refactor: simplify check functions

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

internal/servicecheck/neighbours.go

@@ -95,7 +95,7 @@ func (c *Checker) checkNeighbours(nh []*Neighbour) {
 	}
 
 	for _, neighbour := range nh {
-		check := func(ctx context.Context) (string, error) {
+		check := func(ctx context.Context) string {
 			if c.UseTLS {
 				return c.doRequest(ctx, "https://"+neighbour.PodIP+":8443/alwayshappy", true)
 			}

internal/servicecheck/servicecheck.go

@@ -118,9 +118,9 @@ func (c *Checker) StopScheduled() {
 }
 
 // APIServerDirect checks the /version endpoint of the Kubernetes API Server through the direct link
-func (c *Checker) APIServerDirect(ctx context.Context) (string, error) {
+func (c *Checker) APIServerDirect(ctx context.Context) string {
 	if c.SkipCheckAPIServerDirect {
-		return skippedStr, nil
+		return skippedStr
 	}
 
 	apiurl := fmt.Sprintf("https://%s:%s/version", c.KubernetesServiceHost, c.KubernetesServicePort)
@@ -129,9 +129,9 @@ func (c *Checker) APIServerDirect(ctx context.Context) (string, error) {
 }
 
 // APIServerDNS checks the /version endpoint of the Kubernetes API Server through the Cluster DNS URL
-func (c *Checker) APIServerDNS(ctx context.Context) (string, error) {
+func (c *Checker) APIServerDNS(ctx context.Context) string {
 	if c.SkipCheckAPIServerDNS {
-		return skippedStr, nil
+		return skippedStr
 	}
 
 	apiurl := fmt.Sprintf("https://kubernetes.default.svc.cluster.local:%s/version", c.KubernetesServicePort)
@@ -140,18 +140,18 @@ func (c *Checker) APIServerDNS(ctx context.Context) (string, error) {
 }
 
 // MeIngress checks if the kubenurse is reachable at the /alwayshappy endpoint behind the ingress
-func (c *Checker) MeIngress(ctx context.Context) (string, error) {
+func (c *Checker) MeIngress(ctx context.Context) string {
 	if c.SkipCheckMeIngress {
-		return skippedStr, nil
+		return skippedStr
 	}
 
 	return c.doRequest(ctx, c.KubenurseIngressURL+"/alwayshappy", false) //nolint:goconst // readability
 }
 
 // MeService checks if the kubenurse is reachable at the /alwayshappy endpoint through the kubernetes service
-func (c *Checker) MeService(ctx context.Context) (string, error) {
+func (c *Checker) MeService(ctx context.Context) string {
 	if c.SkipCheckMeService {
-		return skippedStr, nil
+		return skippedStr
 	}
 
 	return c.doRequest(ctx, c.KubenurseServiceURL+"/alwayshappy", false)
@@ -163,8 +163,5 @@ func (c *Checker) measure(check Check, requestType string) string {
 	// metrics and errors based with the label
 	ctx := context.WithValue(context.Background(), kubenurseTypeKey{}, requestType)
 
-	// Execute check
-	res, _ := check(ctx) // this error is ignored as it is already logged in httptrace
-
-	return res
+	return check(ctx)
 }

internal/servicecheck/transport.go

@@ -6,6 +6,7 @@ import (
 	"crypto/x509"
 	"errors"
 	"fmt"
+	"log/slog"
 	"net/http"
 	"os"
 	"strings"
@@ -18,11 +19,12 @@ const (
 )
 
 // doRequest does an http request only to get the http status code
-func (c *Checker) doRequest(ctx context.Context, url string, addOriginHeader bool) (string, error) {
+func (c *Checker) doRequest(ctx context.Context, url string, addOriginHeader bool) string {
 	// Read Bearer Token file from ServiceAccount
 	token, err := os.ReadFile(K8sTokenFile)
 	if err != nil {
-		return errStr, fmt.Errorf("load kubernetes serviceaccount token from %s: %w", K8sTokenFile, err)
+		slog.Error("error in doRequest while reading k8sTokenFile", "err", err)
+		return errStr
 	}
 
 	req, _ := http.NewRequestWithContext(ctx, "GET", url, http.NoBody)
@@ -39,17 +41,17 @@ func (c *Checker) doRequest(ctx context.Context, url string, addOriginHeader boo
 
 	resp, err := c.httpClient.Do(req)
 	if err != nil {
-		return err.Error(), err
+		return err.Error()
 	}
 
 	// Body is non-nil if err is nil, so close it
 	_ = resp.Body.Close()
 
 	if resp.StatusCode == http.StatusOK {
-		return okStr, nil
+		return okStr
 	}
 
-	return resp.Status, errors.New(resp.Status)
+	return resp.Status
 }
 
 // generateTLSConfig returns a TLSConfig including K8s CA and the user-defined extraCA

internal/servicecheck/types.go

@@ -60,4 +60,4 @@ type Checker struct {
 }
 
 // Check is the signature used by all checks that the checker can execute.
-type Check func(ctx context.Context) (string, error)
+type Check func(ctx context.Context) string