[pbs-devel] [PATCH proxmox-backup] realm sync: show warnings if attributes do not meet their constraints

[Lukas Wagner <l.wagner@proxmox.com>]

Previously, if the value of a synced property did not validate properly
(e.g only 1 character in length instead of the required 2), the whole
sync job failed without any useful error message.

In this commit, the values are validated manually by their
respective StringSchema. If the validation fails, the value is
ignored and a warning is displayed in the task log.

In addition to that, some error messages have been improved.
Also, user sync is now more fault-tolerant in general, showing
warnings if something goes wrong while creating/updating a
single user, instead of aborting the whole sync job.

Reported-by: Friedrich Weber <f.weber@proxmox.com>
Signed-off-by: Lukas Wagner <l.wagner@proxmox.com>
---
 src/server/realm_sync_job.rs | 98 ++++++++++++++++++++++++++----------
 1 file changed, 72 insertions(+), 26 deletions(-)

diff --git a/src/server/realm_sync_job.rs b/src/server/realm_sync_job.rs
index 0fd8adfe..874fe850 100644
--- a/src/server/realm_sync_job.rs
+++ b/src/server/realm_sync_job.rs
@@ -1,16 +1,18 @@
 use anyhow::{bail, Context, Error};
 use pbs_config::{acl::AclTree, token_shadow, BackupLockGuard};
+use proxmox_lang::try_block;
 use proxmox_ldap::{Config, Connection, SearchParameters, SearchResult};
 use proxmox_rest_server::WorkerTask;
-use proxmox_schema::ApiType;
+use proxmox_schema::{ApiType, Schema};
 use proxmox_section_config::SectionConfigData;
-use proxmox_sys::task_log;
+use proxmox_sys::{task_log, task_warn};
 
 use std::{collections::HashSet, sync::Arc};
 
 use pbs_api_types::{
     ApiToken, Authid, LdapRealmConfig, Realm, RemoveVanished, SyncAttributes as LdapSyncAttributes,
-    SyncDefaultsOptions, User, Userid, REMOVE_VANISHED_ARRAY, USER_CLASSES_ARRAY,
+    SyncDefaultsOptions, User, Userid, EMAIL_SCHEMA, FIRST_NAME_SCHEMA, LAST_NAME_SCHEMA,
+    REMOVE_VANISHED_ARRAY, USER_CLASSES_ARRAY,
 };
 
 use crate::{auth, server::jobstate::Job};
@@ -157,20 +159,32 @@ impl LdapRealmSyncJob {
         let mut retrieved_users = HashSet::new();
 
         for result in users {
-            let mut username = result
-                .attributes
-                .get(&self.ldap_sync_settings.user_attr)
-                .context("userid attribute not in search result")?
-                .get(0)
-                .context("userid attribute array is empty")?
-                .clone();
-
-            username.push_str(&format!("@{}", self.realm.as_str()));
-
-            let userid: Userid = username.parse()?;
-            retrieved_users.insert(userid.clone());
-
-            self.create_or_update_user(user_config, userid, result)?;
+            let user_id_attribute = &self.ldap_sync_settings.user_attr;
+
+            let result = try_block!({
+                let username = result
+                    .attributes
+                    .get(user_id_attribute)
+                    .context(format!(
+                        "userid attribute `{user_id_attribute}` not in LDAP search result"
+                    ))?
+                    .get(0)
+                    .context("userid attribute array is empty")?
+                    .clone();
+
+                let username = format!("{username}@{realm}", realm = self.realm.as_str());
+
+                let userid: Userid = username
+                    .parse()
+                    .context(format!("could not parse username `{username}`"))?;
+                retrieved_users.insert(userid.clone());
+
+                self.create_or_update_user(user_config, &userid, result)?;
+                anyhow::Ok(())
+            });
+            if let Err(e) = result {
+                task_log!(self.worker, "could not create/update user: {e}");
+            }
         }
 
         Ok(retrieved_users)
@@ -179,7 +193,7 @@ impl LdapRealmSyncJob {
     fn create_or_update_user(
         &self,
         user_config: &mut SectionConfigData,
-        userid: Userid,
+        userid: &Userid,
         result: &SearchResult,
     ) -> Result<(), Error> {
         let existing_user = user_config.lookup::<User>("user", userid.as_str()).ok();
@@ -213,37 +227,67 @@ impl LdapRealmSyncJob {
     fn construct_or_update_user(
         &self,
         result: &SearchResult,
-        userid: Userid,
+        userid: &Userid,
         existing_user: Option<&User>,
     ) -> User {
-        let lookup = |a: Option<&String>| {
-            a.and_then(|e| result.attributes.get(e))
+        let lookup = |attribute: &str, ldap_attribute: Option<&String>, schema: Schema| {
+            ldap_attribute
+                .and_then(|e| result.attributes.get(e))
                 .and_then(|v| v.get(0))
+                .and_then(|value| {
+                    let schema = schema.unwrap_string_schema();
+
+                    if let Err(e) = schema.check_constraints(value) {
+                        task_warn!(
+                            self.worker,
+                            "{userid}: ignoring attribute `{attribute}`: {e}"
+                        );
+
+                        None
+                    } else {
+                        Some(value)
+                    }
+                })
                 .cloned()
         };
 
         User {
-            userid,
+            userid: userid.clone(),
             comment: existing_user.as_ref().and_then(|u| u.comment.clone()),
             enable: existing_user
                 .and_then(|o| o.enable)
                 .or(Some(self.general_sync_settings.enable_new)),
             expire: existing_user.and_then(|u| u.expire).or(Some(0)),
-            firstname: lookup(self.ldap_sync_settings.firstname_attr.as_ref()).or_else(|| {
+            firstname: lookup(
+                "firstname",
+                self.ldap_sync_settings.firstname_attr.as_ref(),
+                FIRST_NAME_SCHEMA,
+            )
+            .or_else(|| {
                 if !self.general_sync_settings.should_remove_properties() {
                     existing_user.and_then(|o| o.firstname.clone())
                 } else {
                     None
                 }
             }),
-            lastname: lookup(self.ldap_sync_settings.lastname_attr.as_ref()).or_else(|| {
+            lastname: lookup(
+                "lastname",
+                self.ldap_sync_settings.lastname_attr.as_ref(),
+                LAST_NAME_SCHEMA,
+            )
+            .or_else(|| {
                 if !self.general_sync_settings.should_remove_properties() {
                     existing_user.and_then(|o| o.lastname.clone())
                 } else {
                     None
                 }
             }),
-            email: lookup(self.ldap_sync_settings.email_attr.as_ref()).or_else(|| {
+            email: lookup(
+                "email",
+                self.ldap_sync_settings.email_attr.as_ref(),
+                EMAIL_SCHEMA,
+            )
+            .or_else(|| {
                 if !self.general_sync_settings.should_remove_properties() {
                     existing_user.and_then(|o| o.email.clone())
                 } else {
@@ -304,7 +348,9 @@ impl LdapRealmSyncJob {
                     user_config.sections.remove(&tokenid_string);
 
                     if !self.dry_run {
-                        token_shadow::delete_secret(&tokenid)?;
+                        if let Err(e) = token_shadow::delete_secret(&tokenid) {
+                            task_warn!(self.worker, "could not delete token for user {userid}: {e}",)
+                        }
                     }
 
                     if self.general_sync_settings.should_remove_acls() {
-- 
2.30.2