fix(cron): Add documentation and test on multiple sources

Closes apache#5158

docs/modules/ROOT/partials/apis/camel-k-crds.adoc

@@ -6490,7 +6490,7 @@ require to be activated at specific hours of the day or with a periodic delay of
 For such tasks, the cron trait can materialize the integration as a Kubernetes CronJob instead of a standard deployment,
 in order to save resources when the integration does not need to be executed.
 
-Integrations that start from the following components are evaluated by the cron trait: `timer`, `cron`, `quartz`.
+Integrations that start from the following components are evaluated by the cron trait: `timer`, `cron`, `quartz`. The trait does support multiple evaluated components only if they have the same schedule, else it will fallback to Camel implementation instead of instanciating a Kubernetes CronJob.
 
 WARNING: In case of native build-mode defined in xref:traits:quarkus.adoc[quarkus] trait, the component can't be customized.
 

docs/modules/traits/pages/cron.adoc

@@ -8,7 +8,7 @@ require to be activated at specific hours of the day or with a periodic delay of
 For such tasks, the cron trait can materialize the integration as a Kubernetes CronJob instead of a standard deployment,
 in order to save resources when the integration does not need to be executed.
 
-Integrations that start from the following components are evaluated by the cron trait: `timer`, `cron`, `quartz`.
+Integrations that start from the following components are evaluated by the cron trait: `timer`, `cron`, `quartz`. The trait does support multiple evaluated components only if they have the same schedule, else it will fallback to Camel implementation instead of instanciating a Kubernetes CronJob.
 
 WARNING: In case of native build-mode defined in xref:traits:quarkus.adoc[quarkus] trait, the component can't be customized.
 

pkg/apis/camel/v1/trait/cron.go

@@ -24,7 +24,7 @@ package trait
 // For such tasks, the cron trait can materialize the integration as a Kubernetes CronJob instead of a standard deployment,
 // in order to save resources when the integration does not need to be executed.
 //
-// Integrations that start from the following components are evaluated by the cron trait: `timer`, `cron`, `quartz`.
+// Integrations that start from the following components are evaluated by the cron trait: `timer`, `cron`, `quartz`. The trait does support multiple evaluated components only if they have the same schedule, else it will fallback to Camel implementation instead of instanciating a Kubernetes CronJob.
 //
 // WARNING: In case of native build-mode defined in xref:traits:quarkus.adoc[quarkus] trait, the component can't be customized.
 //

pkg/trait/cron_test.go

@@ -298,6 +298,86 @@ func TestCronDeps(t *testing.T) {
 	assert.Contains(t, environment.Integration.Status.Dependencies, "mvn:org.apache.camel.k:camel-k-cron")
 }
 
+func TestCronMultipleScheduleFallback(t *testing.T) {
+	catalog, err := camel.DefaultCatalog()
+	assert.Nil(t, err)
+
+	client, _ := test.NewFakeClient()
+	traitCatalog := NewCatalog(nil)
+
+	environment := Environment{
+		CamelCatalog: catalog,
+		Catalog:      traitCatalog,
+		Client:       client,
+		Integration: &v1.Integration{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      "test",
+				Namespace: "ns",
+			},
+			Status: v1.IntegrationStatus{
+				Phase: v1.IntegrationPhaseInitialization,
+			},
+			Spec: v1.IntegrationSpec{
+				Profile: v1.TraitProfileKnative,
+				Sources: []v1.SourceSpec{
+					{
+						DataSpec: v1.DataSpec{
+							Name:    "routes.java",
+							Content: `from("cron:tab?schedule=0 0/2 * * ?").to("log:test")`,
+						},
+						Language: v1.LanguageJavaSource,
+					},
+					{
+						DataSpec: v1.DataSpec{
+							Name:    "routes2.java",
+							Content: `from("cron:tab?schedule=0 0/3 * * ?").to("log:test")`,
+						},
+						Language: v1.LanguageJavaSource,
+					},
+				},
+				Traits: v1.Traits{},
+			},
+		},
+		IntegrationKit: &v1.IntegrationKit{
+			Status: v1.IntegrationKitStatus{
+				Phase: v1.IntegrationKitPhaseReady,
+			},
+		},
+		Platform: &v1.IntegrationPlatform{
+			Spec: v1.IntegrationPlatformSpec{
+				Cluster: v1.IntegrationPlatformClusterOpenShift,
+				Build: v1.IntegrationPlatformBuildSpec{
+					PublishStrategy: v1.IntegrationPlatformBuildPublishStrategyS2I,
+					Registry:        v1.RegistrySpec{Address: "registry"},
+					RuntimeVersion:  catalog.Runtime.Version,
+				},
+				Profile: v1.TraitProfileKnative,
+			},
+			Status: v1.IntegrationPlatformStatus{
+				Phase: v1.IntegrationPlatformPhaseReady,
+			},
+		},
+		EnvVars:        make([]corev1.EnvVar, 0),
+		ExecutedTraits: make([]Trait, 0),
+		Resources:      kubernetes.NewCollection(),
+	}
+	environment.Platform.ResyncStatusFullConfig()
+
+	c, err := NewFakeClient("ns")
+	assert.Nil(t, err)
+
+	tc := NewCatalog(c)
+	conditions, err := tc.apply(&environment)
+
+	assert.Nil(t, err)
+	assert.Empty(t, conditions)
+	assert.NotEmpty(t, environment.ExecutedTraits)
+
+	ct, _ := environment.GetTrait("cron").(*cronTrait)
+	assert.NotNil(t, ct)
+	assert.NotNil(t, ct.Fallback, "Should apply Fallback since non equivalent scheduling for mutiple cron compatible component")
+}
+
 func TestCronDepsFallback(t *testing.T) {
 	catalog, err := camel.DefaultCatalog()
 	require.NoError(t, err)