Bluetooth: Not Available in Sierra on the Macintosh

After software update in Sierra on my Macintosh, my Bluetooth mouse usually stops working.

The toolbar displays the Bluetooth not available icon: 

When I click it, the “Bluetooth: Not Available” message is displayed.

There are two recommended actions we can take to bring Bluetooth back to life. If the first one does not help, try to execute them together during the same shutdown and restart cycle.

Delete the file from Library / Preferences

  1. Start Finder,
  2. In the Go menu select Go to Folder,
  3. Enter /Library/Preferences into the text box and click the Go button,
  4. Move the file to the trash,
  5. Shut down the Macintosh,
  6. Start the computer again.

Reset the SMC to reinitialize the Bluetooth module

  1. Shut down the Macintosh,
  2. Disconnect all peripherals (external display, drives, mouse, printer),
  3. Make sure the power adapter is connected to the computer,
  4. Press and hold the Shift, Control and Option buttons for 10 seconds,
  5. Start the computer with the power button, with the peripherals still disconnected,
  6. Re-connect the peripherals.

Minimum Windows workstation setup to work with Windows servers

If you work on a Mac or Linux workstation and need to script and administer Windows servers, you need a few Windows tools. You can create a Windows Virtual Machine hosted in the free Virtual Box from Oracle. For installation instructions see Install the DevOps development tools on Windows

  • Notepad++
  • Chocolatey
  • Git
  • AWS CLI (Amazon Web Services Command Line Interface)


Keep multiple versions of applications on Macintosh

Most of the DevOps tools are still in beta versions, many times the new version is not compatible with your existing scripts or have an error that stops your scripts working. To be able to keep multiple versions of the applications and easily switch between them, create symbolic links and point to the version you want to execute.

Create version-specific locations

Create a folder for your optional applications.

mkdir /opt

Set you as the owner of the “opt” directory and its children.

YOUR_GROUP should be on:

  • MacOS: wheel
  • Ubuntu: your username 
sudo chown -R YOUR_USER_NAME:YOUR_GROUP /opt

Set the security of the folder.

sudo chmod 755 /opt

We will create a directory structure to place each version of the application into its own folder. This example uses Packer.

Create a symbolic link to point to the application in the appropriate version folder. These are the examples for Packer, Terraform, and Vagrant. Notice, that the Vagrant application is in the “bin” directory, so the symbolic link has to point there.

If there is an existing symbolic link that points to the latest version of the application, rename it to be able to quickly return to the prior version of the application. This can come handy when we need to destroy instances created with the prior version of Terraform.

cd /opt/terraform
mv terraform terraform_v_0.9.11
cd /opt/packer
mv packer packer_v_1.0.4

Create a new symbolic link that points to the latest version of the application.

# For Packer
cd /opt/packer
ln -s /opt/packer/packer_1.2.0/packer packer

# For Terraform
cd /opt/terraform
ln -s /opt/terraform/terraform_0.10.0/terraform terraform

# For Vagrant
cd /opt/vagrant
ln -s /opt/vagrant/vagrant_1.9.5/bin/vagrant vagrant #The vagrant application is in the bin folder

Add the main application folder to the path in the config file of your terminal

  • for iTerm2 with zterminal: ~/.zshrc
  • for other terminals: ~/.bash_profile


For Vagrant installation see Vagrant

To change the version you want to execute

  • Delete the symbolic link,
    cd /opt/packer
    rm packer
  • Create a new symbolic link pointing to the other version of the application as above.

Disable the Caps Lock key on the Macintosh

I am not sure who uses the Caps Lock button anymore. It was important in the age of typewriters to be able to type all uppercase titles without holding the shift key, but these days I don’t remember the last time I needed it. In fact I frequently press it accidentally and prevents me to log into my computer.


To disable the Caps Lock key on Sierra

  • In Settings open Keyboard,
  • Click the Modifier Keys… button,
  • Set the Caps Lock key to No Action.

DevOps Engineering part 1. (Mac) – Install the DevOps development tools on Macintosh

Enable the right-click

To be able the right-click on the mouse

  1. Open settings.
  2. Enable Secondary click for the mouse and the trackpad.

Lock the screen

To be able to lock the screen from the menu bar:

  1. In Finder search for Keychain Access and start it,
  2. In the Keychain Access menu select Preferences,
  3. Check the Show keychain status in menu bar checkbox,
    This will place a lock icon in the menu bar.

To lock your screen

  1. Click the lock icon in the menu bar
  2. Select Lock Screen

Show the full path in Finder

  1. Open Finder
  2. In the View menu select Show Path Bar
    Finder will show the full path of the current folder at the bottom of the window. 

To jump to a folder shown in the path bar just double click it.

Show hidden files and folders

  1. Open the terminal and execute the following line
    defaults write AppleShowAllFiles YES
  2. For the change to take effect relaunch Finder.
    • Press the ‘Option/Alt’ key, right click on the Finder icon in the dock and click Relaunch

Apple Id without credit card

If you don’t have an Apple Id, create one. To obtain one without a credit card, you need to create the account in an older version of iTunes. In version 12.7 Apple removed the access to the App Store.

  1. Downgrade iTunes on your Mac to version 12.6. Follow the instructions at
  2. Start iTunes 12.6 on your Macintosh,
  3. Click the drop-down menu in the upper left corner,
  4. If Apps is visible, select it, otherwise click Edit Menu
    • Select Apps, and click Done to display it in the drop down.
  5. Search for a free app in the App Store and start to download it,
  6. Create a new Apple Id and select None for credit card type.

Show the user home directory

  1. Open Finder
  2. In the Finder menu select Preferences
  3. In the Favorites section select the checkbox next to your user name

Create a directory for optional applications

Create the opt folder in the root of the hard disk.

Memory usage monitor

  1. Download  Dr. Cleaner Elite from the App Store to be able to monitor memory, CPU and network usage from the Menu Bar.

UTC Clock in the menu bar

BitBar is a plugin manager that can display plugins in the menu bar. One of them is World Clock that can display multiple clocks in a drop down of the menu.

Install BitBar

  1. Navigate to
  2. Click the Get BitBar button
  3. Click the downloaded ZIP file to extract the application
  4. Move the BitBar application to the Applications folder
  5. Launch BitBar form the Launcher
    • The first time BitBar launches, opens the Finder to point to the BitBar plugins folder
      • Click the New Folder button to create a folder for plugins in the Documents folder: BitBar Plugins
      • Click the Use As Plugins Directory to select the new folder as the plugins folder

Add World Clock to BitBar

  1. Navigate to
  2. Click the + Add to BitBar button

Customize World Clock

To customize World Clock edit the file in the BitBar Plugins folder

To change the displayed timezones, edit the ZONES variable inthe file:

ZONES="US/Pacific UTC Europe/London Europe/Berlin Asia/Kolkata Asia/Tokyo Australia/Sydney"

To change the display format, edit the data formats.

  1. To remove the seconds from the menu bar, delete the :%S from the format line
date -u +'%H:%M UTC'

To add the day of the week and date to the clocks in the World Clock drop down


  • %a for the day of the week
  • %Y for the four digit year
  • %b for the name of the month
  • %d for the date
  • %z for the time zone offset
echo "$(TZ=$zone date +'%H:%M - %a, %Y %b %d %z') $zone"

To refresh the dropdown formats after making changes in the config file

  1. Click the World Clock in the menu bar
  2. Select Preferences, Refresh all



Homebrew can install packages on your Macintosh that apple does not provide.

Installation instructions are at


NPM is another package manager. Install it to be able to install other applications later on this page, including the SQL Command utility

brew install node

Remote Desktop Client

Download the Microsoft Remote Desktop app from the App Store

  1. Open the App Store
  2. Search for “microsoft remote desktop”
  3. Click the Microsoft Remote Desktop icon
  4. Click the blue Get button
  5. Click the green Install App button

Text Editor


  1. Download it from
  2. Double click the downloaded ZIP file to extract the application,
  3. Drag the Atom application into Applications

Configure Atom

See Atom text editor configuration


Terminal Window


Install iTerm2, a smart terminal emulator to issue Bash commands and log into Linux servers.

  1. Download iTerm2 from
  2. Double click the downloaded ZIP file to extract the application,
  3. Move the iTerm application to Applications.

iTerm2 configuration

Enable unlimited scroll back

  1. Start iTerm2 and open the preferences window by pressing ⌘, (command-comma)
  2. On the Terminal tab click the Unlimited scrollback check box.

Start iTerm2 from Finder

To be able to open iTerm2 in any folder from Finder follow the steps below based on

  1. Start Automator,
  2. Select Service and click Choose,

  3. On the top of the screen set Service receives selected to files and folders,
  4. Set in to Finder,

  5. On the second side bar from the left double click Run AppleScript,

  6. Paste the code from the website referenced above into the editor window replacing the sample script in the editor window,
  7. In the File menu save the script,
  8. Do not run it, it does not execute in the Automator.

To use it

  1. Open Finder and navigate to the location you want to work in,
  2. Right click a folder to work in that folder or a file to work in the current folder
  3. Select Services, iTerm2 in Finder


“Solarized” color scheme

  1. Download the color scheme to the Desktop with the following Bash command:
    curl -o ~/Desktop/solarized.itermcolors
  2. Import the color scheme to iTerm2
    • Press ⌘, (command-comma) to open the Preferences window
    • Select Profiles
    • In the lower right corner of the Colors tab click the Color Presets… drop down
    • Select Import
    • On the Desktop select the downloaded solarized.itermcolors file
    • In the  Color Presets… drop down select Solarized Dark

 Meslo Powerline font

  • Import the Meslo Powerline font with the following bash command:
    git clone && cd fonts && ./
  • Select the font in iTerm2
    • Press ⌘, (command-comma) to open the Preferences window
    • Select Profiles
    • On the Font section of the Text tab click the Change Font button
    • Select the 12pt Meslo LG L Regular for Powerline

Make the prompt shorter

to remove your username@computername from the prompt

  • Edit the ~/.zshrc file
  • Add the following line

Colored prompt

To color the prompt:

  • Download the agnoster theme
sh -c "$(curl -fsSL"
  • Edit the ~/.zshrc file and set the ZSH_THEME to ZSH_THEME=”agnoster”

More configuration suggestions are at

Information on how terminals read settings at


  • Navigate to to download Git for the Macintosh. The page automatically downloads the installer for the operating system you use.
  • This app is not trusted by Apple, so to install it
    • Control-click (right-click) the downloaded file and select Open
    • Click the Open button to confirm the action

Configure Git

To configure Git see Git configuration.


For the VirtualBox installation on your operating system see: VirtualBox


For Vagrant installation see Vagrant.


Ruby is already a part of the operating system.

Chef Development Kit

Terraform by Hashicorp

 Terraform Installation

  • Download Terraform from
  • Double click the downloaded ZIP file to extract the application
  • Create a directory, terraform for the Terraform application in the /opt folder
  • Move the Terraform application into the terraform directoryin the /opt folder

Add the location to the path

Depending on the terminal window you use, it may open different configuration files. If you use iTerm2 you need to update the path in the~/.zshrc file.  Other terminal windows usually read the configuration from the  ~/.bash_profile file. To be safe you can add the following to both configuration files:

# PATH Export
export PATH


Graphviz is a Dependency Graph Visualization Software. We will use this utility to display the Terraform graphs.

To install execute the following in the terminal

brew install graphviz


The Amazon Web Services command line interface installation will set up your workstation to launch instances in AWS from Test Kitchen. If you know you will work with AWS, see DevOps Engineering part 3. – Working with AWS for the AWS CLI installation.

SQL Command

To be able to execute Microsoft SQL commands from the command line or through Terraform, install the MS SQL utility

npm install -g sql-cli

Version information

mssql --version

More information on the tool is at


We use Packer to create custom AWS AMIs that contain the fundamental configuration and applications that are common in every instance we launch.

Install Packer

  • Add the Packer installation directory to the system path

Working with Windows servers from the Mac

If you want to work with Windows servers, you may need to run Windows applications on your workstation.

See Minimum Windows workstation setup to work with Windows servers


Set up the DevOps development environment in Beginner’s Guide to DevOps Engineering part 2.


to the Tutorials page

Your session has timed out. Please try again. Code 5107 in the

To download apps from the Apple Store you need an Apple Id. If the app is free, you may not want to enter credit card information during the registration. If you try to create the Apple Id without the credit card in the App Store application, you may get the following error message:

Your session has timed out. Please try again. Code 5107

To create the Apple Id without a credit card

  • Start iTunes on your Macintosh,
  • Click the drop down menu in the upper left corner,
  • If Apps is visible, select it, otherwise click Edit Menu… in the same drop down,

    • To display Apps in the drop down, select the check box next to it.
  • On the top of the screen click the App Store button,
  • In the upper right corner search for a free app in the App Store and start to download it,
  • Create a new Apple Id and select None for credit card type.

QWERTY Hungarian keyboard on an English Macintosh keyboard

The English characters on the English and Hungarian keyboards are almost at the same place. The exceptions are the Z and Y keys, those are swapped.

When you activate the Hungarian keyboard on a Mac with an English keyboard the Z key will display Y and the Y key will display Z on the screen. That is the German QWERTZ keyboard layout. On an English keyboard, it is much easier to use the QWERTY layout for the Hungarian language too.

In the past, the following page contained a Hungarian layout for English keyboards at by “Felho”

The page is not available anymore, but I have found the keyboard layout files in the Wayback Machine internet archive at*/

I have downloaded the ZIP file from the archive and you can download it below in step 1.

Get a QWERTY Hungarian layout

To set up the QWERTY Hungarian keyboard layout

  1. Download the keyboard file ZIP archive at felhokeylayout
  2. Click the Downloads shortcut on your desktop
    open downloads folder
  3. Click the downloaded layout file to open it
    hungarian qwerty keyboard open downloaded file
  4. Select the two files
    hungarian qwerty keyboard files
  5. Copy the two files into the Macintosh HardDrive -> Keyboard Layouts folder
    keyboard layouts folder
  6. Log out of the computer
  7. When you log in again your Mac will find the new keyboard layout
  8. In the Personal section of the System Preferences select Language and Text
    language and text
  9. On the Input Sources tab select the Hungarian PRO FB keyboard
    hungarian qwerty keyboard selection

On the top of the screen between the battery status and the time you will see the name of the keyboard layout you currently use.

keyboard selection

Click the icon to select the other layout.

If you want to create your own special keyboard layout

If you want to create your own keyboard layout, there is a small application that can create a customized keyboard layout: Ukelele.

You can download it from their website at