sless/doc/SESSION_REPORT_2026-04-03.md

Session Report: PostgreSQL Discovery - April 3, 2026

Session Overview

Duration: Single session, April 3, 2026
Focus: Root cause analysis of PostgreSQL terraform lifecycle tests failures
Outcome: 2 major problems identified and documented

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Key Findings

1. ERR-PG-02: FIXED ✅

Previously: ID going to (known after apply) during Update operations

Status: Already fixed in current provider code (internal/provider/postgres_resource.go line ~845)

• Code now explicitly preserves ID from state during Update
• No longer reproducible - no destroy+recreate of dependent resources

Verification: terraform plan shows 0 to destroy (correct behavior)

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2. ERR-PG-06: RECLASSIFIED 🔄

Previously: Claimed that only 1 user per PostgreSQL instance could be created with vault_secrets

Corrected Finding: Multiple users work fine when properly configured

• Successfully created pg_test_user (user0) and pg_test_user3 (u3)
• Both have vault_secrets successfully populated

Root Cause of Original Error: Lack of depends_on between user resources → race condition in Vault writes

Solution: Strict depends_on chain between users is required and works perfectly

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3. ERR-PG-08: NEW PROBLEM ❌

Description: After Update operation completes (even successfully), creating dependent resources fails with 422 "Concurrent operations are not supported"

Symptoms:

Error: Ошибка клиента
  ошибка API 422: {
    "TITLE": "Concurrent operations are not supported (job status: SUCCESS)"
  }

Root Cause: Nubes API maintains internal lock on instance even after operation completion. Post-operation async tasks (Vault sync, state reconciliation) still run.

Impact: Cannot create databases or additional users immediately after instance update in same Terraform apply

Workaround Found: Split apply into phases (comment out DB resource, apply, uncomment, apply again)

Requires: Provider fix - add post-completion delay or retry mechanism in WaitForOperation() method

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Documentation Created

1. /home/naeel/remote_dev/sless/doc/ERR-PG-08-concurrent-operations.md

   • Detailed problem analysis
   • 3 solution options (fixed delay, retry mechanism, instance state query)
   • Recommendation: combine options 1 + 2

2. Updated /home/naeel/remote_dev/sless/doc/errors/log.md

   • Added corrections to ERR-PG-06 (multi-user now works)
   • Added new section for ERR-PG-08 (concurrent ops limitation)

3. Updated /home/naeel/remote_dev/sless/doc/pg-terraform-behavior.md

   • Table (section 6) updated: shows 2nd/3rd user creation now works
   • Added section 3.5: detailed ERR-PG-08 explanation
   • Corrected: "2 users per instance" now says "Works with depends_on"

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Terraform Configuration Status

Current Setup (examples/PG_TEST):

• ✅ nubes_postgres instance created successfully
• ✅ pg_test_user (user0) created successfully
• ✅ pg_test_user3 (u3) created successfully
• ❌ pg_test_db cannot be created (blocked by ERR-PG-08)

Workaround Applied:

• Commented out nubes_postgres_database resource block (lines 87-99)
• Updated outputs.tf to disable database-dependent outputs
• Successfully applied (0 added, 1 changed, 0 destroyed)

Status: Awaiting provider fix to re-enable database creation

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Provider Source Files

Identified locations for fix:

• /home/naeel/terra/terraform/internal/provider/client_impl.go line 240

  • WaitForOperation() method needs post-completion handling
  • Current: returns immediately on IsSuccessful = true
  • Needed: add delay or retry mechanism

• /home/naeel/terra/terraform/internal/provider/postgres_resource.go line 617+

  • Update() method (already has ERR-PG-02 fix)
  • Would benefit from handling ERR-PG-08 retries

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Next Steps (For Future Sessions)

1. Priority FIX: Implement post-completion delay in WaitForOperation()

   • Add 30-60 second sleep after success return
   • Or implement exponential backoff retry for 422 errors

2. Testing: After fix applied

   • Re-enable nubes_postgres_database in postgres.tf
   • Verify terraform apply succeeds fully (0 destroyed)
   • Run stress tests with multiple users and databases

3. Documentation: After fix verified

   • Update pg-terraform-behavior.md table (remove ERR-PG-08 workaround)
   • Mark ERR-PG-08 as "FIXED"
   • Update provider-fix-plan.md with implementation details

4. Codebase: Commit changes

   • Provider fix in /home/naeel/terra/terraform/
   • Documentation updates in /home/naeel/remote_dev/sless/

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Files Modified This Session

In /home/naeel/remote_dev/sless/

• ✅ doc/ERR-PG-08-concurrent-operations.md — CREATED (new)
• ✅ doc/errors/log.md — UPDATED (added corrections + ERR-PG-08)
• ✅ doc/pg-terraform-behavior.md — UPDATED (table + section 3.5)
• ⚠️ examples/PG_TEST/postgres.tf — MODIFIED (commented out DB)
• ⚠️ examples/PG_TEST/outputs.tf — MODIFIED (disabled DB outputs)

On VM /home/naeel/terra/

• No code changes (only investigation)
• Terraform state reflects multi-user success
• Provider source examined but not modified

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Lessons Learned

1. Multi-user creation works when using proper depends_on chains
2. Vault limitation hypothesis was wrong - it was a race condition issue
3. Concurrent operations limit is real and requires provider-level fix
4. Provider already has one fix (ERR-PG-02 id preservation) - shows active maintenance
5. Test environment is functional despite appearing to fail initially

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Technical Debt

• ERR-PG-08 requires provider fix (not blocking test framework, blocking full automation)
• Consider: Is concurrent operations lock intentional safety feature? Document if so.
• Consider: Add configurable retry delays for production resilience

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Session Status: COMPLETE - Major findings documented, actionable recommendations provided

Ready For: Next programmer to implement provider fix based on documented analysis