Error handling; don't panic.

.gitignore

@@ -29,4 +29,3 @@ gen
 
 # Temporary directory
 .tmp/*
-

cmd/run.go

@@ -82,8 +82,6 @@ func run() func(cmd *cobra.Command, args []string) error {
 		log.Info("Running sparrow")
 		if err = s.Run(ctx); err != nil {
 			err = fmt.Errorf("error while running sparrow: %w", err)
-			// by this time all shutdown routines should have been called
-			// so we can exit here
 			return err
 		}
 

internal/helper/retry_test.go

@@ -65,7 +65,7 @@ func TestRetry(t *testing.T) {
 					if effectorFuncCallCounter > 1 {
 						return nil
 					}
-					return fmt.Errorf("Ups sth wrong")
+					return fmt.Errorf("ups sth wrong")
 				},
 				rc: RetryConfig{
 					Count: 2,
@@ -81,7 +81,7 @@ func TestRetry(t *testing.T) {
 			args: args{
 				effector: func(ctx context.Context) error {
 					effectorFuncCallCounter++
-					return fmt.Errorf("Ups sth wrong")
+					return fmt.Errorf("ups sth wrong")
 				},
 				rc: RetryConfig{
 					Count: 2,
@@ -98,7 +98,7 @@ func TestRetry(t *testing.T) {
 				effector: func(ctx context.Context) error {
 					effectorFuncCallCounter++
 					cancel()
-					return errors.New("Ups")
+					return errors.New("ups")
 				},
 				rc: RetryConfig{
 					Count: 2,

internal/logger/logger.go

@@ -36,18 +36,19 @@ func NewLogger(h ...slog.Handler) *slog.Logger {
 	if len(h) > 0 {
 		handler = h[0]
 	} else {
-		handler = slog.NewJSONHandler(os.Stderr, nil)
+		handler = slog.NewJSONHandler(os.Stderr, &slog.HandlerOptions{
+			AddSource: true,
+		})
 	}
 	return slog.New(handler)
 }
 
 // NewContextWithLogger creates a new context based on the provided parent context.
-// It embeds a logger into this new context, which is a child of the logger from the parent context.
-// The child logger inherits settings from the parent and is grouped under the provided childName.
+// It embeds a logger into this new context.
 // It also returns a cancel function to cancel the new context.
-func NewContextWithLogger(parent context.Context, childName string) (context.Context, context.CancelFunc) {
+func NewContextWithLogger(parent context.Context) (context.Context, context.CancelFunc) {
 	ctx, cancel := context.WithCancel(parent)
-	return IntoContext(ctx, FromContext(parent).WithGroup(childName)), cancel
+	return IntoContext(ctx, FromContext(parent)), cancel
 }
 
 // IntoContext embeds the provided slog.Logger into the given context and returns the modified context.
@@ -68,7 +69,7 @@ func FromContext(ctx context.Context) *slog.Logger {
 	return NewLogger()
 }
 
-// Take the logger from the context and add it to the request context
+// Middleware takes the logger from the context and adds it to the request context
 func Middleware(ctx context.Context) func(http.Handler) http.Handler {
 	log := FromContext(ctx)
 	return func(next http.Handler) http.Handler {

pkg/api/routingtree.go

@@ -23,7 +23,7 @@ import (
 	"sync"
 )
 
-// creates a simple routing tree, so checks can easily create and remove handlers
+// RoutingTree creates a simple routing tree, so checks can easily create and remove handlers
 // Maps the method to the path and the handler
 type RoutingTree struct {
 	tree map[string]map[string]http.HandlerFunc

pkg/checks/health.go

@@ -21,6 +21,7 @@ package checks
 import (
 	"context"
 	"fmt"
+	"io"
 	"net/http"
 	"sync"
 	"time"
@@ -80,7 +81,7 @@ func NewHealthCheck() Check {
 
 // Run starts the health check
 func (h *Health) Run(ctx context.Context) error {
-	ctx, cancel := logger.NewContextWithLogger(ctx, "health")
+	ctx, cancel := logger.NewContextWithLogger(ctx)
 	defer cancel()
 	log := logger.FromContext(ctx)
 
@@ -177,7 +178,7 @@ func (h *Health) GetMetricCollectors() []prometheus.Collector {
 // check performs a health check using a retry function
 // to get the health status for all targets
 func (h *Health) check(ctx context.Context) healthData {
-	log := logger.FromContext(ctx).WithGroup("check")
+	log := logger.FromContext(ctx)
 	log.Debug("Checking health")
 	if len(h.config.Targets) == 0 {
 		log.Debug("No targets defined")
@@ -243,12 +244,17 @@ func getHealth(ctx context.Context, url string) error {
 		return err
 	}
 
-	res, err := client.Do(req)
+	res, err := client.Do(req) //nolint:bodyclose
 	if err != nil {
 		log.Error("Http get request failed", "error", err.Error())
 		return err
 	}
-	defer res.Body.Close()
+	defer func(Body io.ReadCloser) {
+		err := Body.Close()
+		if err != nil {
+			log.Error("Failed to close response body", "error", err.Error())
+		}
+	}(res.Body)
 
 	if res.StatusCode != http.StatusOK {
 		log.Error("Http get request failed", "status", res.Status)

pkg/checks/latency.go

@@ -77,7 +77,7 @@ type latencyMetrics struct {
 }
 
 func (l *Latency) Run(ctx context.Context) error {
-	ctx, cancel := logger.NewContextWithLogger(ctx, "latency")
+	ctx, cancel := logger.NewContextWithLogger(ctx)
 	defer cancel()
 	log := logger.FromContext(ctx)
 	log.Info(fmt.Sprintf("Using latency check interval of %s", l.cfg.Interval.String()))
@@ -104,7 +104,7 @@ func (l *Latency) Run(ctx context.Context) error {
 }
 
 func (l *Latency) Startup(ctx context.Context, cResult chan<- Result) error {
-	log := logger.FromContext(ctx).WithGroup("latency")
+	log := logger.FromContext(ctx)
 	log.Debug("Starting latency check")
 
 	l.c = cResult
@@ -193,7 +193,7 @@ func (l *Latency) GetMetricCollectors() []prometheus.Collector {
 }
 
 func (l *Latency) check(ctx context.Context) map[string]LatencyResult {
-	log := logger.FromContext(ctx).WithGroup("check")
+	log := logger.FromContext(ctx)
 	log.Debug("Checking latency")
 	if len(l.cfg.Targets) == 0 {
 		log.Debug("No targets defined")

pkg/checks/oapi.go

@@ -23,7 +23,7 @@ import (
 	"github.com/getkin/kin-openapi/openapi3gen"
 )
 
-// Takes in check perfdata and returns an openapi3.SchemaRef of a result wrapping the perfData
+// OpenapiFromPerfData takes in check perfdata and returns an openapi3.SchemaRef of a result wrapping the perfData
 // this is a workaround, since the openapi3gen.NewSchemaRefForValue function does not work with any types
 func OpenapiFromPerfData[T any](data T) (*openapi3.SchemaRef, error) {
 	checkSchema, err := openapi3gen.NewSchemaRefForValue(Result{}, openapi3.Schemas{})

pkg/config/file.go

@@ -20,6 +20,7 @@ package config
 
 import (
 	"context"
+	"fmt"
 	"os"
 
 	"gopkg.in/yaml.v3"
@@ -41,22 +42,23 @@ func NewFileLoader(cfg *Config, cCfgChecks chan<- map[string]any) *FileLoader {
 	}
 }
 
-func (f *FileLoader) Run(ctx context.Context) {
-	log := logger.FromContext(ctx).WithGroup("FileLoader")
+func (f *FileLoader) Run(ctx context.Context) error {
+	log := logger.FromContext(ctx)
 	log.Info("Reading config from file", "file", f.path)
 	// TODO refactor this to use fs.FS
 	b, err := os.ReadFile(f.path)
 	if err != nil {
 		log.Error("Failed to read config file", "path", f.path, "error", err)
-		panic("failed to read config file " + err.Error())
+		return fmt.Errorf("failed to read config file: %w", err)
 	}
 
 	var cfg RuntimeConfig
 
 	if err := yaml.Unmarshal(b, &cfg); err != nil {
 		log.Error("Failed to parse config file", "error", err)
-		panic("failed to parse config file: " + err.Error())
+		return fmt.Errorf("failed to parse config file: %w", err)
 	}
 
 	f.c <- cfg.Checks
+	return nil
 }

pkg/config/file_test.go

@@ -64,7 +64,13 @@ func TestFileLoader_Run(t *testing.T) {
 				path: tt.fields.path,
 				c:    tt.fields.c,
 			}
-			go f.Run(*tt.args.ctx)
+			go func() {
+				err := f.Run(*tt.args.ctx)
+				if err != nil {
+					t.Errorf("Expected no error, got %v", err)
+					return
+				}
+			}()
 			(*tt.args.cancel)()
 
 			config := <-tt.fields.c

pkg/config/http.go

@@ -51,54 +51,57 @@ func NewHttpLoader(cfg *Config, cCfgChecks chan<- map[string]any) *HttpLoader {
 // The config is will be loaded periodically defined by the
 // loader interval configuration. A failed request will be retried defined
 // by the retry configuration
-func (gl *HttpLoader) Run(ctx context.Context) {
-	ctx, cancel := logger.NewContextWithLogger(ctx, "httpLoader")
+func (hl *HttpLoader) Run(ctx context.Context) error {
+	ctx, cancel := logger.NewContextWithLogger(ctx)
 	defer cancel()
 	log := logger.FromContext(ctx)
-
 	var runtimeCfg *RuntimeConfig
-	for {
-		getConfigRetry := helper.Retry(func(ctx context.Context) error {
-			var err error
-			runtimeCfg, err = gl.GetRuntimeConfig(ctx)
-			return err
-		}, gl.cfg.Loader.Http.RetryCfg)
-
-		if err := getConfigRetry(ctx); err != nil {
-			log.Error("Could not get remote runtime configuration", "error", err)
-			return
-		}
-
-		log.Info("Successfully got remote runtime configuration")
-		gl.cCfgChecks <- runtimeCfg.Checks
 
+	for {
 		select {
 		case <-ctx.Done():
-			return
-		case <-time.After(gl.cfg.Loader.Interval):
+			return ctx.Err()
+		case <-time.After(hl.cfg.Loader.Interval):
+			getConfigRetry := helper.Retry(func(ctx context.Context) error {
+				var err error
+				runtimeCfg, err = hl.GetRuntimeConfig(ctx)
+				return err
+			}, hl.cfg.Loader.Http.RetryCfg)
+
+			if err := getConfigRetry(ctx); err != nil {
+				log.Warn("Could not get remote runtime configuration", "error", err)
+			}
+
+			log.Info("Successfully got remote runtime configuration")
+			hl.cCfgChecks <- runtimeCfg.Checks
 		}
 	}
 }
 
 // GetRuntimeConfig gets the remote runtime configuration
-func (gl *HttpLoader) GetRuntimeConfig(ctx context.Context) (*RuntimeConfig, error) {
-	log := logger.FromContext(ctx).With("url", gl.cfg.Loader.Http.Url)
+func (hl *HttpLoader) GetRuntimeConfig(ctx context.Context) (*RuntimeConfig, error) {
+	log := logger.FromContext(ctx).With("url", hl.cfg.Loader.Http.Url)
 
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, gl.cfg.Loader.Http.Url, http.NoBody)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, hl.cfg.Loader.Http.Url, http.NoBody)
 	if err != nil {
 		log.Error("Could not create http GET request", "error", err.Error())
 		return nil, err
 	}
-	if gl.cfg.Loader.Http.Token != "" {
-		req.Header.Add("Authorization", fmt.Sprintf("Bearer %s", gl.cfg.Loader.Http.Token))
+	if hl.cfg.Loader.Http.Token != "" {
+		req.Header.Add("Authorization", fmt.Sprintf("Bearer %s", hl.cfg.Loader.Http.Token))
 	}
 
-	res, err := gl.client.Do(req)
+	res, err := hl.client.Do(req) //nolint:bodyclose
 	if err != nil {
 		log.Error("Http get request failed", "error", err.Error())
 		return nil, err
 	}
-	defer res.Body.Close()
+	defer func(Body io.ReadCloser) {
+		err = Body.Close()
+		if err != nil {
+			log.Error("Failed to close response body", "error", err.Error())
+		}
+	}(res.Body)
 
 	if res.StatusCode != http.StatusOK {
 		log.Error("Http get request failed", "status", res.Status)

pkg/config/loader.go

@@ -23,7 +23,7 @@ import (
 )
 
 type Loader interface {
-	Run(context.Context)
+	Run(context.Context) error
 }
 
 // NewLoader Get a new typed runtime configuration loader

pkg/config/validate.go

@@ -29,7 +29,7 @@ import (
 
 // Validate validates the config
 func (c *Config) Validate(ctx context.Context) error {
-	ctx, cancel := logger.NewContextWithLogger(ctx, "configValidation")
+	ctx, cancel := logger.NewContextWithLogger(ctx)
 	defer cancel()
 	log := logger.FromContext(ctx)
 

pkg/config/validate_test.go

@@ -28,7 +28,7 @@ import (
 )
 
 func TestConfig_Validate(t *testing.T) {
-	ctx, cancel := logger.NewContextWithLogger(context.Background(), "validation-test")
+	ctx, cancel := logger.NewContextWithLogger(context.Background())
 	defer cancel()
 
 	type fields struct {

pkg/db/db.go

@@ -62,7 +62,7 @@ func (i *InMemory) Get(check string) (checks.Result, bool) {
 	return *result, true
 }
 
-// Returns a copy of the map
+// List returns a copy of the map
 func (i *InMemory) List() map[string]checks.Result {
 	results := make(map[string]checks.Result)
 	i.data.Range(func(key, value any) bool {