Development repository for Opscode Cookbook application

jtimberman 7772487d15 increment version for development 5 years ago
libraries f9b875f8d2 Only call #converge if it's defined; this lets us tell platforms affected by CHEF-3589 / CHEF-3493 by those where they are fixed. 5 years ago
providers aa0f9da3e2 Merge pull request #25 from devops-israel/master 5 years ago
recipes a5106f6b2e [COOK-1820] - remove deprecations from metadata 5 years ago
resources 30b30643fd fix COOK-2812 allow block for restart_command 5 years ago
templates 311bba36c1 [COOK-1820] Remove deprecated recipes; their expiration date has come and gone. 6 years ago
test ce5e2d5a1e Do run the new tests. 6 years ago
.gitignore c6fef02c9d Git ignore file. 6 years ago
CHANGELOG.md e9eac70b72 release v2.0.4 5 years ago
CONTRIBUTING.md 1bc22925c2 release v2.0.0 5 years ago
Gemfile 075ed609ce better constrain non 1.0 test-kitchen dep 5 years ago
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README.md 56a643965c Revert "Merge pull request #23 from Youscribe/addRoot" 5 years ago
metadata.rb 7772487d15 increment version for development 5 years ago

README.md

Application cookbook

This cookbook is designed to be able to describe and deploy web applications. It provides the basic infrastructure; other cookbooks are required to support specific combinations of frameworks and application servers. The following cookbooks are available at this time:

  • application_java (Java and Tomcat)
  • application_nginx (nginx reverse proxy)
  • application_php (PHP with mod_php_apache2)
  • application_python (Django with Gunicorn)
  • application_ruby (Rails with Passenger or Unicorn)

Backward compatibility

As of version 2.0.0 of this cookbook, the recipes using configuration stored in the apps data bag are fully deprecated and removed. Version 1.0.4 of this cookbook is the last release where these recipes were available.

See COOK-1820.

Requirements

Chef 0.10.0 or higher required (for Chef environment use).

The previous dependencies have been moved out to the application-stack-specific cookbooks, and this cookbook has no external dependencies.

Resources/Providers

The application LWRP configures the basic properties of most applications, regardless of the framework or application server they use. These include:

  • SCM information for the deployment, such as the repository URL and branch name;
  • deployment destination, including the filesystem path to deploy to;
  • any OS packages to install as dependencies;
  • optional callback to control the deployment.

This LWRP uses the deploy_revision LWRP to perform the bulk of its tasks, and many concepts and parameters map directly to it. Check the documentation for deploy_revision for more information.

Configuration of framework-specific aspects of the application are performed by invoking a sub-resource; see the appropriate cookbook for more documentation.

Actions

  • :deploy: deploy an application, including any necessary configuration, restarting the associated service if necessary
  • :force_deploy: same as :deploy, but it will send a :force_deploy action to the deploy resource, directing it to deploy the application even if the same revision is already deployed

Attribute Parameters

  • name: name attribute. The name of the application you are setting up. This will be used to derive the default value for other attribute
  • packages: an Array or Hash of packages to be installed before starting the deployment
  • path: target path of the deployment; it will be created if it does not exist
  • owner: the user that shall own the target path
  • group: the group that shall own the target path
  • strategy: the underlying LWRP that will be used to perform the deployment. The default is :deploy_revision, and it should never be necessary to change it
  • scm_provider: the provider class to use for the deployment. It defaults to Chef::Provider::Git, you can set it to Chef::Provider::Subversion to deploy from an SVN repository
  • repository: the URL of the repository the application should be checked out from
  • revision: an identifier pointing to the revision that should be checked out
  • deploy_key: the private key to use to access the repository via SSH
  • rollback_on_error: if true, exceptions during a deployment will be caught and a clean rollback to the previous version will be attempted; the exception will then be re-raised. Defaults to true; change it only if you know what you are doing
  • environment: a Hash of environment variables to set while running migrations
  • purge_before_symlink: an Array of paths (relative to the checkout) to remove before creating symlinks
  • create_dirs_before_symlink: an Array of paths (relative to the checkout) pointing to directories to create before creating symlinks
  • symlinks: a Hash of shared/dir/path => release/dir/path. It determines which files and dirs in the shared directory get symlinked to the current release directory
  • symlink_before_migrate: similar to symlinks, except that they will be linked before any migration is run
  • migrate: if true then migrations will be run; defaults to false
  • migration_command: a command to run to migrate the application from the previous to the current state
  • restart_command: a command to run when restarting the application
  • environment_name: the name of a framework-specific "environment" (for example the Rails environment). By default it is the same as the Chef environment, unless it is _default, in which case it is set to production
  • enable_submodules: whether to enable git submodules in the deploy, passed into the deploy resource.

Callback Attributes

You can also set a few attributes on this LWRP that are interpreted as callback to be called at specific points during a deployment. If you pass a block, it will be evaluated within a new context. If you pass a string, it will be interpreted as a path (relative to the release directory) to a file; if it exists, it will be loaded and evaluated as though it were a Chef recipe.

The following callback attributes are available:

  • before_deploy: invoked immediately after initial setup and before the deployment proper is started. This callback will be invoked on every Chef run
  • before_migrate
  • before_symlink
  • before_restart
  • after_restart

Sub-resources

Anything that is not a known attribute will be interpreted as the name of a sub-resource; the resource will be looked up, and any nested attribute will be passed to it. More than one sub-resource can be added to an application; the order is significant, with the latter sub-resources overriding any sub-resource that comes before.

Sub-resources can set their own values for some attributes; if they do, they will be merged together with the attribute set on the main resource. The attributes that support this behavior are the following:

  • environment: environment variables from the application and from sub-resources will be merged together, with later resources overriding values set in the application or previous resources
  • migration_command: commands from the application and from sub-resources will be concatenated together joined with '&&' and run as a single shell command. The migration will only succeed if all the commands succeed
  • restart_command: commands from the application and from sub-resources will be evaluated in order
  • symlink_before_migrate: will be concatenated as a single array
  • callbacks: sub-resources callbacks will be invoked first, followed by the application callbacks

Usage

To use the application cookbook we recommend creating a cookbook named after the application, e.g. my_app. In metadata.rb you should declare a dependency on this cookbook and any framework cookbook the application may need. For example a Rails application may include:

depends "application"
depends "application_ruby"

The default recipe should describe your application using the application LWRP; you may also include additional recipes, for example to set up a database, queues, search engines and other components of your application.

A recipe using this LWRP may look like this:

application "my_app" do
  path "/deploy/to/dir"
  owner "app-user"
  group "app-group"

  repository "http://git.example.com/my-app.git"
  revision "production"

  # Apply the rails LWRP from application_ruby
  rails do
    # Rails-specific configuration. See the README in the
    # application_ruby cookbook for more information.
  end

  # Apply the passenger_apache2 LWRP, also from application_ruby
  passenger_apache2 do
    # Passenger-specific configuration.
  end
end

You can of course use any code necessary to determine the value of attributes:

application "my_app" do
  repository "http://git.example.com/my-app.git"
  revision node.chef_environment == "production" ? "production" : "develop"
end

Attributes from the application and from sub-resources are merged together:

application "my_app" do
  restart_command "kill -1 `cat /var/run/one.pid`"
  environment "LC_ALL" => "en", "FOO" => "bar"

  rails do
    restart_command "touch /tmp/something"
    environment "LC_ALL" => "en_US"
  end

  passenger_apache2 do
    environment "FOO" => "baz"
  end
end

# at the end, you will have:
#
# restart_command #=> kill -1 `cat /var/run/one.pid` && touch /tmp/something
# environment #=> LC_ALL=en_US FOO=baz

Most databases have the concept of migrations (or you can just use your own):

application "my_app" do
  path "/deploy/to/dir"
  owner "app-user"
  group "app-group"

  repository "http://git.example.com/my-app.git"
  revision "production"

  php do
    migrate true
    migration_command "your-applications-migrate-command"
  end
end

This will run your-applications-migrate-command, with the current directory set to the directory of the current checkout.

To use the application cookbook, we recommend creating a role named after the application, e.g. my_app. Create a Ruby DSL role in your chef-repo, or create the role directly with knife.

% knife role show my_app -Fj
{
  "name": "my_app",
  "chef_type": "role",
  "json_class": "Chef::Role",
  "default_attributes": {
  },
  "description": "",
  "run_list": [
    "recipe[my_app]"
  ],
  "override_attributes": {
  }
}

License and Author

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.