

GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin21)
Copyright (C) 2007 Free Software Foundation, Inc.

I noticed that one can use Homebrew to install Bash 5.X: -

brew install bash

which gives us: -

bash --version

GNU bash, version 5.1.16(1)-release (x86_64-apple-darwin21.1.0)
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

TIL: Suppressing Apple's "nagware" about ZSH

Whilst helping a colleague get to grips with shells on his Mac, including seeing what shells are out there: -

cat /etc/shells

# List of acceptable shells for chpass(1).
# Ftpd will not allow users to connect who are not using
# one of these shells.
/bin/bash
/bin/csh
/bin/dash
/bin/ksh
/bin/sh
/bin/tcsh
/bin/zsh

and switching between them: -

chsh -s /bin/dash hayd

Changing shell for hayd.

Password for hayd: 

chsh -s /bin/bash hayd

Changing shell for hayd.

Password for hayd: 

we also discussed the "nagware" that  includes in macOS to get us to switch away from the oh-so-ancient Bash 3.2: -

bash --version

GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin21)
Copyright (C) 2007 Free Software Foundation, Inc.

namely: -

Last login: Fri Jan 14 17:06:42 on ttys001
java version "1.8.0_311"
Java(TM) SE Runtime Environment (build 1.8.0_311-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.311-b11, mixed mode)
The default interactive shell is now zsh.
To update your account to use zsh, please run `chsh -s /bin/zsh`.
For more details, please visit https://support.apple.com/kb/HT208050.

Using this: -

How to hide the ‘default interactive shell is now zsh’ message in Terminal on macOS

as source, I coached him to add: -

export BASH_SILENCE_DEPRECATION_WARNING=1

to ~/.bash_profile 

and now we just see this: -

Last login: Fri Jan 14 17:14:33 on ttys001
java version "1.8.0_311"
Java(TM) SE Runtime Environment (build 1.8.0_311-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.311-b11, mixed mode)

Wednesday, 12 January 2022

Today I Learned - IBM Container Registry - Formatting the output ...

Having got into the use of JSON to format the output from various different IBM Cloud CLI tools, using jq and jsonpath as per this example: -

JQ vs jsonpath

However, for reasons known to them, the Container Registry (CR) plugin uses a different mechanism to format output, namely Go templates.

This is well documented here: -

Formatting and filtering the CLI output for IBM Cloud Container Registry commands

So, as an example, if I want to look for images that are greater than 1,000,000 bytes ( 1 Mb ) and wish to display the repository, tag and security status, this is what I'd run: -

ic cr image-list --format "{{ if gt .Size 1000000 }}{{ .Repository }}:{{ .Tag }} {{ .SecurityStatus.Status }}{{end}}"

Similarly, if I want to list all images, regardless of size, but including the namespace: -

ic cr image-list --format "{{ .Repository }}:{{ .Tag }} {{ .Namespace }} {{ .SecurityStatus.Status }}"

The documentation covers the formatting options in WAAAAAY more detail: -

Tuesday, 11 January 2022

IBM Cloud - Cleaning things up

I've been looking through my IBM Cloud account, with a view to nuking unwanted / unused components, services, capabilities etc.

Today I'm targeting Cloud Foundry (CF), and, via the web UI, I found that I had a Cloud Foundry Org harking back to 2014, named david_hay@uk.ibm.com which contains a space called dev.

However, I was trying / failing to find / delete it from the command-line.

I ran: -

ic cf spaces

which returned: -

Invoking 'cf spaces'...

Getting spaces in org david_hay@uk.ibm.com as david_hay@uk.ibm.com...

No spaces found.

Similarly, when I tried to delete the dev space: -

ic cf delete-space dev

Invoking 'cf delete-space dev'...

Really delete the space dev? [yN]: y
Deleting space dev in org david_hay@uk.ibm.com as david_hay@uk.ibm.com...
Space 'dev' not found.
FAILED

And then ... looking back at the web UI, I saw: -

Region: US South

and thought "Ah, hah"

From the CLI, I ran: -

ic target 

which reported: -

Region:            eu-gb   

So I switched my region: -

ic target -r us-south

and re-ran: -

ic cf spaces

Invoking 'cf spaces'...

Getting spaces in org david_hay@uk.ibm.com as david_hay@uk.ibm.com...

name
dev

and then: -

ic cf delete-space dev

Invoking 'cf delete-space dev'...

Really delete the space dev? [yN]: y
Deleting space dev in org david_hay@uk.ibm.com as david_hay@uk.ibm.com...
OK

Nice!

Hey Aptitude, where's my disk space gone ?

Whilst upgrading an Ubuntu 20.04.3 LTS box, I hit messages such as: -

...

Ign:25 http://ubuntu.example.net/ubuntu-ports focal-security/universe s390x Packages

Err:27 http://ubuntu.example.net/ubuntu-ports focal-security/universe s390x c-n-f Metadata

  Write error - write (28: No space left on device)

Ign:14 http://ubuntu.example.net/ubuntu-ports focal-updates/universe Translation-en

Get:28 http://ubuntu.example.net/ubuntu-ports focal-security/multiverse s390x Packages [3,232 B]

Get:26 http://ubuntu.example.net/ubuntu-ports focal-security/universe Translation-en [154 kB]

Err:26 http://ubuntu.example.net/ubuntu-ports focal-security/universe Translation-en

  

Err:9 http://ubuntu.example.net/ubuntu-ports focal-updates/main Translation-en

  Write error - write (28: No space left on device)

...

which was somewhat worrying.

I checked my available disk space: -

df -kmh

and noticed that /var was full: -

/dev/mapper/basevg-var   2.9G  2.8G  8.8M 100% /var

Noting that that file-system has 2.9 GB of space, I wanted to see what was eating it: -

du -hs /var/* | sort -h

0 /var/lock
0 /var/run
4.0K /var/local
12K /var/opt
16K /var/lost+found
32K /var/spool
40K /var/tmp
648K /var/mail
2.0M /var/backups
405M /var/log
1.2G /var/lib
1.3G /var/cache

I took a random guess, and assumed that /var/cache was somehow related to Aptitude ( apt ), given the error that I was seeing.

Thankfully, the internet ( as ever ) has the answer: -


The trick is to run: -

sudo apt-get clean

Given that I'm already running as root, I ran: -

apt-get clean

which returns nothing but ....

du -hs /var/* | sort -h

0 /var/lock
0 /var/run
4.0K /var/local
12K /var/opt
16K /var/lost+found
32K /var/spool
40K /var/tmp
648K /var/mail
2.0M /var/backups
8.6M /var/cache
405M /var/log
1.2G /var/lib

so /var/cache is now 8.6 MB rather than 1.3 GB, and /var is way smaller: -

df -kmh

/dev/mapper/basevg-var   2.9G  1.6G  1.3G  56% /var

and, perhaps, more importantly, my upgrade runs to completion : -

apt-get update && apt-get upgrade -y

Nice!

Monday, 10 January 2022

Kubernetes - messing about with nodes and taints

I've probably blogged about this before, but, today, I'm tinkering with Kubernetes ( well, OpenShift Container Platform ) nodes, in terms of understanding what taints are applied to what nodes, in order that I can assign pods accordingly.

This command was immensely useful: -

kubectl get nodes -o custom-columns=NAME:.metadata.name,TAINTS:.spec.taints

NAME           TAINTS
192.168.0.4    <none>
192.168.16.4   [map[effect:NoExecute key:dedicated value:transit]]
192.168.20.4   [map[effect:NoExecute key:dedicated value:transit]]
192.168.24.4   [map[effect:NoExecute key:dedicated value:transit]]
192.168.32.4   [map[effect:NoExecute key:dedicated value:edge]]
192.168.36.4   [map[effect:NoExecute key:dedicated value:edge]]
192.168.4.4    <none>
192.168.40.4   [map[effect:NoExecute key:dedicated value:edge]]
192.168.8.4    <none>
with thanks to StackOverflow: -


The official Kubernetes documentation has much to say about taints: -



JQ vs jsonpath

Not sure why I'm not doing more with jsonpath but I do admire the elegance and simplicity of this: -

kubectl get service cluster-proxy -n default -o=jsonpath='{.spec.clusterIP}'

as compared to my default muscle memory using jq : -

kubectl get service cluster-proxy -n default --output JSON | jq -r .spec.clusterIP

The jsonpath alternate definitely requires fewer keystrokes AND doesn't require me to install jq 

Although, to be honest, I'm not going to stop using jq for all my other JSON wrangling ....


Friday, 7 January 2022

TIL: Logging into RedHat OpenShift Container Platform using an API key

So I've been logging into various OpenShift Container Platform (OCP) clusters for the longest time now, mostly using an API key.

To facilitate this, I have an alias in my current shell ( I'm using macOS 12.1 and mainly live in Terminal ) that parses a JSON document containing said API key and pulls it out: -

alias apikey='export APIKEY=$(cat ~/key_file_production.json | jq -r .apikey) && echo $APIKEY'

Now this handily dumps the result of the operation out to the screen - which can be problematic.

Therefore, wouldn't it be nice if I could use that alias inside another command when I login to my cluster ?

Well, I can: -

oc login -u apikey -p $(apikey)

Login successful.

You have access to 68 projects, the list has been suppressed. You can list all projects with 'oc projects'

Using project "default".

Now I could've combined the two things together: -

oc login -u apikey -p $(cat ~/key_file_production.json | jq -r .apikey)

Login successful.

You have access to 68 projects, the list has been suppressed. You can list all projects with 'oc projects'

Using project "default".

which is way more typing ...

Unless I create another alias ...

code ~/.bash_profile 

...
alias oclogin='oc login -u apikey -p $(cat ~/key_file_production.json | jq -r .apikey)'
...

source ~/.bash_profile

and now I have this: -

oclogin 

Login successful.

You have access to 68 projects, the list has been suppressed. You can list all projects with 'oc projects'

Using project "default".

I love my shell!!!

TIL: Tracing IBM Cloud CLI

For no particular reason, I've "discovered" how to trace the IBM Cloud Command Line Interface (CLI) tool, which is useful.

I'm mainly running on macOS and Linux and, in both cases, I can trace the CLI by setting the variable IBMCLOUD_TRACE to true: -

export IBMCLOUD_TRACE=true

and now I see the HTTP request and response headers: -

ic plugin list

Listing installed plug-ins...

REQUEST: [2022-01-07T12:56:22Z]

GET /ibm-cloud-cli-plugin-metadata/bluemix-repo-index.yml HTTP/1.1

Host: download.clis.cloud.ibm.com

Accept: application/json

Accept-Language: en-US

Accept-Language: en

Content-Type: application/json

User-Agent: IBM Cloud CLI 2.3.0 / darwin

RESPONSE: [2022-01-07T12:56:24Z] Elapsed: 1618ms

HTTP/1.1 200 OK

Content-Length: 666352

Accept-Ranges: bytes

Connection: keep-alive

Content-Type: binary/octet-stream

Date: Fri, 07 Jan 2022 12:56:24 GMT

Etag: "863b7cd704c756d503a86834edab6709"

Last-Modified: Thu, 06 Jan 2022 15:15:24 GMT

Server: Cleversafe

X-Amz-Request-Id: c96d5071-20db-485e-9245-4ffb4b52e66b

X-Clv-Request-Id: c96d5071-20db-485e-9245-4ffb4b52e66b

X-Clv-S3-Version: 2.5



[SKIP BINARY OCTET-STREAM CONTENT]

Plugin Name                                  Version   Status             Private endpoints supported   

container-service[kubernetes-service]        1.0.353                      false   

key-protect                                  0.6.9                        true   

logging                                      0.0.8                        false   

sdk-gen                                      0.1.12                       false   

vpc-infrastructure[infrastructure-service]   2.1.0                        true   

cloud-functions[wsk/functions/fn]            1.0.56    Update Available   false   

cloud-object-storage                         1.3.1                        false   

container-registry                           0.1.553   Update Available   true   

which is nice

And now to update my plugins: -

ic plugin update

TIL - read-only variables in Linux

 A co-worker was seeing an exception: -  line 8: TMOUT: readonly variable when trying to SCP a file from a remote Linux box. I did some digg...