DCAE Controller documentation DCAEGEN2-213
Issue-ID: DCAEGEN2-213
Change-Id: I7f2023b7f88b73eef852eca0bbf9086e14903cd6
Signed-off-by: Ralph Knag <rhknag@research.att.com>
diff --git a/docs/sections/components/intro.rst b/docs/sections/components/intro.rst
new file mode 100755
index 0000000..8a31e84
--- /dev/null
+++ b/docs/sections/components/intro.rst
@@ -0,0 +1,97 @@
+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+
+.. _intro:
+
+
+Component Developer Overview
+============================
+
+DCAE components are services that provide a specific functionality and
+are written to be composable with other DCAE service components. The
+DCAE platform is responsible for running and managing DCAE service
+components reliably.
+
+Currently, the DCAE platform supports two types of components, CDAP
+applications and Docker containers. For each, there are requirements
+that must be met for the component to integrate into the DCAE platform
+(see :doc:`CDAP <component-type-cdap>` and :doc:`Docker <component-type-docker>`.
+
+Components requires one or more data formats.
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Components are software applications that do some function. Components
+don’t run independently, they depend upon other components. A
+component’s function could require connecting to other components to
+fulfill that function. A component could also be providing its function
+as a service through an interface for other components to use.
+
+Components cannot connect to or be connected with any other component.
+The upstream and downstream components must *speak* the same vocabulary
+or *data format*. The output of an one component must match another
+component’s input. This is necessary for components to function
+correctly and without errors.
+
+The platform requires data formats to ensure that a component will be
+run with other *compatible* components.
+
+Data formats can and should be shared by multiple components.
+
+Each Component requires a component specification.
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The component specification is a JSON artifact that fully specifies the
+component, it’s interfaces, and configuration. It’s standardized for
+CDAP and Docker applications and is validated using a :any:`JSON
+schema <dcae-component-schema>`.
+
+The component specification fully specifies all the configuration
+parameters of the component. This is used by the designer and by policy
+(future) to configure the runtime behavior of the component.
+
+The component specification is used to *generate* application
+configuration in a standardized JSON that the platform will make
+available to the component. This application configuration JSON will
+include:
+
+- Parameters that have been assigned values from the component
+ specification, policy, and/or the designer
+- Connection details of downstream components
+
+The component specification is transformed by DCAE tooling (explained
+later) into TOSCA models (one for the component, and in the future, one
+for Policy). The TOSCA models then get transformed into Cloudify
+blueprints.
+
+The component specification is used by:
+
+- dcae_cli tool - to validate it
+- Design Tools - TOSCA models are generated from the component
+ specification so that the component can be used by designers to
+ compose new DCAE services in SDC.
+- Policy (future) - TOSCA models are generated from the component
+ specification so that operations can create policy models used to
+ dynamically configure the component.
+- the runtime platform - The component’s application configuration
+ (JSON) is generated from the component specification and will be
+ provided to the component at runtime.
+
+Onboarding
+----------
+
+Onboarding is a process that ensures that the component is compliant
+with the DCAE platform rules. A command-line tool called :doc:`dcae-cli <dcae-cli/quickstart>` is provided to help with onboarding. The high level summary of the onboarding process is:
+
+1. Defining the :doc:`data formats <data-formats>` if they don’t already
+ exist.
+2. Define the :doc:`component specification <component-specification/common-specification>`. See :doc:`Docker <component-specification/docker-specification>` and :doc:`CDAP <component-specification/cdap-specification>`.
+3. Use the dcae_cli tool to :any:`add the data formats <adding-data-formats>`
+ and :any:`add the component <adding-component>` to
+ the onboarding catalog. This process will validate them as well.
+4. Use the dcae_cli tool to :any:`deploy <development-and-testing>`
+ the component. (The component is deployed to the environment
+ indicated in :any:`profile <setting-profile>`).
+5. Test the component. Also do pairwise-test the component with any
+ other components it connects with.
+6. Publish the component and data formats into the Service Design and
+ Creation (SDC) ‘catalog’. (Currently, this is a manual step).