kubernetesapi-report: Support authentication via kube config file (#174)

plugins/kubernetesapi-report/README.md

@@ -15,11 +15,13 @@ sauron.plugins:
   kubernetesapi-report:
     serviceLabel: "label/service.name" # The label that will used as a selector to find the resource by serviceName
     # When checks are needed in different clusters:
-    #  - deploy https://hub.docker.com/r/bitnami/kubectl/ as service in the desired cluster
-    #  - set below the url for the cluster     
+    #  - Set up a kube config file, see https://kubernetes.io/docs/concepts/configuration/organize-cluster-access-kubeconfig/.
+    #  - Set up an association between the environment name and the name of a context in the kube config file.
+    #  - Optionally, use kubeConfigFile to set the location of the kube config file. Defaults to "$HOME/.kube/config" if not set.
     apiClientConfig:
       default: "default"
-      clusterName: "cluster-url"
+      environmentName: "kubeConfigContextName"
+    kubeConfigFile: "/home/user/.kube/config"
     selectors:
       pod:
         - label
@@ -51,4 +53,4 @@ The possible selectors can be found in
 
 - All the selector's value that can be found assigned to the specified resources
 - All the environment variables and its values that were found in the running pod
-- All the values found in the property files for the running pod
+- All the values found in the property files for the running pod

plugins/kubernetesapi-report/src/main/java/com/freenow/sauron/plugins/APIClientFactory.java

@@ -3,15 +3,23 @@
 import com.freenow.sauron.model.DataSet;
 import com.freenow.sauron.properties.PluginsConfigurationProperties;
 import io.kubernetes.client.openapi.ApiClient;
+import io.kubernetes.client.util.ClientBuilder;
 import io.kubernetes.client.util.Config;
+import io.kubernetes.client.util.KubeConfig;
+import java.io.File;
+import java.io.FileReader;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
 import lombok.NoArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 
 import static com.freenow.sauron.plugins.KubernetesApiReport.API_CLIENT_CONFIG_PROPERTY;
+import static com.freenow.sauron.plugins.KubernetesApiReport.KUBE_CONFIG_FILE_PROPERTY;
 import static com.freenow.sauron.plugins.KubernetesApiReport.PLUGIN_ID;
+import static io.kubernetes.client.util.KubeConfig.ENV_HOME;
+import static io.kubernetes.client.util.KubeConfig.KUBECONFIG;
+import static io.kubernetes.client.util.KubeConfig.KUBEDIR;
 import static org.apache.commons.lang3.StringUtils.EMPTY;
 
 @Slf4j
@@ -31,28 +39,41 @@ public APIClientFactory(final Map<String, ApiClient> apiClients)
     }
 
 
+    /**
+     * Creates the Kubernetes API client for an environment.
+     * It reads the environment from the field "environment" in the DataSet.
+     * If no client for the environment can be found, then it falls back to a default client.
+     * <p>
+     * The configuration of this plugin supports multiple ways to create an API client:
+     * <pre>
+     *     kubernetesapi-report:
+     *       # ...
+     *       apiClientConfig:
+     *         default: default # Use the default client
+     *         clusterOne: "https://clusterOne.local" # Use a URL
+     *         clusterTwo: clusterTwo # Use the context "clusterTwo" from the kube config file at $HOME/.kube/config
+     *       # ...
+     * </pre>
+     *
+     * @param input The current DataSet.
+     * @param properties Plugin configuration.
+     * @return Kubernetes API client.
+     */
     public ApiClient get(final DataSet input, final PluginsConfigurationProperties properties)
     {
         if (apiClients.isEmpty())
         {
+            String kubeConfigFile;
+            if (properties.getPluginConfigurationProperty(PLUGIN_ID, KUBE_CONFIG_FILE_PROPERTY).isPresent())
+            {
+                kubeConfigFile = (String) properties.getPluginConfigurationProperty(PLUGIN_ID, KUBE_CONFIG_FILE_PROPERTY).get();
+            } else {
+                kubeConfigFile = "";
+            }
+
             properties.getPluginConfigurationProperty(PLUGIN_ID, API_CLIENT_CONFIG_PROPERTY)
                 .ifPresent(config -> ((Map<String, String>) config).forEach((k, v) -> {
-                    if (DEFAULT_CLIENT_CONFIG.equalsIgnoreCase(k))
-                    {
-                        try
-                        {
-                            apiClients.put(DEFAULT_CLIENT_CONFIG, Config.defaultClient());
-                        }
-                        catch (Exception e)
-                        {
-                            log.error("API Client not initialized. Error: {}", e.getMessage(), e);
-                            throw new RuntimeException(e);
-                        }
-                    }
-                    else
-                    {
-                        apiClients.put(k, Config.fromUrl(v));
-                    }
+                    apiClients.put(k, createClient(k, v, kubeConfigFile));
                 }));
 
             if (apiClients.isEmpty())
@@ -70,4 +91,44 @@ public ApiClient get(final DataSet input, final PluginsConfigurationProperties p
         }
         return Optional.ofNullable(apiClients.get(input.getStringAdditionalInformation(ENVIRONMENT).orElse(EMPTY))).orElse(apiClients.get(DEFAULT_CLIENT_CONFIG));
     }
+
+    private ApiClient createClient(String cluster, String value, String kubeConfigFile)
+    {
+        try
+        {
+            if (DEFAULT_CLIENT_CONFIG.equalsIgnoreCase(cluster))
+            {
+                log.debug("Creating default Kubernetes client for cluster {}", cluster);
+                return Config.defaultClient();
+            }
+
+            if (value.startsWith("https://"))
+            {
+                log.debug("Creating Kubernetes client from URL {} for cluster {}", value, cluster);
+                return Config.fromUrl(value);
+            }
+
+            log.debug("Creating Kubernetes client from config for cluster {}", cluster);
+            // Create KubeConfig here because it allows setting the context.
+            File configFile = getKubeConfig(kubeConfigFile);
+            KubeConfig kubeConfig = KubeConfig.loadKubeConfig(new FileReader(configFile));
+            kubeConfig.setContext(value);
+            return ClientBuilder.kubeconfig(kubeConfig).build();
+        }
+        catch (Exception e)
+        {
+            log.error("API Client for {} not initialized. Error: {}", cluster, e.getMessage(), e);
+            throw new RuntimeException(e);
+        }
+    }
+
+    private File getKubeConfig(String path)
+    {
+        if (path == null || path.isEmpty())
+        {
+            return new File(new File(System.getenv(ENV_HOME), KUBEDIR), KUBECONFIG);
+        }
+
+        return new File(path);
+    }
 }

plugins/kubernetesapi-report/src/main/java/com/freenow/sauron/plugins/KubernetesApiReport.java

@@ -21,6 +21,7 @@ public class KubernetesApiReport implements SauronExtension
     static final String SELECTORS_PROPERTY = "selectors";
     static final String ENV_VARS_PROPERTY = "environmentVariablesCheck";
     static final String PROPERTIES_FILES_CHECK = "propertiesFilesCheck";
+    static final String KUBE_CONFIG_FILE_PROPERTY = "kubeConfigFile";
 
     private APIClientFactory apiClientFactory = new APIClientFactory();
     private KubernetesLabelAnnotationReader kubernetesLabelAnnotationReader = new KubernetesLabelAnnotationReader();
@@ -64,4 +65,4 @@ public DataSet apply(PluginsConfigurationProperties properties, DataSet input)
         });
         return input;
     }
-}
+}

plugins/kubernetesapi-report/src/test/java/com/freenow/sauron/plugins/APIClientFactoryTest.java

@@ -3,25 +3,43 @@
 import com.freenow.sauron.model.DataSet;
 import com.freenow.sauron.properties.PluginsConfigurationProperties;
 import io.kubernetes.client.openapi.ApiClient;
+import io.kubernetes.client.util.ClientBuilder;
 import io.kubernetes.client.util.Config;
+import io.kubernetes.client.util.KubeConfig;
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
 import java.util.Map;
+import java.util.Objects;
+import org.apache.commons.io.IOUtils;
 import org.junit.Test;
 import org.mockito.MockedStatic;
 import org.mockito.Mockito;
 
 import static com.freenow.sauron.plugins.KubernetesApiReport.PLUGIN_ID;
+import static io.kubernetes.client.util.KubeConfig.ENV_HOME;
+import static io.kubernetes.client.util.KubeConfig.KUBECONFIG;
+import static io.kubernetes.client.util.KubeConfig.KUBEDIR;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 public class APIClientFactoryTest
 {
     private static final String DEFAULT = "default";
     private static final String CLUSTER_A = "cluster-a";
     private static final String CLUSTER_B = "cluster-b";
+    private static final String CLUSTER_C = "cluster-c";
     private static final String KUBERNETES_CLUSTER_DEFAULT = "http://localhost";
     public static final String KUBERNETES_CLUSTER_A_COM = "https://kubernetes.cluster-a.com";
     public static final String KUBERNETES_CLUSTER_B_COM = "https://kubernetes.cluster-b.com";
+    public static final String KUBERNETES_CLUSTER_C_LOCAL = "https://kubernetes.cluster-c.local";
     private APIClientFactory apiClientFactory = new APIClientFactory();
 
 
@@ -61,6 +79,30 @@ public void clusterBApiClient()
     }
 
 
+    @Test
+    public void configApiClient()
+    {
+        URL kubeConfigFile = this.getClass().getClassLoader().getResource("kubeConfigFile.yaml");
+        PluginsConfigurationProperties properties = dummyPluginConfig();
+        properties.put(
+            PLUGIN_ID,
+            Map.of(
+                "apiClientConfig", Map.of(
+                    CLUSTER_C, CLUSTER_C
+                ),
+                "kubeConfigFile", kubeConfigFile.getFile()
+            )
+        );
+
+        final var apiClient = apiClientFactory.get(dummyDataSet(CLUSTER_C), properties);
+        assertNotNull(apiClient);
+        assertEquals(KUBERNETES_CLUSTER_C_LOCAL, apiClient.getBasePath());
+        assertFalse(apiClient.getBasePath().contains(KUBERNETES_CLUSTER_DEFAULT));
+        assertFalse(apiClient.getBasePath().contains(CLUSTER_A));
+        assertFalse(apiClient.getBasePath().contains(CLUSTER_B));
+    }
+
+
     private DataSet dummyDataSet(final String environment)
     {
         DataSet dataSet = new DataSet();
@@ -85,4 +127,4 @@ private PluginsConfigurationProperties dummyPluginConfig()
         );
         return properties;
     }
-}
+}

plugins/kubernetesapi-report/src/test/resources/kubeConfigFile.yaml

@@ -0,0 +1,16 @@
+apiVersion: v1
+kind: Config
+
+clusters:
+  - cluster:
+      server: https://kubernetes.cluster-c.local
+    name: cluster-c
+
+users:
+  - name: unittest
+
+contexts:
+  - context:
+      cluster: cluster-c
+      user: unittest
+    name: cluster-c