wip: Expose postgres publicly. Created tlsroute capability and postgres implementations

This is our first Higher Order Topology (see ADR-015)

Cargo.lock

@@ -1835,6 +1835,21 @@ dependencies = [
  "url",
 ]
 
+[[package]]
+name = "example-operatorhub-catalogsource"
+version = "0.1.0"
+dependencies = [
+ "cidr",
+ "env_logger",
+ "harmony",
+ "harmony_cli",
+ "harmony_macros",
+ "harmony_types",
+ "log",
+ "tokio",
+ "url",
+]
+
 [[package]]
 name = "example-opnsense"
 version = "0.1.0"

adr/015-higher-order-topologies.md

@@ -0,0 +1,114 @@
+# Architecture Decision Record: Higher-Order Topologies
+
+**Initial Author:** Jean-Gabriel Gill-Couture  
+**Initial Date:** 2025-12-08  
+**Last Updated Date:** 2025-12-08  
+
+## Status
+
+Implemented
+
+## Context
+
+Harmony models infrastructure as **Topologies** (deployment targets like `K8sAnywhereTopology`, `LinuxHostTopology`) implementing **Capabilities** (tech traits like `PostgreSQL`, `Docker`).
+
+**Higher-Order Topologies** (e.g., `FailoverTopology<T>`) compose/orchestrate capabilities *across* multiple underlying topologies (e.g., primary+replica `T`).
+
+Naive design requires manual `impl Capability for HigherOrderTopology<T>` *per T per capability*, causing:
+- **Impl explosion**: N topologies × M capabilities = N×M boilerplate.
+- **ISP violation**: Topologies forced to impl unrelated capabilities.
+- **Maintenance hell**: New topology needs impls for *all* orchestrated capabilities; new capability needs impls for *all* topologies/higher-order.
+- **Barrier to extension**: Users can't easily add topologies without todos/panics.
+
+This makes scaling Harmony impractical as ecosystem grows.
+
+## Decision
+
+Use **blanket trait impls** on higher-order topologies to *automatically* derive orchestration:
+
+````rust
+/// Higher-Order Topology: Orchestrates capabilities across sub-topologies.
+pub struct FailoverTopology<T> {
+    /// Primary sub-topology.
+    primary: T,
+    /// Replica sub-topology.
+    replica: T,
+}
+
+/// Automatically provides PostgreSQL failover for *any* `T: PostgreSQL`.
+/// Delegates to primary for queries; orchestrates deploy across both.
+#[async_trait]
+impl<T: PostgreSQL> PostgreSQL for FailoverTopology<T> {
+    async fn deploy(&self, config: &PostgreSQLConfig) -> Result<String, String> {
+        // Deploy primary; extract certs/endpoint;
+        // deploy replica with pg_basebackup + TLS passthrough.
+        // (Full impl logged/elaborated.)
+    }
+
+    // Delegate queries to primary.
+    async fn get_replication_certs(&self, cluster_name: &str) -> Result<ReplicationCerts, String> {
+        self.primary.get_replication_certs(cluster_name).await
+    }
+    // ...
+}
+
+/// Similarly for other capabilities.
+#[async_trait]
+impl<T: Docker> Docker for FailoverTopology<T> {
+    // Failover Docker orchestration.
+}
+````
+
+**Key properties:**
+- **Auto-derivation**: `Failover<K8sAnywhere>` gets `PostgreSQL` iff `K8sAnywhere: PostgreSQL`.
+- **No boilerplate**: One blanket impl per capability *per higher-order type*.
+
+## Rationale
+
+- **Composition via generics**: Rust trait solver auto-selects impls; zero runtime cost.
+- **Compile-time safety**: Missing `T: Capability` → compile error (no panics).
+- **Scalable**: O(capabilities) impls per higher-order; new `T` auto-works.
+- **ISP-respecting**: Capabilities only surface if sub-topology provides.
+- **Centralized logic**: Orchestration (e.g., cert propagation) in one place.
+
+**Example usage:**
+````rust
+// ✅ Works: K8sAnywhere: PostgreSQL → Failover provides failover PG
+let pg_failover: FailoverTopology<K8sAnywhereTopology> = ...;
+pg_failover.deploy_pg(config).await;
+
+// ✅ Works: LinuxHost: Docker → Failover provides failover Docker
+let docker_failover: FailoverTopology<LinuxHostTopology> = ...;
+docker_failover.deploy_docker(...).await;
+
+// ❌ Compile fail: K8sAnywhere !: Docker
+let invalid: FailoverTopology<K8sAnywhereTopology>;
+invalid.deploy_docker(...); // `T: Docker` bound unsatisfied
+````
+
+## Consequences
+
+**Pros:**
+- **Extensible**: New topology `AWSTopology: PostgreSQL` → instant `Failover<AWSTopology>: PostgreSQL`.
+- **Lean**: No useless impls (e.g., no `K8sAnywhere: Docker`).
+- **Observable**: Logs trace every step.
+
+**Cons:**
+- **Monomorphization**: Generics generate code per T (mitigated: few Ts).
+- **Delegation opacity**: Relies on rustdoc/logs for internals.
+
+## Alternatives considered
+
+| Approach | Pros | Cons |
+|----------|------|------|
+| **Manual per-T impls**<br>`impl PG for Failover<K8s> {..}`<br>`impl PG for Failover<Linux> {..}` | Explicit control | N×M explosion; violates ISP; hard to extend. |
+| **Dynamic trait objects**<br>`Box<dyn AnyCapability>` | Runtime flex | Perf hit; type erasure; error-prone dispatch. |
+| **Mega-topology trait**<br>All-in-one `OrchestratedTopology` | Simple wiring | Monolithic; poor composition. |
+| **Registry dispatch**<br>Runtime capability lookup | Decoupled | Complex; no compile safety; perf/debug overhead. |
+
+**Selected**: Blanket impls leverage Rust generics for safe, zero-cost composition.
+
+## Additional Notes
+
+- Applies to `MultisiteTopology<T>`, `ShardedTopology<T>`, etc.
+- `FailoverTopology` in `failover.rs` is first implementation.

adr/015-higher-order-topologies/example.rs

@@ -0,0 +1,153 @@
+//! Example of Higher-Order Topologies in Harmony.
+//! Demonstrates how `FailoverTopology<T>` automatically provides failover for *any* capability
+//! supported by a sub-topology `T` via blanket trait impls.
+//! 
+//! Key insight: No manual impls per T or capability -- scales effortlessly.
+//! Users can:
+//! - Write new `Topology` (impl capabilities on a struct).
+//! - Compose with `FailoverTopology` (gets capabilities if T has them).
+//! - Compile fails if capability missing (safety).
+
+use async_trait::async_trait;
+use tokio;
+
+/// Capability trait: Deploy and manage PostgreSQL.
+#[async_trait]
+pub trait PostgreSQL {
+    async fn deploy(&self, config: &PostgreSQLConfig) -> Result<String, String>;
+    async fn get_replication_certs(&self, cluster_name: &str) -> Result<ReplicationCerts, String>;
+}
+
+/// Capability trait: Deploy Docker.
+#[async_trait]
+pub trait Docker {
+    async fn deploy_docker(&self) -> Result<String, String>;
+}
+
+/// Configuration for PostgreSQL deployments.
+#[derive(Clone)]
+pub struct PostgreSQLConfig;
+
+/// Replication certificates.
+#[derive(Clone)]
+pub struct ReplicationCerts;
+
+/// Concrete topology: Kubernetes Anywhere (supports PostgreSQL).
+#[derive(Clone)]
+pub struct K8sAnywhereTopology;
+
+#[async_trait]
+impl PostgreSQL for K8sAnywhereTopology {
+    async fn deploy(&self, _config: &PostgreSQLConfig) -> Result<String, String> {
+        // Real impl: Use k8s helm chart, operator, etc.
+        Ok("K8sAnywhere PostgreSQL deployed".to_string())
+    }
+
+    async fn get_replication_certs(&self, _cluster_name: &str) -> Result<ReplicationCerts, String> {
+        Ok(ReplicationCerts)
+    }
+}
+
+/// Concrete topology: Linux Host (supports Docker).
+#[derive(Clone)]
+pub struct LinuxHostTopology;
+
+#[async_trait]
+impl Docker for LinuxHostTopology {
+    async fn deploy_docker(&self) -> Result<String, String> {
+        // Real impl: Install/configure Docker on host.
+        Ok("LinuxHost Docker deployed".to_string())
+    }
+}
+
+/// Higher-Order Topology: Composes multiple sub-topologies (primary + replica).
+/// Automatically derives *all* capabilities of `T` with failover orchestration.
+/// 
+/// - If `T: PostgreSQL`, then `FailoverTopology<T>: PostgreSQL` (blanket impl).
+/// - Same for `Docker`, etc. No boilerplate!
+/// - Compile-time safe: Missing `T: Capability` → error.
+#[derive(Clone)]
+pub struct FailoverTopology<T> {
+    /// Primary sub-topology.
+    pub primary: T,
+    /// Replica sub-topology.
+    pub replica: T,
+}
+
+/// Blanket impl: Failover PostgreSQL if T provides PostgreSQL.
+/// Delegates reads to primary; deploys to both.
+#[async_trait]
+impl<T: PostgreSQL + Send + Sync + Clone> PostgreSQL for FailoverTopology<T> {
+    async fn deploy(&self, config: &PostgreSQLConfig) -> Result<String, String> {
+        // Orchestrate: Deploy primary first, then replica (e.g., via pg_basebackup).
+        let primary_result = self.primary.deploy(config).await?;
+        let replica_result = self.replica.deploy(config).await?;
+        Ok(format!("Failover PG deployed: {} | {}", primary_result, replica_result))
+    }
+
+    async fn get_replication_certs(&self, cluster_name: &str) -> Result<ReplicationCerts, String> {
+        // Delegate to primary (replica follows).
+        self.primary.get_replication_certs(cluster_name).await
+    }
+}
+
+/// Blanket impl: Failover Docker if T provides Docker.
+#[async_trait]
+impl<T: Docker + Send + Sync + Clone> Docker for FailoverTopology<T> {
+    async fn deploy_docker(&self) -> Result<String, String> {
+        // Orchestrate across primary + replica.
+        let primary_result = self.primary.deploy_docker().await?;
+        let replica_result = self.replica.deploy_docker().await?;
+        Ok(format!("Failover Docker deployed: {} | {}", primary_result, replica_result))
+    }
+}
+
+#[tokio::main]
+async fn main() {
+    let config = PostgreSQLConfig;
+
+    println!("=== ✅ PostgreSQL Failover (K8sAnywhere supports PG) ===");
+    let pg_failover = FailoverTopology {
+        primary: K8sAnywhereTopology,
+        replica: K8sAnywhereTopology,
+    };
+    let result = pg_failover.deploy(&config).await.unwrap();
+    println!("Result: {}", result);
+
+    println!("\n=== ✅ Docker Failover (LinuxHost supports Docker) ===");
+    let docker_failover = FailoverTopology {
+        primary: LinuxHostTopology,
+        replica: LinuxHostTopology,
+    };
+    let result = docker_failover.deploy_docker().await.unwrap();
+    println!("Result: {}", result);
+
+    println!("\n=== ❌ Would fail to compile (K8sAnywhere !: Docker) ===");
+    // let invalid = FailoverTopology {
+    //     primary: K8sAnywhereTopology,
+    //     replica: K8sAnywhereTopology,
+    // };
+    // invalid.deploy_docker().await.unwrap(); // Error: `K8sAnywhereTopology: Docker` not satisfied!
+    // Very clear error message :
+    // error[E0599]: the method `deploy_docker` exists for struct `FailoverTopology<K8sAnywhereTopology>`, but its trait bounds were not satisfied
+    //   --> src/main.rs:90:9
+    //    |
+    //  4 | pub struct FailoverTopology<T> {
+    //    | ------------------------------ method `deploy_docker` not found for this struct because it doesn't satisfy `FailoverTopology<K8sAnywhereTopology>: Docker`
+    // ...
+    // 37 | struct K8sAnywhereTopology;
+    //    | -------------------------- doesn't satisfy `K8sAnywhereTopology: Docker`
+    // ...
+    // 90 | invalid.deploy_docker(); // `T: Docker` bound unsatisfied
+    //    |         ^^^^^^^^^^^^^ method cannot be called on `FailoverTopology<K8sAnywhereTopology>` due to unsatisfied trait bounds
+    //    |
+    // note: trait bound `K8sAnywhereTopology: Docker` was not satisfied
+    //   --> src/main.rs:61:9
+    //    |
+    // 61 | impl<T: Docker + Send + Sync> Docker for FailoverTopology<T> {
+    //    |         ^^^^^^                ------     -------------------
+    //    |         |
+    //    |         unsatisfied trait bound introduced here
+    // note: the trait `Docker` must be implemented
+}
+

docs/modules/Multisite_PostgreSQL.md

@@ -1,7 +1,7 @@
 # Design Document: Harmony PostgreSQL Module
 
 **Status:** Draft
-**Last Updated:** 2023-10-27
+**Last Updated:** 2025-12-01
 **Context:** Multi-site Data Replication & Orchestration
 
 ## 1. Overview

examples/operatorhub_catalog/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "example-operatorhub-catalogsource"
+edition = "2024"
+version.workspace = true
+readme.workspace = true
+license.workspace = true
+publish = false
+
+[dependencies]
+harmony = { path = "../../harmony" }
+harmony_cli = { path = "../../harmony_cli" }
+harmony_types = { path = "../../harmony_types" }
+cidr = { workspace = true }
+tokio = { workspace = true }
+harmony_macros = { path = "../../harmony_macros" }
+log = { workspace = true }
+env_logger = { workspace = true }
+url = { workspace = true }

examples/operatorhub_catalog/src/main.rs

@@ -0,0 +1,22 @@
+use std::str::FromStr;
+
+use harmony::{
+    inventory::Inventory,
+    modules::{k8s::apps::OperatorHubCatalogSourceScore, postgresql::CloudNativePgOperatorScore},
+    topology::K8sAnywhereTopology,
+};
+
+#[tokio::main]
+async fn main() {
+    let operatorhub_catalog = OperatorHubCatalogSourceScore::default();
+    let cnpg_operator = CloudNativePgOperatorScore::default();
+
+    harmony_cli::run(
+        Inventory::autoload(),
+        K8sAnywhereTopology::from_env(),
+        vec![Box::new(operatorhub_catalog), Box::new(cnpg_operator)],
+        None,
+    )
+    .await
+    .unwrap();
+}

examples/postgresql/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "example-postgresql"
+edition = "2024"
+version.workspace = true
+readme.workspace = true
+license.workspace = true
+publish = false
+
+[dependencies]
+harmony = { path = "../../harmony" }
+harmony_cli = { path = "../../harmony_cli" }
+harmony_types = { path = "../../harmony_types" }
+cidr = { workspace = true }
+tokio = { workspace = true }
+harmony_macros = { path = "../../harmony_macros" }
+log = { workspace = true }
+env_logger = { workspace = true }
+url = { workspace = true }

examples/postgresql/src/main.rs

@@ -0,0 +1,22 @@
+use harmony::{
+    inventory::Inventory, modules::postgresql::PostgreSQLScore, topology::K8sAnywhereTopology,
+};
+
+#[tokio::main]
+async fn main() {
+    let postgresql = PostgreSQLScore {
+        name: "harmony-postgres-example".to_string(), // Override default name
+        namespace: "harmony-postgres-example".to_string(),
+        ..Default::default() // Use harmony defaults, they are based on CNPG's default values :
+                             // "default" namespace, 1 instance, 1Gi storage
+    };
+
+    harmony_cli::run(
+        Inventory::autoload(),
+        K8sAnywhereTopology::from_env(),
+        vec![Box::new(postgresql)],
+        None,
+    )
+    .await
+    .unwrap();
+}

harmony/src/domain/topology/failover.rs

@@ -0,0 +1,19 @@
+use async_trait::async_trait;
+
+use crate::topology::{PreparationError, PreparationOutcome, Topology};
+
+pub struct FailoverTopology<T> {
+    pub primary: T,
+    pub replica: T,
+}
+
+#[async_trait]
+impl<T: Send + Sync> Topology for FailoverTopology<T> {
+    fn name(&self) -> &str {
+        "FailoverTopology"
+    }
+
+    async fn ensure_ready(&self) -> Result<PreparationOutcome, PreparationError> {
+        todo!()
+    }
+}

harmony/src/domain/topology/mod.rs

@@ -1,5 +1,7 @@
+mod failover;
 mod ha_cluster;
 pub mod ingress;
+pub use failover::*;
 use harmony_types::net::IpAddress;
 mod host_binding;
 mod http;

harmony/src/domain/topology/router.rs

@@ -1,11 +1,19 @@
+use async_trait::async_trait;
 use cidr::Ipv4Cidr;
 use derive_new::new;
 
 use super::{IpAddress, LogicalHost};
 
+/// Basic network router abstraction (L3 IP routing/gateway).
+/// Distinguished from TlsRouter (L4 TLS passthrough).
 pub trait Router: Send + Sync {
+    /// Gateway IP address for this subnet/router.
     fn get_gateway(&self) -> IpAddress;
+
+    /// CIDR block managed by this router.
     fn get_cidr(&self) -> Ipv4Cidr;
+
+    /// Logical host associated with this router.
     fn get_host(&self) -> LogicalHost;
 }
 
@@ -38,3 +46,76 @@ impl Router for UnmanagedRouter {
         todo!()
     }
 }
+
+
+#[derive(Clone, Debug)]
+
+/// Desired state config for a TLS passthrough route.
+/// Forwards external TLS (port 443) → backend service:target_port (no termination at router).
+/// Inspired by CNPG multisite: exposes `-rw`/`-ro` services publicly via OKD Route/HAProxy/K8s
+/// Gateway etc.
+/// 
+/// # Example
+/// ```
+/// use harmony::domain::topology::router::TlsRoute;
+/// let postgres_rw = TlsRoute {
+///     hostname: "postgres-cluster-example.public.domain.io".to_string(),
+///     backend: "postgres-cluster-example-rw".to_string(),  // k8s Service or HAProxy upstream
+///     target_port: 5432,
+/// };
+/// ```
+pub struct TlsRoute {
+    /// Public hostname clients connect to (TLS SNI, port 443 implicit).
+    /// Router matches this for passthrough forwarding.
+    pub hostname: String,
+
+    /// Backend/host identifier (k8s Service, HAProxy upstream, IP/FQDN, etc.).
+    pub backend: String,
+
+    /// Backend TCP port (Postgres: 5432).
+    pub target_port: u16,
+}
+
+#[async_trait]
+
+/// Installs and queries TLS passthrough routes (L4 TCP/SNI forwarding, no TLS termination).
+/// Agnostic to impl: OKD Route, AWS NLB+HAProxy, k3s Envoy Gateway, Apache ProxyPass.
+/// Used by PostgreSQL capability to expose CNPG clusters multisite (site1 → site2 replication).
+/// 
+/// # Usage
+/// ```rust,no_run
+/// // After CNPG deploy, expose RW endpoint
+/// let topology = okd_topology();
+/// let route = TlsRoute { /* ... */ };
+/// topology.install_route(route).await?;  // OKD Route, HAProxy reload, etc.
+/// 
+/// // Client: psql \\"host={route.hostname} port=443 sslmode=verify-ca sslnegotiation=direct\\"
+/// let public_ep = Endpoint { host: topology.hostname(), port: 443 };
+/// ```
+pub trait TlsRouter: Send + Sync {
+/// Provisions the route (idempotent where possible).
+    /// Example: OKD Route{ host, to: backend:target_port, tls: {passthrough} };
+    ///          HAProxy frontend→backend \"postgres-upstream\".
+    async fn install_route(&self, config: TlsRoute) -> Result<(), String>;
+
+    /// Installed route's public hostname.
+    fn hostname(&self) -> String;
+
+    /// Installed route's backend identifier.
+    fn backend(&self) -> String;
+
+    /// Installed route's backend port.
+    fn target_port(&self) -> u16;
+}
+
+impl std::fmt::Debug for dyn TlsRouter {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_fmt(format_args!(
+            "TlsRouter[hostname={}, backend={}:{}]",
+            self.hostname(),
+            self.backend(),
+            self.target_port()
+        ))
+    }
+}
+

harmony/src/infra/network_manager.rs

@@ -17,6 +17,12 @@ use crate::{
     topology::{HostNetworkConfig, NetworkError, NetworkManager, k8s::K8sClient},
 };
 
+/// TODO document properly the non-intuitive behavior or "roll forward only" of nmstate in general
+/// It is documented in nmstate official doc, but worth mentionning here :
+///
+/// - You create a bond, nmstate will apply it
+/// - You delete de bond from nmstate, it will NOT delete it
+/// - To delete it you have to update it with configuration set to null
 pub struct OpenShiftNmStateNetworkManager {
     k8s_client: Arc<K8sClient>,
 }
@@ -31,6 +37,7 @@ impl std::fmt::Debug for OpenShiftNmStateNetworkManager {
 impl NetworkManager for OpenShiftNmStateNetworkManager {
     async fn ensure_network_manager_installed(&self) -> Result<(), NetworkError> {
         debug!("Installing NMState controller...");
+        // TODO use operatorhub maybe?
         self.k8s_client.apply_url(url::Url::parse("https://github.com/nmstate/kubernetes-nmstate/releases/download/v0.84.0/nmstate.io_nmstates.yaml
 ").unwrap(), Some("nmstate"))
             .await?;

harmony/src/modules/k8s/apps/crd/catalogsources_operators_coreos_com.rs

@@ -0,0 +1,157 @@
+use std::collections::BTreeMap;
+
+use k8s_openapi::{
+    api::core::v1::{Affinity, Toleration},
+    apimachinery::pkg::apis::meta::v1::ObjectMeta,
+};
+use kube::CustomResource;
+use schemars::JsonSchema;
+use serde::{Deserialize, Serialize};
+use serde_json::Value;
+
+#[derive(CustomResource, Deserialize, Serialize, Clone, Debug)]
+#[kube(
+    group = "operators.coreos.com",
+    version = "v1alpha1",
+    kind = "CatalogSource",
+    plural = "catalogsources",
+    namespaced = true,
+    schema = "disabled"
+)]
+#[serde(rename_all = "camelCase")]
+pub struct CatalogSourceSpec {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub address: Option<String>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub config_map: Option<String>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub description: Option<String>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub display_name: Option<String>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub grpc_pod_config: Option<GrpcPodConfig>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub icon: Option<Icon>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub image: Option<String>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub priority: Option<i64>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub publisher: Option<String>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub run_as_root: Option<bool>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub secrets: Option<Vec<String>>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub source_type: Option<String>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub update_strategy: Option<UpdateStrategy>,
+}
+
+#[derive(Deserialize, Serialize, Clone, Debug)]
+#[serde(rename_all = "camelCase")]
+pub struct GrpcPodConfig {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub affinity: Option<Affinity>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub extract_content: Option<ExtractContent>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub memory_target: Option<Value>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub node_selector: Option<BTreeMap<String, String>>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub priority_class_name: Option<String>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub security_context_config: Option<String>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tolerations: Option<Vec<Toleration>>,
+}
+
+#[derive(Deserialize, Serialize, Clone, Debug, JsonSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct ExtractContent {
+    pub cache_dir: String,
+    pub catalog_dir: String,
+}
+
+#[derive(Deserialize, Serialize, Clone, Debug, JsonSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct Icon {
+    pub base64data: String,
+    pub mediatype: String,
+}
+
+#[derive(Deserialize, Serialize, Clone, Debug, JsonSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct UpdateStrategy {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub registry_poll: Option<RegistryPoll>,
+}
+
+#[derive(Deserialize, Serialize, Clone, Debug, JsonSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct RegistryPoll {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub interval: Option<String>,
+}
+
+impl Default for CatalogSource {
+    fn default() -> Self {
+        Self {
+            metadata: ObjectMeta::default(),
+            spec: CatalogSourceSpec {
+                address: None,
+                config_map: None,
+                description: None,
+                display_name: None,
+                grpc_pod_config: None,
+                icon: None,
+                image: None,
+                priority: None,
+                publisher: None,
+                run_as_root: None,
+                secrets: None,
+                source_type: None,
+                update_strategy: None,
+            },
+        }
+    }
+}
+
+impl Default for CatalogSourceSpec {
+    fn default() -> Self {
+        Self {
+            address: None,
+            config_map: None,
+            description: None,
+            display_name: None,
+            grpc_pod_config: None,
+            icon: None,
+            image: None,
+            priority: None,
+            publisher: None,
+            run_as_root: None,
+            secrets: None,
+            source_type: None,
+            update_strategy: None,
+        }
+    }
+}

harmony/src/modules/k8s/apps/crd/mod.rs

@@ -0,0 +1,4 @@
+mod catalogsources_operators_coreos_com;
+pub use catalogsources_operators_coreos_com::*;
+mod subscriptions_operators_coreos_com;
+pub use subscriptions_operators_coreos_com::*;

harmony/src/modules/k8s/apps/crd/subscriptions_operators_coreos_com.rs

@@ -0,0 +1,68 @@
+use k8s_openapi::apimachinery::pkg::apis::meta::v1::ObjectMeta;
+use kube::CustomResource;
+use serde::{Deserialize, Serialize};
+
+#[derive(CustomResource, Deserialize, Serialize, Clone, Debug)]
+#[kube(
+    group = "operators.coreos.com",
+    version = "v1alpha1",
+    kind = "Subscription",
+    plural = "subscriptions",
+    namespaced = true,
+    schema = "disabled"
+)]
+#[serde(rename_all = "camelCase")]
+pub struct SubscriptionSpec {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub channel: Option<String>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub config: Option<SubscriptionConfig>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub install_plan_approval: Option<String>,
+
+    pub name: String,
+
+    pub source: String,
+
+    pub source_namespace: String,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub starting_csv: Option<String>,
+}
+#[derive(Deserialize, Serialize, Clone, Debug)]
+#[serde(rename_all = "camelCase")]
+pub struct SubscriptionConfig {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub env: Option<Vec<k8s_openapi::api::core::v1::EnvVar>>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub node_selector: Option<std::collections::BTreeMap<String, String>>,
+
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tolerations: Option<Vec<k8s_openapi::api::core::v1::Toleration>>,
+}
+
+impl Default for Subscription {
+    fn default() -> Self {
+        Subscription {
+            metadata: ObjectMeta::default(),
+            spec: SubscriptionSpec::default(),
+        }
+    }
+}
+
+impl Default for SubscriptionSpec {
+    fn default() -> SubscriptionSpec {
+        SubscriptionSpec {
+            name: String::new(),
+            source: String::new(),
+            source_namespace: String::new(),
+            channel: None,
+            config: None,
+            install_plan_approval: None,
+            starting_csv: None,
+        }
+    }
+}

harmony/src/modules/k8s/apps/mod.rs

@@ -0,0 +1,3 @@
+mod operatorhub;
+pub use operatorhub::*;
+pub mod crd;

harmony/src/modules/k8s/apps/operatorhub.rs

@@ -0,0 +1,107 @@
+// Write operatorhub catalog score
+// for now this will only support on OKD with the default catalog and operatorhub setup and does not verify OLM state or anything else. Very opinionated and bare-bones to start
+
+use k8s_openapi::apimachinery::pkg::apis::meta::v1::ObjectMeta;
+use serde::Serialize;
+
+use crate::interpret::Interpret;
+use crate::modules::k8s::apps::crd::{
+    CatalogSource, CatalogSourceSpec, RegistryPoll, UpdateStrategy,
+};
+use crate::modules::k8s::resource::K8sResourceScore;
+use crate::score::Score;
+use crate::topology::{K8sclient, Topology};
+
+/// Installs the CatalogSource in a cluster which already has the required services and CRDs installed.
+///
+/// ```rust
+/// use harmony::modules::k8s::apps::OperatorHubCatalogSourceScore;
+///
+/// let score = OperatorHubCatalogSourceScore::default();
+/// ```
+///
+/// Required services:
+/// - catalog-operator
+/// - olm-operator
+///
+/// They are installed by default with OKD/Openshift
+///
+/// **Warning** : this initial implementation does not manage the dependencies. They must already
+/// exist in the cluster.
+#[derive(Debug, Clone, Serialize)]
+pub struct OperatorHubCatalogSourceScore {
+    pub name: String,
+    pub namespace: String,
+    pub image: String,
+}
+
+impl OperatorHubCatalogSourceScore {
+    pub fn new(name: &str, namespace: &str, image: &str) -> Self {
+        Self {
+            name: name.to_string(),
+            namespace: namespace.to_string(),
+            image: image.to_string(),
+        }
+    }
+}
+
+impl Default for OperatorHubCatalogSourceScore {
+    /// This default implementation will create this k8s resource :
+    ///
+    /// ```yaml
+    /// apiVersion: operators.coreos.com/v1alpha1
+    /// kind: CatalogSource
+    /// metadata:
+    ///   name: operatorhubio-catalog
+    ///   namespace: openshift-marketplace
+    /// spec:
+    ///   sourceType: grpc
+    ///   image: quay.io/operatorhubio/catalog:latest
+    ///   displayName: Operatorhub Operators
+    ///   publisher: OperatorHub.io
+    ///   updateStrategy:
+    ///     registryPoll:
+    ///       interval: 60m
+    /// ```
+    fn default() -> Self {
+        OperatorHubCatalogSourceScore {
+            name: "operatorhubio-catalog".to_string(),
+            namespace: "openshift-marketplace".to_string(),
+            image: "quay.io/operatorhubio/catalog:latest".to_string(),
+        }
+    }
+}
+
+impl<T: Topology + K8sclient> Score<T> for OperatorHubCatalogSourceScore {
+    fn create_interpret(&self) -> Box<dyn Interpret<T>> {
+        let metadata = ObjectMeta {
+            name: Some(self.name.clone()),
+            namespace: Some(self.namespace.clone()),
+            ..ObjectMeta::default()
+        };
+
+        let spec = CatalogSourceSpec {
+            source_type: Some("grpc".to_string()),
+            image: Some(self.image.clone()),
+            display_name: Some("Operatorhub Operators".to_string()),
+            publisher: Some("OperatorHub.io".to_string()),
+            update_strategy: Some(UpdateStrategy {
+                registry_poll: Some(RegistryPoll {
+                    interval: Some("60m".to_string()),
+                }),
+            }),
+            ..CatalogSourceSpec::default()
+        };
+
+        let catalog_source = CatalogSource {
+            metadata,
+            spec: spec,
+        };
+
+        K8sResourceScore::single(catalog_source, Some(self.namespace.clone())).create_interpret()
+    }
+
+    fn name(&self) -> String {
+        format!("OperatorHubCatalogSourceScore({})", self.name)
+    }
+}

harmony/src/modules/k8s/mod.rs

@@ -1,3 +1,4 @@
+pub mod apps;
 pub mod deployment;
 pub mod ingress;
 pub mod namespace;

harmony/src/modules/mod.rs

@@ -13,6 +13,7 @@ pub mod load_balancer;
 pub mod monitoring;
 pub mod okd;
 pub mod opnsense;
+pub mod postgresql;
 pub mod prometheus;
 pub mod storage;
 pub mod tenant;

harmony/src/modules/postgresql/capability.rs

@@ -0,0 +1,85 @@
+use async_trait::async_trait;
+use harmony_types::storage::StorageSize;
+use serde::Serialize;
+use std::collections::HashMap;
+
+#[async_trait]
+pub trait PostgreSQL: Send + Sync {
+    async fn deploy(&self, config: &PostgreSQLConfig) -> Result<String, String>;
+
+    /// Extracts PostgreSQL-specific replication certs (PEM format) from a deployed primary cluster.
+    /// Abstracts away storage/retrieval details (e.g., secrets, files).
+    async fn get_replication_certs(&self, cluster_name: &str) -> Result<ReplicationCerts, String>;
+
+    /// Gets the internal/private endpoint (e.g., k8s service FQDN:5432) for the cluster.
+    async fn get_endpoint(&self, cluster_name: &str) -> Result<PostgreSQLEndpoint, String>;
+
+    /// Gets the public/externally routable endpoint if configured (e.g., OKD Route:443 for TLS passthrough).
+    /// Returns None if no public endpoint (internal-only cluster).
+    /// UNSTABLE: This is opinionated for initial multisite use cases. Networking abstraction is complex
+    /// (cf. k8s Ingress -> Gateway API evolution); may move to higher-order Networking/PostgreSQLNetworking trait.
+    async fn get_public_endpoint(
+        &self,
+        cluster_name: &str,
+    ) -> Result<Option<PostgreSQLEndpoint>, String>;
+}
+
+#[derive(Clone, Debug, Serialize)]
+pub struct PostgreSQLConfig {
+    pub cluster_name: String,
+    pub instances: u32,
+    pub storage_size: StorageSize,
+    pub role: PostgreSQLClusterRole,
+}
+
+#[derive(Clone, Debug, Serialize)]
+pub enum PostgreSQLClusterRole {
+    Primary,
+    Replica(ReplicaConfig),
+}
+
+#[derive(Clone, Debug, Serialize)]
+pub struct ReplicaConfig {
+    /// Name of the primary cluster this replica will sync from
+    pub primary_cluster_name: String,
+    /// Certs extracted from primary via Topology::get_replication_certs()
+    pub replication_certs: ReplicationCerts,
+    /// Bootstrap method (e.g., pg_basebackup from primary)
+    pub bootstrap: BootstrapConfig,
+    /// External cluster connection details for CNPG spec.externalClusters
+    pub external_cluster: ExternalClusterConfig,
+}
+
+#[derive(Clone, Debug, Serialize)]
+pub struct BootstrapConfig {
+    pub strategy: BootstrapStrategy,
+}
+
+#[derive(Clone, Debug, Serialize)]
+pub enum BootstrapStrategy {
+    PgBasebackup,
+}
+
+#[derive(Clone, Debug, Serialize)]
+pub struct ExternalClusterConfig {
+    /// Name used in CNPG externalClusters list
+    pub name: String,
+    /// Connection params (host/port set by multisite logic, sslmode='verify-ca', etc.)
+    pub connection_parameters: HashMap<String, String>,
+}
+
+#[derive(Clone, Debug, Serialize)]
+pub struct ReplicationCerts {
+    /// PEM-encoded CA cert from primary
+    pub ca_cert_pem: String,
+    /// PEM-encoded streaming_replica client cert (tls.crt)
+    pub streaming_replica_cert_pem: String,
+    /// PEM-encoded streaming_replica client key (tls.key)
+    pub streaming_replica_key_pem: String,
+}
+
+#[derive(Clone, Debug)]
+pub struct PostgreSQLEndpoint {
+    pub host: String,
+    pub port: u16,
+}

harmony/src/modules/postgresql/cnpg/crd.rs

@@ -0,0 +1,58 @@
+use kube::{api::ObjectMeta, CustomResource};
+use serde::{Deserialize, Serialize};
+
+#[derive(CustomResource, Deserialize, Serialize, Clone, Debug)]
+#[kube(
+    group = "postgresql.cnpg.io",
+    version = "v1",
+    kind = "Cluster",
+    plural = "clusters",
+    namespaced = true,
+    schema = "disabled"
+)]
+#[serde(rename_all = "camelCase")]
+pub struct ClusterSpec {
+    pub instances: i32,
+    pub image_name: Option<String>,
+    pub storage: Storage,
+    pub bootstrap: Bootstrap,
+}
+
+impl Default for Cluster {
+    fn default() -> Self {
+        Cluster {
+            metadata: ObjectMeta::default(),
+            spec: ClusterSpec::default(),
+        }
+    }
+}
+
+impl Default for ClusterSpec {
+    fn default() -> Self {
+        Self {
+            instances: 1,
+            image_name: None,
+            storage: Storage::default(),
+            bootstrap: Bootstrap::default(),
+        }
+    }
+}
+
+#[derive(Deserialize, Serialize, Clone, Debug, Default)]
+#[serde(rename_all = "camelCase")]
+pub struct Storage {
+    pub size: String,
+}
+
+#[derive(Deserialize, Serialize, Clone, Debug, Default)]
+#[serde(rename_all = "camelCase")]
+pub struct Bootstrap {
+    pub initdb: Initdb,
+}
+
+#[derive(Deserialize, Serialize, Clone, Debug, Default)]
+#[serde(rename_all = "camelCase")]
+pub struct Initdb {
+    pub database: String,
+    pub owner: String,
+}

harmony/src/modules/postgresql/cnpg/mod.rs

@@ -0,0 +1,2 @@
+mod crd;
+pub use crd::*;

harmony/src/modules/postgresql/failover.rs

@@ -0,0 +1,125 @@
+use async_trait::async_trait;
+use log::debug;
+use log::info;
+use std::collections::HashMap;
+
+use crate::{
+    modules::postgresql::capability::{
+        BootstrapConfig, BootstrapStrategy, ExternalClusterConfig, PostgreSQL,
+        PostgreSQLClusterRole, PostgreSQLConfig, PostgreSQLEndpoint, ReplicaConfig,
+        ReplicationCerts,
+    },
+    topology::FailoverTopology,
+};
+
+#[async_trait]
+impl<T: PostgreSQL> PostgreSQL for FailoverTopology<T> {
+    async fn deploy(&self, config: &PostgreSQLConfig) -> Result<String, String> {
+        info!(
+            "Starting deployment of failover topology '{}'",
+            config.cluster_name
+        );
+
+        let primary_config = PostgreSQLConfig {
+            cluster_name: config.cluster_name.clone(),
+            instances: config.instances,
+            storage_size: config.storage_size.clone(),
+            role: PostgreSQLClusterRole::Primary,
+        };
+
+        info!(
+            "Deploying primary cluster '{{}}' ({} instances, {:?} storage)",
+            primary_config.cluster_name, primary_config.storage_size
+        );
+
+        let primary_cluster_name = self.primary.deploy(&primary_config).await?;
+
+        info!("Primary cluster '{primary_cluster_name}' deployed successfully");
+
+        info!("Retrieving replication certificates for primary '{primary_cluster_name}'");
+
+        let certs = self
+            .primary
+            .get_replication_certs(&primary_cluster_name)
+            .await?;
+
+        info!("Replication certificates retrieved successfully");
+
+        info!("Retrieving public endpoint for primary '{primary_cluster_name}");
+
+        let endpoint = self
+            .primary
+            .get_public_endpoint(&primary_cluster_name)
+            .await?
+            .ok_or_else(|| "No public endpoint configured on primary cluster".to_string())?;
+
+        info!(
+            "Public endpoint '{}:{}' retrieved for primary",
+            endpoint.host, endpoint.port
+        );
+
+        info!("Configuring replica connection parameters and bootstrap");
+
+        let mut connection_parameters = HashMap::new();
+        connection_parameters.insert("host".to_string(), endpoint.host);
+        connection_parameters.insert("port".to_string(), endpoint.port.to_string());
+        connection_parameters.insert("dbname".to_string(), "postgres".to_string());
+        connection_parameters.insert("user".to_string(), "streaming_replica".to_string());
+        connection_parameters.insert("sslmode".to_string(), "verify-ca".to_string());
+        connection_parameters.insert("sslnegotiation".to_string(), "direct".to_string());
+
+        debug!("Replica connection parameters: {:?}", connection_parameters);
+
+        let external_cluster = ExternalClusterConfig {
+            name: primary_cluster_name.clone(),
+            connection_parameters,
+        };
+
+        let bootstrap_config = BootstrapConfig {
+            strategy: BootstrapStrategy::PgBasebackup,
+        };
+
+        let replica_cluster_config = ReplicaConfig {
+            primary_cluster_name: primary_cluster_name.clone(),
+            replication_certs: certs,
+            bootstrap: bootstrap_config,
+            external_cluster,
+        };
+
+        let replica_config = PostgreSQLConfig {
+            cluster_name: format!("{}-replica", primary_cluster_name),
+            instances: config.instances,
+            storage_size: config.storage_size.clone(),
+            role: PostgreSQLClusterRole::Replica(replica_cluster_config),
+        };
+
+        info!(
+            "Deploying replica cluster '{}' ({} instances, {:?} storage) on replica topology",
+            replica_config.cluster_name, replica_config.instances, replica_config.storage_size
+        );
+
+        self.replica.deploy(&replica_config).await?;
+
+        info!(
+            "Replica cluster '{}' deployed successfully; failover topology '{}' ready",
+            replica_config.cluster_name, config.cluster_name
+        );
+
+        Ok(primary_cluster_name)
+    }
+
+    async fn get_replication_certs(&self, cluster_name: &str) -> Result<ReplicationCerts, String> {
+        self.primary.get_replication_certs(cluster_name).await
+    }
+
+    async fn get_endpoint(&self, cluster_name: &str) -> Result<PostgreSQLEndpoint, String> {
+        self.primary.get_endpoint(cluster_name).await
+    }
+
+    async fn get_public_endpoint(
+        &self,
+        cluster_name: &str,
+    ) -> Result<Option<PostgreSQLEndpoint>, String> {
+        self.primary.get_public_endpoint(cluster_name).await
+    }
+}

harmony/src/modules/postgresql/mod.rs

@@ -0,0 +1,11 @@
+pub mod capability;
+mod score;
+pub use score::*;
+mod score_public;
+pub use score_public::*;
+
+pub mod failover;
+mod operator;
+pub use operator::*;
+
+pub mod cnpg;

harmony/src/modules/postgresql/operator.rs

@@ -0,0 +1,102 @@
+use k8s_openapi::apimachinery::pkg::apis::meta::v1::ObjectMeta;
+use serde::Serialize;
+
+use crate::interpret::Interpret;
+use crate::modules::k8s::apps::crd::{Subscription, SubscriptionSpec};
+use crate::modules::k8s::resource::K8sResourceScore;
+use crate::score::Score;
+use crate::topology::{K8sclient, Topology};
+
+/// Install the CloudNativePg (CNPG) Operator via an OperatorHub `Subscription`.
+///
+/// This Score creates a a `Subscription` Custom Resource in the specified namespace.
+///
+/// The default implementation pulls the `cloudnative-pg` operator from the
+/// `operatorhubio-catalog` source.
+///
+/// # Goals
+/// - Deploy the CNPG Operator to manage PostgreSQL clusters in OpenShift/OKD environments.
+///
+/// # Usage
+/// ```
+/// use harmony::modules::postgresql::CloudNativePgOperatorScore;
+/// let score = CloudNativePgOperatorScore::default();
+/// ```
+///
+/// Or, you can take control of most relevant fiedls this way :
+///
+/// ```
+/// use harmony::modules::postgresql::CloudNativePgOperatorScore;
+///
+/// let score = CloudNativePgOperatorScore {
+///     namespace: "custom-cnpg-namespace".to_string(),
+///     channel: "unstable-i-want-bleedingedge-v498437".to_string(),
+///     install_plan_approval: "Manual".to_string(),
+///     source: "operatorhubio-catalog-but-different".to_string(),
+///     source_namespace: "i-customize-everything-marketplace".to_string(),
+/// };
+/// ```
+///
+/// # Limitations
+/// - **OperatorHub dependency**: Requires OperatorHub catalog sources (e.g., `operatorhubio-catalog` in `openshift-marketplace`).
+/// - **OKD/OpenShift assumption**: Catalog/source names and namespaces are hardcoded for OKD-like setups; adjust for upstream OpenShift.
+/// - **Hardcoded values in Default implementation**: Operator name (`cloudnative-pg`), channel (`stable-v1`), automatic install plan approval.
+/// - **No config options**: Does not support custom `SubscriptionConfig` (env vars, node selectors, tolerations).
+/// - **Single namespace**: Targets one namespace per score instance.
+#[derive(Debug, Clone, Serialize)]
+pub struct CloudNativePgOperatorScore {
+    pub namespace: String,
+    pub channel: String,
+    pub install_plan_approval: String,
+    pub source: String,
+    pub source_namespace: String,
+}
+
+impl Default for CloudNativePgOperatorScore {
+    fn default() -> Self {
+        Self {
+            namespace: "openshift-operators".to_string(),
+            channel: "stable-v1".to_string(),
+            install_plan_approval: "Automatic".to_string(),
+            source: "operatorhubio-catalog".to_string(),
+            source_namespace: "openshift-marketplace".to_string(),
+        }
+    }
+}
+
+impl CloudNativePgOperatorScore {
+    pub fn new(namespace: &str) -> Self {
+        Self {
+            namespace: namespace.to_string(),
+            ..Default::default()
+        }
+    }
+}
+
+impl<T: Topology + K8sclient> Score<T> for CloudNativePgOperatorScore {
+    fn create_interpret(&self) -> Box<dyn Interpret<T>> {
+        let metadata = ObjectMeta {
+            name: Some("cloudnative-pg".to_string()),
+            namespace: Some(self.namespace.clone()),
+            ..ObjectMeta::default()
+        };
+
+        let spec = SubscriptionSpec {
+            channel: Some(self.channel.clone()),
+            config: None,
+            install_plan_approval: Some(self.install_plan_approval.clone()),
+            name: "cloudnative-pg".to_string(),
+            source: self.source.clone(),
+            source_namespace: self.source_namespace.clone(),
+            starting_csv: None,
+        };
+
+        let subscription = Subscription { metadata, spec };
+
+        K8sResourceScore::single(subscription, Some(self.namespace.clone())).create_interpret()
+    }
+
+    fn name(&self) -> String {
+        format!("CloudNativePgOperatorScore({})", self.namespace)
+    }
+}

harmony/src/modules/postgresql/score.rs

@@ -0,0 +1,93 @@
+use serde::Serialize;
+
+use crate::interpret::Interpret;
+use crate::modules::k8s::resource::K8sResourceScore;
+use crate::modules::postgresql::cnpg::{Bootstrap, Cluster, ClusterSpec, Initdb, Storage};
+use crate::score::Score;
+use crate::topology::{K8sclient, Topology};
+use k8s_openapi::apimachinery::pkg::apis::meta::v1::ObjectMeta;
+
+/// Deploys an opinionated, highly available PostgreSQL cluster managed by CNPG.
+///
+/// # Goals
+/// - Production-ready Postgres HA (3 instances), persistent storage, app DB.
+///
+/// # Usage
+/// ```
+/// use harmony::modules::postgresql::PostgreSQLScore;
+/// let score = PostgreSQLScore::new("my-app-ns");
+/// ```
+///
+/// # Limitations (Happy Path)
+/// - Requires CNPG operator installed (use CloudNativePgOperatorScore).
+/// - No backups, monitoring, extensions configured.
+///
+/// TODO : refactor this to declare a clean dependency on cnpg operator. Then cnpg operator will
+/// self-deploy either using operatorhub or helm chart depending on k8s flavor. This is cnpg
+/// specific behavior
+#[derive(Debug, Clone, Serialize)]
+pub struct PostgreSQLScore {
+    pub name: String,
+    /// **Note :** on OpenShfit based clusters, the namespace `default` has security
+    /// settings incompatible with the default CNPG behavior.
+    pub namespace: String,
+    pub instances: i32,
+    pub storage_size: String,
+    pub image_name: Option<String>,
+}
+
+impl Default for PostgreSQLScore {
+    fn default() -> Self {
+        Self {
+            name: "harmony-pg".to_string(),
+            // We are using the namespace harmony by default since some clusters (openshift family)
+            // have incompatible configuration of the default namespace with cnpg
+            namespace: "harmony".to_string(),
+            instances: 1,
+            storage_size: "1Gi".to_string(),
+            image_name: None, // This lets cnpg use its default image
+        }
+    }
+}
+
+impl PostgreSQLScore {
+    pub fn new(namespace: &str) -> Self {
+        Self {
+            namespace: namespace.to_string(),
+            ..Default::default()
+        }
+    }
+}
+
+impl<T: Topology + K8sclient> Score<T> for PostgreSQLScore {
+    fn create_interpret(&self) -> Box<dyn Interpret<T>> {
+        let metadata = ObjectMeta {
+            name: Some(self.name.clone()),
+            namespace: Some(self.namespace.clone()),
+            ..ObjectMeta::default()
+        };
+
+        let spec = ClusterSpec {
+            instances: self.instances,
+            image_name: self.image_name.clone(),
+            storage: Storage {
+                size: self.storage_size.clone(),
+            },
+            bootstrap: Bootstrap {
+                initdb: Initdb {
+                    database: "app".to_string(),
+                    owner: "app".to_string(),
+                },
+            },
+            ..ClusterSpec::default()
+        };
+
+        let cluster = Cluster { metadata, spec };
+
+        K8sResourceScore::single(cluster, Some(self.namespace.clone())).create_interpret()
+    }
+
+    fn name(&self) -> String {
+        format!("PostgreSQLScore({})", self.namespace)
+    }
+}

harmony/src/modules/postgresql/score_public.rs

@@ -0,0 +1,89 @@
+use async_trait::async_trait;
+use serde::Serialize;
+
+use crate::domain::topology::router::{TlsRoute, TlsRouter};
+use crate::interpret::Interpret;
+use crate::modules::k8s::resource::K8sResourceScore;
+use crate::modules::postgresql::cnpg::{Bootstrap, Cluster, ClusterSpec, Initdb, Storage};
+use crate::modules::postgresql::PostgreSQLScore;
+use crate::score::Score;
+use crate::topology::{K8sclient, Topology};
+use k8s_openapi::apimachinery::pkg::apis::meta::v1::ObjectMeta;
+
+/// Deploys a public PostgreSQL cluster: CNPG + TLS passthrough route for RW endpoint.
+/// For failover/multisite: exposes single-instance or small HA Postgres publicly.
+/// 
+/// Sequence: PostgreSQLScore → TlsRouter::install_route (RW backend).
+/// 
+/// # Usage
+/// ```
+/// use harmony::modules::postgresql::PublicPostgreSQLScore;
+/// let score = PublicPostgreSQLScore::new("harmony", "pg-rw.example.com");
+/// ```
+#[derive(Debug, Clone, Serialize)]
+pub struct PublicPostgreSQLScore {
+    /// Inner non-public Postgres cluster config.
+    pub inner: PostgreSQLScore,
+    /// Public hostname for RW TLS passthrough (port 443 → cluster-rw:5432).
+    pub hostname: String,
+}
+
+impl Default for PublicPostgreSQLScore {
+    fn default() -> Self {
+        Self {
+            inner: PostgreSQLScore::default(),
+            hostname: "postgres.default.public".to_string(),
+        }
+    }
+}
+
+impl PublicPostgreSQLScore {
+    pub fn new(namespace: &str, hostname: &str) -> Self {
+        Self {
+            inner: PostgreSQLScore::new(namespace),
+            hostname: hostname.to_string(),
+        }
+    }
+}
+
+/// Custom interpret: deploy Postgres then install public TLS route.
+#[derive(Debug, Clone)]
+struct PublicPostgreSQLInterpret {
+    postgres_score: PostgreSQLScore,
+    tls_route: TlsRoute,
+}
+
+#[async_trait]
+impl<T: Topology + K8sclient + TlsRouter + Send + Sync> Interpret<T> for PublicPostgreSQLInterpret {
+    async fn interpret(&self, topo: &T) -> Result<(), Box<dyn std::error::Error>> {
+        // Deploy CNPG cluster first (creates -rw service)
+        self.postgres_score.create_interpret().interpret(topo).await?;
+
+        // Expose RW publicly via TLS passthrough
+        topo.install_route(self.tls_route.clone()).await.map_err(|e| Box::new(std::io::Error::new(std::io::ErrorKind::Other, e)) as Box<dyn std::error::Error>)?;
+
+        Ok(())
+    }
+}
+
+impl<T: Topology + K8sclient + TlsRouter + Send + Sync> Score<T> for PublicPostgreSQLScore {
+    fn create_interpret(&self) -> Box<dyn Interpret<T>> {
+        let rw_backend = format!("{}-rw", self.inner.name);
+        let tls_route = TlsRoute {
+            hostname: self.hostname.clone(),
+            backend: rw_backend,
+            target_port: 5432,
+        };
+
+        Box::new(PublicPostgreSQLInterpret {
+            postgres_score: self.inner.clone(),
+            tls_route,
+        })
+    }
+
+    fn name(&self) -> String {
+        format!("PublicPostgreSQLScore({}:{})", self.inner.namespace, self.hostname)
+    }
+} 
+
+// TODO: Add RO route (separate hostname/backend="cluster-ro"), backups, failover logic.

harmony_types/src/lib.rs

@@ -1,3 +1,4 @@
 pub mod id;
 pub mod net;
+pub mod storage;
 pub mod switch;

harmony_types/src/storage.rs

@@ -0,0 +1,6 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Serialize, Deserialize, PartialOrd, Ord, Debug)]
+pub struct StorageSize {
+    size_bytes: u64,
+}