[8.x] [Fleet] Retry on conflict when updating agent space (#205964) (#…

…206302)

# Backport

This will backport the following commits from `main` to `8.x`:
- [[Fleet] Retry on conflict when updating agent space
(#205964)](#205964)

<!--- Backport version: 9.4.3 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sqren/backport)

<!--BACKPORT [{"author":{"name":"Nicolas
Chaulet","email":"[email protected]"},"sourceCommit":{"committedDate":"2025-01-10T15:44:33Z","message":"[Fleet]
Retry on conflict when updating agent space
(#205964)","sha":"eddbbb1895920c36e7687854a10d598f913e206c","branchLabelMapping":{"^v9.0.0$":"main","^v8.18.0$":"8.x","^v(\\d+).(\\d+).\\d+$":"$1.$2"}},"sourcePullRequest":{"labels":["release_note:skip","Team:Fleet","v9.0.0","backport:prev-minor"],"title":"[Fleet]
Retry on conflict when updating agent
space","number":205964,"url":"https://github.com/elastic/kibana/pull/205964","mergeCommit":{"message":"[Fleet]
Retry on conflict when updating agent space
(#205964)","sha":"eddbbb1895920c36e7687854a10d598f913e206c"}},"sourceBranch":"main","suggestedTargetBranches":[],"targetPullRequestStates":[{"branch":"main","label":"v9.0.0","branchLabelMappingKey":"^v9.0.0$","isSourceBranch":true,"state":"MERGED","url":"https://github.com/elastic/kibana/pull/205964","number":205964,"mergeCommit":{"message":"[Fleet]
Retry on conflict when updating agent space
(#205964)","sha":"eddbbb1895920c36e7687854a10d598f913e206c"}}]}]
BACKPORT-->

Co-authored-by: Nicolas Chaulet <[email protected]>

x-pack/platform/plugins/shared/fleet/server/services/spaces/agent_policy.ts

@@ -154,21 +154,6 @@ export async function updateAgentPolicySpaces({
     ignore_unavailable: true,
     refresh: true,
   });
-  await esClient.updateByQuery({
-    index: AGENTS_INDEX,
-    query: {
-      bool: {
-        must: {
-          terms: {
-            policy_id: [agentPolicyId],
-          },
-        },
-      },
-    },
-    script: `ctx._source.namespaces = [${newSpaceIds.map((spaceId) => `"${spaceId}"`).join(',')}]`,
-    ignore_unavailable: true,
-    refresh: true,
-  });
 
   const agentIndexExists = await esClient.indices.exists({
     index: AGENTS_INDEX,
@@ -195,6 +180,21 @@ export async function updateAgentPolicySpaces({
           break;
         }
 
+        const agentBulkRes = await esClient.bulk({
+          operations: agents.flatMap(({ id }) => [
+            { update: { _id: id, _index: AGENTS_INDEX, retry_on_conflict: 5 } },
+            { doc: { namespaces: newSpaceIds } },
+          ]),
+          refresh: 'wait_for',
+          index: AGENTS_INDEX,
+        });
+
+        for (const item of agentBulkRes.items) {
+          if (item.update?.error) {
+            throw item.update?.error;
+          }
+        }
+
         const lastAgent = agents[agents.length - 1];
         searchAfter = lastAgent.sort;