Adding upstream version 2.52.6.

Signed-off-by: Daniel Baumann <daniel@debian.org>

docs/api/middleware/healthcheck.md

@@ -0,0 +1,106 @@
+---
+id: healthcheck
+---
+
+# Health Check
+
+Liveness and readiness probes middleware for [Fiber](https://github.com/gofiber/fiber) that provides two endpoints for checking the liveness and readiness state of HTTP applications.
+
+## Overview
+
+- **Liveness Probe**: Checks if the server is up and running.
+  - **Default Endpoint**: `/livez`
+  - **Behavior**: By default returns `true` immediately when the server is operational.
+
+- **Readiness Probe**: Assesses if the application is ready to handle requests.
+  - **Default Endpoint**: `/readyz`
+  - **Behavior**: By default returns `true` immediately when the server is operational.
+
+- **HTTP Status Codes**:
+  - `200 OK`: Returned when the checker function evaluates to `true`.
+  - `503 Service Unavailable`: Returned when the checker function evaluates to `false`.
+
+## Signatures
+
+```go
+func New(config Config) fiber.Handler
+```
+
+## Examples
+
+Import the middleware package that is part of the [Fiber](https://github.com/gofiber/fiber) web framework
+```go
+import (
+    "github.com/gofiber/fiber/v2"
+    "github.com/gofiber/fiber/v2/middleware/healthcheck"
+)
+```
+
+After you initiate your [Fiber](https://github.com/gofiber/fiber) app, you can use the following possibilities:
+
+```go
+// Provide a minimal config
+app.Use(healthcheck.New())
+
+// Or extend your config for customization
+app.Use(healthcheck.New(healthcheck.Config{
+    LivenessProbe: func(c *fiber.Ctx) bool {
+        return true
+    },
+    LivenessEndpoint: "/live",
+    ReadinessProbe: func(c *fiber.Ctx) bool {
+        return serviceA.Ready() && serviceB.Ready() && ...
+    },
+    ReadinessEndpoint: "/ready",
+}))
+```
+
+## Config
+
+```go
+type Config struct {
+	// Next defines a function to skip this middleware when returned true.
+	//
+	// Optional. Default: nil
+	Next func(c *fiber.Ctx) bool
+
+	// Function used for checking the liveness of the application. Returns true if the application
+	// is running and false if it is not. The liveness probe is typically used to indicate if 
+	// the application is in a state where it can handle requests (e.g., the server is up and running).
+	//
+	// Optional. Default: func(c *fiber.Ctx) bool { return true }
+	LivenessProbe HealthChecker
+
+	// HTTP endpoint at which the liveness probe will be available.
+	//
+	// Optional. Default: "/livez"
+	LivenessEndpoint string
+
+	// Function used for checking the readiness of the application. Returns true if the application
+	// is ready to process requests and false otherwise. The readiness probe typically checks if all necessary
+	// services, databases, and other dependencies are available for the application to function correctly.
+	//
+	// Optional. Default: func(c *fiber.Ctx) bool { return true }
+	ReadinessProbe HealthChecker
+
+	// HTTP endpoint at which the readiness probe will be available.
+	// Optional. Default: "/readyz"
+	ReadinessEndpoint string
+}
+```
+
+## Default Config
+
+The default configuration used by this middleware is defined as follows:
+```go
+func defaultLivenessProbe(*fiber.Ctx) bool { return true }
+
+func defaultReadinessProbe(*fiber.Ctx) bool { return true }
+
+var ConfigDefault = Config{
+	LivenessProbe:     defaultLivenessProbe,
+	ReadinessProbe:    defaultReadinessProbe,
+	LivenessEndpoint:  "/livez",
+	ReadinessEndpoint: "/readyz",
+}
+```