fix: current node hash can never be in the map

Signed-off-by: Clément Nussbaumer <clement.nussbaumer@postfinance.ch>

internal/kubenurse/server.go

@@ -143,8 +143,11 @@ func New(ctx context.Context, c client.Client) (*Server, error) { //nolint:funle
  chk.NeighbourFilter = os.Getenv("KUBENURSE_NEIGHBOUR_FILTER")
  neighLimit := os.Getenv("KUBENURSE_NEIGHBOUR_LIMIT")
 
- if chk.NeighbourLimit, err = strconv.Atoi(neighLimit); err != nil {
- return nil, err
+ if neighLimit != "" {
+ chk.NeighbourLimit, err = strconv.Atoi(neighLimit)
+ if err != nil {
+ return nil, err
+ }
  }
 
  //nolint:goconst // No need to make "false" a constant in my opinion, readability is better like this.

internal/servicecheck/neighbours.go

@@ -13,7 +13,11 @@ import (
  "sigs.k8s.io/controller-runtime/pkg/client"
 )
 
-var osHostname = os.Hostname //nolint:gochecknoglobals // used during testing
+//nolint:gochecknoglobals // used during testing
+var (
+ osHostname = os.Hostname
+ currentNode string
+)
 
 // Neighbour represents a kubenurse which should be reachable
 type Neighbour struct {
@@ -60,7 +64,8 @@ func (c *Checker) GetNeighbours(ctx context.Context, namespace, labelSelector st
  continue
  }
 
- if pod.Name == hostname { // only quey other pods, not the currently running pod
+ if pod.Name == hostname { // only query other pods, not the currently running pod
+ currentNode = pod.Spec.NodeName
  continue
  }
 
@@ -108,19 +113,13 @@ func (c *Checker) filterNeighbours(nh []*Neighbour) []*Neighbour {
 
  slices.Sort(l)
 
- currentHostName, _ := osHostname()
- hostnameHash := sha256String(currentHostName)
-
- if m[hostnameHash].NodeName != currentHostName {
- panic("the current hostname hash doesn't match the value in the map")
- }
-
- idx, _ := slices.BinarySearch(l, hostnameHash)
+ currentNodeHash := sha256String(currentNode)
+ idx, _ := slices.BinarySearch(l, currentNodeHash)
 
  filteredNeighbours := make([]*Neighbour, 0, c.NeighbourLimit)
 
  for i := 0; i < c.NeighbourLimit; i++ {
- hash := l[(idx+i+1)%len(l)]
+ hash := l[(idx+i)%len(l)]
  filteredNeighbours = append(filteredNeighbours, m[hash])
  }
 

internal/servicecheck/neighbours_test.go

@@ -30,11 +30,6 @@ func TestNodeFiltering(t *testing.T) {
  nh := generateNeighbours(n)
  require.NotNil(t, nh)
 
- trueOsHostname := osHostname
- defer func() { osHostname = trueOsHostname }()
-
- // fake client, with a dummy neighbour pod
- // fakeClient := fake.NewFakeClient(&fakeNeighbourPod)
  checker := Checker{
  NeighbourLimit: neighbourLimit,
  }
@@ -43,9 +38,7 @@ func TestNodeFiltering(t *testing.T) {
  counter := make(map[string]int, n)
 
  for i := range n {
- osHostname = func() (name string, err error) {
- return nh[i].NodeName, nil
- }
+ currentNode = nh[i].NodeName
  filtered := checker.filterNeighbours(nh)
  require.Equal(t, neighbourLimit, len(filtered))