From 9796aeaada5591839f6d2542cff72cc14ed6ed14 Mon Sep 17 00:00:00 2001
From: Christian Schwarz <christian@neon.tech>
Date: Wed, 27 Sep 2023 16:35:00 +0200
Subject: [PATCH] Revert "load_tenant_config: fail if there is no config"

This reverts commit 4ce39ee55e1bfeecb6e16846d05793747f59ea5d.
---
 pageserver/src/tenant.rs | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/pageserver/src/tenant.rs b/pageserver/src/tenant.rs
index ad3e5e7409..47bfd4a8ef 100644
--- a/pageserver/src/tenant.rs
+++ b/pageserver/src/tenant.rs
@@ -2108,14 +2108,6 @@ where
     Ok(result)
 }
 
-#[derive(Debug, thiserror::Error)]
-pub(super) enum LoadTenantConfigError {
-    #[error("tenant config file does not exist")]
-    ConfigFileDoesNotExist,
-    #[error(transparent)]
-    Other(#[from] anyhow::Error),
-}
-
 impl Tenant {
     pub fn tenant_specific_overrides(&self) -> TenantConfOpt {
         *self.tenant_conf.read().unwrap()
@@ -2360,15 +2352,19 @@ impl Tenant {
     pub(super) fn load_tenant_config(
         conf: &'static PageServerConf,
         tenant_id: &TenantId,
-    ) -> Result<TenantConfOpt, LoadTenantConfigError> {
+    ) -> anyhow::Result<TenantConfOpt> {
         let target_config_path = conf.tenant_config_path(tenant_id);
         let target_config_display = target_config_path.display();
 
         info!("loading tenantconf from {target_config_display}");
 
+        // FIXME If the config file is not found, assume that we're attaching
+        // a detached tenant and config is passed via attach command.
+        // https://github.com/neondatabase/neon/issues/1555
+        // OR: we're loading after incomplete deletion that managed to remove config.
         if !target_config_path.exists() {
             info!("tenant config not found in {target_config_display}");
-            return Err(LoadTenantConfigError::ConfigFileDoesNotExist);
+            return Ok(TenantConfOpt::default());
         }
 
         // load and parse file
@@ -2388,7 +2384,8 @@ impl Tenant {
                         format!("Failed to parse config from file '{target_config_display}' as pageserver config")
                     })?;
                 }
-                _ => return Err(LoadTenantConfigError::Other(anyhow::anyhow!("config file {target_config_display} has unrecognized pageserver option '{key}'"))),
+                _ => bail!("config file {target_config_display} has unrecognized pageserver option '{key}'"),
+
             }
         }