ckan-import

A stand-alone webapp to automate importing data from various sources into CKAN and its DataStore.

Install and Deployment

Get it from github:

git clone ...

We use foreman (as provided by Heroku)

foreman start -f Procfile-dev

Implementation

Focus on import of Data Package stored in Github

Import of a Generic Data Package

• Given URL to datapackage.json
  • optionally a specific file(s) that have changed
  • plus the CKAN API Key (our bearer token)
• Identify target CKAN dataset
  • Use DataPackage.name attribute for Dataset name
  • Identify target resources (by name)
• Start import process for each data file

Import of a Single Tabular Data Package resource

Require

• CSV file URL
• schema (optional?)
• Target resource id (or dataset name + resource name?)
• CKAN API Key

Steps:

• Load CSV file (into memory or do we stream?)
• (?) Check Schema is valid
• Convert Schema to DataStore schema
• Send data to DataStore

Github hook

• Receive webhook payload
• Determine if any action needed
• Boot up Data package import process

Extras / questions

• Handle data file renames
• How do we deal with a schema change (e.g. a change in type)
  • Ans: if we drop data resource content and recreate we should be ok ...
• Do we try to be smart with updates and only push changed rows (probably not)

User Stories

Persona:

• Data User - less sophisticated (uses Excel but may not know what an API is)
• Data Wrangler - more sophisticated (knows what an API is)

Import File and get Data API

As a Data Wrangler I want to provide my file and have it imported into CKAN so that I get a Data API

What kind of file?

• CSV file
• Excel file
• GeoJSON file
• ...

How do I provide

• web interface
• API (POST/GET url string or POST file content)

Questions:

• Do we validate the file?
• Do we have some process for e.g. tweaking the field types
• What is the mapping between file and Dataset / Resource

Implementation

• DataPusher already does most of this
  • What's missing is any kind of edit metadata step
  • No user interface

As a XXX I want to push my data file to github and have it automatically create/update the CKAN DataStore so that my Data API is up to date

• This is very similar to import file - only difference is we get push notifications (github webhooks). so merge this with that example.

Github import

As a XXX I want to push my tabular data package to github and have it automatically create/update the CKAN DataStore so that my Data API is up to date

• As it is already a data package importing should be very simple
• If file is large we may need to worry about queues etc but probably keep it simple for present
• How do we determine dataset to associate this with in CKAN?

One-Click Create a Dataset

As a XXX I want to provide my file and have it imported into CKAN so that I get a nice Dataset

• what distinguishes from existing system? Ans: one-click nature

Automated regular import

As a Data Wrangler I want to have my data file automatically re-imported at regular intervals so that the DataStore (and Data API) stays up to date with my data.