Use env variables for kubernetes url, no need for config (#110)

README.adoc

@@ -2,6 +2,8 @@
 
 A container that will read mounted container logfiles, then enriches them using Kubernetes API server, and forwards them with RELP to wanted target server.
 
+It uses KUBERNETES_SERVICE_HOST and KUBERNETES_SERVICE_PORT environment variables to connect to the Kubernetes API.
+
 ## Example Helm Chart usage
 
 See `k8s_01/` directory for more information
@@ -14,8 +16,6 @@ Currently supported:
 
  - `K8S_01_RELP_PORT` overwrites `.relp.port`
 
- - `K8S_01_KUBERNETES_URL` overwrites `.kubernetes.url`
-
 ## Example test cluster usage
 
 You can find example cluster in `/example` directory

example/combined.yaml

@@ -41,7 +41,6 @@ data:
       },
       "kubernetes": {
         "logdir": "/var/log/containers",
-        "url": "https://127.0.0.1:8443",
         "timezone": "Europe/Helsinki",
         "cacheExpireInterval": 300,
         "cacheMaxEntries": 4096,
@@ -109,7 +108,7 @@ data:
     </Configuration>
 kind: ConfigMap
 metadata:
-  name: app-config-5tmb2cmh92
+  name: app-config-674ff8b7bd
 ---
 apiVersion: v1
 data:
@@ -293,12 +292,11 @@ spec:
   - args:
     - -c
     - export K8S_01_RELP_TARGET="${RELP_SERVICE_SERVICE_HOST}"; export K8S_01_RELP_PORT="${RELP_SERVICE_SERVICE_PORT}";
-      export K8S_01_KUBERNETES_URL="https://${KUBERNETES_SERVICE_HOST}:${KUBERNETES_SERVICE_PORT}";
       cd /opt/teragrep/k8s_01 || exit 1; exec /usr/bin/java -Dlog4j2.configurationFile=file:etc/log4j2.xml
       -jar lib/k8s_01.jar;
     command:
     - /usr/bin/bash
-    image: ghcr.io/teragrep/k8s_01/app:latest
+    image: ghcr.io/teragrep/k8s_01:latest
     imagePullPolicy: IfNotPresent
     name: kubelogreader
     volumeMounts:
@@ -326,7 +324,7 @@ spec:
   terminationGracePeriodSeconds: 30
   volumes:
   - configMap:
-      name: app-config-5tmb2cmh92
+      name: app-config-674ff8b7bd
     name: app-config
   - hostPath:
       path: /var/log/containers

example/config/k8s_01/config.json

@@ -4,7 +4,6 @@
   },
   "kubernetes": {
     "logdir": "/var/log/containers",
-    "url": "https://127.0.0.1:8443",
     "timezone": "Europe/Helsinki",
     "cacheExpireInterval": 300,
     "cacheMaxEntries": 4096,

example/pods/k8s_01.json

@@ -54,7 +54,7 @@
     ],
     "containers": [
       {
-        "image": "ghcr.io/teragrep/k8s_01/app:latest",
+        "image": "ghcr.io/teragrep/k8s_01:latest",
         "imagePullPolicy": "IfNotPresent",
         "name": "kubelogreader",
         "volumeMounts": [
@@ -88,7 +88,7 @@
         ],
         "args": [
           "-c",
-          "export K8S_01_RELP_TARGET=\"${RELP_SERVICE_SERVICE_HOST}\"; export K8S_01_RELP_PORT=\"${RELP_SERVICE_SERVICE_PORT}\"; export K8S_01_KUBERNETES_URL=\"https://${KUBERNETES_SERVICE_HOST}:${KUBERNETES_SERVICE_PORT}\"; cd /opt/teragrep/k8s_01 || exit 1; exec /usr/bin/java -Dlog4j2.configurationFile=file:etc/log4j2.xml -jar lib/k8s_01.jar;"
+          "export K8S_01_RELP_TARGET=\"${RELP_SERVICE_SERVICE_HOST}\"; export K8S_01_RELP_PORT=\"${RELP_SERVICE_SERVICE_PORT}\"; cd /opt/teragrep/k8s_01 || exit 1; exec /usr/bin/java -Dlog4j2.configurationFile=file:etc/log4j2.xml -jar lib/k8s_01.jar;"
         ]
       }
     ],

k8s_01/values.yaml

@@ -12,8 +12,6 @@ config:
   kubernetes:
     # Base path where logs are read from. Uses {logdir}/{logfiles}
     logdir: /var/log/containers
-    # Kubernetes API url where metadata is asked from. Can be dynamically set with "K8S_01_KUBERNETES_URL" environment variable.
-    url: https://127.0.0.1:8443
     # Timezone used by the logs
     timezone: Europe/Helsinki
     # How long API responses are cached

rpm/config.json

@@ -4,7 +4,6 @@
   },
   "kubernetes": {
     "logdir": "/var/log/containers",
-    "url": "https://127.0.0.1:8443",
     "timezone": "Europe/Helsinki",
     "cacheExpireInterval": 900,
     "cacheMaxEntries": 4096,

src/main/java/com/teragrep/k8s_01/K8SConsumer.java

@@ -61,14 +61,17 @@ public class K8SConsumer implements Consumer<FileRecord> {
     private static final Pattern appNamePattern = Pattern.compile("^[\\x21-\\x7e]+$"); // DEC 33 - DEC 126 as specified in RFC5424
     private final boolean discardEnabled;
     private final String discardLabel;
+    private final String apiUrl;
     K8SConsumer(
             AppConfig appConfig,
             KubernetesCachingAPIClient cacheClient,
-            BlockingQueue<RelpOutput> relpOutputPool
+            BlockingQueue<RelpOutput> relpOutputPool,
+            String apiUrl
     ) {
         this.appConfig = appConfig;
         this.cacheClient = cacheClient;
         this.relpOutputPool = relpOutputPool;
+        this.apiUrl = apiUrl;
         this.timezoneId = ZoneId.of(appConfig.getKubernetes().getTimezone());
         this.discardEnabled = appConfig.getKubernetes().getLabels().getDiscard().isEnabled();
         this.discardLabel = appConfig.getKubernetes().getLabels().getDiscard().getLabel();
@@ -207,7 +210,7 @@ public void accept(FileRecord record) {
                     namespaceMetadataContainer,
                     podMetadataContainer,
                     ContainerInfo.getContainerName(record.getFilename()),
-                    appConfig.getKubernetes().getUrl()
+                    apiUrl
             );
             JsonObject dockerMetadata = new JsonObject();
             dockerMetadata.addProperty("container_id", containerId);

src/main/java/com/teragrep/k8s_01/K8SConsumerSupplier.java

@@ -19,8 +19,6 @@
 
 import com.teragrep.k8s_01.config.AppConfig;
 import com.teragrep.rlo_13.FileRecord;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 import java.util.concurrent.BlockingQueue;
 import java.util.function.Consumer;
@@ -30,19 +28,22 @@ public class K8SConsumerSupplier implements Supplier<Consumer<FileRecord>> {
     private final AppConfig appConfig;
     private final KubernetesCachingAPIClient cacheClient;
     private final BlockingQueue<RelpOutput> relpOutputPool;
+    private final String apiUrl;
 
     K8SConsumerSupplier(
             AppConfig appConfig,
             KubernetesCachingAPIClient cacheClient,
-            BlockingQueue<RelpOutput> relpOutputPool
+            BlockingQueue<RelpOutput> relpOutputPool,
+            String apiUrl
     ) {
         this.appConfig = appConfig;
         this.cacheClient = cacheClient;
         this.relpOutputPool = relpOutputPool;
+        this.apiUrl = apiUrl;
     }
 
     @Override
     public Consumer<FileRecord> get() {
-        return new K8SConsumer(appConfig, cacheClient, relpOutputPool);
+        return new K8SConsumer(appConfig, cacheClient, relpOutputPool, apiUrl);
     }
 }

src/main/java/com/teragrep/k8s_01/KubernetesCachingAPIClient.java

@@ -43,11 +43,11 @@ class KubernetesCachingAPIClient {
     private LoadingCache<String, NamespaceMetadataContainer> namespaceCache;
     private final AppConfigKubernetes config;
 
-    KubernetesCachingAPIClient(AppConfigKubernetes appConfigKubernetes) throws IOException {
+    KubernetesCachingAPIClient(AppConfigKubernetes appConfigKubernetes, String apiUrl) throws IOException {
         config = appConfigKubernetes;
         LOGGER.info(
                 "Starting Caching API Client using {}",
-                config.getUrl()
+                apiUrl
         );
         LOGGER.info(
                 "Keeping up to {} cached entries for {} seconds before evicting.",
@@ -60,7 +60,7 @@ class KubernetesCachingAPIClient {
         );
         try {
             ApiClient client = Config.fromCluster();
-            client.setBasePath(config.getUrl());
+            client.setBasePath(apiUrl);
             Configuration.setDefaultApiClient(client);
             api = new CoreV1Api();
         } catch (Exception e) {

src/main/java/com/teragrep/k8s_01/KubernetesLogReader.java

@@ -75,7 +75,6 @@ public static void main(String[] args) throws IOException, InterruptedException
             return;
         }
         try {
-            appConfig.getKubernetes().handleOverrides();
             appConfig.getRelp().handleOverrides();
             appConfig.validate();
         }
@@ -86,13 +85,22 @@ public static void main(String[] args) throws IOException, InterruptedException
             );
             return;
         }
+
+        String apiAddress = System.getenv("KUBERNETES_SERVICE_HOST");
+        String apiPort = System.getenv("KUBERNETES_SERVICE_PORT");
+        if(apiAddress == null || apiPort == null) {
+            LOGGER.error("Can't resolve KUBERNETES_SERVICE_HOST and/or KUBERNETES_SERVICE_PORT environment variables, can't continue.");
+            return;
+        }
+        String apiUrl = String.format("https://%s:%s", apiAddress, apiPort);
+
         if(appConfig.getKubernetes().getLabels().getDiscard().isEnabled()) {
             LOGGER.warn(
                     "WARNING: Event discarding is enabled. This will lose any data from pods that has label <[{}]> that is equal to \"true\".",
                     appConfig.getKubernetes().getLabels().getDiscard().getLabel()
             );
         }
-        KubernetesCachingAPIClient cacheClient = new KubernetesCachingAPIClient(appConfig.getKubernetes());
+        KubernetesCachingAPIClient cacheClient = new KubernetesCachingAPIClient(appConfig.getKubernetes(), apiUrl);
         PrometheusMetrics prometheusMetrics = new PrometheusMetrics(appConfig.getMetrics().getPort());
 
         // Pool of Relp output threads to be shared by every consumer
@@ -124,7 +132,7 @@ public static void main(String[] args) throws IOException, InterruptedException
         }
 
         // consumer supplier, returns always the same instance
-        K8SConsumerSupplier consumerSupplier = new K8SConsumerSupplier(appConfig, cacheClient, relpOutputPool);
+        K8SConsumerSupplier consumerSupplier = new K8SConsumerSupplier(appConfig, cacheClient, relpOutputPool, apiUrl);
         String[] logfiles = appConfig.getKubernetes().getLogfiles();
         LOGGER.debug(
                 "Monitored logfiles: {}",

src/main/java/com/teragrep/k8s_01/config/AppConfigKubernetes.java

@@ -25,22 +25,11 @@
 /* POJO representing the .kubernetes part of config.json */
 public class AppConfigKubernetes implements BaseConfig {
     private static final Logger LOGGER = LoggerFactory.getLogger(AppConfigKubernetes.class);
-    public void handleOverrides() {
-        String kubernetesUrl = System.getenv("K8S_01_KUBERNETES_URL");
-        if(kubernetesUrl != null) {
-            LOGGER.info(
-                    "Found K8S_01_KUBERNETES_URL environment variable <[{}]>, using it as kubernetes url.",
-                    kubernetesUrl
-            );
-            this.url = kubernetesUrl;
-        }
-    }
     private Integer cacheExpireInterval;
     private Integer cacheMaxEntries;
     private String logdir;
     private AppConfigLabels labels;
     private String[] logfiles;
-    private String url;
     private String timezone;
     private Integer maxLogReadingThreads;
 
@@ -59,10 +48,6 @@ public AppConfigLabels getLabels() {
     public String[] getLogfiles() {
         return logfiles;
     }
-
-    public String getUrl() {
-        return url;
-    }
     public Integer getCacheMaxEntries() {
         return cacheMaxEntries;
     }
@@ -102,10 +87,6 @@ public void validate() throws InvalidConfigurationException {
             }
         }
 
-        if(url == null) {
-            throw new InvalidConfigurationException("url not found or is null in kubernetes config object");
-        }
-
         if(timezone == null) {
             throw new InvalidConfigurationException("timezone not found or is null in kubernetes config object");
         }