App-Metadata

• App-Metadata
  • Description
  • Getting started
  • External dependencies
  • Packages
    • handlers
    • metadata
    • repository

Description

App metadata is a REST-API to store a metadata in yaml format

Getting started

• It requires go version >= 1.11 to enable go modules
• Clone it from https://github.com/elumbantoruan/app-metadata.git (https) or git@github.com:elumbantoruan/app-metadata.git (ssh)
• To build, run go build ./...
• To run unit test, run go test ./...
• To run the app, execute go run main.go. This will enable the endpoint at localhost:5000/app-metadata
• Example of POST operation returns 201, and the created payload

curl -d '
> title: Valid App 1
> version: 1.0.1
> maintainers:
> - name: First Maintainer App1
>   email: firstmaintainer@hotmail.com
> - name: Second Maintainer App1
>   email: secondmaitainer@gmail.com
> company: pellucid Computing
> website: http://pellucidcomputing.com
> source: https://github.com/company/app-metadata
> license: Apache-2.0
> description: |-
>   ### Interesting title
>   Some application content' -i http://localhost:5000/app-metadata

• Example of POST operation returns 400 because of invalid payload

curl -d '
> title: Valid App 1
> maintainers:
> - name: First Maintainer App1
>   email: firstmaintainer@hotmail.com
> - name: Second Maintainer App1
>   email: secondmaitainer@gmail.com
> company: pellucid Computing
> website: http://pellucidcomputing.com
> source: https://github.com/company/app-metadata
> license: Apache-2.0
> description: |-
>   ### Interesting title
>   Some application content' -i http://localhost:5000/app-metadata

External dependencies

Go modules (go.mod) will simply download all dependencies after running the build command

• Gorilla mux It's URL router and dispatcher
• UUID It's a UUID to generate a unique id
• Testify Tools for unit test such as assert, suite, and mock]
• yaml YAML support for the Go language

Packages

handlers

MetadataHandler contains a set of methods to perform POST, PUT, GET, and DELETE for REST API operations.
Here are the list of http methods along with response code

POST   /app-metadata
    201 - resource created
    400 - invalid yaml format, missing required field
    500 - error from data storage
PUT    /app-metadata/{appID}
    200 - resource updated
    400 - invalid yaml format, missing required field
    409 - conflict when id is not found during update
    500 - error from data storage
GET    /app-metadata/{appID}
    200 - resource is found and returned
    400 - missing appID parameter
    404 - resources not found (appID is not found in storage)
    500 - error from data storage
GET    /app-metadata
    200 - resource is found and returned
    404 - resource not found
    500 - error from data storage
DELETE /app-metadata/{appID}
    204 - resource deleted (no content)
    400 - missing appID parameter
    409 - conflict when id is not found during delete
    500 - error from data storage

It has a dependency on repository interface to perform a create, get, update, and delete repository actions.

It also contains a unit test for all REST API operations

metadata

ApplicationMetadata is a payload used in the application which is marshalled into yaml format

repository

Repository contains a MetadataRepository interface and InMemoryMetadataRepository type. The intent of the interface is to allow flexibility for swapping different repository mechanisms. It also enables a mock up repository to be used in unit test

type MetadataRepository interface {
    Create(appID string, data *metadata.ApplicationMetadata) error
    Update(appID string, data *metadata.ApplicationMetadata) error
    Get(appID string) (*metadata.ApplicationMetadata, error)
    GetAll() ([]metadata.ApplicationMetadata, error)
    Delete(appID string) error
}

InMemoryMetadataRepository is a concrete implementation of MetadataRepository interface