29 questions foundA refresh makes ArgoCD re-check Git and recompute status without applying; a hard refresh also re-runs manifest generation (bypassing the repo cache), useful when a Helm/Kustomize render or external chart changed but the cache is stale. Use `argocd app get --refresh` or `--hard-refresh`, or the UI refresh options.
argocd app get my-app --refresh
argocd app get my-app --hard-refresh
Real-world example After updating a values file, a hard refresh forces ArgoCD to re-render the chart instead of using cached manifests.
Common follow-ups: When is a hard refresh needed? | Does refresh apply changes?
Applications GitOps Principles Sync & Health
Add Lua scripts under resource.customizations.health in the argocd-cm ConfigMap keyed by group_kind. The script inspects the resource's status and returns a health status and message. ArgoCD ships many built-ins (e.g., for cert-manager, Rollouts); you add scripts for CRDs it doesn't know so aggregated app health is accurate.
resource.customizations.health.cert-manager.io_Certificate: |
hs = {}
for i, c in ipairs(obj.status.conditions) do
if c.type == "Ready" and c.status == "True" then
hs.status = "Healthy"; return hs
end
end
hs.status = "Progressing"; return hs
Real-world example A Certificate resource reports Healthy only once its Ready condition is true, thanks to a custom Lua check.
Common follow-ups: Where are custom health scripts stored? | What does a Lua health script return?
Applications Sync Waves & Hooks Sync & Health
Perpetual OutOfSync usually means a field differs every reconcile: mutating webhooks or controllers add/change fields, defaults are injected, or ordering/normalization differs. Fixes include ignoreDifferences for controller-managed fields, correct resource normalization, ServerSideApply, or aligning the manifest with what the API server returns.
spec:
ignoreDifferences:
- group: ""
kind: Service
jqPathExpressions:
- .spec.clusterIP
Real-world example A Service showing constant drift is fixed by ignoring the auto-assigned clusterIP field the API server injects.
Common follow-ups: What commonly injects drift-causing fields? | How does ignoreDifferences help?
Applications GitOps Principles Sync & Health
The Argo CD Notifications controller (now built-in) sends alerts to Slack, email, Teams, webhooks, etc., based on triggers (e.g., on-sync-failed, on-health-degraded) and templates. You configure triggers/templates in a ConfigMap and subscribe apps via annotations, enabling proactive alerting on failures or drift.
metadata:
annotations:
notifications.argoproj.io/subscribe.on-health-degraded.slack: my-channel
Real-world example When an app goes Degraded, the team gets a Slack alert immediately via the notifications controller.
Common follow-ups: What triggers are available? | How do you subscribe an app to notifications?
Applications Sync & Health RBAC
ArgoCD deploys the manifests, but progressive delivery is handled by Argo Rollouts, which replaces Deployment with a Rollout resource supporting canary and blue-green strategies, traffic shifting, and analysis. ArgoCD syncs the Rollout from Git and (with the Rollouts health extension) reports its progressive status as health.
kind: Rollout
spec:
strategy:
canary:
steps:
- setWeight: 20
- pause: { duration: 5m }
Real-world example A new version rolls out to 20% of traffic, pauses for analysis, then proceeds—managed by Argo Rollouts and synced by ArgoCD.
Common follow-ups: How does Argo Rollouts relate to ArgoCD? | What strategies does it support?
Applications Sync Waves & Hooks Sync & Health
The diff view shows the differences between the desired state (Git) and the live state for each out-of-sync resource, highlighting added, removed, or changed fields. It's used to review exactly what a sync will change before applying, and to diagnose why an app is OutOfSync.
argocd app diff my-app
Real-world example Before approving a production sync, the reviewer inspects the diff to confirm only the intended image tag changed.
Common follow-ups: Why review the diff before sync? | Where do you see the diff?
Applications GitOps Principles Sync & Health
You can disable automated sync temporarily (remove/patch syncPolicy.automated), use sync windows to block syncs during a change freeze, set the app to manual, or add maintenance annotations. Sync windows (defined on the Project) allow/deny syncs on a schedule so automated reconciliation pauses during sensitive periods.
kind: AppProject
spec:
syncWindows:
- kind: deny
schedule: '0 22 * * *'
duration: 8h
applications: ['*']
Real-world example A nightly deny sync window freezes deployments during the change-freeze period so no auto-sync fires.
Common follow-ups: What is a sync window? | How do you pause auto-sync safely?
Applications RBAC Sync & Health
During a sync, ArgoCD orders resources by waves and runs hooks (PreSync/Sync/PostSync) at the right phases, waiting for each wave's resources to become Healthy before proceeding. So health assessment gates progression: if a resource in an earlier wave isn't Healthy, later waves and PostSync hooks won't run.
Real-world example A database migration PreSync hook must complete Healthy before the app's Deployment in the next wave is applied.
Common follow-ups: How does health gate wave progression? | What are the hook phases?
Sync Waves & Hooks Applications Sync & Health
ArgoCD exposes Prometheus metrics from its controllers (app sync counts, reconciliation performance, health status, repo-server and API server metrics). You scrape them, build Grafana dashboards, and alert on sync failures, reconciliation latency, or OutOfSync counts. Logs and the app events/audit provide deeper diagnostics.
# ServiceMonitor scraping argocd-metrics, repo-server, api-server
# Alert on: argocd_app_info{sync_status="OutOfSync"} and sync failures
Real-world example A Grafana dashboard tracks sync success rate and reconciliation latency, alerting when OutOfSync apps spike.
Common follow-ups: Which components expose metrics? | What would you alert on?
Applications Multi-cluster Sync & Health
If applying a resource fails, the sync operation is marked failed; ArgoCD stops progressing further waves and reports the error on the resource. With retry configured it backs off and retries. Already-applied resources remain; you fix the cause (manifest error, RBAC, missing CRD) and re-sync. Hooks may run failure hooks if defined.
Real-world example A sync fails because a manifest references a missing CRD; ArgoCD reports the error, and after installing the CRD the re-sync succeeds.
Common follow-ups: Does a failed sync roll back applied resources? | What is a SyncFail hook?
Sync Waves & Hooks Applications Sync & Health