Add Linux devcontainer (#9003)

Add a devcontainer.json to help streamline Linux development from other
platforms. The container builds from `swift:nightly-main`.

Author: plemarquand

.devcontainer/devcontainer.json

@@ -0,0 +1,34 @@
+{
+    "name": "Swift Nightly Main",
+    "image": "swiftlang/swift:nightly-main",
+    "features": {
+        "ghcr.io/devcontainers/features/common-utils:2": {
+            "installZsh": "false",
+            "username": "root",
+            "upgradePackages": "false"
+        },
+        "ghcr.io/devcontainers/features/git:1": {
+            "version": "os-provided",
+            "ppa": "false"
+        }
+    },
+    "postCreateCommand": "apt-get update && apt-get install -y curl sqlite3 libsqlite3-dev libncurses5-dev python3 build-essential",
+    "runArgs": [
+        "--cap-add=SYS_PTRACE",
+        "--security-opt",
+        "seccomp=unconfined"
+    ],
+    "customizations": {
+        "vscode": {
+            "settings": {
+                "lldb.library": "/usr/lib/liblldb.so"
+            },
+            "extensions": [
+                "swiftlang.swift-vscode"
+            ]
+        }
+    },
+    // Use 'forwardPorts' to make a list of ports inside the container available locally.
+    // "forwardPorts": [],
+    "remoteUser": "root"
+}

.gitignore

@@ -19,5 +19,4 @@ Package.resolved
 .docc-build
 .vscode
 Utilities/InstalledSwiftPMConfiguration/config.json
-.devcontainer
 Fixtures/BinaryLibraries/Static/Package1/Simple.artifactbundle/build

CONTRIBUTING.md

@@ -96,6 +96,40 @@ swift build
 swift test
 ```
 
+## Developing in the Linux devcontainer
+
+SwiftPM includes a devcontainer configuration that allows you to develop in a containerized environment with VS Code. This approach provides a consistent development environment with all necessary dependencies pre-installed, regardless of your host operating system.
+
+### Prerequisites
+
+1. Install [Visual Studio Code](https://code.visualstudio.com/)
+2. Install the [Dev Containers extension](https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers) for VS Code
+3. Install [Docker](https://www.docker.com/products/docker-desktop/) on your system
+
+### Opening the Project in a Container
+
+1. Clone the SwiftPM repository (if you haven't already)
+2. Open the SwiftPM folder in VS Code
+3. VS Code will detect the devcontainer configuration and prompt you to "Reopen in Container". Click this button to start building and opening the container
+   - Alternatively, you can press `F1`, type "Dev Containers: Reopen in Container", and press Enter
+4. Wait for the container to build and initialize (this may take a few minutes the first time)
+
+### What's Included in the Dev Container
+
+The SwiftPM devcontainer is based on the `swiftlang/swift:nightly-main` Docker image and includes:
+
+- Swift nightly build from the main branch
+- Git
+- Common development utilities
+- VS Code Swift extension for syntax highlighting and language support
+- Debugging support with LLDB
+
+### Building and Testing in the Container
+
+Once you've opened the project in VS Code, choose `> Dev Containers: Build and Reopen in Container` from the command pallete. Once the container finishes building it will open and you can develop as if you are on Linux using VS Code.
+
+All the commands described in the "Local Development" section below will work in the container environment.
+
 ## Local Development
 
 With a Swift toolchain installed and the SwiftPM code cloned, you are ready to make changes and test them locally.