From 07bc4a21ffa5f302fa195b6a58174f6e440b974a Mon Sep 17 00:00:00 2001
From: Simone Gotti <simone.gotti@gmail.com>
Date: Wed, 24 Apr 2019 13:25:41 +0200
Subject: [PATCH] runservice scheduler: automatically remove dynamic executors

---
 .../runservice/scheduler/api/executor.go      | 49 +++++++++++++++++--
 .../runservice/scheduler/scheduler.go         |  2 +-
 2 files changed, 46 insertions(+), 5 deletions(-)

diff --git a/internal/services/runservice/scheduler/api/executor.go b/internal/services/runservice/scheduler/api/executor.go
index 3e093a4..676c576 100644
--- a/internal/services/runservice/scheduler/api/executor.go
+++ b/internal/services/runservice/scheduler/api/executor.go
@@ -16,6 +16,7 @@ package api
 
 import (
 	"bufio"
+	"context"
 	"encoding/json"
 	"io"
 	"net/http"
@@ -33,12 +34,13 @@ import (
 )
 
 type ExecutorStatusHandler struct {
-	e *etcd.Store
-	c chan<- *types.ExecutorTask
+	log *zap.SugaredLogger
+	e   *etcd.Store
+	ch  *command.CommandHandler
 }
 
-func NewExecutorStatusHandler(e *etcd.Store, c chan<- *types.ExecutorTask) *ExecutorStatusHandler {
-	return &ExecutorStatusHandler{e: e, c: c}
+func NewExecutorStatusHandler(logger *zap.Logger, e *etcd.Store, ch *command.CommandHandler) *ExecutorStatusHandler {
+	return &ExecutorStatusHandler{log: logger.Sugar(), e: e, ch: ch}
 }
 
 func (h *ExecutorStatusHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
@@ -58,6 +60,45 @@ func (h *ExecutorStatusHandler) ServeHTTP(w http.ResponseWriter, r *http.Request
 		http.Error(w, "", http.StatusInternalServerError)
 		return
 	}
+
+	if err := h.deleteStaleExecutors(ctx, executor); err != nil {
+		http.Error(w, "", http.StatusInternalServerError)
+		return
+	}
+}
+
+func (h *ExecutorStatusHandler) deleteStaleExecutors(ctx context.Context, curExecutor *types.Executor) error {
+	executors, err := store.GetExecutors(ctx, h.e)
+	if err != nil {
+		return err
+	}
+
+	for _, executor := range executors {
+		if executor.ID == curExecutor.ID {
+			continue
+		}
+		if !executor.Dynamic {
+			continue
+		}
+		if executor.ExecutorGroup != curExecutor.ExecutorGroup {
+			continue
+		}
+		// executor is dynamic and in the same executor group
+		active := false
+		for _, seID := range curExecutor.SiblingsExecutors {
+			if executor.ID == seID {
+				active = true
+				break
+			}
+		}
+		if !active {
+			if err := h.ch.DeleteExecutor(ctx, executor.ID); err != nil {
+				h.log.Errorf("failed to delete executor %q: %v", executor.ID, err)
+			}
+		}
+	}
+
+	return nil
 }
 
 type ExecutorTaskStatusHandler struct {
diff --git a/internal/services/runservice/scheduler/scheduler.go b/internal/services/runservice/scheduler/scheduler.go
index b60ea1d..a6d23fe 100644
--- a/internal/services/runservice/scheduler/scheduler.go
+++ b/internal/services/runservice/scheduler/scheduler.go
@@ -1625,7 +1625,7 @@ func (s *Scheduler) Run(ctx context.Context) error {
 	corsHandler = ghandlers.CORS(corsAllowedMethodsOptions, corsAllowedHeadersOptions, corsAllowedOriginsOptions)
 
 	// executor dedicated api, only calls from executor should happen on these handlers
-	executorStatusHandler := api.NewExecutorStatusHandler(s.e, ch)
+	executorStatusHandler := api.NewExecutorStatusHandler(logger, s.e, s.ch)
 	executorTaskStatusHandler := api.NewExecutorTaskStatusHandler(s.e, ch)
 	executorTaskHandler := api.NewExecutorTaskHandler(s.e)
 	executorTasksHandler := api.NewExecutorTasksHandler(s.e)