feat: ability to defaultAzureCredential for azure-blob-storage (#64)

This patch adds support for Azure AD-based authentication using the
DefaultAzureCredential mechanism.

Closes #59

Signed-off-by: Tao Li <tao.li@enterprisedb.com>
Signed-off-by: Armando Ruocco <armando.ruocco@enterprisedb.com>
Co-authored-by: Armando Ruocco <armando.ruocco@enterprisedb.com>

Author: litaocdl

pkg/command/commandbuilder.go

@@ -111,6 +111,10 @@ func appendCloudProviderOptions(
 			"--cloud-provider",
 			"azure-blob-storage")
 
+		if useDefaultAzureCredentials(ctx) {
+			break
+		}
+
 		if !credentials.Azure.InheritFromAzureAD {
 			break
 		}
@@ -143,3 +147,26 @@ func appendCloudProviderOptions(
 
 	return options, nil
 }
+
+type contextKey string
+
+// contextKeyUseDefaultAzureCredentials contains a bool indicating if the default azure credentials should be used
+const contextKeyUseDefaultAzureCredentials contextKey = "useDefaultAzureCredentials"
+
+func useDefaultAzureCredentials(ctx context.Context) bool {
+	v := ctx.Value(contextKeyUseDefaultAzureCredentials)
+	if v == nil {
+		return false
+	}
+	result, ok := v.(bool)
+	if !ok {
+		return false
+	}
+	return result
+}
+
+// ContextWithDefaultAzureCredentials create a context that contains the contextKeyUseDefaultAzureCredentials flag.
+// When set to true barman-cloud will use the default Azure credentials.
+func ContextWithDefaultAzureCredentials(ctx context.Context, enabled bool) context.Context {
+	return context.WithValue(ctx, contextKeyUseDefaultAzureCredentials, enabled)
+}

pkg/command/commandbuilder_test.go

@@ -17,6 +17,7 @@ limitations under the License.
 package command
 
 import (
+	"context"
 	"strings"
 
 	barmanApi "github.com/cloudnative-pg/barman-cloud/pkg/api"
@@ -57,3 +58,24 @@ var _ = Describe("barmanCloudWalRestoreOptions", func() {
 				))
 	})
 })
+
+var _ = Describe("useDefaultAzureCredentials", func() {
+	It("should be false by default", func(ctx SpecContext) {
+		Expect(useDefaultAzureCredentials(ctx)).To(BeFalse())
+	})
+
+	It("should be false if ctx contains an invalid value", func(ctx SpecContext) {
+		newCtx := context.WithValue(ctx, contextKeyUseDefaultAzureCredentials, "invalidValue")
+		Expect(useDefaultAzureCredentials(newCtx)).To(BeFalse())
+	})
+
+	It("should be false if ctx contains false value", func(ctx SpecContext) {
+		newCtx := context.WithValue(ctx, contextKeyUseDefaultAzureCredentials, false)
+		Expect(useDefaultAzureCredentials(newCtx)).To(BeFalse())
+	})
+
+	It("should be true only if ctx contains true value", func(ctx SpecContext) {
+		newCtx := context.WithValue(ctx, contextKeyUseDefaultAzureCredentials, true)
+		Expect(useDefaultAzureCredentials(newCtx)).To(BeTrue())
+	})
+})