chore: remove "caching" of results and simplify code

Signed-off-by: Clément Nussbaumer <[email protected]>

internal/kubenurse/handler.go

@@ -38,15 +38,15 @@ func (s *Server) aliveHandler() func(w http.ResponseWriter, r *http.Request) {
 			Neighbourhood      []servicecheck.Neighbour `json:"neighbourhood"`
 		}
 
-		// Run checks now
-		res, haserr := s.checker.Run()
-		if haserr {
+		res := s.checker.LastCheckResult
+		if res == nil {
 			w.WriteHeader(http.StatusInternalServerError)
+			return
 		}
 
 		// Add additional data
 		out := Output{
-			Result:             res,
+			Result:             *res,
 			Headers:            r.Header,
 			UserAgent:          r.UserAgent(),
 			RequestURI:         r.RequestURI,

internal/kubenurse/server.go

@@ -118,7 +118,7 @@ func New(ctx context.Context, c client.Client) (*Server, error) { //nolint:funle
 	}
 
 	// setup checker
-	chk, err := servicecheck.New(ctx, c, promRegistry, server.allowUnschedulable, 3*time.Second, histogramBuckets)
+	chk, err := servicecheck.New(ctx, c, promRegistry, server.allowUnschedulable, 1*time.Second, histogramBuckets)
 	if err != nil {
 		return nil, err
 	}

internal/servicecheck/servicecheck.go

@@ -96,12 +96,6 @@ func (c *Checker) Run() (Result, bool) {
 		err    error
 	)
 
-	// Check if a result is cached and return it
-	cacheRes := c.retrieveResultFromCache()
-	if cacheRes != nil {
-		return *cacheRes, false
-	}
-
 	// Run Checks
 	res := Result{}
 
@@ -134,8 +128,8 @@ func (c *Checker) Run() (Result, bool) {
 		}
 	}
 
-	// Cache result
-	c.cacheResult(&res)
+	// Cache result (used for /alive handler)
+	c.LastCheckResult = &res
 
 	return res, haserr
 }

internal/servicecheck/types.go

@@ -45,8 +45,8 @@ type Checker struct {
 	// Http Client for https requests
 	httpClient *http.Client
 
-	// cachedResult represents a cached check result
-	cachedResult *CachedResult
+	// LastCheckResult represents a cached check result
+	LastCheckResult *Result
 
 	// cacheTTL defines the TTL of how long a cached result is valid
 	cacheTTL time.Duration
@@ -67,9 +67,3 @@ type Result struct {
 
 // Check is the signature used by all checks that the checker can execute.
 type Check func(ctx context.Context) (string, error)
-
-// CachedResult represents a cached check result that is valid until the expiration.
-type CachedResult struct {
-	result     *Result
-	expiration time.Time
-}