Heroku使用

先要生成一个公钥，使用命令:
$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/user/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/user/.ssh/id_rsa.
Your public key has been saved in /home/user/.ssh/id_rsa.pub.
The key fingerprint is:
a6:88:0a:bb:74:70:c6:e0:d5:49:65:e3:04:d5:6c:3e user@workstation.local

把公钥加入到Heroku
$ heroku keys:add
Uploading ssh public key /home/user/.ssh/id_rsa.pub

如果想删除公钥，可以用命令：
$ heroku keys:remove user@workstation.local

查看公钥，用命令：
$ heroku keys

现在就可以创建一个项目了(预先要安装好rails)。
$ rails myapp
$ git init
$ git add .
$ git commit -m "my first commit"
Created initial commit 5df2d09: my first commit
44 files changed, 8393 insertions(+), 0 deletions(-)
create mode 100644 README
create mode 100644 Rakefile
create mode 100644 app/controllers/application.rb
...

把这个项目创建到Heroku上。
＄ heroku create myapp
Enter your Heroku credentials.
Email: user@example.com
Password:
Uploading ssh public key /home/user/.ssh/id_rsa.pub
（当第一次运行heroku命令时，会创建~/.heroku/credentials文件，这个文件记录了你输入的用户名和密码，这个是在Heroku注册的用户名和密码。）

接下来运行：
$ git push heroku master
Counting objects: 65, done.
Compressing objects: 100% (58/58), done.
Writing objects: 100% (65/65), 80.54 KiB, done.
Total 65 (delta 14), reused 0 (delta 0)

-----> Heroku receiving push
-----> Rails app detected
       Compiled slug size is 0.1MB
-----> Launching....... done
       App deployed to Heroku

To git@heroku.com:vivid-mountain-91.git
* [new branch]      master -> master

再做一个数据库迁移：
$ heroku rake db:migrate

现在就可以像平常使用Rails一样编写程序了。
更新代码可以用：
$ git push herku
将本地数据更新到Heroku网站上:
$ heroku db:push
（这个命令会使用taps，如果没有安装，请先安装。）

要打开网页浏览，就可以用
$ heroku open