Run the upgrade of a collector instance after the status changes from unmanaged to managed

.chloggen/1890-run-upgrade-for-previously-unmanaged-instances.yaml

@@ -0,0 +1,16 @@
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. operator, target allocator, github action)
+component: operator
+
+# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Run the upgrade mechanism when there is a change in an instance to ensure it is upgraded. This is useful for cases where the instance uses the unmanaged state, the operator is upgraded and the instance changes to use a managed state."
+
+# One or more tracking issues related to the change
+issues: [1890]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:

pkg/collector/reconcile/opentelemetry.go

@@ -30,6 +30,7 @@ import (
 
 	"github.com/open-telemetry/opentelemetry-operator/apis/v1alpha1"
 	"github.com/open-telemetry/opentelemetry-operator/internal/version"
+	collectorupgrade "github.com/open-telemetry/opentelemetry-operator/pkg/collector/upgrade"
 )
 
 // Self updates this instance's self data. This should be the last item in the reconciliation, as it causes changes
@@ -38,6 +39,17 @@ import (
 func Self(ctx context.Context, params manifests.Params) error {
 	changed := params.Instance
 
+	up := &collectorupgrade.VersionUpgrade{
+		Log:      params.Log,
+		Version:  version.Get(),
+		Client:   params.Client,
+		Recorder: params.Recorder,
+	}
+	changed, err := up.ManagedInstance(ctx, changed)
+	if err != nil {
+		return fmt.Errorf("failed to upgrade the OpenTelemetry CR: %w", err)
+	}
+
 	// this field is only changed for new instances: on existing instances this
 	// field is reconciled when the operator is first started, i.e. during
 	// the upgrade mechanism
@@ -46,7 +58,7 @@ func Self(ctx context.Context, params manifests.Params) error {
 		changed.Status.Version = version.OpenTelemetryCollector()
 	}
 
-	if err := updateScaleSubResourceStatus(ctx, params.Client, &changed); err != nil {
+	if err = updateScaleSubResourceStatus(ctx, params.Client, &changed); err != nil {
 		return fmt.Errorf("failed to update the scale subresource status for the OpenTelemetry CR: %w", err)
 	}