feat: add shutdown func to kernel

README.md

@@ -4,11 +4,10 @@ Bootstrap package for building Services in Go, Handle Signaling and Config comin
 ## Example
 
 ```golang
-
-
 func main() {
 	kernel := snout.Kernel[Config]{
 		RunE: Run,
+		Shutdown: Shutdown,
 	}
 	kernelBootstrap := kernel.Bootstrap(
 	    context.Background(),
@@ -31,9 +30,13 @@ type Config struct {
 	} `snout:"app"`
 }
 
-func Run(ctx context.Context, cfg Config) error{
+func Run(ctx context.Context, cfg Config) error {
   //
   // ..  
   //
 }
+
+func Shutdown(ctx context.Context) error {
+	// shutdown stuff
+}
 ```

bootstrap.go

@@ -25,9 +25,10 @@ var logger = slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{AddSou
 // ServiceConfig is a generic type for service configuration.
 type ServiceConfig any
 
-// Kernel represents a service kernel with a run function.
+// Kernel represents a service kernel with run and shutdown functions.
 type Kernel[T ServiceConfig] struct {
-	RunE func(ctx context.Context, cfg T) error
+	RunE     func(ctx context.Context, cfg T) error
+	Shutdown func(ctx context.Context) error
 }
 
 // Env represents the environment configuration.
@@ -84,20 +85,22 @@ func (k *Kernel[T]) Bootstrap(ctx context.Context, opts ...Options) KernelBootst
 		opt(kernelOpts)
 	}
 
-	ctx = setUpSignalHandling(ctx)
+	ctx, cancel := setUpSignalHandling(ctx, k)
 	cfg := k.fetchVars(kernelOpts)
 
-	return KernelBootstrap[T]{ctx, cfg, k.RunE}
+	return KernelBootstrap[T]{ctx, cfg, k.RunE, k.Shutdown, cancel}
 }
 
-// KernelBootstrap holds the context, configuration, and run function for the kernel.
+// KernelBootstrap holds the context, configuration, and run/shutdown functions for the kernel.
 type KernelBootstrap[T ServiceConfig] struct {
-	context context.Context
-	cfg     T
-	runE    func(ctx context.Context, cfg T) error
+	context  context.Context
+	cfg      T
+	runE     func(ctx context.Context, cfg T) error
+	shutdown func(ctx context.Context) error
+	cancel   context.CancelFunc
 }
 
-// Initialize validates the configuration and runs the kernel.
+// Initialize validates the configuration, runs the kernel, and handles shutdown.
 func (kb KernelBootstrap[T]) Initialize() (err error) {
 	validate := validator.New()
 
@@ -118,7 +121,19 @@ func (kb KernelBootstrap[T]) Initialize() (err error) {
 		}
 	}()
 
-	return kb.runE(kb.context, kb.cfg)
+	// Run the main function
+	if err = kb.runE(kb.context, kb.cfg); err != nil {
+		return err
+	}
+
+	// Call the shutdown function if defined
+	if kb.shutdown != nil {
+		if shutdownErr := kb.shutdown(kb.context); shutdownErr != nil {
+			return shutdownErr
+		}
+	}
+
+	return nil
 }
 
 // ErrPanic is an error indicating a panic occurred.
@@ -161,11 +176,21 @@ func (k *Kernel[T]) fetchVars(options *KernelOptions) T {
 	return cfg
 }
 
-// setUpSignalHandling sets up a context with signal notifications.
-func setUpSignalHandling(ctx context.Context) context.Context {
-	ctx, _ = signal.NotifyContext(ctx, syscall.SIGTERM, syscall.SIGINT)
+// setUpSignalHandling sets up a context with signal notifications and handles shutdown.
+func setUpSignalHandling(ctx context.Context, kernel any) (context.Context, context.CancelFunc) {
+	ctx, cancel := context.WithCancel(ctx)
+	signals := make(chan os.Signal, 1)
+	signal.Notify(signals, syscall.SIGTERM, syscall.SIGINT)
+
+	go func() {
+		<-signals
+		if k, ok := kernel.(*Kernel[any]); ok && k.Shutdown != nil {
+			_ = k.Shutdown(ctx) // Call Shutdown if defined
+		}
+		cancel()
+	}()
 
-	return ctx
+	return ctx, cancel
 }
 
 // setDefaultValues sets default values recursively for configuration fields.

bootstrap_test.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"github.com/chiguirez/snout/v3"
 	"os"
+	"syscall"
 	"testing"
 	"time"
 
@@ -395,3 +396,39 @@ func (s *snoutSuite) TestBooleanPanic() {
 		})
 	})
 }
+
+func (s *snoutSuite) TestKernelWithShutdown() {
+	s.Run("Given a Kernel with a Shutdown function", func() {
+		shutdownCalled := false
+
+		kernel := snout.Kernel[struct{}]{
+			RunE: func(ctx context.Context, _ struct{}) error {
+				<-ctx.Done()
+				return nil
+			},
+			Shutdown: func(ctx context.Context) error {
+				shutdownCalled = true
+				return nil
+			},
+		}
+
+		s.Run("When a termination signal is sent", func() {
+			ctx, cancel := context.WithCancel(context.Background())
+			defer cancel()
+
+			go func() {
+				// Simulate sending a SIGTERM signal
+				time.Sleep(100 * time.Millisecond)
+				p, _ := os.FindProcess(os.Getpid())
+				_ = p.Signal(syscall.SIGTERM)
+			}()
+
+			err := kernel.Bootstrap(ctx).Initialize()
+
+			s.Run("Then the Shutdown function is called", func() {
+				s.Require().NoError(err)
+				s.Require().True(shutdownCalled)
+			})
+		})
+	})
+}

go.mod

@@ -1,7 +1,9 @@
 module github.com/chiguirez/snout/v3
 
+go 1.24.3
+
 require (
-	github.com/go-playground/validator/v10 v10.22.0
+	github.com/go-playground/validator/v10 v10.26.0
 	github.com/mitchellh/mapstructure v1.5.0
 	github.com/octago/sflags v0.2.0
 	github.com/spf13/pflag v1.0.5
@@ -12,7 +14,7 @@ require (
 require (
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/fsnotify/fsnotify v1.7.0 // indirect
-	github.com/gabriel-vasile/mimetype v1.4.4 // indirect
+	github.com/gabriel-vasile/mimetype v1.4.8 // indirect
 	github.com/go-playground/locales v0.14.1 // indirect
 	github.com/go-playground/universal-translator v0.18.1 // indirect
 	github.com/hashicorp/hcl v1.0.0 // indirect
@@ -28,13 +30,11 @@ require (
 	github.com/subosito/gotenv v1.6.0 // indirect
 	go.uber.org/atomic v1.9.0 // indirect
 	go.uber.org/multierr v1.9.0 // indirect
-	golang.org/x/crypto v0.24.0 // indirect
+	golang.org/x/crypto v0.33.0 // indirect
 	golang.org/x/exp v0.0.0-20230905200255-921286631fa9 // indirect
-	golang.org/x/net v0.26.0 // indirect
-	golang.org/x/sys v0.21.0 // indirect
-	golang.org/x/text v0.16.0 // indirect
+	golang.org/x/net v0.34.0 // indirect
+	golang.org/x/sys v0.30.0 // indirect
+	golang.org/x/text v0.22.0 // indirect
 	gopkg.in/ini.v1 v1.67.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
-
-go 1.18

go.sum

@@ -3,22 +3,27 @@ github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSs
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHkI4W8=
+github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
 github.com/fsnotify/fsnotify v1.7.0 h1:8JEhPFa5W2WU7YfeZzPNqzMP6Lwt7L2715Ggo0nosvA=
 github.com/fsnotify/fsnotify v1.7.0/go.mod h1:40Bi/Hjc2AVfZrqy+aj+yEI+/bRxZnMJyTJwOpGvigM=
-github.com/gabriel-vasile/mimetype v1.4.4 h1:QjV6pZ7/XZ7ryI2KuyeEDE8wnh7fHP9YnQy+R0LnH8I=
-github.com/gabriel-vasile/mimetype v1.4.4/go.mod h1:JwLei5XPtWdGiMFB5Pjle1oEeoSeEuJfJE+TtfvdB/s=
+github.com/gabriel-vasile/mimetype v1.4.8 h1:FfZ3gj38NjllZIeJAmMhr+qKL8Wu+nOoI3GqacKw1NM=
+github.com/gabriel-vasile/mimetype v1.4.8/go.mod h1:ByKUIKGjh1ODkGM1asKUbQZOLGrPjydw3hYPU2YU9t8=
 github.com/go-playground/assert/v2 v2.2.0 h1:JvknZsQTYeFEAhQwI4qEt9cyV5ONwRHC+lYKSsYSR8s=
+github.com/go-playground/assert/v2 v2.2.0/go.mod h1:VDjEfimB/XKnb+ZQfWdccd7VUvScMdVu0Titje2rxJ4=
 github.com/go-playground/locales v0.14.1 h1:EWaQ/wswjilfKLTECiXz7Rh+3BjFhfDFKv/oXslEjJA=
 github.com/go-playground/locales v0.14.1/go.mod h1:hxrqLVvrK65+Rwrd5Fc6F2O76J/NuW9t0sjnWqG1slY=
 github.com/go-playground/universal-translator v0.18.1 h1:Bcnm0ZwsGyWbCzImXv+pAJnYK9S473LQFuzCbDbfSFY=
 github.com/go-playground/universal-translator v0.18.1/go.mod h1:xekY+UJKNuX9WP91TpwSH2VMlDf28Uj24BCp08ZFTUY=
-github.com/go-playground/validator/v10 v10.22.0 h1:k6HsTZ0sTnROkhS//R0O+55JgM8C4Bx7ia+JlgcnOao=
-github.com/go-playground/validator/v10 v10.22.0/go.mod h1:dbuPbCMFw/DrkbEynArYaCwl3amGuJotoKCe95atGMM=
+github.com/go-playground/validator/v10 v10.26.0 h1:SP05Nqhjcvz81uJaRfEV0YBSSSGMc/iMaVtFbr3Sw2k=
+github.com/go-playground/validator/v10 v10.26.0/go.mod h1:I5QpIEbmr8On7W0TktmJAumgzX4CA1XNl4ZmDuVHKKo=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/leodido/go-urn v1.4.0 h1:WT9HwE9SGECu3lg4d/dIA+jxlljEa1/ffXKmRjqdmIQ=
 github.com/leodido/go-urn v1.4.0/go.mod h1:bvxc+MVxLKB4z00jd1z+Dvzr47oO32F/QSNjSBOlFxI=
 github.com/magiconair/properties v1.8.7 h1:IeQXZAiQcpL9mgcAe1Nu6cX9LLw6ExEHKjN0VQdvPDY=
@@ -33,6 +38,7 @@ github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZN
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
+github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/sagikazarmark/locafero v0.4.0 h1:HApY1R9zGo4DBgr7dqsTH/JJxLTTsOt7u6keLGt6kNQ=
 github.com/sagikazarmark/locafero v0.4.0/go.mod h1:Pe1W6UlPYUk/+wc/6KFhbORCfqzgYEpgQ3O5fPuL3H4=
 github.com/sagikazarmark/slog-shim v0.1.0 h1:diDBnUNK9N/354PgrxMywXnAwEr1QZcOr6gto+ugjYE=
@@ -63,18 +69,19 @@ go.uber.org/atomic v1.9.0 h1:ECmE8Bn/WFTYwEW/bpKD3M8VtR/zQVbavAoalC1PYyE=
 go.uber.org/atomic v1.9.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
 go.uber.org/multierr v1.9.0 h1:7fIwc/ZtS0q++VgcfqFDxSBZVv/Xo49/SYnDFupUwlI=
 go.uber.org/multierr v1.9.0/go.mod h1:X2jQV1h+kxSjClGpnseKVIxpmcjrj7MNnI0bnlfKTVQ=
-golang.org/x/crypto v0.24.0 h1:mnl8DM0o513X8fdIkmyFE/5hTYxbwYOjDS/+rK6qpRI=
-golang.org/x/crypto v0.24.0/go.mod h1:Z1PMYSOR5nyMcyAVAIQSKCDwalqy85Aqn1x3Ws4L5DM=
+golang.org/x/crypto v0.33.0 h1:IOBPskki6Lysi0lo9qQvbxiQ+FvsCC/YWOecCHAixus=
+golang.org/x/crypto v0.33.0/go.mod h1:bVdXmD7IV/4GdElGPozy6U7lWdRXA4qyRVGJV57uQ5M=
 golang.org/x/exp v0.0.0-20230905200255-921286631fa9 h1:GoHiUyI/Tp2nVkLI2mCxVkOjsbSXD66ic0XW0js0R9g=
 golang.org/x/exp v0.0.0-20230905200255-921286631fa9/go.mod h1:S2oDrQGGwySpoQPVqRShND87VCbxmc6bL1Yd2oYrm6k=
-golang.org/x/net v0.26.0 h1:soB7SVo0PWrY4vPW/+ay0jKDNScG2X9wFeYlXIvJsOQ=
-golang.org/x/net v0.26.0/go.mod h1:5YKkiSynbBIh3p6iOc/vibscux0x38BZDkn8sCUPxHE=
-golang.org/x/sys v0.21.0 h1:rF+pYz3DAGSQAxAu1CbC7catZg4ebC4UIeIhKxBZvws=
-golang.org/x/sys v0.21.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/text v0.16.0 h1:a94ExnEXNtEwYLGJSIUxnWoxoRz/ZcCsV63ROupILh4=
-golang.org/x/text v0.16.0/go.mod h1:GhwF1Be+LQoKShO3cGOHzqOgRrGaYc9AvblQOmPVHnI=
+golang.org/x/net v0.34.0 h1:Mb7Mrk043xzHgnRM88suvJFwzVrRfHEHJEl5/71CKw0=
+golang.org/x/net v0.34.0/go.mod h1:di0qlW3YNM5oh6GqDGQr92MyTozJPmybPK4Ev/Gm31k=
+golang.org/x/sys v0.30.0 h1:QjkSwP/36a20jFYWkSue1YwXzLmsV5Gfq7Eiy72C1uc=
+golang.org/x/sys v0.30.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/text v0.22.0 h1:bofq7m3/HAFvbF51jz3Q9wLg3jkvSPuiZu/pD1XwgtM=
+golang.org/x/text v0.22.0/go.mod h1:YRoo4H8PVmsu+E3Ou7cqLVH8oXWIHVoX0jqUWALQhfY=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
+gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/ini.v1 v1.67.0 h1:Dgnx+6+nfE+IfzjUEISNeydPJh9AXNNsWbGP9KzCsOA=
 gopkg.in/ini.v1 v1.67.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=