How to create a bootable USB drive to install Windows

If the computer you want to install Microsoft WIndows on, does not have a DVD drive, you can install Windows from a USB drive. To start the computer from the USB drive, you need to prepare the drive to make it bootable.

Microsoft has a free tool that can download the edition of the Windows operating system you need, format the USB drive, make it bootable, and place the installer file on it.

  1. Using a web browser navigate to https://www.microsoft.com/en-us/software-download/windows10,
  2. Click the Download tool now button to install the Microsoft Media Creation Tool,
  3. Start the downloaded MediaCreationTool.exe program and follow the prompts.

Setup failed: Failed to copy slug dir: lstat /Users: no such file or directory error in Terraform Enterprise

When you try to execute a Terraform configuration in Terraform Enterprise (Atlas) you may get the error message:

Setup failed: Failed to copy slug dir: lstat /Users: no such file or directory

Cause:

The Git repository contains the .terraform/modules directory, and the Terraform Enterprise server cannot get the latest modules from GitHub.

Solution:

  1. Create a .gitignore file in the repository and add these lines:
    */.terraform/modules/
    
    # Ignore DS_Store if working on a mac
    .DS_Store
  2. Delete the .terraform directory and push the changes to GitHub

 

 

Install a Python package

To install a Python package on Macintosh

  1. Download the Python package to your workstation,
  2. Unpack the package,
  3. Open a terminal window,
  4. Start sudo,
    sudo -i
  5. Change to the directory of the package,
  6. Install the package.
    pip install PACKAGE_NAME

If you don’t install the package in sudo mode, you will get “Permission denied” errors during the package installation.

Troubleshooting

When you encounter the warning message

WARNING: The directory ‘/Users/…/Library/Caches/pip’ or its parent directory is not owned or is not writable by the current user. The cache has been disabled. Check the permissions and owner of that directory. If executing pip with sudo, you should use sudo’s -H flag.

To make yourself the owner of the /Users/…/Library/Caches/pip directory execute

sudo chown -R $(whoami) ~/Library/Caches/pip

PyCharm configuration

When you install PyCharm, the default Python interpreter is may not the version you want to use for your new projects. When you create a new project, and the project interpreter is not set, you may get the following error message:

Executed command:
/var/folders/_x/_f0zzs1s4sx6bk4s8n78l2jsbn9r3z/T/tmpBoQLx_pycharm-management/pip-9.0.1/setup.py install

Error occurred:
40:357: execution error: /System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/distutils/dist.py:266: UserWarning: Unknown distribution option: ‘python_requires’

Command output:
40:357: execution error: /System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/distutils/dist.py:266: UserWarning: Unknown distribution option: ‘python_requires’
warnings.warn(msg)
warning: build_py: byte-compiling is disabled, skipping.
warning: install_lib: byte-compiling is disabled, skipping.
error: byte-compiling is disabled.
(1)

Solution:

Set the default Python interpreter to the latest installed version before you create your project:

  1. Start PyCharm
  2. In the File menu select Default Settings
  3. On the left side select Project Interpreter,
  4. On the right side click the arrow of the Project Interpreter drop-down
  5. Select the Python interpreter you want to use by default, and click the OK button.

Python ImportError: No module named …

Symptom:

from MY_FOLDER.MY_FILE import MY_CLASS causes an error:
ImportError: No module named MY_FOLDER.MY_FILE

Debugging:

  1. Execute the program in debug mode,
  2. In the Variables window expand Special Variables,
  3. Read the __warningregistry__ value.

Possible cause:

The __init__.py file is missing in the directory of the referenced class.

Solution:

Create an empty __init__.py file in the directory where the class is referenced from.

Python basics

Great Python introductory video for C# developers
https://www.youtube.com/watch?v=jj60geqaP08

__  (double underscore) Starting the attribute name with double underscore attribute makes it private. To expose the private attributes and methods

print(dir(MY_CLASS))

 

Code hierarchy

In Python indentation denotes the hierarchy of the instructions, not curly braces, like in C# or Java.

Directories

When you create a directory in your project, create an empty __init__.py file in the new directory to be able to reference objects from that directory, and avoid

from MY_FOLDER.MY_FILE import MY_CLASS causes an error:
ImportError: No module named MY_FOLDER.MY_FILE

Classes

Predefined methods

__init__(self)  Initializer method (constructor)

__repr__(self)  Representation

__iter__(self)  Method to define hot to iterate through the object

Decorators

@property  Exposes a method as a property of the class

from _04_anonymous.anonobject import AnonObject
ImportError: No module named _04_anonymous.anonobject

{(“Not importing directory ‘/Users/pinterl/Git/devops-scripts/Python_Tutorial/Python/Python_for_C_sharp_developers/_04_anonymous’: missing __init__.py”, <type ‘exceptions.ImportWarning’>, 6): True}

Working with PyCharm

Project management

Create a new project in PyCharm

  1. In the File menu select New Project…,
  2. On the left side select the Python framework you want to use,
  3. Enter the name for your project to the end of the Location path,
  4. If you have selected a framework that asks for more information
    1. Click the More Settings link and enter the additional values,
    2. Click the Create button,
    3. PyCharm generates folders for your project and application,
    4. When PyCharm asks you about compatibility inspection, enable it, to make sure your code is compatible with future versions of Python.
    5. PyCharm will enable Code compatibility inspection. Click OK to save the setting.
    6. PyCharm will still set your project interpreter to 2.6, so set it to 2.7. In the PyCharm menu select Preferences…,
    7. On the left side select Project:…, Project Interpreter,
    8. In the Project Interpreter drop-down select 2.7 and click the OK button.

Delete a project in PyCharm

The PyCharm project explorer does not have a delete option. To delete a PyCharm project

  1. Open the project location in Finder,
  2. Move the project folder to the Trash,
  3. The PyCharm project explorer window will reflect the change.

Shortcuts, tips, and tricks

 Auto generate

Auto generate functions, classes, attributes

  1. Enter the name of the undefined element where you want to use it,
  2. Click the light bulb, or press ⌥⏎ (Alt-Enter) to pop up the Intention Action alert,
  3. Select the action to generate the definition.

Auto generate fields for classes

  1. Enter the __init__ function of the class with the field names,
  2. Place the cursor on the field you want to generate the definition for,
  3. Click the light bulb, or press ⌥⏎ (Alt-Enter) to pop up the Intention Action alert,
  4. Select Add field ‘…’ to class …,
  5. Press Enter to select the option,
  6. Press Enter at the end of the new line to move the cursor to the next line, otherwise, the Intention Action alert does not pop up when you press ⌥⏎ (Alt-Enter)

 

Code completion

  • Press Ctrl-Space to complete the name of the element.
  • Press Ctrl-Space twice to complete the name of any class, even if it is not yet imported. The import statement will be automatically added.

Quick documentation

To get a short documentation on an element under the cursor, press F1. (By default on a Macintosh you need to press fn-F1, because the F1 button is programmed to adjust the brightness.)

For more information

Auto completing code, see https://www.jetbrains.com/help/pycharm/auto-completing-code.html

Keyboard shortcuts
https://www.jetbrains.com/help/pycharm/keyboard-shortcuts-and-mouse-reference.html

Create a Terraform Enterprise environment

If you just start to work with Terraform Enterprise, you need to create a Terraform environment.

Preparation

GitHub account

To access GitHub from Terraform Enterprise, create a GitHub team and account with admin access to the GitHub repository that will store the Terraform scripts.

  1. Create a GitHub team who will have admin access to the Terraform script repository,
  2. Create a GitHub user what Terraform Enterprise will use to access the Terraform script repository,
  3. Add the new GitHub user to your GitHub organization,
  4. Log into GitHub with the new user account credentials and wait for the email verification email from GitHub,
  5. Open the verification email from GitHub and click the button in the email to verify your email address,
  6. Stay logged into GitHub with the new user account and wait for the invitation email from GitHub to join the organization,
  7. Open the invitation email from GitHub and click the button to accept the invitation,
  8. In GitHub add the new GitHub user to the new team,
  9. Create a GitHub repository to store the Terraform scripts,
  10. Add the new team to the Terraform script repository with admin rights.

If the Terraform modules are in a separate GitHub repository, add the new team to that repository with Read rights.

AWS account

Create a new user account that Terraform Enterprise will use to access AWS

  1. Create a new AWS user,
  2. Add user rights
    1. AmazonEC2FullAccess
    2. AmazonS3FullAccess

Connect your Atlas account to GitHub

We will authorize Terraform Enterprise to access the Terraform script GitHub repository. We set this connection up in our personal profile in Terraform enterprise, but when we create new Terraform environments Terraform Enterprise will use this connection to access the GitHub repository the environment will be connected to. Do not use your personal GitHub account to make the connection, because if your personal account loses access to the GitHub repository, the Terraform environment will not be able to connect to it. For this connection, we have already created a new user in GitHub above.

  1. In a web browser log into GitHub with the user account you want Terraform Enterprise use to access the GitHub repository,
  2. In the same web browser open a new tab and navigate to https://atlas.hashicorp.com/settings/connections and log into Atlas with your Hashicorp account,
  3. Click Connect GitHub to Atlas
  4. On the GitHub authorization page click the Authorize hashicorp button,
  5. Later if you want to unlink Atlas from your GitHub account, in the Personal section select Connections, and click the Unlink button.

Create the GitHub repository

Create a repository in GitHub to store the Terraform config files. You can specify subdirectories for each Terraform environment to watch, so one repository can serve the security group creation, and EC2 instance creation for the same developer group.

  1. Create the GitHub repository,
  2. Create a folder that the Terraform Enterprise environment will monitor for changes.

Create a new environment

    1. In a web browser navigate to https://atlas.hashicorp.com/configurations/import,
    2. Log in with your Atlas user account,
    3. In the dropdown list of the New Environment page (click the text of the dropdown, not the arrow) select Link to GitHub.
      Name the environment to include the type of the server you want to launch and the server environment, for example, test_linux_sandbox.
      To save the environment click the Create & Continue button,
    4. On the left side select Variables,
    5. In the Environment section click the Edit button,
  1. If the environment is linked to the Terraform Enterprise Server

    1. The environment has been created. Click the your account settings page to create a personal token. It will allow you to access your account without using your username and password.
    2. Enter a description for the token and click the Generate Token button,
    3. Save the token value at a safe place
    4. To return back to the Runs page select Terraform Enterprise in the upper left corner
    5. Click the name of the environment you want to work with
    6. Configure the environment. On the left side click Settings
      1. Uncheck Plan on artifact uploads
    7. Store your personal access token on your workstation to be able to access Terraform Enterprise. Open a Bash window and execute the export command:

      export ATLAS_TOKEN=[YOUR AUTHENTICATION TOKEN]
    8. Add the terraform backend configuration to the .tf file on your workstation

      terraform {
        backend "atlas" {
          name    = "YOUR_ORGANIZATION/YOUR_ENVIRONMENT"
          address = "https://atlas.hashicorp.com"
        }
      }
    9. Navigate to the Terraform configuration folder and initialize it with the backend configuration you have entered to the .tf file.
      terraform init
    10. Push the Terraform configuration to the Enterprise server

      terraform push -name="YOUR_ORGANIZATION/YOUR_ENVIRONMENT" -atlas-address="https://atlas.hashicorp.com"
    11. On the left side click Configurations to see the list of configs your organization have pushed to the server.
    12. Run a Terraform Plan to see if your code works
      terraform plan
    13. Execute your Terraform config on your workstation
      terraform apply
    14. Push the result of the run to the Terraform Enterprise server
      terraform push -name="YOUR_ORGANIZATION/YOUR_ENVIRONMENT" -atlas-address="https://atlas.hashicorp.com"
    15. To view the result of the run, on the left side click Runs.
    16. To view the created infrastructure states on the left side click States

Create the Terraform scripts

 

More resources

For a tutorial on Multiple Environments in Terraform see https://github.com/hashicorp/multiple-envs

No instances for regex `’, try running `kitchen list’ in Chef Test Kitchen

When I tried to execute the “kitchen list” command in Chef Test Kitchen the following error came up:

No instances for regex `’, try running `kitchen list’

I could not find the reason for the error, so I opened the .kitchen.yml file in the Atom editor, added a space to one of the comments, and saved the file. The error went away.