enh: validate gardenctl config on load

gardener · petersutter · Dec 13, 2022 · Nov 21, 2022 · Nov 21, 2022 · Nov 21, 2022
commit e8a9c411e1603d87431ab647378fa84c6cc4244b
@@ -28,9 +28,10 @@ Attention `brew` users: `gardenctl-v2` uses the same binary name as the legacy `
 
 ### Install from Github Release
 
-If you install via GitHub releases, you need to 
-- put the `gardenctl` binary on your path 
-- and [install gardenlogin](https://github.com/gardener/gardenlogin#installation). 
+If you install via GitHub releases, you need to
+
+- put the `gardenctl` binary on your path
+- and [install gardenlogin](https://github.com/gardener/gardenlogin#installation).
 
 The other install methods do this for you.
 
@@ -61,7 +62,8 @@ sudo mv "./gardenctl_v2_${os}_${arch}" /usr/local/bin/gardenctl
 You can modify this file directly using the `gardenctl config` command. It allows adding, modifying and deleting gardens.
 
 Example `config` command:
-``` bash
+
+```bash
 # Adapt the path to your kubeconfig file for the garden cluster
 export KUBECONFIG=~/relative/path/to/kubeconfig.yaml
 
@@ -80,15 +82,17 @@ cluster_identity=$(echo ${identity_status#"$prefix"})
 # Configure garden cluster
 gardenctl config set-garden $cluster_identity --kubeconfig $KUBECONFIG
 ```
+
 This command will create or update a garden with the provided identity and kubeconfig path of your garden cluster.
 
 ### Example Config
 
 ```yaml
 gardens:
-- identity: landscape-dev # Unique identity of the garden cluster. See cluster-identity ConfigMap in kube-system namespace of the garden cluster
-  kubeconfig: ~/relative/path/to/kubeconfig.yaml
-# context: different-context # Overrides the current-context of the garden cluster kubeconfig  
+  - identity: landscape-dev # Unique identity of the garden cluster. See cluster-identity ConfigMap in kube-system namespace of the garden cluster
+    kubeconfig: ~/relative/path/to/kubeconfig.yaml
+# name: my-name # An alternative, unique garden name for targeting
+# context: different-context # Overrides the current-context of the garden cluster kubeconfig
 # patterns: ~ # List of regex patterns for pattern targeting
 ```
 
@@ -115,23 +119,27 @@ this leads to an error and gardenctl cannot be executed. The `target.yaml` and t
 
 You can make sure that `GCTL_SESSION_ID` or `TERM_SESSION_ID` is always present by adding
 the following code to your terminal profile `~/.profile`, `~/.bashrc` or comparable file.
+
 ```sh
 bash and zsh: [ -n "$GCTL_SESSION_ID" ] || [ -n "$TERM_SESSION_ID" ] || export GCTL_SESSION_ID=$(uuidgen)
 ```
+
 ```sh
 fish:         [ -n "$GCTL_SESSION_ID" ] || [ -n "$TERM_SESSION_ID" ] || set -gx GCTL_SESSION_ID (uuidgen)
 ```
+
 ```ps
 powershell:   if ( !(Test-Path Env:GCTL_SESSION_ID) -and !(Test-Path Env:TERM_SESSION_ID) ) { $Env:GCTL_SESSION_ID = [guid]::NewGuid().ToString() }
 ```
 
 ### Completion
 
 Gardenctl supports completion that will help you working with the CLI and save you typing effort.
-It will also help you find clusters by providing suggestions for gardener resources such as shoots or projects. 
+It will also help you find clusters by providing suggestions for gardener resources such as shoots or projects.
 Completion is supported for `bash`, `zsh`, `fish` and `powershell`.
 You will find more information on how to configure your shell completion for gardenctl by executing the help for
 your shell completion command. Example:
+
 ```bash
 gardenctl completion bash --help
 ```
@@ -145,29 +153,34 @@ You can set a target to use it in subsequent commands. You can also overwrite th
 Note that this will not affect your KUBECONFIG env variable. To update the KUBECONFIG env for your current target see [Configure KUBECONFIG](#configure-kubeconfig-for-shoot-clusters) section
 
 Example:
+
 ```bash
 # target control plane
 gardenctl target --garden landscape-dev --project my-project --shoot my-shoot --control-plane
 ```
+
 Find more information in the [documentation](docs/usage/targeting.md).
 
 ### Configure KUBECONFIG for Shoot Clusters
 
 Generate a script that points KUBECONFIG to the targeted cluster for the specified shell. Use together with `eval` to configure your shell. Example for `bash`:
+
 ```bash
 eval $(gardenctl kubectl-env bash)
 ```
 
 ### Configure Cloud Provider CLIs
 
 Generate the cloud provider CLI configuration script for the specified shell. Use together with `eval` to configure your shell. Example for `bash`:
+
 ```bash
 eval $(gardenctl provider-env bash)
 ```
 
 ### SSH
 
 Establish an SSH connection to a Shoot cluster's node.
+
 ```bash
 gardenctl ssh my-node
 ```
@@ -99,9 +99,46 @@ func LoadFromFile(filename string) (*Config, error) {
 		config.LinkKubeconfig = &val
 	}
 
+	if err := config.validate(); err != nil {
+		return nil, err
+	}
+
 	return config, nil
 }
 
+// validate checks the config for static errors. It does not check if the kubeconfig file exists.
+func (config *Config) validate() error {
+	seen := make(map[string]bool, len(config.Gardens))
+
+	for i := range config.Gardens {
+		garden := config.Gardens[i]
+
+		if garden.Name == "" {
+			return fmt.Errorf("identity is required for gardens in the gardenctl configuration")
+		}
+
+		if garden.Kubeconfig == "" {
+			return fmt.Errorf("kubeconfig is required for gardens in the gardenctl configuration")
+		}
+
+		if seen[garden.Name] {
+			return fmt.Errorf("identity and alias must be unique but %q was found multiple times in gardenctl configuration", garden.Name)
+		}
+
+		if garden.Alias != "" {
+			if seen[garden.Alias] {
+				return fmt.Errorf("identity and alias must be unique but %q was found multiple times in gardenctl configuration", garden.Alias)
+			}
+
+			seen[garden.Alias] = true
+		}
+
+		seen[garden.Name] = true
+	}
+
+	return nil
+}
+
 // SymlinkTargetKubeconfig indicates if the kubeconfig of the current target should be always symlinked.
 func (config *Config) SymlinkTargetKubeconfig() bool {
 	return config.LinkKubeconfig == nil || *config.LinkKubeconfig
@@ -157,16 +194,9 @@ func (config *Config) Garden(name string) (*Garden, error) {
 
 	for idx := range config.Gardens {
 		cfg := &config.Gardens[idx]
-
-		if name != cfg.Name && name != cfg.Alias {
-			continue
+		if name == cfg.Name || name == cfg.Alias {
+			return cfg, nil
 		}
-
-		if gardenConfig != nil {
-			return nil, fmt.Errorf("identity or alias %q must be unique but was found multiple times in gardenctl configuration", cfg.Name)
-		}
-
-		gardenConfig = cfg
 	}
 
 	if gardenConfig == nil {