Fetch PR and title from GitHub

.gitignore

@@ -1,2 +1,3 @@
 .envrc
+!/tmp/.keep
 /tmp

bin/fetch-pr

@@ -0,0 +1,25 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+require "net/http"
+require "json"
+require "uri"
+
+def github_token
+  ENV.fetch("GITHUB_PUBLIC_REPO_TOKEN") { raise "Missing GITHUB_PUBLIC_REPO_TOKEN!" }
+end
+
+def pull_request_number
+  ENV.fetch("BUILDKITE_PULL_REQUEST") { raise "Missing BUILDKITE_PULL_REQUEST!" }
+end
+
+uri = URI("https://api.github.com/repos/rails/rails/pulls/#{pull_request_number}")
+
+req = Net::HTTP::Get.new(uri)
+req["Authorization"] = "token #{github_token}"
+
+res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) do |http|
+  http.request(req)
+end
+
+puts res.body

lib/buildkite/config/build_context.rb

@@ -25,7 +25,7 @@ def nightly?
 
     def skip?
       # [ci skip], [skip ci], [ci-skip], or [skip-ci]
-      [ENV["BUILDKITE_MESSAGE"]].grep(/(ci skip|skip ci|ci-skip|skip-ci)/i).any?
+      [ENV["BUILDKITE_MESSAGE"], FetchPr.title].grep(/(ci skip|skip ci|ci-skip|skip-ci)/i).any?
     end
 
     def rails_root

lib/buildkite/config/fetch_pr.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+require "json"
+
+module Buildkite::Config
+  module FetchPr
+    def self.title
+      pr = JSON.parse(File.read(".buildkite/tmp/.pr-meta.json"))
+      pr["title"]
+    rescue
+      ""
+    end
+  end
+end

lib/buildkite_config.rb

@@ -11,6 +11,7 @@ module Config
     autoload :Diff
     autoload :DockerBuild
     autoload :BuildContext
+    autoload :FetchPr
     autoload :RakeCommand
     autoload :RubyConfig
     autoload :RubyGroup

pipelines/rails-ci/initial.yml

@@ -26,6 +26,16 @@ steps:
       git clone -b "$$GIT_BRANCH" "$$GIT_REPO" .buildkite
 
       rm -rf .buildkite/.git
+
+      echo "Fetching pull-request metadata:"
+      (docker run --rm \
+        -v "$$PWD":/app:ro -w /app \
+        -e GITHUB_PUBLIC_REPO_TOKEN \
+        -e BUILDKITE_PULL_REQUEST \
+        ruby:latest \
+        .buildkite/bin/fetch-pr > .buildkite/tmp/.pr-meta.json) || true
+
+      echo "Generating pipeline:"
       sh -c "$$PIPELINE_COMMAND"
 
       ([ -f .buildkite/.dockerignore ] && cp .buildkite/.dockerignore .dockerignore) || true

pipelines/rails-ci/pipeline.rb

@@ -13,7 +13,7 @@
   if build_context.skip?
     command do
       label "skip"
-      command "echo 'Build skipped'"
+      command "echo '+++ :bk-status-passed: Build skipped'"
     end
 
     next