cmp parameter to enable git creds to be shared from repo server to th…

…e plugin

Signed-off-by: jmcshane <[email protected]>

cmpserver/plugin/config.go

@@ -28,6 +28,7 @@ type PluginConfigSpec struct {
 	Discover         Discover   `json:"discover"`
 	Parameters       Parameters `yaml:"parameters"`
 	PreserveFileMode bool       `json:"preserveFileMode,omitempty"`
+	ProvideGitCreds  bool       `json:"provideGitCreds,omitempty"`
 }
 
 // Discover holds find and fileName

cmpserver/plugin/plugin.go

@@ -427,7 +427,7 @@ func getParametersAnnouncement(ctx context.Context, appDir string, announcements
 
 func (s *Service) CheckPluginConfiguration(ctx context.Context, _ *empty.Empty) (*apiclient.CheckPluginConfigurationResponse, error) {
 	isDiscoveryConfigured := s.isDiscoveryConfigured()
-	response := &apiclient.CheckPluginConfigurationResponse{IsDiscoveryConfigured: isDiscoveryConfigured}
+	response := &apiclient.CheckPluginConfigurationResponse{IsDiscoveryConfigured: isDiscoveryConfigured, ProvideGitCreds: s.initConstants.PluginConfig.Spec.ProvideGitCreds}
 
 	return response, nil
 }

cmpserver/plugin/plugin.proto

@@ -61,6 +61,7 @@ message File {
 // CheckPluginConfigurationResponse contains a list of plugin configuration flags.
 message CheckPluginConfigurationResponse {
     bool isDiscoveryConfigured = 1;
+    bool provideGitCreds = 2;
 }
 
 // ConfigManagementPlugin Service

docs/operator-manual/config-management-plugins.md

@@ -113,6 +113,10 @@ spec:
   # If set to `true` then the plugin receives repository files with original file mode. Dangerous since the repository
   # might have executable files. Set to true only if you trust the CMP plugin authors.
   preserveFileMode: false
+
+  # If set to `true` then the plugin can retrieve git credentials from the reposerver during generate. Plugin authors 
+  # should ensure these credentials are appropriately protected during execution
+  provideGitCreds: false
 ```
 
 !!! note
@@ -503,3 +507,36 @@ spec:
     args: ["sample args"]
   preserveFileMode: true
 ```
+
+##### Provide Git Credentials
+
+By default, the config management plugin is responsible for providing its own credentials to additional Git repositories
+that may need to be accessed during manifest generation. The reposerver has these credentials available in its git creds
+store. When credential sharing is allowed, the git credentials used by the reposerver to clone the repository contents
+are shared for the lifetime of the execution of the config management plugin, utilizing git's `ASKPASS` method to make a
+call from the config management sidecar container to the reposerver to retrieve the initialized git credentials.
+
+Utilizing `ASKPASS` means that credentials are not proactively shared, but rather only provided when an operation requires
+them.
+
+To allow the plugin to access the reposerver git credentials, you can set `provideGitCreds` to `true` in the plugin spec:
+
+!!! warning
+    Make sure you trust the plugin you are using. If you set `provideGitCreds` to `true` then the plugin will receive
+    credentials used to clone the source Git repository.
+
+```yaml
+apiVersion: argoproj.io/v1alpha1
+kind: ConfigManagementPlugin
+metadata:
+  name: pluginName
+spec:
+  init:
+    command: ["sample command"]
+    args: ["sample args"]
+  generate:
+    command: ["sample command"]
+    args: ["sample args"]
+  provideGitCreds: true
+```
+

reposerver/repository/repository.go

@@ -31,6 +31,8 @@ import (
 	"golang.org/x/sync/semaphore"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
+	"google.golang.org/protobuf/types/known/emptypb"
+
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
@@ -1458,7 +1460,7 @@ func GenerateManifests(ctx context.Context, appPath, repoRoot, revision string,
 			pluginName = q.ApplicationSource.Plugin.Name
 		}
 		// if pluginName is provided it has to be `<metadata.name>-<spec.version>` or just `<metadata.name>` if plugin version is empty
-		targetObjs, err = runConfigManagementPluginSidecars(ctx, appPath, repoRoot, pluginName, env, q, opt.cmpTarDoneCh, opt.cmpTarExcludedGlobs, opt.cmpUseManifestGeneratePaths)
+		targetObjs, err = runConfigManagementPluginSidecars(ctx, appPath, repoRoot, pluginName, env, q, q.Repo.GetGitCreds(gitCredsStore), opt.cmpTarDoneCh, opt.cmpTarExcludedGlobs, opt.cmpUseManifestGeneratePaths)
 		if err != nil {
 			err = fmt.Errorf("plugin sidecar failed. %s", err.Error())
 		}
@@ -1975,7 +1977,7 @@ func getPluginParamEnvs(envVars []string, plugin *v1alpha1.ApplicationSourcePlug
 	return env, nil
 }
 
-func runConfigManagementPluginSidecars(ctx context.Context, appPath, repoPath, pluginName string, envVars *v1alpha1.Env, q *apiclient.ManifestRequest, tarDoneCh chan<- bool, tarExcludedGlobs []string, useManifestGeneratePaths bool) ([]*unstructured.Unstructured, error) {
+func runConfigManagementPluginSidecars(ctx context.Context, appPath, repoPath, pluginName string, envVars *v1alpha1.Env, q *apiclient.ManifestRequest, creds git.Creds, tarDoneCh chan<- bool, tarExcludedGlobs []string, useManifestGeneratePaths bool) ([]*unstructured.Unstructured, error) {
 	// compute variables.
 	env, err := getPluginEnvs(envVars, q)
 	if err != nil {
@@ -1996,6 +1998,22 @@ func runConfigManagementPluginSidecars(ctx context.Context, appPath, repoPath, p
 		log.Debugf("common root path calculated for application %s: %s", q.AppName, rootPath)
 	}
 
+	pluginConfigResponse, err := cmpClient.CheckPluginConfiguration(ctx, &emptypb.Empty{})
+	if err != nil {
+		return nil, fmt.Errorf("error calling cmp-server checkPluginConfiguration: %w", err)
+	}
+
+	if pluginConfigResponse.ProvideGitCreds {
+		if creds != nil {
+			closer, environ, err := creds.Environ()
+			if err != nil {
+				return nil, fmt.Errorf("failed to retrieve git creds environment variables: %w", err)
+			}
+			defer func() { _ = closer.Close() }()
+			env = append(env, environ...)
+		}
+	}
+
 	// generate manifests using commands provided in plugin config file in detected cmp-server sidecar
 	cmpManifests, err := generateManifestsCMP(ctx, appPath, rootPath, env, cmpClient, tarDoneCh, tarExcludedGlobs)
 	if err != nil {