Azure Cache for Redis input binding for Azure Functions

A C# function can be created by using one of the following C# modes:

• Isolated worker model: Compiled C# function that runs in a worker process that's isolated from the runtime. Isolated worker process is required to support C# functions running on LTS and non-LTS versions .NET and the .NET Framework. Extensions for isolated worker process functions use Microsoft.Azure.Functions.Worker.Extensions.* namespaces.
• In-process model: Compiled C# function that runs in the same process as the Functions runtime. In a variation of this model, Functions can be run using C# scripting, which is supported primarily for C# portal editing. Extensions for in-process functions use Microsoft.Azure.WebJobs.Extensions.* namespaces.

The following code uses the key from the pub/sub trigger to obtain and log the value from an input binding using a GET command:

using Microsoft.Extensions.Logging;

namespace Microsoft.Azure.Functions.Worker.Extensions.Redis.Samples.RedisInputBinding
{
    public class SetGetter
    {
        private readonly ILogger<SetGetter> logger;

        public SetGetter(ILogger<SetGetter> logger)
        {
            this.logger = logger;
        }

        [Function(nameof(SetGetter))]
        public void Run(
            [RedisPubSubTrigger(Common.connectionStringSetting, "__keyevent@0__:set")] string key,
            [RedisInput(Common.connectionStringSetting, "GET {Message}")] string value)
        {
            logger.LogInformation($"Key '{key}' was set to value '{value}'");
        }
    }
}

using Microsoft.Extensions.Logging;

namespace Microsoft.Azure.WebJobs.Extensions.Redis.Samples.RedisPubSubTrigger
{
    internal class SetGetter
    {
        [FunctionName(nameof(SetGetter))]
        public static void Run(
            [RedisPubSubTrigger(Common.connectionStringSetting, "__keyevent@0__:set")] string key,
            [Redis(Common.connectionStringSetting, "GET {Message}")] string value,
            ILogger logger)
        {
            logger.LogInformation($"Key '{key}' was set to value '{value}'");
        }
    }
}

More samples for the Azure Cache for Redis input binding are available in the GitHub repository.

The following code uses the key from the pub/sub trigger to obtain and log the value from an input binding using a GET command:

package com.function.RedisInputBinding;

import com.microsoft.azure.functions.*;
import com.microsoft.azure.functions.annotation.*;
import com.microsoft.azure.functions.redis.annotation.*;

public class SetGetter {
    @FunctionName("SetGetter")
    public void run(
            @RedisPubSubTrigger(
                name = "key",
                connection = "redisConnectionString",
                channel = "__keyevent@0__:set")
                String key,
            @RedisInput(
                name = "value",
                connection = "redisConnectionString",
                command = "GET {Message}")
                String value,
            final ExecutionContext context) {
            context.getLogger().info("Key '" + key + "' was set to value '" + value + "'");
    }
}

This function.json defines both a pub/sub trigger and an input binding to the GET message on an Azure Cache for Redis instance:

{
    "bindings": [
        {
            "type": "redisPubSubTrigger",
            "connection": "redisConnectionString",
            "channel": "__keyevent@0__:set",
            "name": "key",
            "direction": "in"
        },
        {
            "type": "redis",
            "connection": "redisConnectionString",
            "command": "GET {Message}",
            "name": "value",
            "direction": "in"
        }
    ],
    "scriptFile": "run.ps1"
}

This PowerShell code (from run.ps1) retrieves and logs the cached value related to the key provided by the pub/sub trigger.

param($key, $value, $TriggerMetadata)
Write-Host "Key '$key' was set to value '$value'"

The following example uses a pub/sub trigger with an input binding to the GET message on an Azure Cache for Redis instance. The example depends on whether you use the v1 or v2 Python programming model.

{
    "bindings": [
        {
            "type": "redisPubSubTrigger",
            "connection": "redisConnectionString",
            "channel": "__keyevent@0__:set",
            "name": "key",
            "direction": "in"
        },
        {
            "type": "redis",
            "connection": "redisConnectionString",
            "command": "GET {Message}",
            "name": "value",
            "direction": "in"
        }
    ]
}

import logging

def main(key: str, value: str):
    logging.info("Key '" + key + "' was set to value '" + value + "'")

Attributes

Annotations

The RedisInput annotation supports these properties:

Configuration

The following table explains the binding configuration properties that you set in the function.json file.

When you use a custom type as the binding parameter, the extension tries to deserialize a JSON-formatted string into the custom type of this parameter.