Adding Volumes to PrometheusSpec

Added ability to express additional Volumes on the PrometheusSpec object, and to have those Volumes propagated out to the generated StatefulSet config.

Documentation/api.md

@@ -353,6 +353,7 @@ PrometheusSpec is a specification of the desired behavior of the Prometheus clus
 | routePrefix | The route prefix Prometheus registers HTTP handlers for. This is useful, if using ExternalURL and a proxy is rewriting HTTP routes of a request, and the actual ExternalURL is still true, but the server serves requests under a different route prefix. For example for use with `kubectl proxy`. | string | false |
 | query | QuerySpec defines the query command line flags when starting Prometheus. | *[QuerySpec](#queryspec) | false |
 | storage | Storage spec to specify how storage shall be used. | *[StorageSpec](#storagespec) | false |
+| volumes | Volumes allows configuration of additional volumes on the output StatefulSet definition. Volumes specified will be appended to other volumes that are generated as a result of StorageSpec objects. | []v1.Volume | false |
 | ruleSelector | A selector to select which PrometheusRules to mount for loading alerting rules from. Until (excluding) Prometheus Operator v0.24.0 Prometheus Operator will migrate any legacy rule ConfigMaps to PrometheusRule custom resources selected by RuleSelector. Make sure it does not match any config maps that you do not want to be migrated. | *[metav1.LabelSelector](https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.11/#labelselector-v1-meta) | false |
 | ruleNamespaceSelector | Namespaces to be selected for PrometheusRules discovery. If unspecified, only the same namespace as the Prometheus object is in is used. | *[metav1.LabelSelector](https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.11/#labelselector-v1-meta) | false |
 | alerting | Define details regarding alerting. | *[AlertingSpec](#alertingspec) | false |

pkg/apis/monitoring/v1/openapi_generated.go

@@ -1743,6 +1743,19 @@ func schema_pkg_apis_monitoring_v1_PrometheusSpec(ref common.ReferenceCallback)
 							Ref:         ref("github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.StorageSpec"),
 						},
 					},
+					"volumes": {
+						SchemaProps: spec.SchemaProps{
+							Description: "Volumes allows configuration of additional volumes on the output StatefulSet definition. Volumes specified will be appended to other volumes that are generated as a result of StorageSpec objects.",
+							Type:        []string{"array"},
+							Items: &spec.SchemaOrArray{
+								Schema: &spec.Schema{
+									SchemaProps: spec.SchemaProps{
+										Ref: ref("k8s.io/api/core/v1.Volume"),
+									},
+								},
+							},
+						},
+					},
 					"ruleSelector": {
 						SchemaProps: spec.SchemaProps{
 							Description: "A selector to select which PrometheusRules to mount for loading alerting rules from. Until (excluding) Prometheus Operator v0.24.0 Prometheus Operator will migrate any legacy rule ConfigMaps to PrometheusRule custom resources selected by RuleSelector. Make sure it does not match any config maps that you do not want to be migrated.",
@@ -1936,7 +1949,7 @@ func schema_pkg_apis_monitoring_v1_PrometheusSpec(ref common.ReferenceCallback)
 			},
 		},
 		Dependencies: []string{
-			"github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.APIServerConfig", "github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.AlertingSpec", "github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.QuerySpec", "github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.RemoteReadSpec", "github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.RemoteWriteSpec", "github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.Rules", "github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.StorageSpec", "github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.ThanosSpec", "k8s.io/api/core/v1.Affinity", "k8s.io/api/core/v1.Container", "k8s.io/api/core/v1.LocalObjectReference", "k8s.io/api/core/v1.PodSecurityContext", "k8s.io/api/core/v1.ResourceRequirements", "k8s.io/api/core/v1.SecretKeySelector", "k8s.io/api/core/v1.Toleration", "k8s.io/apimachinery/pkg/apis/meta/v1.LabelSelector", "k8s.io/apimachinery/pkg/apis/meta/v1.ObjectMeta"},
+			"github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.APIServerConfig", "github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.AlertingSpec", "github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.QuerySpec", "github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.RemoteReadSpec", "github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.RemoteWriteSpec", "github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.Rules", "github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.StorageSpec", "github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1.ThanosSpec", "k8s.io/api/core/v1.Affinity", "k8s.io/api/core/v1.Container", "k8s.io/api/core/v1.LocalObjectReference", "k8s.io/api/core/v1.PodSecurityContext", "k8s.io/api/core/v1.ResourceRequirements", "k8s.io/api/core/v1.SecretKeySelector", "k8s.io/api/core/v1.Toleration", "k8s.io/api/core/v1.Volume", "k8s.io/apimachinery/pkg/apis/meta/v1.LabelSelector", "k8s.io/apimachinery/pkg/apis/meta/v1.ObjectMeta"},
 	}
 }
 

pkg/apis/monitoring/v1/types.go

@@ -167,6 +167,9 @@ type PrometheusSpec struct {
 	Query *QuerySpec `json:"query,omitempty"`
 	// Storage spec to specify how storage shall be used.
 	Storage *StorageSpec `json:"storage,omitempty"`
+	// Volumes allows configuration of additional volumes on the output StatefulSet definition. Volumes specified will
+	// be appended to other volumes that are generated as a result of StorageSpec objects.
+	Volumes []v1.Volume `json:"volumes,omitempty"`
 	// A selector to select which PrometheusRules to mount for loading alerting
 	// rules from. Until (excluding) Prometheus Operator v0.24.0 Prometheus
 	// Operator will migrate any legacy rule ConfigMaps to PrometheusRule custom

pkg/apis/monitoring/v1/zz_generated.deepcopy.go

@@ -738,6 +738,13 @@ func (in *PrometheusSpec) DeepCopyInto(out *PrometheusSpec) {
 		*out = new(StorageSpec)
 		(*in).DeepCopyInto(*out)
 	}
+	if in.Volumes != nil {
+		in, out := &in.Volumes, &out.Volumes
+		*out = make([]corev1.Volume, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
 	if in.RuleSelector != nil {
 		in, out := &in.RuleSelector, &out.RuleSelector
 		*out = new(metav1.LabelSelector)

pkg/prometheus/statefulset.go

@@ -225,6 +225,10 @@ func makeStatefulSet(
 		statefulset.Spec.VolumeClaimTemplates = append(statefulset.Spec.VolumeClaimTemplates, pvcTemplate)
 	}
 
+	for _, volume := range p.Spec.Volumes {
+		statefulset.Spec.Template.Spec.Volumes = append(statefulset.Spec.Template.Spec.Volumes, volume)
+	}
+
 	return statefulset, nil
 }