Deployments w/Capistrano

For so long, developers have been moving code with FTP/SFTP. It’s time consuming, and comes with its faults. One false click, and you could easily overwrite a file that you haven’t downloaded yet. And that’s not good. Especially if there’s no version control in place. I know; it’s 2015 and if that happens to you, you kind of deserve it. But the fact of the matter is that a lot of developers at smaller organizations are still doing things this way.

This is where Capistrano comes in. Capistrano is a Ruby gem that makes deployment a one command process. Seriously.

cap production deploy

That command is all you need to push code to your production server.

Capistrano lets you use a git repo to launch your application. Instead of opening up FileZilla, finding a directory, and uploading everything manually, Capistrano will go to your repository, and move that code via a secured connection (SSH) to your server. The Capistrano website has everything you need to get setup so I won’t go into that here, but I will drop in my configuration to show how I’m using it to deploy a Yii2 app.

set :application, 'PROJECT_NAME_HERE'
set :repo_url, 'https://GIT_REPO_HERE.git'

# Default deploy_to directory is /var/www/my_app_name
set :deploy_to, 'DIR_TO_DEPLOY_TO_ON_SERVER'

# Default value for linked_dirs is []
set :linked_dirs, fetch(:linked_dirs, []).push('web/uploads', 'vendor', 'runtime')

# Default value for default_env is {}
# set :default_env, { path: "/opt/ruby/bin:$PATH" }

# Default value for keep_releases is 5
# set :keep_releases, 5


namespace :deploy do

after :restart, :clear_cache do
on roles(:app), in: :groups, limit: 3, wait: 10 do
# # Here we can do anything such as:
# within release_path do
# execute :rake, 'cache:clear'
# end

namespace :symlink do
desc 'Symlink release to current'
task :release do
on release_roles :all do
tmp_current_path = release_path.parent.join(current_path.basename)
execute :ln, '-s', release_path.relative_path_from(current_path.dirname), tmp_current_path
execute :mv, tmp_current_path, current_path.parent

desc 'Symlink files and directories from shared to release'
task :shared do
invoke 'deploy:symlink:linked_files'
invoke 'deploy:symlink:linked_dirs'

desc 'Symlink linked directories'
task :linked_dirs do
next unless any? :linked_dirs
on release_roles :all do
execute :mkdir, '-p', linked_dir_parents(release_path)

fetch(:linked_dirs).each do |dir|
target = release_path.join(dir)
source = shared_path.join(dir)
unless test "[ -L #{target} ]"
if test "[ -d #{target} ]"
execute :rm, '-rf', target
execute :ln, '-s', source.relative_path_from(target.dirname), target

desc 'Symlink linked files'
task :linked_files do
next unless any? :linked_files
on release_roles :all do
execute :mkdir, '-p', linked_file_dirs(release_path)

fetch(:linked_files).each do |file|
target = release_path.join(file)
source = shared_path.join(file)
unless test "[ -L #{target} ]"
if test "[ -f #{target} ]"
execute :rm, target
execute :ln, '-s', source.relative_path_from(target.dirname), target

task :composer do
on roles(:app) do
within release_path do
execute "cd #{release_path} && php-latest ~/composer.phar install"

task :setup do
on roles(:app) do
within release_path do
execute "cd #{release_path} && php-latest yii.php setup"
# execute :php, "yii setup"

after :updated, "deploy:composer"
after :updated, "deploy:setup"



server '',
roles: %w{app},
branch: 'master',
ssh_options: {
keys: %w(~/.ssh/id_rsa),
# forward_agent: false,
auth_methods: %w(publickey)
# password: 'please use keys'

Now, I’m no Ruby developer, so if my code could be cleaned up, which I know it can be, let me know. But let’s take a quick walk through with what we have here. Firstly, anything starting with # shows a commented line. I’ve removed most of mine, but left a few I thought might be helpful. You’ll notice the first three uncommented lines of the deployment file are just setting some variables for the configuration.

The fourth line, set :linked_dirs, is doing something really interesting. When Capistrano deploys my app, it creates a git repo on the server and will keep the last 5 versions. The linked_dirs variable is basically creating a symlink on my server, so that it doesn’t recreate those files every time. This was necessary for my uploads directory, which needs to be have the same location each time I deploy. If I created a new directory each time I deployed, users would get 404’d every time I deployed.

The next few segments actually contain a description so there isn’t much to say about those, other than they were necessary to deploy to MediaTemple’s GridServer. Most of the time, this stuff isn’t necessary, but I had a special case with our server.

task :composer installs all of my dependencies and task :setup runs a custom yii2 command that upgrades the database, if necessary.

Now like I said earlier, I’m using this to deploy a Yii2 app, but really, it could be used for anything. It’s mostly used to deploy Ruby applications, but there really isn’t anything stopping you from deploying something built WordPress or Laravel. If you have some suggestions on how I could streamline my process, let me know!

Dylan Hildenbrand

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