CloudPad is a NuGet package that you can use to build LINQPad scripts that run as Azure Functions. You can develop and test with LINQPad -- as you would expect -- and then publish your script to Azure.
- Getting Started
- Supported Bindings
- Examples
- File Dependencies
- NuGet Dependencies
- Known Issues
- Roadmap
There's minimal setup but you cannot just take any LINQPad script and run it in Azure, you need to have this bootstrapping snippet in your LINQPad program.
Task Main(string[] args) => Program.MainAsync(this, args);Any public, non-static method in the LINQPad script is potentially* an Azure Function that can be invoked. As long as there is a supported trigger on top of the method, it should just work!
Note: you have to make the method public and non-static (i.e. it has to be a public instance method).
Technically, all the 1.x bindings are supported but we don't support intermingled input and output parameters. If you need this level of flex, go write an Azure Function instead.
All triggers support the following parameter types.
CancellationTokenITraceWriterwrapper around theMicrosoft.Azure.WebJobs.Host.TraceWriterclassICloudStorageutilities for Azure Storage
HttpRequestMessage
[HttpTrigger]
public HttpResponseMessage HelloHttp(HttpRequestMessage req)
{
var res = req.CreateResponse(HttpStatusCode.OK);
res.Content = new StringContent("Hello World!", Encoding.UTF8, "text/plain");
return res;
}While you can specify a route, you cannot get the route data by putting a parameter with the same name as a parameter to your function. (CloudPad does parameter binding differently).
[HttpTrigger(AuthorizationLevel.Anonymous, "GET", Route = "Hello/{name}")]
public Task<HttpResponseMessage> HelloHttp(HttpRequestMessage req)
{
// this won't work because of how to Azure Functions does things
req.GetRouteData().Values.Dump();
// this will work, GetRouteValue is an extension method from CloudPad
var name = req.GetRouteValue("name", "");
var res = req.CreateResponse(HttpStatusCode.OK);
res.Content = new StringContent($"Hello {name}!", Encoding.UTF8, "text/plain");
return Task.FromResult(res);
}There is a similar interface for query string parameters.
[HttpTrigger(AuthorizationLevel.Anonymous, "GET", Route = "Hello")]
public Task<HttpResponseMessage> HelloHttpWithQuery(HttpRequestMessage req)
{
// you can do this, or...
req.GetQueryNameValuePairs().Dump();
// you can do this GetQueryValue is an extension method provided by CloudPad (similar to GetRouteValue)
var name = req.GetQueryValue("name", "", isRequired: true);
// note that, by default query string parameters are not required and support multiple values, for example
req.GetQueryValues<string>("name").Dump();
// in the case of multiple values, `GetQueryValue` always gets the first value
// GetQueryValue and GetQueryValues are not case sensitive
var res = req.CreateResponse(HttpStatusCode.OK);
res.Content = new StringContent($"Hello {name}!", Encoding.UTF8, "text/plain");
return Task.FromResult(res);
}ITimerInfowrapper around theMicrosoft.Azure.WebJobs.TimerInfoclass
[TimerTrigger("0 */5 * * * *", RunOnStartup = true)]
public void HelloTimer(ITimerInfo timer)
{
timer.Dump();
}Tand/orCloudQueueMessagethe first parameter of the function is used to infer a message data contract, if it isn'tCloudQueueMessage.
When a message is put in the queue "cloud-pad-queue" we will attempt to deserialize it as JSON as the type specified by the first parameter, i.e. Message. If the type of the first parameter is CloudQueueMessage the message is passed as-is without going through deserialization.
public class Message
{
public string Text { get; set; }
}
// the ICloudStorage is used to add a message to the queue. If the queue does not exist, it will be created for you.
[HttpTrigger]
public async Task HelloQueueProducer(HttpRequestMessage req, ICloudStorage storage)
{
await storage.AddMessageAsync(QueueName, new Message { Text = "Hello World!" });
}
[QueueTrigger("cloud-pad-queue")]
public void HelloQueueConsumer(Message msg)
{
msg.Dump();
}Note the exponential backoff policy. If a queue has been dormant for some time, it may take several minutes for the queue to be processed. Restarting the script may be the fastest way to get the processing moving during development.
CloudBlockBlob
When a blob is added or modified in the blob container "cloud-pad-blob-container" specified by the BlogTrigger the function will run.
[HttpTrigger(AuthorizationLevel.Anonymous, "GET", "POST", Route = "Upload")]
public async Task<HttpResponseMessage> HelloBlobProducer(HttpRequestMessage req, ICloudStorage storage)
{
if (req.Method == HttpMethod.Post)
{
var data = await req.Content.ReadAsMultipartAsync();
var payload = data.Contents.First(c => c.Headers.ContentDisposition.Dump().Name == "\"payload\"");
var source = await payload.ReadAsStreamAsync();
await storage.UploadFromStreamAsync(BlobContainer, payload.Headers.ContentDisposition.FileName.Trim('\"'), source);
return req.CreateResponse(HttpStatusCode.NoContent); // thanks!
}
var res = req.CreateResponse(HttpStatusCode.OK);
res.Content = new StringContent("<form method=POST enctype='multipart/form-data'><input type=file name=payload><input type=submit></form>", Encoding.UTF8, "text/html");
return res;
}
[BlobTrigger(BlobContainer)]
public void HelloBlobConsumer(CloudBlockBlob blob)
{
blob.Uri.Dump("Got the blob!");
}Note that we only support CloudBlockBlob, i.e. a typical file text and/or binary blob. You cannot use an CloudAppendBlob or CloudPageBlob, sorry.
There are lot of examples in the scripts directory. Check them out!
There is a class called FileDependency in CloudPad. It can be used to bundle external files with scripts. The files are resolved relative the LINQPad script.
Note that you have to specify your file dependencies as instance members of your LINQPad query. You cannot create a FileDependency within a function and expect it to work. The FileDependency must be instantiated as your script is instantiated for it to work.
Task Main(string[] args) => Program.MainAsync(this, args);
// Define other methods and classes here
readonly FileDependency html = new FileDependency("index.html"); // ok!
// static FileDependency html = new FileDependency("index.html"); // not ok!
// ^
// these cannot be static!
[HttpTrigger]
public HttpResponseMessage IndexHtml(HttpRequestMessage req)
{
// var html = new FileDependency("index.html"); // not ok!
var res = req.CreateResponse();
res.Content = new StreamContent(html.OpenRead()) {
Headers = {
ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("text/html")
}
};
return res;
}CloudPad 2.0 was built with an explicit minimal set of dependencies to be compatible with the .NET Framework 4.6.1
- Microsoft.AspNet.WebApi.Core 5.2.3
- Newtonsoft.Json 9.0.1
- System.Net.Http 4.3.3
- WindowsAzure.Storage 7.2.1
You should be able to use additional NuGet packages, but there are issues with certain configurations. While CloudPad let's you deploy multiple LINQPad scripts to the same Azure Function host, this can cause an issue with dependencies and versions. Whenever possible. Try to target the .NET Framework 4.6.1 and don't use the most recent release of a NuGet package if it doesn't fix a specific problem for you. Try to use packages that are compatible with the dependencies of CloudPad (the Azure Functions host).
Newtonsoft.Json specifically version 9.0.1 is the snowflake of CloudPad. If you bring in any NuGet package that has a depedency on a higher version it will break the Azure Function Host Runtime. This is beyond our control and something you need to be careful about. The only viable workaround is to find the source code to the NuGet package and downgrade or remove the incompatible depdencies.
CloudPad 3.0 will support .NET 5 (Core) on Windows and LINQPad 6 (assuming that the next version of LINQPad does support .NET Core). However, there is no rush as neither .NET 5 or LINQPad 6 has been released.