Add current Git commit hash to index view

Author: robwise

app/controllers/pages_controller.rb

@@ -1,6 +1,7 @@
 class PagesController < ApplicationController
   def index
     @comments = Comment.all
+    @git_commit_sha = GitCommitSha.current_sha
 
     # NOTE: The below notes apply if you want to set the value of the props in the controller, as
     # compared to he view. However, it's more convenient to use Jbuilder from the view. See

app/models/git_commit_sha.rb

@@ -0,0 +1,23 @@
+class GitCommitSha
+  def self.current_sha
+    return @commit_sha unless @commit_sha.blank?
+    @commit_sha = (retrieve_sha_from_env_var || retrieve_sha_from_git_folder)
+  end
+
+  def self.current_sha=(sha)
+    @commit_sha = sha
+  end
+
+  def self.reset_current_sha
+    self.current_sha = ""
+  end
+
+  def self.retrieve_sha_from_git_folder
+    `git rev-parse HEAD 2>/dev/null`.to_s.strip
+  end
+
+  def self.retrieve_sha_from_env_var
+    env_var = ENV["DEPLOYMENT_SHA"]
+    env_var.blank? ? false : env_var
+  end
+end

app/views/pages/index.html.erb

@@ -1,4 +1,9 @@
 <h2>Using React + Redux + Rails Backend (using the react_on_rails gem)</h2>
+<p>current Git commit:
+  <span id="current-git-commit-sha">
+    <%= @git_commit_sha %>
+  </span>
+</p>
 <ul>
   <li>
     If this work interests you and you're a developer or designer looking for full or part-time remote work: please

scripts/deploy

@@ -0,0 +1,39 @@
+#!/bin/bash
+# Pass in app as either staging or production first -- must match what you seen in git remote -v
+# Examples:
+# ./deploy staging
+# ./deploy staging --force
+# ./deploy production
+
+app=$1
+
+shift
+
+sha=`git rev-parse HEAD 2>/dev/null`
+current_branch=`git symbolic-ref HEAD 2> /dev/null | sed -e 's/refs\/heads\///'`
+
+# echo "current_branch is $current_branch"
+# echo "sha is $sha"
+# echo "app is $app"
+
+if [ "$app" == "" ]; then
+  echo "You must specify a param value for the app, such as production or staging"
+  exit 1
+fi
+
+if [[ "$app" == "production" && "$current_branch" != "master" ]]; then
+  echo "You can only deploy master to production!"
+  exit 1
+fi
+
+echo Running:
+echo git push $app $current_branch:master $@
+git push $app $current_branch:master $@
+
+echo Setting heroku config DEPLOYMENT_SHA
+echo heroku config:set DEPLOYMENT_SHA=$sha --remote $app
+heroku config:set DEPLOYMENT_SHA=$sha --remote $app
+
+# Run migrations always just in case
+heroku run rake db:migrate --remote $app
+heroku restart --remote $app

spec/features/pages_spec.rb

@@ -0,0 +1,27 @@
+require "rails_helper"
+
+shared_examples "Git Commit SHA" do
+  # Keep existing env variable intact
+  let!(:old_sha) { ENV["DEPLOYMENT_SHA"] }
+  after { ENV["DEPLOYMENT_SHA"] = old_sha }
+  background { visit root_path }
+  it "displays the current git commit" do
+    expect(page).to have_css("#current-git-commit-sha", text: sha)
+  end
+end
+
+feature "Git Commit SHA" do
+  context "when env var is not set" do
+    let(:sha) { "94d92356828a56db25fccff9d50f41c525eead5x" }
+    before { GitCommitSha.current_sha = sha }
+    it_behaves_like "Git Commit SHA"
+  end
+  context "when env var is set" do
+    let(:sha) { "94d92356828a56db25fccff9d50f41c525eead5y" }
+    before do
+      ENV["DEPLOYMENT_SHA"] = sha
+      GitCommitSha.reset_current_sha
+    end
+    it_behaves_like "Git Commit SHA"
+  end
+end