package command import ( "fmt" "strings" "github.com/hashicorp/consul/command/base" ) // MaintCommand is a Command implementation that enables or disables // node or service maintenance mode. type MaintCommand struct { base.Command } func (c *MaintCommand) Help() string { helpText := ` Usage: consul maint [options] Places a node or service into maintenance mode. During maintenance mode, the node or service will be excluded from all queries through the DNS or API interfaces, effectively taking it out of the pool of available nodes. This is done by registering an additional critical health check. When enabling maintenance mode for a node or service, you may optionally specify a reason string. This string will appear in the "Notes" field of the critical health check which is registered against the node or service. If no reason is provided, a default value will be used. Maintenance mode is persistent, and will be restored in the event of an agent restart. It is therefore required to disable maintenance mode on a given node or service before it will be placed back into the pool. By default, we operate on the node as a whole. By specifying the "-service" argument, this behavior can be changed to enable or disable only a specific service. If no arguments are given, the agent's maintenance status will be shown. This will return blank if nothing is currently under maintenance. ` + c.Command.Help() return strings.TrimSpace(helpText) } func (c *MaintCommand) Run(args []string) int { var enable bool var disable bool var reason string var serviceID string f := c.Command.NewFlagSet(c) f.BoolVar(&enable, "enable", false, "Enable maintenance mode.") f.BoolVar(&disable, "disable", false, "Disable maintenance mode.") f.StringVar(&reason, "reason", "", "Text describing the maintenance reason.") f.StringVar(&serviceID, "service", "", "Control maintenance mode for a specific service ID.") if err := c.Command.Parse(args); err != nil { return 1 } // Ensure we don't have conflicting args if enable && disable { c.UI.Error("Only one of -enable or -disable may be provided") return 1 } if !enable && reason != "" { c.UI.Error("Reason may only be provided with -enable") return 1 } if !enable && !disable && serviceID != "" { c.UI.Error("Service requires either -enable or -disable") return 1 } // Create and test the HTTP client client, err := c.Command.HTTPClient() if err != nil { c.UI.Error(fmt.Sprintf("Error connecting to Consul agent: %s", err)) return 1 } a := client.Agent() nodeName, err := a.NodeName() if err != nil { c.UI.Error(fmt.Sprintf("Error querying Consul agent: %s", err)) return 1 } if !enable && !disable { // List mode - list nodes/services in maintenance mode checks, err := a.Checks() if err != nil { c.UI.Error(fmt.Sprintf("Error getting checks: %s", err)) return 1 } for _, check := range checks { if check.CheckID == "_node_maintenance" { c.UI.Output("Node:") c.UI.Output(" Name: " + nodeName) c.UI.Output(" Reason: " + check.Notes) c.UI.Output("") } else if strings.HasPrefix(string(check.CheckID), "_service_maintenance:") { c.UI.Output("Service:") c.UI.Output(" ID: " + check.ServiceID) c.UI.Output(" Reason: " + check.Notes) c.UI.Output("") } } return 0 } if enable { // Enable node maintenance if serviceID == "" { if err := a.EnableNodeMaintenance(reason); err != nil { c.UI.Error(fmt.Sprintf("Error enabling node maintenance: %s", err)) return 1 } c.UI.Output("Node maintenance is now enabled") return 0 } // Enable service maintenance if err := a.EnableServiceMaintenance(serviceID, reason); err != nil { c.UI.Error(fmt.Sprintf("Error enabling service maintenance: %s", err)) return 1 } c.UI.Output(fmt.Sprintf("Service maintenance is now enabled for %q", serviceID)) return 0 } if disable { // Disable node maintenance if serviceID == "" { if err := a.DisableNodeMaintenance(); err != nil { c.UI.Error(fmt.Sprintf("Error disabling node maintenance: %s", err)) return 1 } c.UI.Output("Node maintenance is now disabled") return 0 } // Disable service maintenance if err := a.DisableServiceMaintenance(serviceID); err != nil { c.UI.Error(fmt.Sprintf("Error disabling service maintenance: %s", err)) return 1 } c.UI.Output(fmt.Sprintf("Service maintenance is now disabled for %q", serviceID)) return 0 } return 0 } func (c *MaintCommand) Synopsis() string { return "Controls node or service maintenance mode" }