How does Argo CD's ignoreDifferences configuration interact with its automated self-healing (selfHeal) feature?

ignoreDifferences runs first, conceptually: it removes specific fields from Argo CD's diff calculation entirely, so a live value differing from Git in an ignored field is never even seen as drift in the first place — and since selfHeal only acts on detected drift, an ignored field is never a candidate for self-healing to revert, regardless of how much it diverges from the Git-declared value. The two features are complementary rather than competing: ignoreDifferences defines what counts as drift at all, and selfHeal decides what to do about whatever's left after that filtering.

Argo CD's sync status is computed by diffing the live cluster state against what's declared in Git, field by field. ignoreDifferences configures specific fields (or entire paths, via JSON pointers or a Kubernetes-native managedFieldsManagers approach) to be excluded from that diff calculation — meaning Argo CD never even compares those specific fields between live and Git state, so no divergence there is ever registered as drift, regardless of how different the live value actually is.

selfHeal (part of the automated sync policy) acts on whatever is detected as drift — when live state diverges from Git in a field that Argo CD is actually comparing, selfHeal triggers an automatic sync to revert that divergence back to the Git-declared value, without waiting for a human to notice and manually sync. Since ignoreDifferences has already removed certain fields from the comparison entirely, those fields are structurally invisible to selfHeal — there's no drift for it to detect or revert in an ignored field, no matter what value it holds live.

This relationship is exactly why ignoreDifferences is the correct tool for fields legitimately mutated by something other than Argo CD (a mutating webhook injecting a sidecar container spec, a Horizontal Pod Autoscaler adjusting replica count, a cloud provider populating a Service's external IP) — without ignoreDifferences, selfHeal would fight that external mutator, repeatedly reverting its changes back to the Git-declared value the instant they're made, causing a genuinely disruptive reconciliation loop. With the field correctly ignored, selfHeal simply never engages with it, letting the external mutator's changes persist undisturbed while selfHeal still actively protects every field that is being compared.

• ignoreDifferences removes specific fields from Argo CD's diff calculation entirely, before selfHeal ever gets involved.
• selfHeal only acts on fields that are actually being compared — an ignored field is structurally invisible to it, regardless of live drift.
• This is exactly why ignoreDifferences is the correct tool for fields legitimately mutated by something other than Argo CD — without it, selfHeal would fight that external mutator continuously.
• The two features are complementary: ignoreDifferences defines the scope of what counts as drift; selfHeal decides the response to whatever's left in that scope.

• Argo CD: Diffing customization
• Argo CD: Automated sync policy — self healing