feat: DockerEventMonitor — persistent event stream for container lifecycle

Listens to Docker daemon events (die, oom, start, stop) for containers
labeled managed-by=cameleer3-server, updates replica states in Postgres,
and recomputes aggregate deployment status (RUNNING/DEGRADED/FAILED).
Bean is wired in RuntimeOrchestratorAutoConfig via instanceof guard so it
only activates when Docker is available.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cameleer3-server-app/src/main/java/com/cameleer3/server/app/runtime/DockerEventMonitor.java

@@ -0,0 +1,129 @@
+package com.cameleer3.server.app.runtime;
+
+import com.cameleer3.server.app.storage.PostgresDeploymentRepository;
+import com.cameleer3.server.core.runtime.Deployment;
+import com.cameleer3.server.core.runtime.DeploymentStatus;
+import com.github.dockerjava.api.DockerClient;
+import com.github.dockerjava.api.async.ResultCallback;
+import com.github.dockerjava.api.model.Event;
+import com.github.dockerjava.api.model.EventType;
+import jakarta.annotation.PostConstruct;
+import jakarta.annotation.PreDestroy;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.util.*;
+
+public class DockerEventMonitor {
+
+    private static final Logger log = LoggerFactory.getLogger(DockerEventMonitor.class);
+
+    private final DockerClient dockerClient;
+    private final PostgresDeploymentRepository deploymentRepository;
+    private Closeable eventStream;
+
+    public DockerEventMonitor(DockerRuntimeOrchestrator orchestrator,
+                              PostgresDeploymentRepository deploymentRepository) {
+        this.dockerClient = orchestrator.getDockerClient();
+        this.deploymentRepository = deploymentRepository;
+    }
+
+    @PostConstruct
+    public void startListening() {
+        eventStream = dockerClient.eventsCmd()
+                .withEventTypeFilter(EventType.CONTAINER)
+                .withEventFilter("die", "oom", "start", "stop")
+                .exec(new ResultCallback.Adapter<Event>() {
+                    @Override
+                    public void onNext(Event event) {
+                        handleEvent(event);
+                    }
+
+                    @Override
+                    public void onError(Throwable throwable) {
+                        log.warn("Docker event stream error, reconnecting: {}", throwable.getMessage());
+                        reconnect();
+                    }
+                });
+
+        log.info("Docker event monitor started");
+    }
+
+    @PreDestroy
+    public void stop() {
+        if (eventStream != null) {
+            try { eventStream.close(); } catch (IOException e) { /* ignore */ }
+        }
+    }
+
+    private void handleEvent(Event event) {
+        String containerId = event.getId();
+        if (containerId == null) return;
+
+        Map<String, String> labels = event.getActor() != null ? event.getActor().getAttributes() : null;
+        if (labels == null || !"cameleer3-server".equals(labels.get("managed-by"))) return;
+
+        String action = event.getAction();
+        log.debug("Docker event: {} for container {} ({})", action, containerId.substring(0, 12),
+                labels.get("cameleer.app"));
+
+        Optional<Deployment> deploymentOpt = deploymentRepository.findByContainerId(containerId);
+        if (deploymentOpt.isEmpty()) return;
+
+        Deployment deployment = deploymentOpt.get();
+        List<Map<String, Object>> replicas = new ArrayList<>(deployment.replicaStates());
+
+        boolean changed = false;
+        for (int i = 0; i < replicas.size(); i++) {
+            Map<String, Object> replica = replicas.get(i);
+            if (containerId.equals(replica.get("containerId"))) {
+                Map<String, Object> updated = new HashMap<>(replica);
+                switch (action) {
+                    case "die", "oom", "stop" -> {
+                        updated.put("status", "DEAD");
+                        if ("oom".equals(action)) {
+                            updated.put("oomKilled", true);
+                            log.warn("Container {} OOM-killed (app={}, env={})", containerId.substring(0, 12),
+                                    labels.get("cameleer.app"), labels.get("cameleer.environment"));
+                        }
+                    }
+                    case "start" -> updated.put("status", "RUNNING");
+                }
+                replicas.set(i, updated);
+                changed = true;
+                break;
+            }
+        }
+
+        if (!changed) return;
+
+        deploymentRepository.updateReplicaStates(deployment.id(), replicas);
+
+        long running = replicas.stream().filter(r -> "RUNNING".equals(r.get("status"))).count();
+        DeploymentStatus newStatus;
+        if (running == replicas.size()) {
+            newStatus = DeploymentStatus.RUNNING;
+        } else if (running > 0) {
+            newStatus = DeploymentStatus.DEGRADED;
+        } else {
+            newStatus = DeploymentStatus.FAILED;
+        }
+
+        if (deployment.status() != newStatus) {
+            deploymentRepository.updateStatus(deployment.id(), newStatus, deployment.containerId(), deployment.errorMessage());
+            log.info("Deployment {} status: {} -> {} ({}/{} replicas running)",
+                    deployment.id(), deployment.status(), newStatus, running, replicas.size());
+        }
+    }
+
+    private void reconnect() {
+        try {
+            Thread.sleep(5000);
+            startListening();
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+        }
+    }
+}

cameleer3-server-app/src/main/java/com/cameleer3/server/app/runtime/RuntimeOrchestratorAutoConfig.java

@@ -1,5 +1,7 @@
 package com.cameleer3.server.app.runtime;
 
+import com.cameleer3.server.app.storage.PostgresDeploymentRepository;
+import com.cameleer3.server.core.runtime.DeploymentRepository;
 import com.cameleer3.server.core.runtime.RuntimeOrchestrator;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -33,4 +35,13 @@ public class RuntimeOrchestratorAutoConfig {
         }
         return null;
     }
+
+    @Bean
+    public DockerEventMonitor dockerEventMonitor(RuntimeOrchestrator orchestrator,
+                                                  DeploymentRepository deploymentRepository) {
+        if (orchestrator instanceof DockerRuntimeOrchestrator docker) {
+            return new DockerEventMonitor(docker, (PostgresDeploymentRepository) deploymentRepository);
+        }
+        return null;
+    }
 }