Using data sources in simulations

Hoverfly Cloud supports CSV data sources for Enterprise customers to do key value data lookups and simulate persistence within simulations.

Attaching a data source to a simulation

You can upload a csv file when editing your simulation from the Simulation tab.

You can both query data from a CSV data source as well as manipulate data within a data source by adding to it and deleting from it. Hoverfly supports a number of templating methods for simple read, update and delete functions. In addition Hoverfly supports a templating function that allows simple SQL like commands for SELECT, UPDATE and DELETE.

Note that you cannot edit the data sources on a simulation already running on a service. You need to add and remove data sources from the master copy of the simulation, and then start a service running a copy of that simulation.

Add CSV data sources

Looking up a data value from within the response template

To use the data in the csv file, you need to use the {{ csv }} templating function.

{{csv '<data-source-name>' '<key-column>' '<key-value>' '<return-column>'}}

So for example given a data source named "products" with the following csv structure:

You can use the following syntax to render the word "shirt" in a response template (note the use of single quotes):

{{csv 'products' 'productId' '101' 'productName'}}

Or if for example the productId was provided at position 1 on the path:

{{csv 'products' 'productId' (Request.Path.[1]) 'productName'}}

Or if you needed to loop over some JSON array of productIds from the request body and render back data doing lookups for each productId:

{{#each (Request.Body 'jsonpath' '$.products')}}  
ProductId {{this}} is {{csv 'products' 'productId' this 'productName'}}
{{/each}}

There are a number of functions to allow querying, updating, deleting and inserting data into the csv data sources. You can read more about them below:

Querying csv data sources

Updating csv data sources

Deleting data from csv data sources

Inserting data into csv data sources

Guidance on using the SQL like syntax