README
¶
bootstrap/function/adapter/contrib/azure/functions/v1
Runs a function.Handler[T] as an Azure Functions
custom handler
(the azure command): an http server the functions host calls on every
invocation.
fxfact.NewApp(
fx.Provide(func() function.Handler[*event.Event] { return handle }),
azurefx.Module[*event.Event](),
functionfx.Module[*event.Event](middlewares),
).Run()
Set boost.bootstrap.function.default to azure, or run app azure.
Function app
host.json starts the binary as the custom handler; the host gives it the
port in FUNCTIONS_CUSTOMHANDLER_PORT, the default of port:
{
"version": "2.0",
"customHandler": {
"description": { "defaultExecutablePath": "app", "arguments": ["azure"] }
}
}
Each function is a folder with a function.json; the host posts its
invocations to /<folder>:
{
"bindings": [
{ "type": "queueTrigger", "direction": "in", "name": "item", "queueName": "orders", "connection": "AzureWebJobsStorage" },
{ "type": "queue", "direction": "out", "name": "$return", "queueName": "orders-done", "connection": "AzureWebJobsStorage" }
]
}
Triggers
The trigger binding (trigger, or the only input) becomes the CloudEvents:
| Trigger value | CloudEvent |
|---|---|
| a CloudEvent (JSON, or JSON in a message string) | that event |
| an Event Grid event | id, topic as source, subject, event type as type, event time, data |
| an http request (http trigger) | the CloudEvent of its headers or body; otherwise the body as data, the url (without query) as source, type azure.functions.http |
| anything else (queue, Service Bus, Event Hubs, timer, blob…) | the value as data, the message id of the metadata (else the invocation id) as id, source azure://functions/<function>, type azure.functions.invoke, the function as subject |
an array (batch, cardinality: many) |
one event per item, ids <id>-<index> |
A value that is not JSON becomes text/plain data. Every event carries the
extension azureinvocationid.
Results
The result goes to the output binding output: $return, the default, is
the return value of the function; another name is that output binding. A
batch returns the array of the non-nil results.
An http trigger answers its caller through an http output binding (set
output to its name, e.g. res): the result as JSON with 200, 204 when it
is nil, or the error as a restresponse.Error
with its status. With enableForwardingHttpRequest the host forwards the
request itself to /<routePrefix>/<route>, and the answer is written to it the
same way.
Errors
The items of a batch are handled up to maxWorkers at the same time. When
any of them fails, the invocation fails (500), so the trigger retries it; the
others are still handled. An error registered with
errors.Ignore(err, errors.IgnoreAsSuccess) does not fail it. The errors go
to the invocation logs.
Config
| Key | Default | Meaning |
|---|---|---|
boost.bootstrap.function.adapter.azure.port |
FUNCTIONS_CUSTOMHANDLER_PORT, else 8080 |
port the functions host calls |
boost.bootstrap.function.adapter.azure.trigger |
"" |
binding name of the trigger; empty takes the only input |
boost.bootstrap.function.adapter.azure.output |
$return |
output binding that receives the result |
boost.bootstrap.function.adapter.azure.routePrefix |
api |
route prefix of the http functions (extensions.http.routePrefix in host.json) |
boost.bootstrap.function.adapter.azure.maxWorkers |
10 |
items of a batch handled at the same time; 1 keeps their order |
boost.bootstrap.function.adapter.azure.enabled |
true |
adds the adapter in the fx module |
Documentation
¶
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func New ¶
New returns the CmdFunc that runs the handler as an Azure Functions custom handler (the azure command), with the options read from config.
func NewWithOptions ¶
NewWithOptions returns the CmdFunc that runs the handler as an Azure Functions custom handler with the given options.
Types ¶
type Handler ¶
type Handler[T any] struct { // contains filtered or unexported fields }
Handler answers the Azure Functions host: it turns each invocation into CloudEvents and calls the function handler with them.
func NewHandler ¶
NewHandler returns a Handler that calls fn with the given options.
type Options ¶
type Options struct {
// Port is where the functions host calls the custom handler.
Port int
// Trigger is the binding name of the trigger in the invocation data;
// empty takes the only input.
Trigger string
// Output is the output binding that receives the handler result;
// $return is the function return value.
Output string
// RoutePrefix is the route prefix of the http functions, to tell a
// forwarded http request from an invocation.
RoutePrefix string
// MaxWorkers bounds the items of a batch handled at the same time.
MaxWorkers int
}
Options configures the Azure Functions adapter.
func NewOptions ¶
NewOptions returns the options read from config.
Source Files