metax-access

metax-access is a Python module used to communicate with Metax. It contains many utility functions, which help making HTTP requests to Metax.

Installation

If you’re on CentOS, you can install Python interpreter and git by running the following command in terminal:

$ sudo yum install -y python3 git

Clone the metax-access repository to your machine by running:

$ git clone https://github.com/Digital-Preservation-Finland/metax-access.git

Change to the newly created directory and install metax-access by running:

$ cd metax-access
$ make github
$ source venv/bin/activate

make github runs github target in the Makefile, which installs metax-access in a virtual environment and creates a default config file ~/.metax.cfg. source venv/bin/activate activates the newly created virtual environment. Finally, edit the ~/.metax.cfg file with editor of your choice, e.g.:

$ vi ~/.metax.cfg

to look like:

[metax]
host=https://metax.fairdata.fi
user=
password=
token=YOUR_PERSONAL_TOKEN

The token can be acquired from https://metax.fairdata.fi/secure.

Usage

metax-access has a command-line user interface, which is used with the command metax_access. Try:

$ metax_access --help

and:

$ metax_access COMMAND --help

where COMMAND is one of the provided subcommands: post, get, delete or patch. These commands can be used to send POST, GET, DELETE or PATCH requests to Metax correspondingly. The requests are sent to specific Metax resources, which are:

  • file
  • dataset
  • contract

For example, a GET request to dataset with identifier DATASET_IDENTIFIER can be sent with command:

$ metax_access get dataset DATASET_IDENTIFIER

Creating and modifying Metax datasets

Let’s go through a practical example of:

  1. Fetching a minimal dataset template from Metax.
  2. Modifying the template dataset and POSTing it to Metax.
  3. Editing the dataset with a PATCH request.
  4. Deleting the dataset.

GET the minimal dataset template and save it to dataset_template.json with the command:

$ metax_access -o dataset_template.json get template dataset

Modify the template dataset with the editor of your choice, e.g.:

$ vi dataset_template.json

If you are using the Pre-Ingest File Storage API instead of IDA, you should at the very least change the data_catalog to: urn:nbn:fi:att:data-catalog-pas. Once you have edited the template dataset, you can POST it to Metax with the command:

$ metax_access post dataset dataset_template.json

Datasets that have been POSTed to Metax can be edited with PATCH requests. Start by writing the dataset into a file:

$ metax_access -o dataset.json get dataset DATASET_IDENTIFIER

Edit the created file dataset.json to fix the mistakes and send a PATCH request with the command:

$ metax_access patch dataset DATASET_IDENTIFIER dataset.json

Finally, if you want to remove your datasets from metax, you can send a DELETE request:

$ metax_access delete dataset DATASET_IDENTIFIER