feat: load check config on startup (#115)

* feat: healthz endpoint

* feat: add healthz handler
* feat: add health checker component
* feat: check metrics endpoint health
* feat: check health of all check endpoints
* test: add checker tests
* test: add healthz handler tests

* fix: get runtime config once at sparrow startup

* refactor: simplify loader init run

* chore: rm formatting helper function

* refactor: share http.Client instance

* fix: format checker address

* refactor: use internal check states instead of api route states

* chore: add running state to traceroute check

* fix: rm ok handler from unhealthy response

* refactor: return http loader cfg by value

* revert: healthz endpoint

* refactor: test empty config scenario

.pre-commit-config.yaml

@@ -4,22 +4,22 @@ repos:
       - id: go-generate-repo
         name: go generate
         entry: go
-        args: [ generate, ./... ]
+        args: [generate, ./...]
         language: system
-        types: [ go ]
+        types: [go]
         pass_filenames: false
         always_run: true
   - repo: https://github.com/tekwizely/pre-commit-golang
     rev: v1.0.0-rc.1
     hooks:
       - id: go-mod-tidy-repo
       - id: go-test-repo-mod
-        args: [ -race, -count=1 ]
+        args: [-race, -count=1, -timeout 30s]
       - id: go-vet-repo-mod
       - id: go-fumpt-repo
-        args: [ -l, -w ]
+        args: [-l, -w]
       - id: golangci-lint-repo-mod
-        args: [ --config, .golangci.yaml, --, --fix ]
+        args: [--config, .golangci.yaml, --, --fix]
   - repo: https://github.com/norwoodj/helm-docs
     rev: v1.13.0
     hooks:

go.mod

@@ -3,21 +3,17 @@ module github.com/caas-team/sparrow
 go 1.22
 
 require (
+	github.com/aeden/traceroute v0.0.0-20210211061815-03f5f7cb7908
 	github.com/getkin/kin-openapi v0.120.0
 	github.com/go-chi/chi/v5 v5.0.10
+	github.com/google/go-cmp v0.6.0
 	github.com/jarcoal/httpmock v1.3.1
 	github.com/spf13/cobra v1.8.0
 	github.com/spf13/viper v1.18.0
 	github.com/stretchr/testify v1.8.4
 	gopkg.in/yaml.v3 v3.0.1
 )
 
-require github.com/google/go-cmp v0.6.0
-
-require github.com/aeden/traceroute v0.0.0-20210211061815-03f5f7cb7908
-
-require github.com/mitchellh/mapstructure v1.5.0 // indirect
-
 require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.2.0 // indirect
@@ -34,6 +30,7 @@ require (
 	github.com/magiconair/properties v1.8.7 // indirect
 	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
+	github.com/mitchellh/mapstructure v1.5.0 // indirect
 	github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826 // indirect
 	github.com/pelletier/go-toml/v2 v2.1.0 // indirect
 	github.com/perimeterx/marshmallow v1.1.5 // indirect

pkg/api/api.go

@@ -131,7 +131,7 @@ func (a *api) RegisterRoutes(ctx context.Context, routes ...Route) error {
 
 	// Handles requests with simple http ok
 	// Required for global tarMan in checks
-	a.router.Handle("/", okHandler(ctx))
+	a.router.Handle("/", OkHandler(ctx))
 
 	return nil
 }
@@ -148,8 +148,8 @@ func (a *api) registerDefaultRoute(route Route) (err error) {
 	return nil
 }
 
-// okHandler returns a handler that will serve status ok
-func okHandler(ctx context.Context) http.Handler {
+// OkHandler returns a handler that will serve status ok
+func OkHandler(ctx context.Context) http.Handler {
 	log := logger.FromContext(ctx)
 
 	return http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {

pkg/api/api_test.go

@@ -212,7 +212,7 @@ func TestAPI_ShutdownWhenContextCanceled(t *testing.T) {
 	}
 }
 
-func Test_okHandler(t *testing.T) {
+func TestAPI_OkHandler(t *testing.T) {
 	ctx := context.Background()
 
 	req, err := http.NewRequestWithContext(ctx, "GET", "/okHandler", http.NoBody)
@@ -221,7 +221,7 @@ func Test_okHandler(t *testing.T) {
 	}
 
 	rr := httptest.NewRecorder()
-	handler := okHandler(ctx)
+	handler := OkHandler(ctx)
 
 	handler.ServeHTTP(rr, req)
 

pkg/checks/dns/dns.go

@@ -83,8 +83,8 @@ func (d *DNS) Run(ctx context.Context, cResult chan checks.ResultDTO) error {
 	ctx, cancel := logger.NewContextWithLogger(ctx)
 	defer cancel()
 	log := logger.FromContext(ctx)
-	log.Info("Starting dns check", "interval", d.config.Interval.String())
 
+	log.Info("Starting dns check", "interval", d.config.Interval.String())
 	for {
 		select {
 		case <-ctx.Done():

pkg/checks/health/health.go

@@ -75,8 +75,8 @@ func (h *Health) Run(ctx context.Context, cResult chan checks.ResultDTO) error {
 	ctx, cancel := logger.NewContextWithLogger(ctx)
 	defer cancel()
 	log := logger.FromContext(ctx)
-	log.Info("Starting healthcheck", "interval", h.config.Interval.String())
 
+	log.Info("Starting healthcheck", "interval", h.config.Interval.String())
 	for {
 		select {
 		case <-ctx.Done():

pkg/checks/latency/latency.go

@@ -81,8 +81,8 @@ func (l *Latency) Run(ctx context.Context, cResult chan checks.ResultDTO) error
 	ctx, cancel := logger.NewContextWithLogger(ctx)
 	defer cancel()
 	log := logger.FromContext(ctx)
-	log.Info("Starting latency check", "interval", l.config.Interval.String())
 
+	log.Info("Starting latency check", "interval", l.config.Interval.String())
 	for {
 		select {
 		case <-ctx.Done():

pkg/checks/traceroute/traceroute.go

@@ -25,12 +25,12 @@ type Target struct {
 
 func NewCheck() checks.Check {
 	return &Traceroute{
-		config:     Config{},
-		traceroute: newTraceroute,
 		CheckBase: checks.CheckBase{
 			Mu:       sync.Mutex{},
 			DoneChan: make(chan struct{}),
 		},
+		config:     Config{},
+		traceroute: newTraceroute,
 	}
 }
 
@@ -69,8 +69,8 @@ func (tr *Traceroute) Run(ctx context.Context, cResult chan checks.ResultDTO) er
 	ctx, cancel := logger.NewContextWithLogger(ctx)
 	defer cancel()
 	log := logger.FromContext(ctx)
-	log.Info("Starting traceroute check", "interval", tr.config.Interval.String())
 
+	log.Info("Starting traceroute check", "interval", tr.config.Interval.String())
 	for {
 		select {
 		case <-ctx.Done():

pkg/config/file.go

@@ -53,21 +53,23 @@ func NewFileLoader(cfg *Config, cRuntime chan<- runtime.Config) *FileLoader {
 
 // Run gets the runtime configuration from the local file.
 // The config will be loaded periodically defined by the loader interval configuration.
+// If the interval is 0, the configuration is only fetched once and the loader is disabled.
 func (f *FileLoader) Run(ctx context.Context) error {
 	ctx, cancel := logger.NewContextWithLogger(ctx)
 	defer cancel()
 	log := logger.FromContext(ctx)
 
-	if f.config.Interval == 0 {
-		cfg, err := f.getRuntimeConfig(ctx)
-		if err != nil {
-			log.Warn("Could not get local runtime configuration", "error", err)
-			return fmt.Errorf("could not get local runtime configuration: %w", err)
-		}
+	// Get the runtime configuration once on startup
+	cfg, err := f.getRuntimeConfig(ctx)
+	if err != nil {
+		log.Warn("Could not get local runtime configuration", "error", err)
+		err = fmt.Errorf("could not get local runtime configuration: %w", err)
+	}
+	f.cRuntime <- cfg
 
-		f.cRuntime <- cfg
+	if f.config.Interval == 0 {
 		log.Info("File Loader disabled")
-		return nil
+		return err
 	}
 
 	tick := time.NewTicker(f.config.Interval)

pkg/config/http.go

@@ -20,6 +20,7 @@ package config
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -51,61 +52,62 @@ func NewHttpLoader(cfg *Config, cRuntime chan<- runtime.Config) *HttpLoader {
 
 // Run gets the runtime configuration from the remote file of the configured http endpoint.
 // The config will be loaded periodically defined by the loader interval configuration.
-// Returns an error if the loader is shutdown or the context is done.
-func (hl *HttpLoader) Run(ctx context.Context) error {
+// If the interval is 0, the configuration is only fetched once and the loader is disabled.
+func (h *HttpLoader) Run(ctx context.Context) error {
 	ctx, cancel := logger.NewContextWithLogger(ctx)
 	defer cancel()
 	log := logger.FromContext(ctx)
 
-	var runtimeCfg *runtime.Config
+	var cfg runtime.Config
 	getConfigRetry := helper.Retry(func(ctx context.Context) (err error) {
-		runtimeCfg, err = hl.getRuntimeConfig(ctx)
+		cfg, err = h.getRuntimeConfig(ctx)
 		return err
-	}, hl.cfg.Http.RetryCfg)
+	}, h.cfg.Http.RetryCfg)
 
-	if hl.cfg.Interval == 0 {
-		err := getConfigRetry(ctx)
-		if err != nil {
-			log.Warn("Could not get remote runtime configuration", "error", err)
-			return fmt.Errorf("could not get remote runtime configuration: %w", err)
-		}
+	// Get the runtime configuration once on startup
+	err := getConfigRetry(ctx)
+	if err != nil {
+		log.Warn("Could not get remote runtime configuration", "error", err)
+		err = fmt.Errorf("could not get remote runtime configuration: %w", err)
+	}
+	h.cRuntime <- cfg
 
-		hl.cRuntime <- *runtimeCfg
+	if h.cfg.Interval == 0 {
 		log.Info("HTTP Loader disabled")
-		return nil
+		return err
 	}
 
-	tick := time.NewTicker(hl.cfg.Interval)
+	tick := time.NewTicker(h.cfg.Interval)
 	defer tick.Stop()
 
 	for {
 		select {
-		case <-hl.done:
+		case <-h.done:
 			log.Info("HTTP Loader terminated")
 			return nil
 		case <-ctx.Done():
 			return ctx.Err()
 		case <-tick.C:
 			if err := getConfigRetry(ctx); err != nil {
 				log.Warn("Could not get remote runtime configuration", "error", err)
-				tick.Reset(hl.cfg.Interval)
+				tick.Reset(h.cfg.Interval)
 				continue
 			}
 
 			log.Info("Successfully got remote runtime configuration")
-			hl.cRuntime <- *runtimeCfg
-			tick.Reset(hl.cfg.Interval)
+			h.cRuntime <- cfg
+			tick.Reset(h.cfg.Interval)
 		}
 	}
 }
 
 // GetRuntimeConfig gets the remote runtime configuration
-func (hl *HttpLoader) getRuntimeConfig(ctx context.Context) (*runtime.Config, error) {
+func (hl *HttpLoader) getRuntimeConfig(ctx context.Context) (cfg runtime.Config, err error) {
 	log := logger.FromContext(ctx).With("url", hl.cfg.Http.Url)
 	req, err := http.NewRequestWithContext(ctx, http.MethodGet, hl.cfg.Http.Url, http.NoBody)
 	if err != nil {
 		log.Error("Could not create http GET request", "error", err.Error())
-		return nil, err
+		return cfg, err
 	}
 	if hl.cfg.Http.Token != "" {
 		req.Header.Add("Authorization", fmt.Sprintf("Bearer %s", hl.cfg.Http.Token))
@@ -114,34 +116,34 @@ func (hl *HttpLoader) getRuntimeConfig(ctx context.Context) (*runtime.Config, er
 	res, err := hl.client.Do(req) //nolint:bodyclose
 	if err != nil {
 		log.Error("Http get request failed", "error", err.Error())
-		return nil, err
+		return cfg, err
 	}
 	defer func(Body io.ReadCloser) {
-		err = Body.Close()
-		if err != nil {
-			log.Error("Failed to close response body", "error", err.Error())
+		cErr := Body.Close()
+		if cErr != nil {
+			log.Error("Failed to close response body", "error", cErr)
+			err = errors.Join(cErr, err)
 		}
 	}(res.Body)
 
 	if res.StatusCode != http.StatusOK {
 		log.Error("Http get request failed", "status", res.Status)
-		return nil, fmt.Errorf("request failed, status is %s", res.Status)
+		return cfg, fmt.Errorf("request failed, status is %s", res.Status)
 	}
 
-	body, err := io.ReadAll(res.Body)
+	b, err := io.ReadAll(res.Body)
 	if err != nil {
 		log.Error("Could not read response body", "error", err.Error())
-		return nil, err
+		return cfg, err
 	}
 	log.Debug("Successfully got response")
 
-	runtimeCfg := &runtime.Config{}
-	if err := yaml.Unmarshal(body, &runtimeCfg); err != nil {
+	if err := yaml.Unmarshal(b, &cfg); err != nil {
 		log.Error("Could not unmarshal response", "error", err.Error())
-		return nil, err
+		return cfg, err
 	}
 
-	return runtimeCfg, nil
+	return cfg, nil
 }
 
 // Shutdown stops the loader