feat: Add usage as github action

Author: Crown0815

Dockerfile

@@ -0,0 +1,29 @@
+# Build stage
+FROM rust:1.85-slim AS builder
+
+RUN apt-get update && apt-get install -y \
+    pkg-config \
+    libssl-dev \
+    cmake \
+    git \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /usr/src/git-versioner
+COPY . .
+
+RUN cargo build --release
+
+# Final stage
+FROM debian:bookworm-slim
+
+RUN apt-get update && apt-get install -y \
+    libssl3 \
+    ca-certificates \
+    git \
+    && rm -rf /var/lib/apt/lists/*
+
+COPY --from=builder /usr/src/git-versioner/target/release/git-versioner /usr/local/bin/git-versioner
+COPY entrypoint.sh /entrypoint.sh
+RUN chmod +x /entrypoint.sh
+
+ENTRYPOINT ["/entrypoint.sh"]

README.md

@@ -105,6 +105,43 @@ You can install Git Versioner directly from [crates.io](https://crates.io/crates
 cargo install git-versioner
 ```
 
+### GitHub Action
+
+Git Versioner can be used directly as a GitHub Action. 
+It will automatically export the calculated version components to `GITHUB_OUTPUT`.
+Outputs are available with a `GitVersion_` prefix (e.g., `GitVersion_SemVer`) and also in `PascalCase` without prefix (e.g., `SemVer`).
+
+```yaml
+- name: Determine Version
+  uses: crown0815/git-versioner@v1
+  id: versioner
+  with:
+    # Optional configuration (see below for available inputs)
+    as-release: true
+```
+
+#### Example workflow
+
+```yaml
+name: CI
+on: [push]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0 # Required to see all tags and history
+
+      - name: Determine Version
+        id: versioner
+        uses: crown0815/git-versioner@v1
+
+      - name: Use Version
+        run: echo "The version is ${{ steps.versioner.outputs.SemVer }}"
+```
+
 ### From Source
 
 1. Clone the repository:

action.yml

@@ -0,0 +1,42 @@
+name: 'Git Versioner'
+description: 'Automatically calculate version numbers for Git repositories'
+branding:
+  icon: 'tag'
+  color: 'blue'
+inputs:
+  path:
+    description: 'Path to the repository to calculate the version for'
+    required: false
+    default: '.'
+  main-branch:
+    description: 'Regex to detect the main branch'
+    required: false
+  release-branch:
+    description: 'Regex to detect the release branch(es)'
+    required: false
+  feature-branch:
+    description: 'Regex to detect the feature branch(es)'
+    required: false
+  tag-prefix:
+    description: 'Regex to detect version tag(s)'
+    required: false
+  pre-release-tag:
+    description: 'Regex to detect pre-release version tag(s)'
+    required: false
+  continuous-delivery:
+    description: 'Calculate version using continuous delivery mode'
+    required: false
+    default: 'false'
+  commit-message-incrementing:
+    description: "Increment based on conventional commits (set to 'Enabled' or 'Disabled')"
+    required: false
+  as-release:
+    description: 'Forces release generation instead of pre-release'
+    required: false
+    default: 'false'
+  config:
+    description: 'Path to a configuration file (TOML or YAML)'
+    required: false
+runs:
+  using: 'docker'
+  image: 'Dockerfile'

entrypoint.sh

@@ -0,0 +1,50 @@
+#!/bin/sh -l
+
+set -e
+
+# Construct arguments array
+ARGS=""
+
+if [ -n "$INPUT_PATH" ]; then
+  ARGS="$ARGS --path $INPUT_PATH"
+fi
+
+if [ -n "$INPUT_MAIN_BRANCH" ]; then
+  ARGS="$ARGS --main-branch $INPUT_MAIN_BRANCH"
+fi
+
+if [ -n "$INPUT_RELEASE_BRANCH" ]; then
+  ARGS="$ARGS --release-branch $INPUT_RELEASE_BRANCH"
+fi
+
+if [ -n "$INPUT_FEATURE_BRANCH" ]; then
+  ARGS="$ARGS --feature-branch $INPUT_FEATURE_BRANCH"
+fi
+
+if [ -n "$INPUT_TAG_PREFIX" ]; then
+  ARGS="$ARGS --tag-prefix $INPUT_TAG_PREFIX"
+fi
+
+if [ -n "$INPUT_PRE_RELEASE_TAG" ]; then
+  ARGS="$ARGS --pre-release-tag $INPUT_PRE_RELEASE_TAG"
+fi
+
+if [ "$INPUT_CONTINUOUS_DELIVERY" = "true" ]; then
+  ARGS="$ARGS --continuous-delivery"
+fi
+
+if [ -n "$INPUT_COMMIT_MESSAGE_INCREMENTING" ]; then
+  ARGS="$ARGS --commit-message-incrementing $INPUT_COMMIT_MESSAGE_INCREMENTING"
+fi
+
+if [ "$INPUT_AS_RELEASE" = "true" ]; then
+  ARGS="$ARGS --as-release"
+fi
+
+if [ -n "$INPUT_CONFIG" ]; then
+  ARGS="$ARGS --config $INPUT_CONFIG"
+fi
+
+# Run the tool
+# shellcheck disable=SC2086
+git-versioner $ARGS