jmcombs/powershell repository overview

⁠powershell

LTS versions of PowerShell Core and .NET Core in Linux. Published for 64-bit x86 and ARM architectures.

⁠About

This container is based on the the latest Long Term Support (LTS) Ubuntu (Docker Official Image)⁠ image along with the latest LTS releases of .NET Core Runtime and PowerShell Core.

⁠Sponsorship

If this image is part of your daily workflow—whether as an individual developer or in your team's CI/CD pipelines—consider sponsoring on GitHub⁠. Sponsorship helps fund ongoing maintenance, timely .NET and PowerShell LTS updates, and improvements to the prompt and testing infrastructure relied on in automated environments.

⁠Enhanced Prompt Features

This container includes an enhanced PowerShell experience with:

• Oh My Posh⁠ with Blue PSL 10K theme⁠ - Beautiful two-line prompt with Git integration, execution time, and multi-language support
• Terminal-Icons⁠ - Colorized directory listings with file type icons (pre-installed)
• PSReadLine⁠ - Enhanced command-line editing with predictive IntelliSense (pre-installed)
• Nerd Font support - Icons and glyphs for improved visual experience (requires host font configuration)

⁠Versions

This repository does automated weekly builds with the latest published LTS versions of .NET Core and PowerShell Core. Below are the current versions included in the latest build.

⁠How to Use

⁠Requirements

• Container's non-root and default user is coder
• Container's default shell is pwsh
• Container's default working directory is /home/coder
• Host terminal must use a Nerd Font (for example, MesloLGM Nerd Font) for prompt icons; fonts are installed on the host, not inside the container.
• Oh My Posh with Blue PSL 10K theme is enabled by default; see Environment Variables⁠ for customization options.

⁠Running Container

# Default - Blue PSL 10K theme (works offline, no internet required)
docker run -it jmcombs/powershell

⁠Environment Variables

Customize the Oh My Posh prompt behavior at runtime using environment variables:

⁠Examples

# Disable Oh My Posh (use basic PowerShell prompt)
docker run -it -e ENABLE_OHMYPOSH=false jmcombs/powershell

# Use a built-in Oh My Posh theme (downloads from GitHub)
docker run -it -e OHMYPOSH_THEME=atomic jmcombs/powershell
docker run -it -e OHMYPOSH_THEME=jandedobbeleer jmcombs/powershell
docker run -it -e OHMYPOSH_THEME=paradox jmcombs/powershell

# Use a custom theme from URL
docker run -it -e OHMYPOSH_THEME=https://example.com/my-theme.omp.json jmcombs/powershell

⁠Theme Fallback Behavior

The container implements a robust fallback hierarchy:

1. Primary: Uses theme specified in OHMYPOSH_THEME (if set)
2. Fallback: If the specified theme fails to load, automatically falls back to embedded Blue PSL 10K theme
3. Basic: If all else fails, uses the basic PowerShell prompt

This ensures the container always starts with a working prompt, even without internet connectivity.

⁠Development

⁠Testing

This repository uses bats-core⁠ for both unit and integration tests.

• Unit tests (tests/unit/) validate local behavior such as script structure, helper functions, environment file validation, and PowerShell profile logic. They do not require network access.
• Integration tests (tests/integration/) run the version discovery script against the live Microsoft and GitHub endpoints and exercise the built Docker image with various environment variable configurations. These tests require network access and Docker.

Test Coverage:

• .NET and PowerShell LTS version discovery
• Docker image build and runtime behavior
• Oh My Posh environment variables (ENABLE_OHMYPOSH, OHMYPOSH_THEME)
• Container info display control (SHOW_CONTAINER_INFO)
• Theme loading (default, built-in, custom URL, fallback scenarios)
• PowerShell profile initialization and module loading

To run tests locally:

# Install bats-core (if not already installed)
git clone https://github.com/bats-core/bats-core.git
cd bats-core && sudo ./install.sh /usr/local

# Run offline unit tests
bats tests/unit/

# Run live integration tests (requires network and Docker)
bats tests/integration/

⁠Contributing

Please see CONTRIBUTING.md⁠ for guidelines on contributing to this project.