markdown 工程师厨师食谱

Posted 2021-05-05

### Set Up the Chef Environment
* install the engineyard gem in your local environment
  * `sudo gem install engineyard`
  * enter the password for your **engineyard account**
* Fork and clone the `ey-cloud-recipes` repository to your local machine
  * [link to fork the repo](https://github.com/engineyard/ey-cloud-recipes)
  * click fork
  * copy the url of the forked repo to your clipboard
  * `git clone` link : **Do not clone in the same directory as your app repo!**
---
## File Structure
* root of the directory: `cookbooks/`
  * `/main`
    * `attributes/`
    * `definitions/`
    * `libraries/`
    * `recipes/`
* In the cookbooks directory, there are sub-directories that contain recipes for various
components (ex.redis)
  * And so within that `redis` directory, there will be more sub-directories under it
  * in `recipes/default.rb`: the main definition file that defines how Chef performs each
  of its actions to achieve the customization
---
### Turn on a Cookbook
* To turn on a cookbook and have that set of recipes run whenever you deploy your app, you need to uncomment
the recipe in the `cookbooks/main/recipes/default.rb`
* To turn on an existing cookbook:
  * select the cookbook
  * in your local environment: open `cookbooks/main/recipes/default.rb` for editing
  * uncomment the `include_recipe` line for the recipe you want to **turn on**
  * save the file and commit and push your changes locally
  * use the ey recipe commands to **upload and apply the recipes**:
    * `ey recipes upload -e environment_name`
    * `ey recipes apply -e environment_name`
---
### Create your own cookbook
* In local environment: `rake new_cookbook COOKBOOK=nginx_logrotate`
  * which creates `cookbooks/nginx_logrotates/recipes/default.rb`
  * add to the file:
  ```
  remote_file "/etc/logrotate.d/nginx" do 
    owner "root" 
    group "root" 
    mode 0755 
    source "nginx.logrotate" 
    backup false 
    action :create 
  end
  ```
  * create `files/default/nginx_logrotate` with the following content:
  ```
  /var/log/engineyard/nginx/*.log { 
    daily 
    missingok 
    compress 
    rotate 60 
    dateext 
    notifempty 
    sharedscripts 
    extension gz 
    postrotate 
        [ ! -f /var/run/nginx.pid ] || kill -USR1 `cat /var/run/nginx.pid` 
    endscript 
  } 
  ```
  * Edit `cookbook/main/recipes/default.rb` to **enable the recipe**: `include_recipe "nginx_logrotate"`
  * `rake test`
  * commit changes locally and puhs
  * use the commands above to upload and apply the recipes
---
## Displaying Messages to the Dashboard
* dashboard is located on the environment page under the "Instances" heading and allows you to see when the custom portions of
your recipe are running.
* Example code (in `recipes/default.rb`):
```
ey_cloud_report "recipe_name" do
  message "message text"
end
```
---
### Report to a log from custom chef recipes
* custom chef recipes are logged to `var/log/custom.log`
* Default engineyard cloud recipes are logged to `/var/log/chef.main.log`
* Use `Chef::Log.info "message text"`
---
### Specify which instance roles run a recipe
* `if node[:instance_role] == 'instance_role`
* `instance_role` could be `app_master, app, solo, db_master, db_slave, util`
* same applies to utility servers

### Servers
* On Engine Yard, you have many **applications**:
  * `ExampleSumm201`
  * `ExamCold2016`
* Each of these **applications** have their own **environments**:
  * `staging`
  * `production`
* Within these environments, contain **instances**
  * `Application Instances: Application Master` 
  * `Database Instances: Master Database`
  * `Utility Instances: memcached, redis, resque`
  * Each has their own unique address (**some will change upon restarting the environment**)
  * To connect to the app or the database you'll need to create in your `.ssh/config` file
    ```
    Host name-of-connection
      HostName address obtained above (from the EY dashboard)
      User deploy
      IdentityFile ~/.ssh/engineyard
    ```
    * If you don't use this way of connecting to the server:
    ```
    ssh -i ~/.ssh/engineyard deploy@...
    ```
    * terminal : `ssh name-of-connection`
    * Now you are inside the virtual server that contains either the app or database

---
### Chef Recipes
* the chef repo lives in a directory outside of your app!
* In here, you can make recipes or modify existing recipes
* Upload and apply your changes within this directory to your **environment**!

--- 
### Logs
* Logs are located on the **actual server**
* SSH into the server and go into `/var/log` or `etc/chef.log.info`
* Use the `cat` command or `less` to view logs