Use enum-typed PG versions

This makes it possible for the compiler to validate that a match
block matched all PostgreSQL versions we support.

libs/safekeeper_api/Cargo.toml

@@ -10,6 +10,7 @@ const_format.workspace = true
 serde.workspace = true
 serde_json.workspace = true
 postgres_ffi.workspace = true
+postgres_versioninfo.workspace = true
 pq_proto.workspace = true
 tokio.workspace = true
 utils.workspace = true

libs/safekeeper_api/src/lib.rs

@@ -8,6 +8,8 @@ pub mod membership;
 /// Public API types
 pub mod models;
 
+pub use postgres_versioninfo::{PgMajorVersion, PgVersionId};
+
 /// Consensus logical timestamp. Note: it is a part of sk control file.
 pub type Term = u64;
 /// With this term timeline is created initially. It
@@ -20,7 +22,7 @@ pub const INITIAL_TERM: Term = 0;
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct ServerInfo {
     /// Postgres server version
-    pub pg_version: u32,
+    pub pg_version: PgVersionId,
     pub system_id: SystemId,
     pub wal_seg_size: u32,
 }

libs/safekeeper_api/src/models.rs

@@ -4,6 +4,7 @@ use std::net::SocketAddr;
 
 use pageserver_api::shard::ShardIdentity;
 use postgres_ffi::TimestampTz;
+use postgres_versioninfo::PgVersionId;
 use serde::{Deserialize, Serialize};
 use tokio::time::Instant;
 use utils::id::{NodeId, TenantId, TenantTimelineId, TimelineId};
@@ -24,7 +25,7 @@ pub struct TimelineCreateRequest {
     pub timeline_id: TimelineId,
     pub mconf: Configuration,
     /// In the PG_VERSION_NUM macro format, like 140017.
-    pub pg_version: u32,
+    pub pg_version: PgVersionId,
     pub system_id: Option<u64>,
     // By default WAL_SEGMENT_SIZE
     pub wal_seg_size: Option<u32>,