Add ReplicationSlot support for Postgres (#1142)

Signed-off-by: Tamal Saha <tamal@appscode.com> Signed-off-by: souravbiswassanto <saurov@appscode.com> Co-authored-by: souravbiswassanto <saurov@appscode.com>
kubedb · Mar 15, 2024 · e156d7a · e156d7a
1 parent 9c51f2d
commit e156d7a
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Showing 6 changed files with 182 additions and 1 deletion.
diff --git a/apis/kubedb/v1alpha2/openapi_generated.go b/apis/kubedb/v1alpha2/openapi_generated.go
diff --git a/apis/kubedb/v1alpha2/postgres_helpers.go b/apis/kubedb/v1alpha2/postgres_helpers.go
@@ -26,6 +26,8 @@ import (
 	"kubedb.dev/apimachinery/apis/kubedb"
 	"kubedb.dev/apimachinery/crds"
 
+	"github.com/Masterminds/semver/v3"
+	"github.com/pkg/errors"
 	promapi "github.com/prometheus-operator/prometheus-operator/pkg/apis/monitoring/v1"
 	"gomodules.xyz/pointer"
 	core "k8s.io/api/core/v1"
@@ -261,6 +263,7 @@ func (p *Postgres) SetDefaults(postgresVersion *catalog.PostgresVersion, topolog
 	// So that /var/pv directory have the group permission for the RunAsGroup user GID.
 	// Otherwise, We will get write permission denied.
 	p.Spec.PodTemplate.Spec.SecurityContext.FSGroup = p.Spec.PodTemplate.Spec.ContainerSecurityContext.RunAsGroup
+	p.SetDefaultReplicationMode(postgresVersion)
 	p.SetArbiterDefault()
 	p.SetTLSDefaults()
 	p.SetHealthCheckerDefaults()
@@ -278,6 +281,39 @@ func (p *Postgres) SetDefaults(postgresVersion *catalog.PostgresVersion, topolog
 	}
 }
 
+func getMajorPgVersion(postgresVersion *catalog.PostgresVersion) (uint64, error) {
+	ver, err := semver.NewVersion(postgresVersion.Spec.Version)
+	if err != nil {
+		return 0, errors.Wrap(err, "Failed to get postgres major.")
+	}
+	return ver.Major(), nil
+}
+
+// SetDefaultReplicationMode set the default replication mode.
+// Replication slot will be prioritized if no WalLimitPolicy is mentioned
+func (p *Postgres) SetDefaultReplicationMode(postgresVersion *catalog.PostgresVersion) {
+	majorVersion, _ := getMajorPgVersion(postgresVersion)
+	if p.Spec.Replication == nil {
+		p.Spec.Replication = &PostgresReplication{}
+	}
+	if p.Spec.Replication.WALLimitPolicy == "" {
+		if majorVersion <= uint64(12) {
+			p.Spec.Replication.WALLimitPolicy = WALKeepSegment
+		} else {
+			p.Spec.Replication.WALLimitPolicy = WALKeepSize
+		}
+	}
+	if p.Spec.Replication.WALLimitPolicy == WALKeepSegment && p.Spec.Replication.WalKeepSegment == nil {
+		p.Spec.Replication.WalKeepSegment = pointer.Int32P(64)
+	}
+	if p.Spec.Replication.WALLimitPolicy == WALKeepSize && p.Spec.Replication.WalKeepSizeInMegaBytes == nil {
+		p.Spec.Replication.WalKeepSizeInMegaBytes = pointer.Int32P(1024)
+	}
+	if p.Spec.Replication.WALLimitPolicy == ReplicationSlot && p.Spec.Replication.MaxSlotWALKeepSizeInMegaBytes == nil {
+		p.Spec.Replication.MaxSlotWALKeepSizeInMegaBytes = pointer.Int32P(-1)
+	}
+}
+
 func (p *Postgres) SetArbiterDefault() {
 	if p.Spec.Arbiter == nil {
 		p.Spec.Arbiter = &ArbiterSpec{

diff --git a/apis/kubedb/v1alpha2/postgres_types.go b/apis/kubedb/v1alpha2/postgres_types.go
@@ -164,6 +164,28 @@ type PostgresSpec struct {
 	// Arbiter controls spec for arbiter pods
 	// +optional
 	Arbiter *ArbiterSpec `json:"arbiter,omitempty"`
+
+	// +optional
+	Replication *PostgresReplication `json:"replication,omitempty"`
+}
+
+type WALLimitPolicy string
+
+const (
+	WALKeepSize     WALLimitPolicy = "WALKeepSize"
+	ReplicationSlot WALLimitPolicy = "ReplicationSlot"
+	WALKeepSegment  WALLimitPolicy = "WALKeepSegment"
+)
+
+type PostgresReplication struct {
+	WALLimitPolicy WALLimitPolicy `json:"walLimitPolicy"`
+
+	// +optional
+	WalKeepSizeInMegaBytes *int32 `json:"walKeepSize,omitempty"`
+	// +optional
+	WalKeepSegment *int32 `json:"walKeepSegment,omitempty"`
+	// +optional
+	MaxSlotWALKeepSizeInMegaBytes *int32 `json:"maxSlotWALKeepSize,omitempty"`
 }
 
 type ArbiterSpec struct {

diff --git a/apis/kubedb/v1alpha2/zz_generated.deepcopy.go b/apis/kubedb/v1alpha2/zz_generated.deepcopy.go
diff --git a/crds/kubedb.com_postgreses.yaml b/crds/kubedb.com_postgreses.yaml
@@ -4027,6 +4027,22 @@ spec:
               replicas:
                 format: int32
                 type: integer
+              replication:
+                properties:
+                  maxSlotWALKeepSize:
+                    format: int32
+                    type: integer
+                  walKeepSegment:
+                    format: int32
+                    type: integer
+                  walKeepSize:
+                    format: int32
+                    type: integer
+                  walLimitPolicy:
+                    type: string
+                required:
+                - walLimitPolicy
+                type: object
               serviceTemplates:
                 items:
                   properties:

diff --git a/openapi/swagger.json b/openapi/swagger.json
@@ -25362,6 +25362,30 @@
         }
       ]
     },
+    "dev.kubedb.apimachinery.apis.kubedb.v1alpha2.PostgresReplication": {
+      "type": "object",
+      "required": [
+        "walLimitPolicy"
+      ],
+      "properties": {
+        "maxSlotWALKeepSize": {
+          "type": "integer",
+          "format": "int32"
+        },
+        "walKeepSegment": {
+          "type": "integer",
+          "format": "int32"
+        },
+        "walKeepSize": {
+          "type": "integer",
+          "format": "int32"
+        },
+        "walLimitPolicy": {
+          "type": "string",
+          "default": ""
+        }
+      }
+    },
     "dev.kubedb.apimachinery.apis.kubedb.v1alpha2.PostgresSpec": {
       "type": "object",
       "required": [
@@ -25444,6 +25468,9 @@
           "type": "integer",
           "format": "int32"
         },
+        "replication": {
+          "$ref": "#/definitions/dev.kubedb.apimachinery.apis.kubedb.v1alpha2.PostgresReplication"
+        },
         "serviceTemplates": {
           "description": "ServiceTemplates is an optional configuration for services used to expose database",
           "type": "array",