fix: Improve code and repair edge case problems with the internal Pod…

…Spec updates. (#31)

Significant rewrites for parts of podspec_updates.go to fix broken integration test edge cases

- When deleted, the AuthProxyWorkloads resource hangs around for a few minutes with
   its metadata.DeletionTimestamp set. In some cases, we need to ignore workloads that 
   have already been deleted.
- Correctly determine if a port is in use or not. Fixes an edge case where the ConnectionString on an
  AuthProxyWorkload changes, but the port number remains the same.
- Correctly handle EnvVars for removed AuthProxyWorkloads
- Correctly handle Volumes and VolumeMounts for removed AuthProxyWorkloads

Code cleanup from lint in most of the other files.
- Rename function params in podspec_updates.go for consistency

Add the health check spec to proxy containers.

internal/names/names.go

@@ -36,7 +36,7 @@ func ContainerNameFromNamespacedName(r types.NamespacedName) string {
 }
 
 // ContainerName generates a valid name for a corev1.Container object that
-// implements this cloudsql instance. Names must be 63 characters or less and
+// implements this cloudsql instance. Names must be 63 characters or fewer and
 // adhere to the rfc1035/rfc1123 label (DNS_LABEL) format.  r.ObjectMeta.Name
 // already is required to be 63 characters or less because it is a name. Because
 // we are prepending 'csql-' ContainerPrefix as a marker, the generated name with
@@ -61,29 +61,36 @@ func VolumeName(r *cloudsqlapi.AuthProxyWorkload, inst *cloudsqlapi.InstanceSpec
 // to match containers and volumes to configuration. If the names are generated
 // differently between one version of the operator and the next, the operator
 // will break. Existing workloads will not be correctly updated.
-func SafePrefixedName(prefix string, instName string) string {
+func SafePrefixedName(prefix, instName string) string {
 	const maxNameLen = 63 // maximum character limit for a name
+
 	containerPrefixLen := len(prefix)
 
 	if len(instName)+containerPrefixLen > maxNameLen {
 		// string shortener that will still produce a name that is still unique
 		// even though it is truncated.
-		checksum := hash([]byte(instName))
+		checksum := mustHash([]byte(instName))
 		hashSuffix := fmt.Sprintf("-%x", checksum)
 		hashSuffixLen := len(hashSuffix)
 		truncateLen := (maxNameLen - hashSuffixLen - containerPrefixLen) / 2
 		namePrefix := instName[:truncateLen]
 		nameSuffix := instName[len(instName)-truncateLen:]
+
 		return strings.ToLower(strings.Join(
 			[]string{prefix, namePrefix, nameSuffix, hashSuffix}, ""))
 	}
-	return strings.ToLower(prefix + instName)
 
+	return strings.ToLower(prefix + instName)
 }
 
-// hash simply returns the checksum for a slice of bytes
-func hash(bytes []byte) uint32 {
+// mustHash simply returns the checksum for a slice of bytes
+func mustHash(bytes []byte) uint32 {
 	h := fnv.New32a()
-	h.Write(bytes)
+	i, err := h.Write(bytes)
+
+	if err != nil || i != len(bytes) {
+		panic(fmt.Errorf("unable to calculate mustHash for bytes %v %v", bytes, err))
+	}
+
 	return h.Sum32()
 }

internal/names/names_test.go

@@ -49,12 +49,12 @@ func TestSafePrefixedName(t *testing.T) {
 			want: "csql-twas-brillig-and-the-slithy-toves-did-gyre-and-gimble-in-t",
 		},
 		{
-			desc: "truncated difference in middle preserved in hash 1",
+			desc: "truncated difference in middle preserved in mustHash 1",
 			name: "twas-brillig-and-the-slithy-toves-1111-did-gyre-and-gimble-in",
 			want: "csql-twas-brillig-and-the-slit11-did-gyre-and-gimble-in-d0b9860",
 		},
 		{
-			desc: "truncated difference in middle preserved in hash 2",
+			desc: "truncated difference in middle preserved in mustHash 2",
 			name: "twas-brillig-and-the-slithy-toves-2222-did-gyre-and-gimble-in",
 			want: "csql-twas-brillig-and-the-sli2-did-gyre-and-gimble-in-34c209d4",
 		},
@@ -70,7 +70,6 @@ func TestSafePrefixedName(t *testing.T) {
 			}
 		})
 	}
-
 }
 
 func TestContainerName(t *testing.T) {
@@ -80,7 +79,6 @@ func TestContainerName(t *testing.T) {
 	if want != got {
 		t.Errorf("got %v, want %v", got, want)
 	}
-
 }
 
 func TestVolumeName(t *testing.T) {
@@ -90,10 +88,9 @@ func TestVolumeName(t *testing.T) {
 	if want != got {
 		t.Errorf("got %v, want %v", got, want)
 	}
-
 }
 
-func authProxyWorkload(name string, namespace string) *cloudsqlapi.AuthProxyWorkload {
+func authProxyWorkload(name, namespace string) *cloudsqlapi.AuthProxyWorkload {
 	// Create a CloudSqlInstance that matches the deployment
 	return &cloudsqlapi.AuthProxyWorkload{
 		TypeMeta:   metav1.TypeMeta{Kind: "AuthProxyWorkload", APIVersion: cloudsqlapi.GroupVersion.String()},
@@ -109,5 +106,4 @@ func authProxyWorkload(name string, namespace string) *cloudsqlapi.AuthProxyWork
 		},
 		Status: cloudsqlapi.AuthProxyWorkloadStatus{},
 	}
-
 }