From 0666b4ffbf3cf88031dadb2a0d1002a0235d26be Mon Sep 17 00:00:00 2001
From: TusharMohapatra07 <tusharmohapatra.gig@gmail.com>
Date: Thu, 31 Jul 2025 15:09:15 +0530
Subject: [PATCH] events: add support for label filter with key only

Fixes: #26702

Signed-off-by: TusharMohapatra07 <tusharmohapatra.gig@gmail.com>
---
 docs/source/markdown/podman-events.1.md |  2 +-
 libpod/events/filters.go                | 22 ++++++++++++++--------
 test/system/090-events.bats             |  4 ++++
 3 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/docs/source/markdown/podman-events.1.md b/docs/source/markdown/podman-events.1.md
index 4052a50f32..9eb898c93d 100644
--- a/docs/source/markdown/podman-events.1.md
+++ b/docs/source/markdown/podman-events.1.md
@@ -99,7 +99,7 @@ filters are supported:
 | container  | [Name or ID] Container's name or ID |
 | event      | event_status (described above)      |
 | image      | [Name or ID] Image name or ID       |
-| label      | [key=value] label                   |
+| label      | [key] or [key=value] label          |
 | pod        | [Name or ID] Pod name or ID         |
 | volume     | [Name or ID] Volume name or ID      |
 | type       | Event_type (described above)        |
diff --git a/libpod/events/filters.go b/libpod/events/filters.go
index 00bdd19ee5..3bb22114e6 100644
--- a/libpod/events/filters.go
+++ b/libpod/events/filters.go
@@ -67,14 +67,20 @@ func generateEventFilter(filter, filterValue string) (func(e *Event) bool, error
 			var found bool
 			// iterate labels and see if we match a key and value
 			for eventKey, eventValue := range e.Attributes {
-				filterValueSplit := strings.SplitN(filterValue, "=", 2)
-				// if the filter isn't right, just return false
-				if len(filterValueSplit) < 2 {
-					return false
-				}
-				if eventKey == filterValueSplit[0] && eventValue == filterValueSplit[1] {
-					found = true
-					break
+				filterKey, filterVal, hasValue := strings.Cut(filterValue, "=")
+				// match "key=value" or "key"
+				if !hasValue {
+					// match by key only
+					if eventKey == filterKey {
+						found = true
+						break
+					}
+				} else {
+					// match by key and value
+					if eventKey == filterKey && eventValue == filterVal {
+						found = true
+						break
+					}
 				}
 			}
 			return found
diff --git a/test/system/090-events.bats b/test/system/090-events.bats
index ff3ffb8b61..6ad67bbbb5 100644
--- a/test/system/090-events.bats
+++ b/test/system/090-events.bats
@@ -28,6 +28,10 @@ load helpers.network
     run_podman events --since "$before" --filter type=container --filter container=$cname --filter event=start --stream=false
     is "$output" "$expect" "filtering just by container"
 
+    # Filter just by label key (without value)
+    run_podman events --since "$before" --filter type=container --filter label=${labelname} --filter event=start --stream=false
+    is "$output" "$expect" "filtering by label key only"
+
     # check --no-trunc=false
     truncID=${id:0:12}
     run_podman events --since "$before" --filter container=$cname --filter event=start --stream=false --no-trunc=false