dokku · josegonzalez · Oct 10, 2021 · Sep 5, 2021 · Sep 5, 2021
diff --git a/docs/development/plugin-triggers.md b/docs/development/plugin-triggers.md
@@ -428,6 +428,24 @@ case "$DOKKU_DISTRO" in
 esac
 ```
 
+### `deploy`
+
+- Description: Triggers a deploy for the given app. Can override the image tag to deploy, as well as specify a single process type to deploy.
+- Invoked by: `dokku deploy`
+- Arguments: `$APP [$IMAGE_TAG] [$PROC_TYPE]`
+- Example:
+
+```shell
+#!/usr/bin/env bash
+
+set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
+source "$PLUGIN_CORE_AVAILABLE_PATH/common/functions"
+
+APP="$1" IMAGE_TAG="$2" PROC_TYPE="$3"
+
+# TODO
+```
+
 ### `deploy-source`
 
 - Description: Used for reporting what the current detected deployment source is. The first detected source should always win.

diff --git a/docs/processes/process-management.md b/docs/processes/process-management.md
@@ -6,7 +6,7 @@
 ps:inspect <app>                                                  # Displays a sanitized version of docker inspect for an app
 ps:rebuild [--parallel count] [--all|<app>]                       # Rebuilds an app from source
 ps:report [<app>] [<flag>]                                        # Displays a process report for one or more apps
-ps:restart [--parallel count] [--all|<app>]                       # Restart an app
+ps:restart [--parallel count] [--all|<app>]  [<process-name>]     # Restart an app
 ps:restore [<app>]                                                # Start previously running apps e.g. after reboot
 ps:scale [--skip-deploy] <app> <proc>=<count> [<proc>=<count>...] # Get/Set how many instances of a given process to run
 ps:set <app> <key> <value>                                        # Set or clear a ps property for an app
@@ -64,7 +64,13 @@ An app may be restarted using the `ps:restart` command.
 dokku ps:restart node-js-app
 ```
 
-All apps may be restarted by using the `--all` flag.
+A single process type - such as `web` or `worker` - may also be specified. This _does not_ support specifying a given instance of a process type, and only supports restarting all instances of that process type.
+
+```shell
+dokku ps:restart node-js-app web
+```
+
+All apps may be restarted by using the `--all` flag. This flag is incompatible with specifying a process type.
 
 ```shell
 dokku ps:restart --all

diff --git a/plugins/apps/functions.go b/plugins/apps/functions.go
@@ -52,7 +52,7 @@ func destroyApp(appName string) error {
 
 	common.LogInfo1(fmt.Sprintf("Destroying %s (including all add-ons)", appName))
 
-	imageTag, _ := common.GetRunningImageTag(appName)
+	imageTag, _ := common.GetRunningImageTag(appName, "")
 	if err := common.PlugnTrigger("pre-delete", []string{appName, imageTag}...); err != nil {
 		return err
 	}

diff --git a/plugins/common/common.go b/plugins/common/common.go
@@ -226,20 +226,21 @@ func GetAppRunningContainerIDs(appName string, containerType string) ([]string,
 	return runningContainerIDs, nil
 }
 
-// GetRunningImageTag retrieves current image tag for a given app and returns empty string if no deployed containers are found
-func GetRunningImageTag(appName string) (string, error) {
-	containerIDs, err := GetAppContainerIDs(appName, "")
+// GetRunningImageTag retrieves current deployed image tag for a given app
+func GetRunningImageTag(appName string, imageTag string) (string, error) {
+	b, err := PlugnTriggerOutput("deployed-app-image-tag", []string{appName}...)
 	if err != nil {
-		return "", err
+		return imageTag, err
 	}
-
-	for _, containerID := range containerIDs {
-		if image, err := DockerInspect(containerID, "{{ .Config.Image }}"); err == nil {
-			return strings.Split(image, ":")[1], nil
-		}
+	newImageTag := strings.TrimSpace(string(b[:]))
+	if newImageTag != "" {
+		imageTag = newImageTag
+	}
+	if imageTag == "" {
+		imageTag = "latest"
 	}
 
-	return "", errors.New("No image tag found")
+	return imageTag, nil
 }
 
 // DokkuApps returns a list of all local apps

diff --git a/plugins/common/deploy b/plugins/common/deploy
@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+source "$PLUGIN_CORE_AVAILABLE_PATH/common/functions"
+set -eo pipefail
+[[ $DOKKU_TRACE ]] && set -x
+
+cmd-deploy "$@"
diff --git a/plugins/common/functions b/plugins/common/functions
@@ -286,16 +286,14 @@ get_deploying_app_image_name() {
   declare desc="return deploying image identifier for a given app, tag tuple. validate if tag is presented"
   local APP="$1"
   local IMAGE_TAG="$2"
-  IMAGE_REPO="$3"
+  local IMAGE_REPO="$3"
 
+  IMAGE_TAG="$(get_running_image_tag "$APP" "$IMAGE_TAG")"
   local IMAGE_REMOTE_REPOSITORY=$(plugn trigger deployed-app-repository "$APP")
-  local NEW_IMAGE_TAG=$(plugn trigger deployed-app-image-tag "$APP")
   local NEW_IMAGE_REPO=$(plugn trigger deployed-app-image-repo "$APP")
 
   [[ -n "$NEW_IMAGE_REPO" ]] && IMAGE_REPO="$NEW_IMAGE_REPO"
-  [[ -n "$NEW_IMAGE_TAG" ]] && IMAGE_TAG="$NEW_IMAGE_TAG"
   [[ -z "$IMAGE_REPO" ]] && IMAGE_REPO=$(get_app_image_repo "$APP")
-  [[ -z "$IMAGE_TAG" ]] && IMAGE_TAG="latest"
 
   local IMAGE="${IMAGE_REMOTE_REPOSITORY}${IMAGE_REPO}:${IMAGE_TAG}"
   verify_image "$IMAGE" || dokku_log_fail "App image ($IMAGE) not found"
@@ -329,12 +327,14 @@ get_app_scheduler() {
 }
 
 get_running_image_tag() {
-  declare desc="retrieve current image tag for a given app. returns empty string if no deployed containers are found"
-  local APP="$1"
+  declare desc="retrieves current deployed image tag for a given app"
+  local APP="$1" IMAGE_TAG="$2"
 
-  local CIDS=($(get_app_container_ids "$APP"))
-  local RUNNING_IMAGE_TAG=$("$DOCKER_BIN" container inspect --format '{{ .Config.Image }}' "${CIDS[0]}" 2>/dev/null | awk -F: '{ print $2 }' || echo '')
-  echo "$RUNNING_IMAGE_TAG"
+  local NEW_IMAGE_TAG=$(plugn trigger deployed-app-image-tag "$APP")
+  [[ -n "$NEW_IMAGE_TAG" ]] && IMAGE_TAG="$NEW_IMAGE_TAG"
+  [[ -z "$IMAGE_TAG" ]] && IMAGE_TAG="latest"
+
+  echo "$IMAGE_TAG"
 }
 
 is_image_cnb_based() {
@@ -638,12 +638,11 @@ dokku_release() {
 
 cmd-deploy() {
   declare desc="deploy phase"
-  declare APP="$1" IMAGE_TAG="$2"
-  source "$PLUGIN_AVAILABLE_PATH/config/functions"
+  declare APP="$1" IMAGE_TAG="$2" PROCESS_TYPE="$3"
 
   verify_app_name "$APP"
   local DOKKU_SCHEDULER=$(get_app_scheduler "$APP")
-  plugn trigger scheduler-deploy "$DOKKU_SCHEDULER" "$APP" "$IMAGE_TAG"
+  plugn trigger scheduler-deploy "$DOKKU_SCHEDULER" "$APP" "$IMAGE_TAG" "$PROCESS_TYPE"
 }
 
 release_and_deploy() {

diff --git a/plugins/config/config.go b/plugins/config/config.go
@@ -117,7 +117,7 @@ func UnsetAll(appName string, restart bool) (err error) {
 
 func triggerRestart(appName string) {
 	common.LogInfo1(fmt.Sprintf("Restarting app %s", appName))
-	if err := common.PlugnTrigger("app-restart", appName); err != nil {
+	if err := common.PlugnTrigger("release-and-deploy", appName); err != nil {
 		common.LogWarn(fmt.Sprintf("Failure while restarting app: %s", err))
 	}
 }

diff --git a/plugins/ps/functions.go b/plugins/ps/functions.go
@@ -282,12 +282,18 @@ func scaleSet(appName string, skipDeploy bool, clearExisting bool, processTuples
 		return nil
 	}
 
-	imageTag, err := common.GetRunningImageTag(appName)
+	imageTag, err := common.GetRunningImageTag(appName, "")
 	if err != nil {
 		return err
 	}
 
-	return common.PlugnTrigger("release-and-deploy", []string{appName, imageTag}...)
+	for _, formation := range formations {
+		if err := common.PlugnTrigger("deploy", []string{appName, imageTag, formation.ProcessType}...); err != nil {
+			return err
+		}
+	}
+
+	return nil
 }
 
 func updateScale(appName string, clearExisting bool, formationUpdates FormationSlice) error {

diff --git a/plugins/ps/ps.go b/plugins/ps/ps.go
@@ -57,7 +57,37 @@ func Restart(appName string) error {
 		return nil
 	}
 
-	return common.PlugnTrigger("release-and-deploy", []string{appName}...)
+	imageTag, err := common.GetRunningImageTag(appName, "")
+	if err != nil {
+		return err
+	}
+
+	if imageTag == "" {
+		common.LogWarn("No deployed-image-tag property saved, falling back to full release-and-deploy")
+		return common.PlugnTrigger("release-and-deploy", []string{appName}...)
+	}
+
+	return common.PlugnTrigger("deploy", []string{appName, imageTag}...)
+}
+
+// RestartProcess restarts a process type within an app
+func RestartProcess(appName string, processName string) error {
+	if !common.IsDeployed(appName) {
+		common.LogWarn(fmt.Sprintf("App %s has not been deployed", appName))
+		return nil
+	}
+
+	imageTag, err := common.GetRunningImageTag(appName, "")
+	if err != nil {
+		return err
+	}
+
+	if imageTag == "" {
+		common.LogWarn("No deployed-image-tag property saved, falling back to full release-and-deploy")
+		return common.PlugnTrigger("release-and-deploy", []string{appName}...)
+	}
+
+	return common.PlugnTrigger("deploy", []string{appName, imageTag, processName}...)
 }
 
 // Restore ensures an app that should be running is running on boot
@@ -90,7 +120,7 @@ func Restore(appName string) error {
 
 // Start starts the app
 func Start(appName string) error {
-	imageTag, _ := common.GetRunningImageTag(appName)
+	imageTag, _ := common.GetRunningImageTag(appName, "")
 
 	if !common.IsDeployed(appName) {
 		common.LogWarn(fmt.Sprintf("App %s has not been deployed", appName))

diff --git a/plugins/ps/src/commands/commands.go b/plugins/ps/src/commands/commands.go
@@ -21,7 +21,7 @@ Additional commands:`
     ps:inspect <app>, Displays a sanitized version of docker inspect for an app
     ps:rebuild [--parallel count] [--all|<app>], Rebuilds an app from source
     ps:report [<app>] [<flag>], Displays a process report for one or more apps
-    ps:restart [--parallel count] [--all|<app>], Restart an app
+    ps:restart [--parallel count] [--all|<app>] [<process-name>], Restart an app
     ps:restore [<app>], Start previously running apps e.g. after reboot
     ps:scale [--skip-deploy] <app> <proc>=<count> [<proc>=<count>...], Get/Set how many instances of a given process to run
     ps:set <app> <key> <value>, Set or clear a ps property for an app

diff --git a/plugins/ps/src/subcommands/subcommands.go b/plugins/ps/src/subcommands/subcommands.go
@@ -45,7 +45,8 @@ func main() {
 		parallelCount := args.Int("parallel", ps.RunInSerial, "--parallel: number of apps to restart in parallel, -1 to match cpu count")
 		args.Parse(os.Args[2:])
 		appName := args.Arg(0)
-		err = ps.CommandRestart(appName, *allApps, *parallelCount)
+		processName := args.Arg(1)
+		err = ps.CommandRestart(appName, processName, *allApps, *parallelCount)
 	case "restore":
 		args := flag.NewFlagSet("ps:restore", flag.ExitOnError)
 		allApps := args.Bool("all", false, "--all: restore all apps")

diff --git a/plugins/ps/subcommands.go b/plugins/ps/subcommands.go
@@ -54,15 +54,22 @@ func CommandReport(appName string, format string, infoFlag string) error {
 }
 
 // CommandRestart restarts an app
-func CommandRestart(appName string, allApps bool, parallelCount int) error {
+func CommandRestart(appName string, processName string, allApps bool, parallelCount int) error {
 	if allApps {
+		if processName != "" {
+			return errors.New("Unable to restart all apps when specifying a process name")
+		}
 		return common.RunCommandAgainstAllApps(Restart, "restart", parallelCount)
 	}
 
 	if err := common.VerifyAppName(appName); err != nil {
 		return err
 	}
 
+	if processName != "" {
+		return RestartProcess(appName, processName)
+	}
+
 	return Restart(appName)
 }
 

diff --git a/plugins/registry/functions.go b/plugins/registry/functions.go
@@ -57,7 +57,7 @@ func pushToRegistry(appName string, tag int, imageID string, imageRepo string) e
 	common.LogVerboseQuiet("Retrieving image info for app")
 
 	registryServer := getRegistryServerForApp(appName)
-	imageTag, _ := common.GetRunningImageTag(appName)
+	imageTag, _ := common.GetRunningImageTag(appName, "")
 
 	fullImage := fmt.Sprintf("%s%s:%d", registryServer, imageRepo, tag)
 

diff --git a/plugins/scheduler-docker-local/scheduler-deploy b/plugins/scheduler-docker-local/scheduler-deploy
@@ -9,7 +9,8 @@ source "$PLUGIN_AVAILABLE_PATH/scheduler-docker-local/internal-functions"
 trigger-scheduler-docker-local-scheduler-deploy() {
   declare desc="deploys an image tag for a given application"
   declare trigger="scheduler-deploy"
-  declare DOKKU_SCHEDULER="$1" APP="$2" IMAGE_TAG="$3"
+  declare DOKKU_SCHEDULER="$1" APP="$2" IMAGE_TAG="$3" PROCESS_TYPE="$4"
+  local PROCESS_TYPE
 
   if [[ "$DOKKU_SCHEDULER" != "docker-local" ]]; then
     return
@@ -28,7 +29,7 @@ trigger-scheduler-docker-local-scheduler-deploy() {
   local IMAGE_SOURCE_TYPE="dockerfile"
   [[ "$DOKKU_HEROKUISH" == "true" ]] && IMAGE_SOURCE_TYPE="herokuish"
   [[ "$DOKKU_CNB" == "true" ]] && IMAGE_SOURCE_TYPE="pack"
-  local oldids=$(get_app_container_ids "$APP")
+  local oldids=$(get_app_container_ids "$APP" "$PROCESS_TYPE")
 
   DOKKU_NETWORK_BIND_ALL="$(plugn trigger network-get-property "$APP" bind-all-interfaces)"
   DOKKU_DOCKER_STOP_TIMEOUT="$(config_get "$APP" DOKKU_DOCKER_STOP_TIMEOUT || true)"
@@ -54,6 +55,10 @@ trigger-scheduler-docker-local-scheduler-deploy() {
     local PROC_TYPE=${line%%=*}
     local PROC_COUNT=${line#*=}
 
+    if [[ -n "$PROCESS_TYPE" ]] && [[ "$PROC_TYPE" != "$PROCESS_TYPE" ]]; then
+      continue
+    fi
+
     if [[ "$PROC_TYPE" != "web" ]]; then
       echo "$PLUGIN_AVAILABLE_PATH/scheduler-docker-local/bin/scheduler-deploy-process $APP $IMAGE_SOURCE_TYPE $IMAGE $IMAGE_TAG $PROC_TYPE $PROC_COUNT" >>"$TMP_FILE"
       continue