Add CLI flag for OCIRepo verify secret

Signed-off-by: Matheus Pimenta <matheuscscp@gmail.com>

internal/flags/source_oci_verify_provider.go

@@ -0,0 +1,58 @@
+/*
+Copyright 2023 The Flux authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package flags
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/fluxcd/flux2/v2/internal/utils"
+)
+
+var supportedSourceOCIVerifyProviders = []string{
+	"cosign",
+}
+
+type SourceOCIVerifyProvider string
+
+func (p *SourceOCIVerifyProvider) String() string {
+	return string(*p)
+}
+
+func (p *SourceOCIVerifyProvider) Set(str string) error {
+	if strings.TrimSpace(str) == "" {
+		return fmt.Errorf("no source OCI verify provider given, please specify %s",
+			p.Description())
+	}
+	if !utils.ContainsItemString(supportedSourceOCIVerifyProviders, str) {
+		return fmt.Errorf("source OCI verify provider '%s' is not supported, must be one of: %v",
+			str, strings.Join(supportedSourceOCIVerifyProviders, ", "))
+	}
+	*p = SourceOCIVerifyProvider(str)
+	return nil
+}
+
+func (p *SourceOCIVerifyProvider) Type() string {
+	return "sourceOCIVerifyProvider"
+}
+
+func (p *SourceOCIVerifyProvider) Description() string {
+	return fmt.Sprintf(
+		"the OCI verify provider name to use for signature verification, available options are: (%s)",
+		strings.Join(supportedSourceOCIVerifyProviders, ", "),
+	)
+}

internal/flags/source_oci_verify_provider_test.go

@@ -0,0 +1,48 @@
+//go:build !e2e
+// +build !e2e
+
+/*
+Copyright 2023 The Flux authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package flags
+
+import (
+	"testing"
+)
+
+func TestSourceOCIVerifyProvider_Set(t *testing.T) {
+	tests := []struct {
+		name      string
+		str       string
+		expect    string
+		expectErr bool
+	}{
+		{"supported", "cosign", "cosign", false},
+		{"unsupported", "unsupported", "", true},
+		{"empty", "", "", true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var s SourceOCIVerifyProvider
+			if err := s.Set(tt.str); (err != nil) != tt.expectErr {
+				t.Errorf("Set() error = %v, expectErr %v", err, tt.expectErr)
+			}
+			if str := s.String(); str != tt.expect {
+				t.Errorf("Set() = %v, expect %v", str, tt.expect)
+			}
+		})
+	}
+}