feat: add devcontainer for VS Code and GitHub Codespaces

[dlevy-msft-sql]

Summary

This PR adds a development container setup for easier onboarding and consistent development environments.

What's Included

Development Environment

• Go 1.24 with all development tools:
  • gopls (language server)
  • delve (debugger)
  • staticcheck
  • golangci-lint
  • gotext (for translations)

SQL Server 2025

• Developer Edition running as a sidecar container
• Health checks ensure it's ready before dev container starts
• Pre-configured SA password
• Test database (SqlCmdTest) created on startup

VS Code Extensions (pre-installed)

• Go (golang.go)
• MSSQL (ms-mssql.mssql) - with pre-configured connection
• Docker (ms-azuretools.vscode-docker)
• GitHub Copilot
• GitLens

Features

• Docker-in-Docker for container operations (testing sqlcmd create mssql, etc.)
• GitHub CLI pre-installed for PR management
• Locally built sqlcmd added to PATH automatically

Environment Variables

Pre-configured so tests run immediately:

• SQLCMDSERVER=localhost
• SQLCMDUSER=sa
• SQLCMDPASSWORD=SqlCmd@2025!
• SQLCMDDATABASE=master

Helpful Aliases

Alias	Command
gtest	Run all tests
gbuild	Build sqlcmd locally
ginstall	Build and install sqlcmd to ~/bin
glint	Run golangci-lint
sql	Connect to SQL Server interactively
test-db	Test database connection

Usage

VS Code

1. Install the Dev Containers extension
2. Open this repo in VS Code
3. Click "Reopen in Container"
4. Start developing!

GitHub Codespaces

1. Click "Code" > "Codespaces" > "Create codespace"
2. Wait for environment to start
3. Run gtest to verify everything works

Relation to go-mssqldb

This follows the same pattern as go-mssqldb PR #317, making it easy for contributors to work on both projects with consistent environments.

[Copilot]

Pull request overview

Adds a VS Code / GitHub Codespaces devcontainer setup to make onboarding and running integration tests against a local SQL Server container easier and more consistent.

Changes:

• Introduces a full .devcontainer/ configuration (Dockerfile, docker-compose, devcontainer.json, post-create provisioning, and SQL bootstrap script).
• Documents devcontainer usage in both the root README and a dedicated .devcontainer/README.md.
• Adds a root .dockerignore to reduce Docker build context noise.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 12 comments.

Show a summary per file

File	Description
README.md	Adds “Open in Dev Containers” badge and a Development section with quickstart/manual setup.
.dockerignore	Defines ignore rules for Docker builds from the repo root.
.devcontainer/Dockerfile	Dev image with Go toolchain + common Go dev tools and dependencies.
.devcontainer/docker-compose.yml	Orchestrates devcontainer + SQL Server sidecar with healthcheck.
.devcontainer/devcontainer.json	VS Code devcontainer configuration, extensions, forwarded ports, env vars, post-create command.
.devcontainer/post-create.sh	Post-create setup: downloads deps, builds sqlcmd, validates build, waits for DB, runs setup.sql, adds aliases.
.devcontainer/mssql/setup.sql	Creates a SqlCmdTest database and sample objects for quick testing.
.devcontainer/README.md	Detailed documentation for devcontainer usage, troubleshooting, and customization.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 8 comments.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 5 comments.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 8 comments.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.