#!/bin/sh -eu
NUMSECTORS=$(($1*1024*1024*1024/512))
echo "creating ramdisk with $1 GB ($NUMSECTORS sectors)"
MYDEV=$(hdiutil attach -nomount ram://$NUMSECTORS)
echo "created $MYDEV"
diskutil eraseVolume HFS+ "ramdisk-${1}gb" $MYDEV
echo "formatted $MYDEV"

This script creates a ramdisk with the first parameter taken as gigabytes. So runnning ./ramdisk.sh 16 will create a disk with 16 gigabytes and it will be named “ramdisk-16gb” and accessible via /Volumes/ramdisk-16gb. It will show up in finder as mounted volume. To get rid of it simply unmount it with the small icon right to the name.

ATTENTION: Everything stored on this devices will be lost when the mac is turned off or the volume is removed.

#!/bin/zsh
source ./.zshrc

echo "starting local upgrades of homebrew, sdk and nvm\n"

echo "###########################"
echo "# homebrew"
echo "###########################"
# install see https://brew.sh
echo "update installed packages"
brew update
brew upgrade

echo "install packages"
brew install nvm
brew tap buo/cask-upgrade

echo "upgrade casks"
brew cu -ay

brew autoremove
brew cleanup

echo "\n\n\n"
echo "###########################"
echo "# sdk"
echo "###########################"

echo "install sdkman"
# https://sdkman.io/install
#curl -s "https://get.sdkman.io" | bash
sdk selfupdate

echo "update sdkman packages"
sdk update
sdk upgrade

echo "\n\n\n"
echo "###########################"
echo "# nvm"
echo "###########################"
echo "install LTS"
nvm install --lts

echo "\n\n\n"
echo "###########################"
echo "# npm"
echo "###########################"
npm update -g

echo "\n\n\n"
echo "###########################"
echo "done"

Running this keeps most of my system up to date. I only have a few things installed either via AppStore or manually.

But where is the problem and what does this have to do with sudo you ask?

When you have a list of pending updates MacOS will ask you multiple time during a single run of the script for you password because sudo is using a very very short timeout for it. If you want to get rid of that problem run sudo viduso and add the following line after all those Defaults lines you will see in there:

Defaults	timestamp_timeout = -1

This way sudo won’t forget your password in a single session. Of course that -1 could be a problem but for me it isn’t because I always close my terminals when I don’t need them anymore.

You will need the html code you want to use as signature. So have it ready to paste it later.

Got to ~/Library/Mail/V10/MailData/Signatures and check which of the .mailsignature files is the one you want to change. For every signature saved in the mail client there is such a file. Just check the content. Open the right file and replace the html after the header. Everything above that empty line is the header. Here a sample that illustrates this:

Content-Transfer-Encoding: 7bit
Content-Type: text/html;
charset=us-ascii
Message-Id: <12341234-1234-1234-1234-123412341234>
Mime-Version: 1.0 (Mac OS X Mail 16.0 (xxxx))

<old content>

Leave everything as is and replace all text “<old content>” with your new html. Save the file. The right click it and click “Get Info” and there you need to select “Locked”. Otherwise the mail client will overwrite the content and not use it.

With the file locked, open the mail client and you will have your html signature ready to use.

#Apple #MailClient #AppleMailClient #HTMLSignature

Could not kickstart service “com.apple.audio.coreaudiod”: 1: Operation not permitted

This was fixed by the following:

sudo su
rm -rf /opt/homebrew/Caskroom/blackhole-2ch
exit
brew install blackhole-2ch

Another option seems to be to fix the issue with kickstart as described here. But I didn’t try that.

#!/usr/bin/env bash

if [[ "" == "$@" ]]; then
    echo "usage: $0 <file(s) to convert>"
    exit 1
fi

for i in "$@"; do
    directory=$(realpath $(dirname "$i"))
    file=$(basename "$i")
    name=${file%.*}
    extension=$(echo ${file##*.} | tr '[:upper:]' '[:lower:]')

    if [[ "$extension" == "psd" ]]; then
        target="$directory/$name.png"
        if [[ -e "$target" ]]; then
            echo "file already exists: '$target'"
        else
            echo "converting '$i'"
            convert "$i" -background none -flatten "$target" || exit 1
        fi
    fi
done

This takes the file(s) to convert as argument(s). You can also just go with wildcards like *.psd to convert all psd files in a folder. Already converted files will be skipped.

You need ImageMagic installed on your machine to have access to the convert command.

Tested with ImageMagic 7.1.1-27 on MacOS Sonoma 14.3.1.

netstat -anv -p tcp | grep tcp4 | grep "8080"

Replace the 8080 with the wanted port.

You will see a line like this:

tcp4       0      0  127.0.0.1.8080         *.*                    LISTEN       131072  131072  54876      0 00000 00000006 00000000002d50b2 00000000 00000800      2      0 000001

The 54876 is the process id. So you can send a kill 54876.

Homebrew Cask Update Tool makes updating your installed applications a breeze. It automatically detects outdated software installed via Homebrew Cask and updates them with a single command, just like how you’d use APT on Linux. Say goodbye to manually checking for updates and navigating through various application menus.

Streamline your macOS software maintenance with Homebrew Cask Update Tool and enjoy a more efficient and hassle-free experience.

brew tap buo/cask-upgrade
brew cu -iay

➜  ~ docker pull ubuntu                                                                                                                        
Using default tag: latest                                                                                                                      
Error response from daemon: Get "https://registry-1.docker.io/v2/": proxyconnect tcp: dial tcp: lookup http.docker.internal on 192.168.65.7:53:
 read udp 192.168.65.6:62314->192.168.65.7:53: i/o timeout        

192.168.65.0/24 is the configured docker internal network of Docker Desktop. It was running on defaults and I wasn’t aware of any manual changes. DNS of my host system worked properly:

➜  ~ host registry-1.docker.io                                                                                                                 
registry-1.docker.io has address 34.194.164.123                                                                                                
registry-1.docker.io has address 18.215.138.58                                                                                                 
registry-1.docker.io has address 52.1.184.176                                                                                                  
registry-1.docker.io has IPv6 address 2600:1f18:2148:bc00:8334:ca86:c3d6:a507                                                                  
registry-1.docker.io has IPv6 address 2600:1f18:2148:bc02:cfd8:db68:ea1f:277c                                                                  
registry-1.docker.io has IPv6 address 2600:1f18:2148:bc01:a3b0:6734:c617:7c5c 

What exactly caused the issue didn’t reveal but resetting Docker Desktop to factory defaults fixed the problem. You can find this on the top right corner of the window behind the small bug icon -> “Reset to factory defaults” button.

This example would create an amd64 and a aarch64 (arm64/v8) image:

# ARM
docker build --platform=linux/aarch64 -t <dockerhub-username>/<image-name>:<version>-aarch64 .
docker push -t <dockerhub-username>/<image-name>:<version>-aarch64

# AMD
docker build --platform=linux/amd64 -t <dockerhub-username>/<image-name>:<version>-amd64 .
docker push -t <dockerhub-username>/<image-name>:<version>-amd64

Based on these you can create a manifest and upload it:

docker manifest create <dockerhub-username>/<image-name>:<version> \
  --amend <dockerhub-username>/<image-name>:<version>-aarch64 \
  --amend <dockerhub-username>/<image-name>:<version>-amd64
docker manifest push <dockerhub-username>/<image-name>:<version>

This would already provide an image <dockerhub-username>/<image-name>:<version> available for amd64 and aarch64 platform on docker hub. But for convenience we also want a latest tag for that manifest:

docker manifest create <dockerhub-username>/<image-name>:latest \
  --amend <dockerhub-username>/<image-name>:<version>-aarch64 \
  --amend <dockerhub-username>/<image-name>:<version>-amd64
docker manifest push <dockerhub-username>/<image-name>:latest

This uses the same hashes as the version uploaded before.

I am not sure if this is the correct or best way, but at least it works. On my M1 mac buildx didn’t work so I fell back to manifests that aren’t that complicated anyway.

Here an example image that was created and uploaded like this: https://registry.hub.docker.com/r/mbopm/cyberchef.

Who’s required to pay for Docker Desktop?

Docker Desktop requires a paid, per-user subscription for organizations with more than 250 employees or more than $10 million in annual revenue per our terms of service.

https://www.docker.com/pricing/faq/, 2022-12-03

Podman is an open source and free replacement licensed under Apache-2.0. Here the description of it taken from the homepage:

Podman is a daemonless, open source, Linux native tool designed to make it easy to find, run, build, share and deploy applications using Open Containers Initiative (OCI) Containers and Container Images. Podman provides a command line interface (CLI) familiar to anyone who has used the Docker Container Engine. Most users can simply alias Docker to Podman (alias docker=podman) without any problems. Similar to other common Container Engines (Docker, CRI-O, containerd), Podman relies on an OCI compliant Container Runtime (runc, crun, runv, etc) to interface with the operating system and create the running containers. This makes the running containers created by Podman nearly indistinguishable from those created by any other common container engine.

https://docs.podman.io/en/latest/, 2022-12-03

To install it I simply followed these steps on my Mac:

brew install podman
podman machine init # create a qemu virtual machine
podman machine start # start it
export DOCKER_HOST='unix:///Users/manuel/.local/share/containers/podman/machine/podman-machine-default/podman.sock'

With this in place you can continue running docker commands as usual and for most users a simple alias will do the trick if you don’t want to write podman instead of docker.

In IntelliJ you need to configure the TCP socket instead of Docker for Mac in the settings. Then also IntelliJ continues talking to the podman instance as it were a Docker Desktop. I named my host “Podman” instead of “Docker” and right-clicking the compose file and selecting “Run on Podman” worked like a charm. No difference to Docker Desktop before.

When you don’t need docker / podman you can stop it by running

podman machine stop

To restart it simply write “start” instead of stop.

Here is what I added to my .zshrc file:

alias docker='podman'
export DOCKER_HOST='unix:///Users/manuel/.local/share/containers/podman/machine/podman-machine-default/podman.sock'