## Creating First Ckan extension using docker-compose

1. ### Install ckan using docker compose
i. clone okfn docker-ckan repository
`git clone https://github.com/okfn/docker-ckan.git`
ii. move into docker-ckan directory
`cd docker-ckan`
iii. copy env file
`cp .env.example .env`
iv. start ckan using docker-compose in development mode
`docker-compose -f docker-compose.dev.yml up --build`
v. Test that ckan is running successfully with the URL
http://localhost:5000
2. ### Creating a ckan extension
i. open another terminal and move into the okfn docker-ckan directory.
ii. run the command to generate a ckan extension
`docker-compose -f docker-compose.dev.yml exec ckan-dev /bin/bash -c "ckan generate extension --output-dir /srv/app/src_extensions"`
iii. The command will present a few prompt will end up in the extension setup.py file
**NB:** The first prompt is for the name of your ckan extension. CKAN extension names have to begin with `ckanext-` e.g `ckanext-helloword`

3. ### Creating our first plugin
i. move into the src/ directory to see the created extension(ckanext-helloworld) and then locate `plugin.py` file inside the created extension(ckanext-helloworld) directory
`cd src/` and then
`cd ckanext-helloworld/ckanext/helloworld`
ii. open the `plugin.py` file to create a simple ckan extension
iii. Add the below code for simple ckan extension

    import ckan.plugins as plugins
    import ckan.plugins.toolkit as toolkit
    from flask import Blueprint, render_template
    
    def hello_world():
        '''A simple view function'''
        return "Hello World, this is my first ckan extension"
    
    class HellowordPlugin(plugins.SingletonPlugin):
    
        plugins.implements(plugins.IConfigurer)
        plugins.implements(plugins.IBlueprint)

        # IConfigurer
        def update_config(self, config_):

            toolkit.add_template_directory(config_, 'templates')
            toolkit.add_public_directory(config_, 'public')
            toolkit.add_resource('fanstatic',
                'helloword_extension')

        #IBlueprint
        def get_blueprint(self):

            # Create Blueprint for plugin
            blueprint = Blueprint(self.name, self.__module__)
            blueprint.template_folder = 'templates'
            # Add plugin url rules to Blueprint object
            blueprint.add_url_rule(
                u'/hello_world', 
                u'/hello_world', 
                hello_world,
                methods=['GET']
            )
            return blueprint

4. ### Adding our extension as a ckan plugin
i. move back into docker-ckan directory
`cd docker-ckan`
ii. open the .env file
iii. add our extension name to list of plugins in the .env file
`CKAN__PLUGINS=envvars image_view text_view recline_view datastore datapusher helloworld`
iv. Then restart docker-compose
`docker-compose -f docker-compose.dev.yml up --build`
v. Test and view your newly created extension with the URL http://localhost:5000/hello_world

5.