Continue #2724: replace Url-based PgConnectionConfig with a hand-crafted struct

Downsides are:

* We store all components of the config separately. `Url` stores them inside a single
  `String` and a bunch of ints which point to different parts of the URL, which is
  probably more efficient.
* It is now impossible to pass arbitrary connection strings to the configuration file,
  one has to support all components explicitly. However, we never supported anything
  except for `host:port` anyway.

Upsides are:

* This significantly restricts the space of possible connection strings, some of which
  may be either invalid or unsupported. E.g. Postgres' connection strings may include
  a bunch of parameters as query (e.g. `connect_timeout=`, `options=`). These are nether
  validated by the current implementation, nor passed to the postgres client library,
  Hence, storing separate fields expresses the intention better.
* The same connection configuration may be represented as a URL in multiple ways
  (e.g. either `password=` in the query part or a standard URL password).
  Now we have a single canonical way.
* Escaping is provided for `options=`.

Other possibilities considered:

* `newtype` with a `String` inside and some validation on creation.
  This is more efficient, but harder to log for two reasons:
  * Passwords should never end up in logs, so we have to somehow
  * Escaped `options=` are harder to read, especially if URL-encoded,
    and we use `options=` a lot.

control_plane/src/connection.rs

@@ -1,57 +0,0 @@
-use url::Url;
-
-#[derive(Debug)]
-pub struct PgConnectionConfig {
-    url: Url,
-}
-
-impl PgConnectionConfig {
-    pub fn host(&self) -> &str {
-        self.url.host_str().expect("BUG: no host")
-    }
-
-    pub fn port(&self) -> u16 {
-        self.url.port().expect("BUG: no port")
-    }
-
-    /// Return a `<host>:<port>` string.
-    pub fn raw_address(&self) -> String {
-        format!("{}:{}", self.host(), self.port())
-    }
-
-    /// Connect using postgres protocol with TLS disabled.
-    pub fn connect_no_tls(&self) -> Result<postgres::Client, postgres::Error> {
-        postgres::Client::connect(self.url.as_str(), postgres::NoTls)
-    }
-}
-
-impl std::str::FromStr for PgConnectionConfig {
-    type Err = anyhow::Error;
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let mut url: Url = s.parse()?;
-
-        match url.scheme() {
-            "postgres" | "postgresql" => {}
-            other => anyhow::bail!("invalid scheme: {other}"),
-        }
-
-        // It's not a valid connection url if host is unavailable.
-        if url.host().is_none() {
-            anyhow::bail!(url::ParseError::EmptyHost);
-        }
-
-        // E.g. `postgres:bar`.
-        if url.cannot_be_a_base() {
-            anyhow::bail!("URL cannot be a base");
-        }
-
-        // Set the default PG port if it's missing.
-        if url.port().is_none() {
-            url.set_port(Some(5432))
-                .expect("BUG: couldn't set the default port");
-        }
-
-        Ok(Self { url })
-    }
-}

control_plane/src/lib.rs

@@ -9,7 +9,6 @@
 
 mod background_process;
 pub mod compute;
-pub mod connection;
 pub mod etcd;
 pub mod local_env;
 pub mod pageserver;

control_plane/src/pageserver.rs

@@ -6,11 +6,11 @@ use std::path::{Path, PathBuf};
 use std::process::Child;
 use std::{io, result};
 
-use crate::connection::PgConnectionConfig;
 use anyhow::{bail, Context};
 use pageserver_api::models::{
     TenantConfigRequest, TenantCreateRequest, TenantInfo, TimelineCreateRequest, TimelineInfo,
 };
+use postgres_connection::{parse_host_port, PgConnectionConfig};
 use reqwest::blocking::{Client, RequestBuilder, Response};
 use reqwest::{IntoUrl, Method};
 use thiserror::Error;
@@ -77,30 +77,24 @@ pub struct PageServerNode {
 
 impl PageServerNode {
     pub fn from_env(env: &LocalEnv) -> PageServerNode {
+        let (host, port) = parse_host_port(&env.pageserver.listen_pg_addr)
+            .expect("Unable to parse listen_pg_addr");
+        let port = port.unwrap_or(5432);
         let password = if env.pageserver.auth_type == AuthType::NeonJWT {
-            &env.pageserver.auth_token
+            Some(env.pageserver.auth_token.clone())
         } else {
-            ""
+            None
         };
 
         Self {
-            pg_connection_config: Self::pageserver_connection_config(
-                password,
-                &env.pageserver.listen_pg_addr,
-            ),
+            pg_connection_config: PgConnectionConfig::new_host_port(host, port)
+                .set_password(password),
             env: env.clone(),
             http_client: Client::new(),
             http_base_url: format!("http://{}/v1", env.pageserver.listen_http_addr),
         }
     }
 
-    /// Construct libpq connection string for connecting to the pageserver.
-    fn pageserver_connection_config(password: &str, listen_addr: &str) -> PgConnectionConfig {
-        format!("postgresql://no_user:{password}@{listen_addr}/no_db")
-            .parse()
-            .unwrap()
-    }
-
     pub fn initialize(
         &self,
         create_tenant: Option<TenantId>,

control_plane/src/safekeeper.rs

@@ -5,12 +5,12 @@ use std::sync::Arc;
 use std::{io, result};
 
 use anyhow::Context;
+use postgres_connection::PgConnectionConfig;
 use reqwest::blocking::{Client, RequestBuilder, Response};
 use reqwest::{IntoUrl, Method};
 use thiserror::Error;
 use utils::{http::error::HttpErrorBody, id::NodeId};
 
-use crate::connection::PgConnectionConfig;
 use crate::pageserver::PageServerNode;
 use crate::{
     background_process,
@@ -86,10 +86,7 @@ impl SafekeeperNode {
 
     /// Construct libpq connection string for connecting to this safekeeper.
     fn safekeeper_connection_config(port: u16) -> PgConnectionConfig {
-        // TODO safekeeper authentication not implemented yet
-        format!("postgresql://no_user@127.0.0.1:{port}/no_db")
-            .parse()
-            .unwrap()
+        PgConnectionConfig::new_host_port(url::Host::parse("127.0.0.1").unwrap(), port)
     }
 
     pub fn datadir_path_by_id(env: &LocalEnv, sk_id: NodeId) -> PathBuf {