PowerShell Core Web Cmdlets in Depth (Part 3)

Part 3 Intro

In Part 1, I covered the primary changes in the actual code base of the PowerShell Core Web Cmdlets Invoke-RestMethod and Invoke-WebRequest and how those changes manifest themselves in the PowerShell user experience.

In Part 2, I covered outstanding issues as well missing and/or deprecated features.

In Part 3, I will cover new features available in PowerShell Core 6.0.0 Invoke-RestMethod & Invoke-WebRequest. I will also cover future plans for the cmdlets.

If you have not read Part 1 and Part 2, please do so before reading Part 3. This blog series goes in depth and requires a great many words to do so. To save space I will not repeat some information and will assume the reader as read Part 1 and Part 2.

A quick bit of news: PowerShell Core v6.0.0-rc.2 was released. Unless any blocking issues are discovered, this will be the final RC release and the next release will be GA in January 2018.

PowerShell Core Web Cmdlets in Depth (Part 2)

Part 2 Intro

In Part 1, I covered the primary changes in the actual code base of the PowerShell Core Web Cmdlets Invoke-RestMethod and Invoke-WebRequest and how those changes manifest themselves in the PowerShell user experience.

In Part 2, I will cover outstanding issues as well missing and/or deprecated features. Some of this will be an extension of Part 1 because some of the feature reduction is due mostly to the switch to HttpClient. Any plans or fixes I mention in this section are tentative and may change when and/or if they are implemented.

If you have not read Part 1, please do so before reading Part 2. This blog series goes in depth and requires a great many words to do so. To save space I will not repeat some information and will assume the reader as read Part 1.

Also, this will be my first blog post as a new Microsoft MVP. I wanted to take a quick moment to thank the people who nominated me and the PowerShell community for your support in getting me here. It is a great honor and I am overjoyed! Thank you!

PowerShell Core Web Cmdlets in Depth (Part 1)

Intro

I recently spoke at the North Texas PC Users Group's PowerShell Special Interest Group on the topic of the Web Cmdlets in PowerShell Core. I spoke for full hour because there is just so much new and different about Invoke-RestMethod and Invoke-WebRequest between Windows PowerShell 5.1 and PowerShell Core 6.0.0. In fact, because I was limited to an hour, I couldn't go as in depth or cover as many things as I would have liked. This blog series will cover what I covered in that presentation and more. At this time I plan to have 3 parts with a possible 4th as an addendum should anything change between now and GA.

PowerSMells: PowerShell Code Smells (Part 1.5)

Intro

I am writing this next blog post in this series much sooner than I had anticipated. I wanted to do so in order to clarify a few things about PowerSMells and to address some of the negative feedback I have received. I will still include a PowerSMell, but this is mostly to address shortcomings in the Part 1 of the series.

Table of Contents for this series

PowerSMells: PowerShell Code Smells (Part 1)

Intro

A few weeks ago, someone in the slack channel asked what some of the Code Smells are in PowerShell. If you are not familiar with the term Code Smell, a simple definition is code that when you see it you know there will be issues just like when you smell something rotten know you will find something unpleasant. After some joking around the term PowerSMell was coined to describe a Code Smell particular to PowerShell.

This is the first in an ongoing series of Code Smells in PowerShell. Rather than make a massive single entry, I will try to cover only a few at a time and spread them out. Unlike my other series, this one wont be dumped all at once and I will work on this series between other blog posts. I may never truly be done with this series and I have no clue how many parts it will be. There are many Code Smells in PowerShell and it seems like I'm finding more each week.

One possible plan for the future is to begin a community PowerSMell project with PSScriptAnalyzer rules for linting these PowerSMells. I know there are several projects out there that already have some of these, but it would be nice to get them all together. If you are interested in working together on this let me know and we can begin coordinating.

Each PowerSMell will include a "The Smell" and a "The Source" section. The "The Smell" section will have a code example of the PowerSMell. The "The Source" section will have information about the problems that the smell hints to. Some PowerSMells are not always PowerSMells. When a certain PowerSMell has a non-smelly usage, it will include a "The Pleasant Aroma" section providing an example of the non-smelly usage.

Table of Contents for this series

Why pwsh Was Chosen For PowerShell Core

Intro

With the release of PowerShell Core 6.0.0-beta.9 the binary for PowerShell Core was renamed from powershell.exe and powershell on Windows and Linux/Unix/macOS respectively to pwsh.exe and pwsh. This major change has drained the pitchfork and torch emporiums of their stock as PowerShell users from all over the globe have taken to internet forums, twitter, slack, and the PowerShell repo to voice their opposition and disbelief in this change. The responses range from minor annoyance to expletive heavy diatribes.

It's clear that many PowerShell users are not happy with this change.

So why did the PowerShell Team decided to make such and unpopular change? There are several reasons the change was necessary and for why pwsh was chosen. I will attempt my best here to explain them all.

As you read, please keep in mind that I'm not a Microsoft employee nor am I a member of the PowerShell Team. I'm just a community contributor with collaborator access to the GitHub repo. I don't have any special insider knowledge, but I do follow the repo and PowerShell Core very closely. I am speaking to you as a fellow member of the community as someone with a decent insight into the project, not as an outright authority on all things PowerShell.

New PowerShell Core Feature: Basic and OAuth Authentication for Invoke-WebRequest and Invoke-RestMethod

Intro

PowerShell has always supported Basic authentication on Invoke-WebRequest and Invoke-RestMethod via the -Credential parameter. Those of you who have tried to use it on any modern APIs are probably scratching you head at what I just wrote. You probably know full well that the -Credential parameter is not sending Basic Authentication credentials when you expect it to. But it's true, Basic authentication has been there all along. The problem is that PowerShell will only send credentials if challenged.

This is a problem for accessing modern API's, especially for requesting OAuth Tokens from authentication endpoints. Modern APIs often do not issue 401 status codes with WWW-Authenticate headers. This results in the Web Cmdlets not issuing credentials to the remote server even though they were supplied. Modern API's expect you to present your credentials explicitly without being challenged first. This has resulted in a common frustration and feature request.

Additionally, the Web Cmdlets did not have any native support for OAuth bearer tokens. This means that all calls to APIs requiring OAuth tokens required passing an Authorization header. Since many OAuth grant flows require the client ID and client secret be sent as Basic authentication without a challenge, the entire OAuth process becomes a manual task.

I have run into this myself with the PSRAW and PSMSGraph projects. In both projects I have created wrapper functions around Invoke-WebRequest and Invoke-RestMethod that provide OAuth capabilities and handle the conversion of PSCredential to Basic Authentication. I have long wish this functionality was native to the cmdlets.

I'm pleased to announce that beginning with PowerShell Core 6.0.0-Beta.9, Invoke-WebRequest and Invoke-RestMethod  natively support explicit Basic and OAuth authentication.

If you want this functionality now, build the current master branch or pickup the nightly build. this was added in Pull Request #5052.