dokku · josegonzalez · Jan 23, 2021 · Jan 18, 2021 · Jan 22, 2021 · Jan 22, 2021
diff --git a/docs/deployment/logs.md b/docs/deployment/logs.md
@@ -57,6 +57,34 @@ You may also fetch all failed app logs by using the `--all` flag.
 dokku logs:failed --all
 ```
 
+### Docker Log Retention
+
+Docker log retention can be specified via the `logs:set` command by specifying a value for `max-size`. Log retention is set via injected docker options for all applications, but is also available via the `logs-get-property` trigger for alternative schedulers.
+
+```shell
+dokku logs:set node-js-app max-size 20m
+```
+
+The default value may be set by passing an empty value for the option:
+
+```shell
+dokku logs:set node-js-app max-size
+```
+
+Valid values include any integer number followed by a unit of measure (`k`, `m`, or `g`) or the string `unlimited`. Setting to `unlimited` will result in Dokku omitting the log option.
+
+The `max-size` property can also be set globally. The global default is `10m`, and the global value is used when no app-specific value is set.
+
+```shell
+dokku logs:set --global max-size 20m
+```
+
+The default value may be set by passing an empty value for the option.
+
+```shell
+dokku logs:set --global max-size
+```
+
 ### Vector Logging Shipping
 
 > New as of 0.22.6

diff --git a/docs/development/plugin-triggers.md b/docs/development/plugin-triggers.md
@@ -699,6 +699,22 @@ if [[ ! -f  "$DOKKU_ROOT/HOSTNAME" ]]; then
 fi
 ```
 
+### `logs-get-property`
+
+- Description: Fetches a given logs property value
+- Invoked by:
+- Arguments: `$APP` `$PROPERTY`
+- Example:
+
+```shell
+#!/usr/bin/env bash
+
+set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
+APP="$1"; PROPERTY="$2"
+
+# TODO
+```
+
 ### `network-build-config`
 
 - Description: Rebuilds network configuration

diff --git a/plugins/common/properties.go b/plugins/common/properties.go
@@ -8,6 +8,7 @@ import (
 	"os"
 	"path/filepath"
 	"reflect"
+	"sort"
 	"strings"
 )
 
@@ -32,6 +33,7 @@ func CommandPropertySet(pluginName, appName, property, value string, properties
 			validPropertyList[i] = properties[i].String()
 		}
 
+		sort.Strings(validPropertyList)
 		LogFail(fmt.Sprintf("Invalid property specified, valid properties include: %s", strings.Join(validPropertyList, ", ")))
 	}
 

diff --git a/plugins/logs/.gitignore b/plugins/logs/.gitignore
@@ -2,6 +2,7 @@
 /subcommands/*
 /triggers/*
 /triggers
+/docker-args-process-deploy
 /install
 /post-*
 /report
diff --git a/plugins/logs/Makefile b/plugins/logs/Makefile
@@ -1,5 +1,5 @@
 SUBCOMMANDS = subcommands/failed subcommands/report subcommands/set subcommands/vector-logs subcommands/vector-start subcommands/vector-stop
-TRIGGERS = triggers/install triggers/post-delete triggers/report
+TRIGGERS = triggers/docker-args-process-deploy triggers/install triggers/logs-get-property triggers/post-delete triggers/report
 BUILD = commands subcommands triggers
 PLUGIN_NAME = logs
 

diff --git a/plugins/logs/logs.go b/plugins/logs/logs.go
@@ -6,14 +6,19 @@ import (
 	"github.com/dokku/dokku/plugins/common"
 )
 
+// MaxSize is the default max retention size for docker logs
+const MaxSize = "10m"
+
 var (
 	// DefaultProperties is a map of all valid ps properties with corresponding default property values
 	DefaultProperties = map[string]string{
+		"max-size":    "",
 		"vector-sink": "",
 	}
 
 	// GlobalProperties is a map of all valid global logs properties
 	GlobalProperties = map[string]bool{
+		"max-size":    true,
 		"vector-sink": true,
 	}
 )

diff --git a/plugins/logs/report.go b/plugins/logs/report.go
@@ -11,8 +11,11 @@ func ReportSingleApp(appName, infoFlag string) error {
 	}
 
 	flags := map[string]common.ReportFunc{
-		"--logs-vector-sink":        reportVectorSink,
+		"--logs-computed-max-size":  reportComputedMaxSize,
+		"--logs-global-max-size":    reportGlobalMaxSize,
 		"--logs-global-vector-sink": reportGlobalVectorSink,
+		"--logs-max-size":           reportMaxSize,
+		"--logs-vector-sink":        reportVectorSink,
 	}
 
 	flagKeys := []string{}
@@ -26,10 +29,27 @@ func ReportSingleApp(appName, infoFlag string) error {
 	return common.ReportSingleApp("logs", appName, infoFlag, infoFlags, flagKeys, trimPrefix, uppercaseFirstCharacter)
 }
 
-func reportVectorSink(appName string) string {
-	return common.PropertyGet("logs", appName, "vector-sink")
+func reportComputedMaxSize(appName string) string {
+	value := reportMaxSize(appName)
+	if value == "" {
+		value = reportGlobalMaxSize(appName)
+	}
+
+	return value
+}
+
+func reportGlobalMaxSize(appName string) string {
+	return common.PropertyGetDefault("logs", "--global", "max-size", MaxSize)
 }
 
 func reportGlobalVectorSink(appName string) string {
 	return common.PropertyGet("logs", "--global", "vector-sink")
 }
+
+func reportMaxSize(appName string) string {
+	return common.PropertyGet("logs", appName, "max-size")
+}
+
+func reportVectorSink(appName string) string {
+	return common.PropertyGet("logs", appName, "vector-sink")
+}
diff --git a/plugins/logs/set.go b/plugins/logs/set.go
@@ -0,0 +1,58 @@
+package logs
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+)
+
+func validateSetValue(appName string, key string, value string) error {
+	if key == "max-size" {
+		return validateMaxSize(appName, value)
+	}
+
+	if key == "vector-sink" {
+		return validateVectorSink(appName, value)
+	}
+
+	return nil
+}
+
+func validateMaxSize(appName string, value string) error {
+	if value == "" {
+		return nil
+	}
+
+	if value == "unlimited" {
+		return nil
+	}
+
+	last := value[len(value)-1:]
+	if last != "k" && last != "m" && last != "g" {
+		return errors.New("Invalid max-size unit measure, value must end in any of [k, m, g]")
+	}
+
+	if len(value) < 2 {
+		return errors.New("Invalid max-size value, must be a number followed by a unit of measure [k, m, d]")
+	}
+
+	number := value[:len(value)-1]
+	if _, err := strconv.Atoi(number); err != nil {
+		return fmt.Errorf("Invalid max-size value, unable to convert number to int: %s", err.Error())
+	}
+
+	return nil
+}
+
+func validateVectorSink(appName string, value string) error {
+	if value == "" {
+		return nil
+	}
+
+	_, err := valueToConfig(appName, value)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/plugins/logs/src/subcommands/subcommands.go b/plugins/logs/src/subcommands/subcommands.go
@@ -35,6 +35,7 @@ func main() {
 	case "set":
 		args := flag.NewFlagSet("logs:set", flag.ExitOnError)
 		global := args.Bool("global", false, "--global: set a global property")
+		valueOverride := args.Bool("1", false, "-1: negative value (for max-size)")
 		args.Parse(os.Args[2:])
 		appName := args.Arg(0)
 		property := args.Arg(1)
@@ -44,6 +45,11 @@ func main() {
 			property = args.Arg(0)
 			value = args.Arg(1)
 		}
+
+		if *valueOverride {
+			value = "-1"
+		}
+
 		err = logs.CommandSet(appName, property, value)
 	case "vector-logs":
 		args := flag.NewFlagSet("logs:vector-logs", flag.ExitOnError)

diff --git a/plugins/logs/src/triggers/triggers.go b/plugins/logs/src/triggers/triggers.go
@@ -18,8 +18,15 @@ func main() {
 
 	var err error
 	switch trigger {
+	case "docker-args-process-deploy":
+		appName := flag.Arg(0)
+		err = logs.TriggerDockerArgsProcessDeploy(appName)
 	case "install":
 		err = logs.TriggerInstall()
+	case "logs-get-property":
+		appName := flag.Arg(0)
+		property := flag.Arg(1)
+		err = logs.TriggerLogsGetProperty(appName, property)
 	case "post-delete":
 		appName := flag.Arg(0)
 		err = logs.TriggerPostDelete(appName)

diff --git a/plugins/logs/subcommands.go b/plugins/logs/subcommands.go
@@ -69,11 +69,8 @@ func CommandReport(appName string, infoFlag string) error {
 
 // CommandSet sets or clears a logs property for an app
 func CommandSet(appName string, property string, value string) error {
-	if property == "vector-sink" && value != "" {
-		_, err := valueToConfig(appName, value)
-		if err != nil {
-			return err
-		}
+	if err := validateSetValue(appName, property, value); err != nil {
+		return err
 	}
 
 	common.CommandPropertySet("logs", appName, property, value, DefaultProperties, GlobalProperties)

diff --git a/plugins/logs/triggers.go b/plugins/logs/triggers.go
@@ -1,13 +1,35 @@
 package logs
 
 import (
+	"errors"
 	"fmt"
+	"io/ioutil"
 	"os"
 	"path/filepath"
 
 	"github.com/dokku/dokku/plugins/common"
 )
 
+// TriggerDockerArgsProcessDeploy outputs the logs plugin docker options for an app
+func TriggerDockerArgsProcessDeploy(appName string) error {
+	stdin, err := ioutil.ReadAll(os.Stdin)
+	if err != nil {
+		return err
+	}
+
+	maxSize := common.PropertyGet("logs", appName, "max-size")
+	if maxSize == "" {
+		maxSize = common.PropertyGetDefault("logs", "--global", "max-size", MaxSize)
+	}
+
+	if maxSize != "unlimited" {
+		fmt.Printf(" --log-opt max-size=%s ", maxSize)
+	}
+
+	fmt.Print(string(stdin))
+	return nil
+}
+
 // TriggerInstall initializes app restart policies
 func TriggerInstall() error {
 	if err := common.PropertySetup("logs"); err != nil {
@@ -35,6 +57,21 @@ func TriggerInstall() error {
 	return nil
 }
 
+// TriggerLogsGetProperty writes the logs key to stdout for a given app container
+func TriggerLogsGetProperty(appName string, key string) error {
+	if key != "max-size" {
+		return errors.New("Invalid logs property specified")
+	}
+
+	value := common.PropertyGet("logs", appName, "max-size")
+	if value == "" {
+		value = common.PropertyGetDefault("logs", "--global", "max-size", MaxSize)
+	}
+
+	fmt.Println(value)
+	return nil
+}
+
 // TriggerPostDelete destroys the network property for a given app container
 func TriggerPostDelete(appName string) error {
 	return common.PropertyDestroy("logs", appName)