Check for app health checks and volume mounts before bluegreen build

internal/appconfig/config.go

@@ -389,3 +389,31 @@ func (cfg *Config) DeployStrategy() string {
 	}
 	return cfg.Deploy.Strategy
 }
+
+// HasHealthChecks returns true if there is at least one health check defined in
+// the configuration. It inspects top-level checks as well as checks defined for
+// any service or the http_service.
+func (cfg *Config) HasHealthChecks() bool {
+	if len(cfg.Checks) > 0 || len(cfg.MachineChecks) > 0 {
+		return true
+	}
+
+	if cfg.HTTPService != nil {
+		if len(cfg.HTTPService.HTTPChecks) > 0 || len(cfg.HTTPService.MachineChecks) > 0 {
+			return true
+		}
+	}
+
+	for _, svc := range cfg.Services {
+		if len(svc.HTTPChecks) > 0 || len(svc.TCPChecks) > 0 || len(svc.MachineChecks) > 0 {
+			return true
+		}
+	}
+
+	return false
+}
+
+// HasMounts returns true if the configuration defines any mounts.
+func (cfg *Config) HasMounts() bool {
+	return len(cfg.Mounts) > 0
+}

internal/command/deploy/deploy.go

@@ -352,6 +352,21 @@ func DeployWithConfig(ctx context.Context, appConfig *appconfig.Config, userID i
 		}
 	}
 
+	strategy := flag.GetString(ctx, "strategy")
+	if strategy == "" {
+		strategy = appConfig.DeployStrategy()
+	}
+	if strategy == "bluegreen" {
+		if appConfig.HasMounts() {
+			fmt.Fprint(io.ErrOut, volumesRequirementMsg)
+			return ErrValidationError
+		}
+		if !appConfig.HasHealthChecks() {
+			fmt.Fprint(io.ErrOut, healthChecksRequirementMsg)
+			return ErrValidationError
+		}
+	}
+
 	httpFailover := flag.GetHTTPSFailover(ctx)
 	usingWireguard := flag.GetWireguard(ctx)
 	recreateBuilder := flag.GetRecreateBuilder(ctx)

internal/command/deploy/strategy_bluegreen.go

@@ -49,6 +49,9 @@ var (
 	safeToDestroyValue = "safe_to_destroy"
 )
 
+const healthChecksRequirementMsg = "\n\nYou need to define at least 1 check in order to use bluegreen deployments. Refer to https://fly.io/docs/reference/configuration/#services-tcp_checks\n"
+const volumesRequirementMsg = "\n\nBluegreen deployments are not supported when machines have attached volumes.\n"
+
 type RollbackLog struct {
 	// this ensures that user invoked aborts after green machines are healthy
 	// doesn't cause the greeen machines to be removed. eg. if someone aborts after cordoning blue machines
@@ -688,6 +691,16 @@ func (bg *blueGreen) Deploy(ctx context.Context) error {
 		return ErrOrgLimit
 	}
 
+	if bg.appConfig.HasMounts() && len(bg.blueMachines) != 0 {
+		fmt.Fprint(bg.io.ErrOut, volumesRequirementMsg)
+		return ErrValidationError
+	}
+
+	if !bg.appConfig.HasHealthChecks() && len(bg.blueMachines) != 0 {
+		fmt.Fprint(bg.io.ErrOut, healthChecksRequirementMsg)
+		return ErrValidationError
+	}
+
 	fmt.Fprintf(bg.io.ErrOut, "\nVerifying if app can be safely deployed \n")
 
 	err = bg.DetectMultipleImageVersions(ctx)
@@ -709,7 +722,7 @@ func (bg *blueGreen) Deploy(ctx context.Context) error {
 	}
 
 	if totalChecks == 0 && len(bg.blueMachines) != 0 {
-		fmt.Fprintf(bg.io.ErrOut, "\n\nYou need to define at least 1 check in order to use blue-green deployments. Refer to https://fly.io/docs/reference/configuration/#services-tcp_checks\n")
+		fmt.Fprint(bg.io.ErrOut, healthChecksRequirementMsg)
 		return ErrValidationError
 	}
 

internal/command/deploy/strategy_bluegreen_test.go

@@ -39,11 +39,18 @@ func newBlueGreenStrategy(client flapsutil.FlapsClient, numberOfExistingMachines
 		apiClient:     &mockWebClient{},
 		flaps:         client,
 		maxConcurrent: 10,
-		appConfig:     &appconfig.Config{},
-		io:            ios,
-		colorize:      ios.ColorScheme(),
-		timeout:       1 * time.Second,
-		blueMachines:  machines,
+		appConfig: &appconfig.Config{
+			Checks: map[string]*appconfig.ToplevelCheck{
+				"alive": {
+					Type: fly.Pointer("tcp"),
+					Port: fly.Pointer(8080),
+				},
+			},
+		},
+		io:           ios,
+		colorize:     ios.ColorScheme(),
+		timeout:      1 * time.Second,
+		blueMachines: machines,
 	}
 	strategy.initialize()