Capistrano Staging Deploy Requires Whole New Database Migration

问题

I have Capistrano set up such that it allows me to deploy the staging version of my Ruby on Rails website to an amazon server from a git repository successfully. However, after deploying, I must run a migration on the database on the server. If I do not, any page with login forms or database-based content cannot load. When I run the migration on the server, I see every singly migration on the site being migrated, not just the most recent ones.

I know that Capistrano can maintain the previous migrations, and I thought it did that automatically. My question is, how do stop the apparent database wipe or loss which is occurring so that a migration is only needed if there are actually new migrations?

I see no unusual errors in the Capistrano output and I am a novice when it comes to Capistrano and databases. I noticed that my database.yml file has no entry for staging and I was wondering if it could be as simple as adding an entry for staging with the database set to db/development.sqlite3?

here is my deploy.rb file:

set :application, "staging"
set :scm, :git
set :repository, "."
set :deploy_via, :copy
#set :copy_cache, true
set :copy_exclude, [".git"]
set :user, "username"
set :use_sudo, false

default_run_options[:pty] = true

server "server_url", :app, :web, :db, :primary => true
set :deploy_to, "/var/www/staging"

# if you want to clean up old releases on each deploy uncomment this:
set :keep_releases, 3
after "deploy:restart", "deploy:cleanup"

# If you are using Passenger mod_rails uncomment this:
namespace :deploy do
  task :start do ; end
  task :stop do ; end
  task :restart, :roles => :app, :except => { :no_release => true } do
     run "touch #{File.join(current_path,'tmp','restart.txt')}"
  end
end

And my database.yml file:

# SQLite version 3.x
#   gem install sqlite3
#
#   Ensure the SQLite 3 gem is defined in your Gemfile
#   gem 'sqlite3'
development:
  adapter: sqlite3
  database: db/development.sqlite3
  pool: 5
  timeout: 5000

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  adapter: sqlite3
  database: db/test.sqlite3
  pool: 5
  timeout: 5000

production:
  adapter: sqlite3
  database: db/production.sqlite3
  pool: 5
  timeout: 5000

回答1:

Capistrano is not the one that maintains your migration number. rails does. If you want capistrano to run the migrations for you as part of deploy, add this to your config/deploy.rb

after "deploy:update_code", "deploy:migrate"

you should probably have a different location for production sqlite3 file where it will not get rewritten for every deploy, instead of db/production.sqlite3. Something like /home/user/production.sqlite3

来源：https://stackoverflow.com/questions/17173119/capistrano-staging-deploy-requires-whole-new-database-migration

标签

ruby-on-rails

migration

capistrano