From daaf00893c06be84224a2555aeb200277dbc0113 Mon Sep 17 00:00:00 2001
From: sneak <sneak@sneak.berlin>
Date: Mon, 29 Dec 2025 15:48:23 +0700
Subject: [PATCH] Implement container logs handler

- Add Docker client to handlers for container operations
- Implement HandleAppLogs() to fetch and return container logs
- Support ?tail=N query parameter (default 500 lines)
- Handle missing container gracefully
---
 internal/handlers/app.go           | 32 ++++++++++++++++++++++++++----
 internal/handlers/handlers.go      |  4 ++++
 internal/handlers/handlers_test.go |  7 ++++---
 3 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/internal/handlers/app.go b/internal/handlers/app.go
index 120a29d..55cd8ed 100644
--- a/internal/handlers/app.go
+++ b/internal/handlers/app.go
@@ -331,6 +331,9 @@ func (h *Handlers) HandleAppDeployments() http.HandlerFunc {
 	}
 }
 
+// defaultLogTail is the default number of log lines to fetch.
+const defaultLogTail = "500"
+
 // HandleAppLogs returns the container logs handler.
 func (h *Handlers) HandleAppLogs() http.HandlerFunc {
 	return func(writer http.ResponseWriter, request *http.Request) {
@@ -343,16 +346,37 @@ func (h *Handlers) HandleAppLogs() http.HandlerFunc {
 			return
 		}
 
-		// Container logs fetching not yet implemented
-		writer.Header().Set("Content-Type", "text/plain")
+		writer.Header().Set("Content-Type", "text/plain; charset=utf-8")
 
 		if !application.ContainerID.Valid {
-			_, _ = writer.Write([]byte("No container running"))
+			_, _ = writer.Write([]byte("No container running\n"))
 
 			return
 		}
 
-		_, _ = writer.Write([]byte("Container logs not implemented yet"))
+		tail := request.URL.Query().Get("tail")
+		if tail == "" {
+			tail = defaultLogTail
+		}
+
+		logs, logsErr := h.docker.ContainerLogs(
+			request.Context(),
+			application.ContainerID.String,
+			tail,
+		)
+		if logsErr != nil {
+			h.log.Error("failed to get container logs",
+				"error", logsErr,
+				"app", application.Name,
+				"container", application.ContainerID.String,
+			)
+
+			_, _ = writer.Write([]byte("Failed to fetch container logs\n"))
+
+			return
+		}
+
+		_, _ = writer.Write([]byte(logs))
 	}
 }
 
diff --git a/internal/handlers/handlers.go b/internal/handlers/handlers.go
index 2d8c3ec..f3c1989 100644
--- a/internal/handlers/handlers.go
+++ b/internal/handlers/handlers.go
@@ -9,6 +9,7 @@ import (
 	"go.uber.org/fx"
 
 	"git.eeqj.de/sneak/upaas/internal/database"
+	"git.eeqj.de/sneak/upaas/internal/docker"
 	"git.eeqj.de/sneak/upaas/internal/globals"
 	"git.eeqj.de/sneak/upaas/internal/healthcheck"
 	"git.eeqj.de/sneak/upaas/internal/logger"
@@ -30,6 +31,7 @@ type Params struct {
 	App         *app.Service
 	Deploy      *deploy.Service
 	Webhook     *webhook.Service
+	Docker      *docker.Client
 }
 
 // Handlers provides HTTP request handlers.
@@ -42,6 +44,7 @@ type Handlers struct {
 	appService *app.Service
 	deploy     *deploy.Service
 	webhook    *webhook.Service
+	docker     *docker.Client
 }
 
 // New creates a new Handlers instance.
@@ -55,6 +58,7 @@ func New(_ fx.Lifecycle, params Params) (*Handlers, error) {
 		appService: params.App,
 		deploy:     params.Deploy,
 		webhook:    params.Webhook,
+		docker:     params.Docker,
 	}, nil
 }
 
diff --git a/internal/handlers/handlers_test.go b/internal/handlers/handlers_test.go
index 5bf5d61..77e207c 100644
--- a/internal/handlers/handlers_test.go
+++ b/internal/handlers/handlers_test.go
@@ -86,7 +86,7 @@ func createAppServices(
 	logInstance *logger.Logger,
 	dbInstance *database.Database,
 	cfg *config.Config,
-) (*auth.Service, *app.Service, *deploy.Service, *webhook.Service) {
+) (*auth.Service, *app.Service, *deploy.Service, *webhook.Service, *docker.Client) {
 	t.Helper()
 
 	authSvc, authErr := auth.New(fx.Lifecycle(nil), auth.ServiceParams{
@@ -128,7 +128,7 @@ func createAppServices(
 	})
 	require.NoError(t, webhookErr)
 
-	return authSvc, appSvc, deploySvc, webhookSvc
+	return authSvc, appSvc, deploySvc, webhookSvc, dockerClient
 }
 
 func setupTestHandlers(t *testing.T) *testContext {
@@ -138,7 +138,7 @@ func setupTestHandlers(t *testing.T) *testContext {
 
 	globalInstance, logInstance, dbInstance, hcInstance := createCoreServices(t, cfg)
 
-	authSvc, appSvc, deploySvc, webhookSvc := createAppServices(
+	authSvc, appSvc, deploySvc, webhookSvc, dockerClient := createAppServices(
 		t,
 		logInstance,
 		dbInstance,
@@ -156,6 +156,7 @@ func setupTestHandlers(t *testing.T) *testContext {
 			App:         appSvc,
 			Deploy:      deploySvc,
 			Webhook:     webhookSvc,
+			Docker:      dockerClient,
 		},
 	)
 	require.NoError(t, handlerErr)