Azure Search Emulator

Containerized Azure Cognitive Search Emulator for development purposes. If your project is using Azure Cognitive Search, which cannot be containerized, this tool is a good replacement for local development.

It is insecure and should never be used in production! It even has a localhost signed https certificate bundled with it.

It consists of a simple .NET 5.0 Web API, which translates and forwards Azure Search Queries to Solr.

Has been tested with Solr 7 and 8.11. Currently doesn't work with Solr 9 (latest).

Installation

The best way to use this tool is do just download it from Docker Hub and add it to your docker compose.

Example from docker-compose.yml, which can be found in the demo folder:

  searchqueryservice:
    image: tomee/azure-search-emulator
    ports:
      - "8000:443"
    environment:
      - ASPNETCORE_ENVIRONMENT=Development
      - ASPNETCORE_URLS=https://+:443
      - ASPNETCORE_Kestrel__Certificates__Default__Password=password
      - ASPNETCORE_Kestrel__Certificates__Default__Path=/srv/cert/testcert.pfx
    volumes:
      - "./indexes:/srv/data"
    restart: on-failure
    depends_on:
      - solr

Currently the only way to use this tool, is to precreate Solr cores. This took me a lot of time to figure out, but it (sadly) is the best option. This is beacuse solr API doesn't support creating multiple configurations for core schemas (indexes) and they have to be created manually.

Another example from docker-compose.yml:

services:
  solr:
    image: solr:7
    container_name: SolrService
    ports:
     - "8983:8983"
    volumes:
     - data:/var/solr
    entrypoint:
     - bash
     - "-c"
     - "precreate-core catalog-internal-index; precreate-core invoicingindex; exec solr -f"

By default, the service expects Solr container to listen on http://solr:8983. If for any reason you need to change the container name or port, Solr URL can be configured through SEARCH_URL Environment variable

The localhost https certificate bundled with the service should be valid until 10/2031. If you want to use another one, it can also be set in docker-compose.

Index files should:

• use the basic Azure Search index format (example in demo/indexes)
• be named index.json and placed in separate folders
• be mounted to /srv/data folder

If you also want to pre-populate the index with som data, just add a mockData.json file with the data next to the index.json file.

Due to another limitation in Solr API, the primary key cannot be changed via API - Issue, and therefore has been set to id, but Id is also supported, due to camelCasing of property names.

Whole index creation process uses ILogger for logging the status, which can be read off the container's log.

Settings

RemoveNullValuesOnMerge - this settings specifies, whether fields that receive null value in mergeOrUpdate should be removed.

Default value is true, as this is the default behaviour of Azure Cognitive Search. For some reason, the Azure Search SDK sends null values, even when it doesn't want to remove the fields. If you encounter the same problem, and update isn't working properly, set this to false.

Features

Currently supports:

• Basic search functions (fulltext search, top, skip, filter, ordering), using both: GET and POST requests
• Document indexing operations (add, update)

Debugging

To debug requests and responses of the service, just add - Logging__Console__LogLevel__Microsoft=Information to environment variables of the container.

Demo

An example can be found in the demo folder. It includes an example docker-compose and a EshopDemo.Api project, which uses the Azure.Search.Documents library for indexing and searching documents.

Health checks

Health checks can be viewed on the /health endpoint of the search service. E.g. https://localhost:8000/health

Contributing

Contributions are welcome. If there is any missing feature that you would like to be added or maybe you found a bug, feel free to open up a PR or contact me.