Set annotation featureRestartCount

CHANGELOG.md

@@ -7,6 +7,8 @@
 - Check added on startup if the configured directories exist and are
   writable by the Stackable agent ([#273]).
 - Missing directories are created ([#274]).
+- Annotation `featureRestartCount` added to the pods to indicate if the
+  restart count is set properly ([#289]).
 
 ### Changed
 - Lazy validation of repository URLs changed to eager validation
@@ -35,6 +37,7 @@
 [#273]: https://github.com/stackabletech/agent/pull/273
 [#274]: https://github.com/stackabletech/agent/pull/274
 [#276]: https://github.com/stackabletech/agent/pull/276
+[#289]: https://github.com/stackabletech/agent/pull/289
 
 ## 0.5.0 - 2021-07-26
 

Cargo.toml

@@ -50,8 +50,8 @@ tar = "0.4"
 thiserror = "1.0"
 tokio = { version = "1.11", features = ["macros", "rt-multi-thread", "time"] }
 url = "2.2"
-zbus = { git = "https://gitlab.freedesktop.org/dbus/zbus", rev = "0a8a4268be0f844ab4bca429f27766347dc3af58" } # version 2.0.0-beta.6 + merge request !354 (fixes a race condition)
-zvariant = { git = "https://gitlab.freedesktop.org/dbus/zbus", rev = "0a8a4268be0f844ab4bca429f27766347dc3af58" } # version 2.8.0 which is compatible with the zbus version
+zbus = { git = "https://gitlab.freedesktop.org/dbus/zbus", rev = "ff08cbbbcd3eead16464012b92e3862d4dcb6f16" } # version 2.0.0-beta.6 + merge request !354 (fixes a race condition) + commit 6cdfe48cda5e0bf7b0dd8675be7a84439678afa9 (fixes another race condition)
+zvariant = { git = "https://gitlab.freedesktop.org/dbus/zbus", rev = "ff08cbbbcd3eead16464012b92e3862d4dcb6f16" } # version 2.8.0 which is compatible with the zbus version
 
 [dev-dependencies]
 indoc = "1.0"

docs/modules/ROOT/pages/monitoring/restarts.adoc

@@ -0,0 +1,17 @@
+= Restarts
+
+The restart count is stored in the container status if systemd version
+235 or newer is running on the node which is the case for Debian 10 and
+CentOS 8 but not for CentOS 7. The annotation `featureRestartCount`
+indicates whether or not the restart count is set properly.
+
+    $ kubectl get pod <pod-name>
+    NAME         READY   STATUS    RESTARTS   AGE
+    <pod-name>   1/1     Running   4          10m
+
+    $ kubectl describe pod <pod-name>
+    Name:         <pod-name>
+    Annotations:  featureRestartCount: true
+    Containers:
+      <service-name>:
+        Restart Count:  4

src/provider/states/pod/starting.rs

@@ -1,3 +1,5 @@
+use std::collections::HashMap;
+
 use super::running::Running;
 use crate::provider::{
     kubernetes::status::patch_container_status, systemdmanager::service::ServiceState, PodHandle,
@@ -79,41 +81,46 @@ async fn start_service_units(
             );
         }
 
-        add_annotation(
-            &client,
-            pod,
+        let mut annotations = HashMap::new();
+        annotations.insert(
             "featureLogs",
-            &systemd_service.invocation_id().await.is_ok().to_string(),
-        )
-        .await?;
+            systemd_service.invocation_id().await.is_ok().to_string(),
+        );
+        annotations.insert(
+            "featureRestartCount",
+            systemd_service.restart_count().await.is_ok().to_string(),
+        );
+
+        add_annotations(&client, pod, &annotations).await?;
 
         patch_container_status(&client, pod, &container_key, &Status::running()).await;
     }
 
     Ok(())
 }
 
-/// Adds an annotation to the given pod.
+/// Adds annotations to the given pod.
 ///
 /// If there is already an annotation with the given key then the value
 /// is replaced.
 /// The function returns when the patch is sent. It does not await the
 /// changes to be visible to the watching clients.
-async fn add_annotation(client: &Client, pod: &Pod, key: &str, value: &str) -> kube::Result<Pod> {
+async fn add_annotations(
+    client: &Client,
+    pod: &Pod,
+    annotations: &HashMap<&str, String>,
+) -> kube::Result<Pod> {
     debug!(
-        "Adding annotation [{}: {}] to pod [{:?}]",
-        key,
-        value,
+        "Adding annotations [{:?}] to pod [{:?}]",
+        annotations,
         PodKey::from(pod)
     );
 
     let api: Api<Pod> = Api::namespaced(client.clone(), pod.namespace());
 
     let patch = json!({
         "metadata": {
-            "annotations": {
-                key: value
-            }
+            "annotations": annotations
         }
     });
 

src/provider/systemdmanager/service.rs

@@ -112,6 +112,9 @@ impl SystemdService {
         Ok(service_state)
     }
 
+    /// Retrieves the current restart count.
+    ///
+    /// The restart counter was introduced in systemd version 235.
     pub async fn restart_count(&self) -> anyhow::Result<u32> {
         self.service_proxy
             .nrestarts()