Discover Argo Workflows 4.0: 24 New Features, Performance Gains & UI Upgrades

Release Overview

Argo Workflows 4.0 is generally available. The release adds usability, security, and performance improvements for AI/ML pipelines, data pipelines, and CI/CD across multiple clusters.

Release Statistics

24 new features

122 bug fixes

73 contributors (including 37 new)

General Highlights

Artifact driver as a plugin – Implement a gRPC server, package it as a container image, and register it as an artifact driver plugin. Upload and download can target any repository implemented by the plugin.

Full CRD validation – CEL‑based validation enforces limits (max 200 templates, max 500 parameters per workflow) and catches errors before objects are persisted.

Deprecation of singular sync primitives – The singular mutex, semaphore, and schedule fields are removed; use the plural forms introduced in v3.6.

Name filtering for archived workflows – New nameFilter parameter supports prefix, contains, or exact matching, enabling search of archived workflows.

Real‑time parallelism updates – Changes to the workflow-controller-configmap are applied immediately without restarting the controller.

OIDC SSO custom CA support – Inline or file‑path configuration allows self‑signed or private CAs for OIDC SSO.

Write‑back informer disabled by default – Prevents unintended controller writes; may increase conflict errors slightly but improves stability.

Extended field‑selector support – metadata.name= and metadata.name!= selectors are now accepted.

Automatic restart of pre‑failed Pods – Pods that fail before start (e.g., node eviction) are automatically restarted when enabled in the controller ConfigMap.

Context‑aware structured logging – Log entries now include workflow identifiers throughout the call stack.

Feature documentation requirement – New features must include a .features/pending file describing user‑visible impact.

UI Improvements

CronWorkflow deletion now shows a confirmation dialog warning that generated workflows will also be removed.

WorkflowTemplates UI keeps the ?label=key%3Dvalue query parameter in sync with UI state.

“Name not equal” filter allows exclusion of workflows by name in the list view.

Custom link target handling: target="blank" opens links in a new tab, target="self" keeps the current tab.

Archived workflow pagination speedup – Uses indexed checks instead of full table scans, greatly improving performance on large datasets.

CLI Improvements

argo semaphore create configmap …

creates a semaphore backed by a ConfigMap without manual YAML. argo semaphore create db … creates a semaphore with an external database backend. argo convert migrates existing Workflows, CronWorkflows, and (Cluster)WorkflowTemplates to the v4.0 schema, rewrites objects, and performs lint‑like validation.

Getting Started

Pull the latest Argo Workflows container image, update the controller ConfigMap with the new settings, and try the name filter, artifact‑driver plugins, and custom CA support. Report issues at https://github.com/argoproj/argo-workflows.