Merge pull request #7327 from kubeservice-stack/support-round-robin-dns

feat: Add `round_robin_dns` option from prometheus RemoteWriteConfig

Documentation/api-reference/api.md

@@ -14947,6 +14947,26 @@ bool
 <p>Whether to enable HTTP2.</p>
 </td>
 </tr>
+<tr>
+<td>
+<code>roundRobinDNS</code><br/>
+<em>
+bool
+</em>
+</td>
+<td>
+<em>(Optional)</em>
+<p>When enabled:
+- The remote-write mechanism will resolve the hostname via DNS.
+- It will randomly select one of the resolved IP addresses and connect to it.</p>
+<p>When disabled (default behavior):
+- The Go standard library will handle hostname resolution.
+- It will attempt connections to each resolved IP address sequentially.</p>
+<p>Note: The connection timeout applies to the entire resolution and connection process.
+If disabled, the timeout is distributed across all connection attempts.</p>
+<p>It requires Prometheus &gt;= v3.1.0.</p>
+</td>
+</tr>
 </tbody>
 </table>
 <h3 id="monitoring.coreos.com/v1.Rule">Rule

bundle.yaml

@@ -26980,6 +26980,21 @@ spec:
                       description: Timeout for requests to the remote write endpoint.
                       pattern: ^(0|(([0-9]+)y)?(([0-9]+)w)?(([0-9]+)d)?(([0-9]+)h)?(([0-9]+)m)?(([0-9]+)s)?(([0-9]+)ms)?)$
                       type: string
+                    roundRobinDNS:
+                      description: |-
+                        When enabled:
+                            - The remote-write mechanism will resolve the hostname via DNS.
+                            - It will randomly select one of the resolved IP addresses and connect to it.
+
+                        When disabled (default behavior):
+                            - The Go standard library will handle hostname resolution.
+                            - It will attempt connections to each resolved IP address sequentially.
+
+                        Note: The connection timeout applies to the entire resolution and connection process.
+                              If disabled, the timeout is distributed across all connection attempts.
+
+                        It requires Prometheus >= v3.1.0.
+                      type: boolean
                     sendExemplars:
                       description: |-
                         Enables sending of exemplars over remote write. Note that
@@ -39365,6 +39380,21 @@ spec:
                       description: Timeout for requests to the remote write endpoint.
                       pattern: ^(0|(([0-9]+)y)?(([0-9]+)w)?(([0-9]+)d)?(([0-9]+)h)?(([0-9]+)m)?(([0-9]+)s)?(([0-9]+)ms)?)$
                       type: string
+                    roundRobinDNS:
+                      description: |-
+                        When enabled:
+                            - The remote-write mechanism will resolve the hostname via DNS.
+                            - It will randomly select one of the resolved IP addresses and connect to it.
+
+                        When disabled (default behavior):
+                            - The Go standard library will handle hostname resolution.
+                            - It will attempt connections to each resolved IP address sequentially.
+
+                        Note: The connection timeout applies to the entire resolution and connection process.
+                              If disabled, the timeout is distributed across all connection attempts.
+
+                        It requires Prometheus >= v3.1.0.
+                      type: boolean
                     sendExemplars:
                       description: |-
                         Enables sending of exemplars over remote write. Note that

example/prometheus-operator-crd-full/monitoring.coreos.com_prometheusagents.yaml

@@ -5820,6 +5820,21 @@ spec:
                       description: Timeout for requests to the remote write endpoint.
                       pattern: ^(0|(([0-9]+)y)?(([0-9]+)w)?(([0-9]+)d)?(([0-9]+)h)?(([0-9]+)m)?(([0-9]+)s)?(([0-9]+)ms)?)$
                       type: string
+                    roundRobinDNS:
+                      description: |-
+                        When enabled:
+                            - The remote-write mechanism will resolve the hostname via DNS.
+                            - It will randomly select one of the resolved IP addresses and connect to it.
+
+                        When disabled (default behavior):
+                            - The Go standard library will handle hostname resolution.
+                            - It will attempt connections to each resolved IP address sequentially.
+
+                        Note: The connection timeout applies to the entire resolution and connection process.
+                              If disabled, the timeout is distributed across all connection attempts.
+
+                        It requires Prometheus >= v3.1.0.
+                      type: boolean
                     sendExemplars:
                       description: |-
                         Enables sending of exemplars over remote write. Note that

example/prometheus-operator-crd-full/monitoring.coreos.com_prometheuses.yaml

@@ -7386,6 +7386,21 @@ spec:
                       description: Timeout for requests to the remote write endpoint.
                       pattern: ^(0|(([0-9]+)y)?(([0-9]+)w)?(([0-9]+)d)?(([0-9]+)h)?(([0-9]+)m)?(([0-9]+)s)?(([0-9]+)ms)?)$
                       type: string
+                    roundRobinDNS:
+                      description: |-
+                        When enabled:
+                            - The remote-write mechanism will resolve the hostname via DNS.
+                            - It will randomly select one of the resolved IP addresses and connect to it.
+
+                        When disabled (default behavior):
+                            - The Go standard library will handle hostname resolution.
+                            - It will attempt connections to each resolved IP address sequentially.
+
+                        Note: The connection timeout applies to the entire resolution and connection process.
+                              If disabled, the timeout is distributed across all connection attempts.
+
+                        It requires Prometheus >= v3.1.0.
+                      type: boolean
                     sendExemplars:
                       description: |-
                         Enables sending of exemplars over remote write. Note that

example/prometheus-operator-crd/monitoring.coreos.com_prometheusagents.yaml

@@ -5821,6 +5821,21 @@ spec:
                       description: Timeout for requests to the remote write endpoint.
                       pattern: ^(0|(([0-9]+)y)?(([0-9]+)w)?(([0-9]+)d)?(([0-9]+)h)?(([0-9]+)m)?(([0-9]+)s)?(([0-9]+)ms)?)$
                       type: string
+                    roundRobinDNS:
+                      description: |-
+                        When enabled:
+                            - The remote-write mechanism will resolve the hostname via DNS.
+                            - It will randomly select one of the resolved IP addresses and connect to it.
+
+                        When disabled (default behavior):
+                            - The Go standard library will handle hostname resolution.
+                            - It will attempt connections to each resolved IP address sequentially.
+
+                        Note: The connection timeout applies to the entire resolution and connection process.
+                              If disabled, the timeout is distributed across all connection attempts.
+
+                        It requires Prometheus >= v3.1.0.
+                      type: boolean
                     sendExemplars:
                       description: |-
                         Enables sending of exemplars over remote write. Note that

example/prometheus-operator-crd/monitoring.coreos.com_prometheuses.yaml

@@ -7387,6 +7387,21 @@ spec:
                       description: Timeout for requests to the remote write endpoint.
                       pattern: ^(0|(([0-9]+)y)?(([0-9]+)w)?(([0-9]+)d)?(([0-9]+)h)?(([0-9]+)m)?(([0-9]+)s)?(([0-9]+)ms)?)$
                       type: string
+                    roundRobinDNS:
+                      description: |-
+                        When enabled:
+                            - The remote-write mechanism will resolve the hostname via DNS.
+                            - It will randomly select one of the resolved IP addresses and connect to it.
+
+                        When disabled (default behavior):
+                            - The Go standard library will handle hostname resolution.
+                            - It will attempt connections to each resolved IP address sequentially.
+
+                        Note: The connection timeout applies to the entire resolution and connection process.
+                              If disabled, the timeout is distributed across all connection attempts.
+
+                        It requires Prometheus >= v3.1.0.
+                      type: boolean
                     sendExemplars:
                       description: |-
                         Enables sending of exemplars over remote write. Note that

jsonnet/prometheus-operator/prometheusagents-crd.json

@@ -4961,6 +4961,10 @@
                           "pattern": "^(0|(([0-9]+)y)?(([0-9]+)w)?(([0-9]+)d)?(([0-9]+)h)?(([0-9]+)m)?(([0-9]+)s)?(([0-9]+)ms)?)$",
                           "type": "string"
                         },
+                        "roundRobinDNS": {
+                          "description": "When enabled:\n    - The remote-write mechanism will resolve the hostname via DNS.\n    - It will randomly select one of the resolved IP addresses and connect to it.\n\nWhen disabled (default behavior):\n    - The Go standard library will handle hostname resolution.\n    - It will attempt connections to each resolved IP address sequentially.\n\nNote: The connection timeout applies to the entire resolution and connection process.\n      If disabled, the timeout is distributed across all connection attempts.\n\nIt requires Prometheus >= v3.1.0.",
+                          "type": "boolean"
+                        },
                         "sendExemplars": {
                           "description": "Enables sending of exemplars over remote write. Note that\nexemplar-storage itself must be enabled using the `spec.enableFeatures`\noption for exemplars to be scraped in the first place.\n\nIt requires Prometheus >= v2.27.0.",
                           "type": "boolean"

jsonnet/prometheus-operator/prometheuses-crd.json

@@ -6340,6 +6340,10 @@
                           "pattern": "^(0|(([0-9]+)y)?(([0-9]+)w)?(([0-9]+)d)?(([0-9]+)h)?(([0-9]+)m)?(([0-9]+)s)?(([0-9]+)ms)?)$",
                           "type": "string"
                         },
+                        "roundRobinDNS": {
+                          "description": "When enabled:\n    - The remote-write mechanism will resolve the hostname via DNS.\n    - It will randomly select one of the resolved IP addresses and connect to it.\n\nWhen disabled (default behavior):\n    - The Go standard library will handle hostname resolution.\n    - It will attempt connections to each resolved IP address sequentially.\n\nNote: The connection timeout applies to the entire resolution and connection process.\n      If disabled, the timeout is distributed across all connection attempts.\n\nIt requires Prometheus >= v3.1.0.",
+                          "type": "boolean"
+                        },
                         "sendExemplars": {
                           "description": "Enables sending of exemplars over remote write. Note that\nexemplar-storage itself must be enabled using the `spec.enableFeatures`\noption for exemplars to be scraped in the first place.\n\nIt requires Prometheus >= v2.27.0.",
                           "type": "boolean"

pkg/apis/monitoring/v1/prometheus_types.go

@@ -1562,6 +1562,22 @@ type RemoteWriteSpec struct {
 	// Whether to enable HTTP2.
 	// +optional
 	EnableHttp2 *bool `json:"enableHTTP2,omitempty"`
+
+	// When enabled:
+	//     - The remote-write mechanism will resolve the hostname via DNS.
+	//     - It will randomly select one of the resolved IP addresses and connect to it.
+	//
+	// When disabled (default behavior):
+	//     - The Go standard library will handle hostname resolution.
+	//     - It will attempt connections to each resolved IP address sequentially.
+	//
+	// Note: The connection timeout applies to the entire resolution and connection process.
+	//       If disabled, the timeout is distributed across all connection attempts.
+	//
+	// It requires Prometheus >= v3.1.0.
+	//
+	// +optional
+	RoundRobinDNS *bool `json:"roundRobinDNS,omitempty"`
 }
 
 // +kubebuilder:validation:Enum=V1.0;V2.0

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

@@ -2750,6 +2750,11 @@ func (in *RemoteWriteSpec) DeepCopyInto(out *RemoteWriteSpec) {
 		*out = new(bool)
 		**out = **in
 	}
+	if in.RoundRobinDNS != nil {
+		in, out := &in.RoundRobinDNS, &out.RoundRobinDNS
+		*out = new(bool)
+		**out = **in
+	}
 }
 
 // DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new RemoteWriteSpec.

pkg/client/applyconfiguration/monitoring/v1/remotewritespec.go

@@ -45,6 +45,7 @@ type RemoteWriteSpecApplyConfiguration struct {
 	QueueConfig                   *QueueConfigApplyConfiguration    `json:"queueConfig,omitempty"`
 	MetadataConfig                *MetadataConfigApplyConfiguration `json:"metadataConfig,omitempty"`
 	EnableHttp2                   *bool                             `json:"enableHTTP2,omitempty"`
+	RoundRobinDNS                 *bool                             `json:"roundRobinDNS,omitempty"`
 }
 
 // RemoteWriteSpecApplyConfiguration constructs a declarative configuration of the RemoteWriteSpec type for use with
@@ -261,3 +262,11 @@ func (b *RemoteWriteSpecApplyConfiguration) WithEnableHttp2(value bool) *RemoteW
 	b.EnableHttp2 = &value
 	return b
 }
+
+// WithRoundRobinDNS sets the RoundRobinDNS field in the declarative configuration to the given value
+// and returns the receiver, so that objects can be built by chaining "With" function invocations.
+// If called multiple times, the RoundRobinDNS field is set to the value of the last call.
+func (b *RemoteWriteSpecApplyConfiguration) WithRoundRobinDNS(value bool) *RemoteWriteSpecApplyConfiguration {
+	b.RoundRobinDNS = &value
+	return b
+}

pkg/prometheus/promcfg.go

@@ -2738,6 +2738,10 @@ func (cg *ConfigGenerator) generateRemoteWriteConfig(s assets.StoreGetter) yaml.
 			cfg = cg.WithMinimumVersion("2.23.0").AppendMapItem(cfg, "metadata_config", metadataConfig)
 		}
 
+		if spec.RoundRobinDNS != nil {
+			cfg = cg.WithMinimumVersion("3.1.0").AppendMapItem(cfg, "round_robin_dns", spec.RoundRobinDNS)
+		}
+
 		cfgs = append(cfgs, cfg)
 	}
 

pkg/prometheus/promcfg_test.go

@@ -4315,6 +4315,15 @@ func TestRemoteWriteConfig(t *testing.T) {
 			},
 			golden: "RemoteWriteConfig_v2.54.0_MessageVersion2.golden",
 		},
+		{
+			version: "v3.1.0",
+			remoteWrite: monitoringv1.RemoteWriteSpec{
+				URL:            "http://example.com",
+				MessageVersion: ptr.To(monitoringv1.RemoteWriteMessageVersion2_0),
+				RoundRobinDNS:  ptr.To(true),
+			},
+			golden: "RemoteWriteConfig_v3.1.0.golden",
+		},
 	} {
 		t.Run(fmt.Sprintf("i=%d,version=%s", i, tc.version), func(t *testing.T) {
 			p := defaultPrometheus()

pkg/prometheus/testdata/RemoteWriteConfig_v3.1.0.golden

@@ -0,0 +1,11 @@
+global:
+  scrape_interval: 30s
+  external_labels:
+    prometheus: default/test
+    prometheus_replica: $(POD_NAME)
+  evaluation_interval: 30s
+scrape_configs: []
+remote_write:
+- url: http://example.com
+  protobuf_message: io.prometheus.write.v2.Request
+  round_robin_dns: true