Flux CLI change to add provider field to GitRepository spec.

- Add provider flag to `flux create source git` command with supported values: azure, generic.

- Unit tests validating the generated yaml and error conditions.

Signed-off-by: Dipti Pai <diptipai89@outlook.com>

internal/flags/source_git_provider.go

@@ -0,0 +1,57 @@
+/*
+Copyright 2024 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"
+	sourcev1 "github.com/fluxcd/source-controller/api/v1"
+)
+
+var supportedSourceGitProviders = []string{
+	sourcev1.GitProviderGeneric,
+	sourcev1.GitProviderAzure,
+}
+
+type SourceGitProvider string
+
+func (p *SourceGitProvider) String() string {
+	return string(*p)
+}
+
+func (p *SourceGitProvider) Set(str string) error {
+	if strings.TrimSpace(str) == "" {
+		return fmt.Errorf("no source Git provider given, please specify %s",
+			p.Description())
+	}
+	if !utils.ContainsItemString(supportedSourceGitProviders, str) {
+		return fmt.Errorf("source Git provider '%s' is not supported, must be one of: %v",
+			str, p.Type())
+	}
+	*p = SourceGitProvider(str)
+	return nil
+}
+
+func (p *SourceGitProvider) Type() string {
+	return strings.Join(supportedSourceGitProviders, "|")
+}
+
+func (p *SourceGitProvider) Description() string {
+	return "the Git provider name"
+}