cli: remove eval broker manipulation from eval delete command.

command/eval_delete.go

@@ -17,11 +17,6 @@ type EvalDeleteCommand struct {
 	filter string
 	yes    bool
 
-	// originalBrokerPaused indicates whether the broker was in a paused state
-	// before the command was run. This indicates what action, if any, should
-	// be taken before the command finishes.
-	originalBrokerPaused bool
-
 	// deleteByArg is set when the command is deleting an evaluation that has
 	// been passed as an argument. This avoids need for confirmation.
 	deleteByArg bool
@@ -49,6 +44,11 @@ Usage: nomad eval delete [options] <evaluation>
   normal and outage scenarios, Nomads reconciliation and state management will
   handle evaluations as needed.
 
+  The eval broker is expected to be paused prior to running this command and
+  un-paused after. This can be done using the following two commands:
+    - nomad operator scheduler set-config -pause-eval-broker=true
+    - nomad operator scheduler set-config -pause-eval-broker=false
+
 General Options:
 
   ` + generalOptionsUsage(usageOptsNoNamespace) + `
@@ -121,10 +121,19 @@ func (e *EvalDeleteCommand) Run(args []string) int {
 	}
 	e.client = client
 
-	// Pause the eval broker to ensure no more work can be dequeued and
-	// processed by the schedulers.
-	if err := e.pauseEvalBroker(); err != nil {
-		e.Ui.Error(fmt.Sprintf("Error pausing eval broker: %s", err))
+	// Ensure the eval broker is paused. This check happens multiple times on
+	// the leader, but this check means we can provide quick and actionable
+	// feedback.
+	schedulerConfig, _, err := e.client.Operator().SchedulerGetConfiguration(nil)
+	if err != nil {
+		e.Ui.Error(fmt.Sprintf("Error querying scheduler configuration: %s", err))
+		return 1
+	}
+
+	if !schedulerConfig.SchedulerConfig.PauseEvalBroker {
+		e.Ui.Error("Eval broker is not paused")
+		e.Ui.Output(`To delete evaluations you must first pause the eval broker by running "nomad operator scheduler set-config -pause-eval-broker=true"`)
+		e.Ui.Output(`After the deletion is complete, unpause the eval broker by running "nomad operator scheduler set-config -pause-eval-broker=false"`)
 		return 1
 	}
 
@@ -160,13 +169,6 @@ func (e *EvalDeleteCommand) Run(args []string) int {
 		e.Ui.Output("No evaluations were deleted")
 	}
 
-	// Always attempt to revert the state of the eval broker. In the event this
-	// succeeds, but the eval deletion failed, maintain the non-zero exit code
-	// so failures are clear.
-	if err := e.revertEvalBroker(); err != nil {
-		e.Ui.Error(fmt.Sprintf("Error reverting eval broker state: %s", err))
-		exitCode = 1
-	}
 	return exitCode
 }
 
@@ -189,68 +191,6 @@ func (e *EvalDeleteCommand) verifyArgsAndFlags(args []string) error {
 	return nil
 }
 
-// pauseEvalBroker pauses the eval broker if it is currently in an enabled
-// state. Its previous state will be stored so the command can later revert any
-// changes made.
-func (e *EvalDeleteCommand) pauseEvalBroker() error {
-
-	schedulerConfig, _, err := e.client.Operator().SchedulerGetConfiguration(nil)
-	if err != nil {
-		return err
-	}
-
-	// Store the current and thus original eval broker paused state.
-	e.originalBrokerPaused = schedulerConfig.SchedulerConfig.PauseEvalBroker
-
-	// It is possible the operator has already paused the broker via the operator
-	// API and CLI. If this is not the case, pause it now.
-	if !e.originalBrokerPaused {
-		schedulerConfig.SchedulerConfig.PauseEvalBroker = true
-
-		newSchedulerConfig, _, err := e.client.Operator().SchedulerCASConfiguration(schedulerConfig.SchedulerConfig, nil)
-		if err != nil {
-			return err
-		}
-
-		if !newSchedulerConfig.Updated {
-			return errors.New("failed to update scheduler config, please check server logs")
-		}
-	}
-
-	return nil
-}
-
-// revertEvalBroker reverts any initial changes made to the state of the eval
-// broker.
-func (e *EvalDeleteCommand) revertEvalBroker() error {
-
-	// Read the configuration state first to ensure we are using the correct
-	// configuration and not overwriting changes.
-	schedulerConfig, _, err := e.client.Operator().SchedulerGetConfiguration(nil)
-	if err != nil {
-		return err
-	}
-
-	// If the broker is paused, and it was paused before this command was
-	// invoked, there is nothing else to do.
-	if schedulerConfig.SchedulerConfig.PauseEvalBroker && e.originalBrokerPaused {
-		return nil
-	}
-
-	// Modify the paused value and write this.
-	schedulerConfig.SchedulerConfig.PauseEvalBroker = false
-
-	newSchedulerConfig, _, err := e.client.Operator().SchedulerCASConfiguration(schedulerConfig.SchedulerConfig, nil)
-	if err != nil {
-		return err
-	}
-
-	if !newSchedulerConfig.Updated {
-		return errors.New("failed to update scheduler config, please check server logs")
-	}
-	return nil
-}
-
 // handleEvalArgDelete handles deletion and evaluation which was passed via
 // it's ID as a command argument. This is the simplest route to take and
 // doesn't require filtering or batching.

website/content/docs/commands/eval/delete.mdx

@@ -2,7 +2,7 @@
 layout: docs
 page_title: 'Commands: eval delete'
 description: |
-The eval delete command is used to delete evaluations.
+  The eval delete command is used to delete evaluations.
 ---
 
 # Command: eval delete
@@ -12,6 +12,11 @@ cautiously and only in outage situations where there is a large backlog of
 evaluations not being processed. During most normal and outage scenarios,
 Nomad's reconciliation and state management will handle evaluations as needed.
 
+The eval broker is expected to be paused prior to running this command and
+un-paused after. These actions can be performed by the
+[`operator scheduler get-config`][scheduler_get_config]
+and [`operator scheduler set-config`][scheduler_set_config] commands respectively.
+
 ## Usage
 
 ```plaintext
@@ -65,3 +70,6 @@ prompts:
 $ nomad eval delete -filter='Scheduler == "system" or Scheduler == "service"' -yes
 Successfuly deleted 23 evaluations
 ```
+
+[scheduler_get_config]: /docs/commands/operator/scheduler-get-config
+[scheduler_set_config]: /docs/commands/operator/scheduler-set-config

website/data/docs-nav-data.json

@@ -372,6 +372,10 @@
             "title": "Overview",
             "path": "commands/eval"
           },
+          {
+            "title": "delete",
+            "path": "commands/eval/delete"
+          },
           {
             "title": "list",
             "path": "commands/eval/list"