🐛 deduplicate machine tags prior to openstack API apply call (#502)

* deduplicate machine tags prior to openstack API apply call

* rename 'filtered' -> 'unique'

* fix typo

* set ci deadline to four minutes

Author: petergardfjall

.golangci.yml

@@ -19,3 +19,5 @@ linters:
 issue:
   max-same-issues: 0
   max-per-linter: 0
+run:
+  deadline: 4m

pkg/cloud/services/compute/instance.go

@@ -18,9 +18,10 @@ package compute
 
 import (
 	"fmt"
-	"sigs.k8s.io/cluster-api-provider-openstack/pkg/record"
 	"time"
 
+	"sigs.k8s.io/cluster-api-provider-openstack/pkg/record"
+
 	"sigs.k8s.io/cluster-api-provider-openstack/pkg/cloud/services/networking"
 	clusterv1 "sigs.k8s.io/cluster-api/api/v1alpha2"
 	"sigs.k8s.io/cluster-api/controllers/noderefutil"
@@ -90,6 +91,9 @@ func (s *Service) InstanceCreate(clusterName string, machine *clusterv1.Machine,
 	// Append cluster scope tags
 	machineTags = append(machineTags, openStackCluster.Spec.Tags...)
 
+	// tags need to be unique or the "apply tags" call will fail.
+	machineTags = deduplicate(machineTags)
+
 	// Get security groups
 	securityGroups, err := getSecurityGroups(s, openStackMachine.Spec.SecurityGroups)
 	if err != nil {
@@ -537,3 +541,20 @@ func (s *Service) InstanceExists(openStackMachine *infrav1.OpenStackMachine) (in
 	}
 	return instanceList[0], nil
 }
+
+// deduplicate takes a slice of input strings and filters out any duplicate
+// string occurrences, for example making ["a", "b", "a", "c"] become ["a", "b",
+// "c"].
+func deduplicate(sequence []string) []string {
+	var unique []string
+	set := make(map[string]bool)
+
+	for _, s := range sequence {
+		if _, ok := set[s]; !ok {
+			unique = append(unique, s)
+			set[s] = true
+		}
+	}
+
+	return unique
+}