feat: add install script and simple action definition (#2)

.gitignore

@@ -0,0 +1,2 @@
+node_modules
+.bin

README.md

@@ -4,4 +4,22 @@ A GitHub action that provides [buf](https://github.com/bufbuild/buf).
 
 ## Usage
 
-TODO
+```yaml
+name: Generate and Lint buf
+
+on:
+  pull_request:
+    branches:
+      - *
+
+jobs:
+  lint:
+    name: buf check lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ory/build-buf-action@v0
+        with:
+          bufVersion: v0.31.1
+          bufArgs: check lint --config buf/api/buf.yaml
+```

action.yml

@@ -1,8 +1,27 @@
 name: Build Buf
 description: A GitHub action that provides buildbuf/buf
+
+inputs:
+  bufVersion:
+    description: The version of buf to use (as in their GitHub releases)
+    default: v0.31.1
+    required: false
+  bufArgs:
+    description: The arguments to pass to buf
+    default: generate
+    required: false
+
 runs:
   using: composite
-  steps: [ ]
+  steps:
+    #    requires actions within actions as tracked in https://github.com/actions/runner/issues/646
+    #    - uses: actions/cache@v2
+    - name: Maybe install and definitely invoke buf
+      shell: bash
+      run: |
+        source scripts/install-buf.sh ${{ inputs.bufVersion }}
+        buf ${{ inputs.bufArgs }}
+
 branding:
   color: blue
   icon: box

package.json

@@ -0,0 +1,26 @@
+{
+  "name": "build-buf-action",
+  "private": true,
+  "description": "A GitHub action that provides [buf](https://github.com/bufbuild/buf).",
+  "main": "index.js",
+  "prettier": "ory-prettier-styles",
+  "config": {
+    "prettierTarget": "{*.yml,*.md}"
+  },
+  "scripts": {
+    "format": "prettier --write ${npm_package_config_prettierTarget}",
+    "format:check": "prettier --check ${npm_package_config_prettierTarget}"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/ory/build-buf-action.git"
+  },
+  "bugs": {
+    "url": "https://github.com/ory/build-buf-action/issues"
+  },
+  "homepage": "https://github.com/ory/build-buf-action#readme",
+  "devDependencies": {
+    "ory-prettier-styles": "^1.1.1",
+    "prettier": "^2.2.0"
+  }
+}

scripts/install-buf.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+set -euo pipefail
+
+UNAME_OS=$(uname -s)
+UNAME_ARCH=$(uname -m)
+
+BUF_VERSION=$1
+
+if [ ! -f ".bin/buf" ]; then
+  echo "Installing buf $BUF_VERSION for OS $UNAME_OS Arch $UNAME_ARCH"
+  mkdir -p .bin
+  curl --fail -sSL "https://github.com/bufbuild/buf/releases/download/$BUF_VERSION/buf-$UNAME_OS-$UNAME_ARCH" -o .bin/buf
+  chmod +x .bin/buf
+fi
+
+PATH=PATH:"$(pwd)/.bin"
+export PATH