add entrypoint script and dockerfile (#1)

* add entrypoint script and dockerfile

Signed-off-by: Ramiro <[email protected]>

Dockerfile

@@ -0,0 +1,4 @@
+FROM ruby:3-slim-buster
+RUN gem install octokit
+ADD entrypoint.sh /entrypoint.sh
+ENTRYPOINT [ "/entrypoint.sh" ]

action.yml

@@ -0,0 +1,15 @@
+name: "Notify PR"
+description: "Send a message to the pull request"
+inputs:
+  message: 
+    description: 'The message'
+    default: 'Your preview environment is ready'
+    required: true
+runs:
+  using: "docker"
+  image: "Dockerfile"
+  args:
+    - ${{ inputs.message }}
+branding:
+  color: 'green'
+  icon: book-open

entrypoint.sh

@@ -0,0 +1,31 @@
+#!/usr/bin/env ruby
+require "octokit"
+require "json"
+
+if !ENV["GITHUB_TOKEN"]
+    puts "Missing GITHUB_TOKEN"
+    exit(1)
+end
+
+if ENV["GITHUB_EVENT_NAME"] != "pull_request"
+    puts "This action only supports pull_request events."
+    exit(1)
+end
+
+message = ARGV[0]
+repo = ENV["GITHUB_REPOSITORY"]
+
+json = File.read(ENV.fetch("GITHUB_EVENT_PATH"))
+event = JSON.parse(json)
+pr = event["number"]
+
+github = Octokit::Client.new(access_token: ENV["GITHUB_TOKEN"])
+comments = github.issue_comments(repo, pr)
+exists = comments.find { |c| c["body"] == message }
+
+if exists
+    puts "Message already exists in the PR"
+    exit(0)
+end
+
+github.add_comment(repo, pr, message)