feat: add initial support for injecting keda addons

plugins/app-json/appjson.go

@@ -3,10 +3,12 @@ package appjson
 import (
 	"encoding/json"
 	"fmt"
+	"math"
 	"os"
 	"strings"
 
 	"github.com/dokku/dokku/plugins/common"
+	"k8s.io/utils/ptr"
 )
 
 var (
@@ -59,6 +61,9 @@ type CronCommand struct {
 
 // Formation is a struct that represents the scale for a process from an app.json file
 type Formation struct {
+	// Autoscaling is whether or not to enable autoscaling
+	Autoscaling *FormationAutoscaling `json:"autoscaling"`
+
 	// Quantity is the number of processes to run
 	Quantity *int `json:"quantity"`
 
@@ -66,6 +71,36 @@ type Formation struct {
 	MaxParallel *int `json:"max_parallel"`
 }
 
+// FormationAutoscaling is a struct that represents the autoscaling configuration for a process from an app.json file
+type FormationAutoscaling struct {
+	// CoolDownSeconds is the number of seconds to wait before scaling again
+	CooldownPeriodSeconds *int `json:"cooldown_period_seconds,omitempty"`
+
+	// MaxQuantity is the maximum number of processes to run
+	MaxQuantity *int `json:"max_quantity,omitempty"`
+
+	// MinQuantity is the minimum number of processes to run
+	MinQuantity *int `json:"min_quantity,omitempty"`
+
+	// PollingIntervalSeconds is the number of seconds to wait between autoscaling checks
+	PollingIntervalSeconds *int `json:"polling_interval_seconds,omitempty"`
+
+	// Triggers is a list of triggers to use for autoscaling
+	Triggers []FormationAutoscalingTrigger `json:"triggers,omitempty"`
+}
+
+// FormationAutoscalingTrigger is a struct that represents a single autoscaling trigger from an app.json file
+type FormationAutoscalingTrigger struct {
+	// Name is the name of the trigger
+	Name string `json:"name,omitempty"`
+
+	// Type is the type of the trigger
+	Type string `json:"type,omitempty"`
+
+	// Metadata is a map of metadata to use for the trigger
+	Metadata map[string]interface{} `json:"metadata,omitempty"`
+}
+
 // Healthcheck is a struct that represents a single healthcheck from an app.json file
 type Healthcheck struct {
 	// Attempts is the number of attempts to make before considering a healthcheck failed
@@ -181,3 +216,45 @@ func GetAppJSON(appName string) (AppJSON, error) {
 
 	return appJSON, nil
 }
+
+func GetAutoscalingConfig(appName string, processType string, replicas int) (FormationAutoscaling, bool, error) {
+	appJSON, err := GetAppJSON(appName)
+	if err != nil {
+		return FormationAutoscaling{}, false, err
+	}
+
+	common.LogWarn(fmt.Sprintf("appJSON: %v", appJSON))
+
+	formation, ok := appJSON.Formation[processType]
+	if !ok {
+		return FormationAutoscaling{}, false, nil
+	}
+
+	if formation.Autoscaling == nil {
+		return FormationAutoscaling{}, false, nil
+	}
+
+	autoscaling := *formation.Autoscaling
+	if autoscaling.CooldownPeriodSeconds == nil {
+		autoscaling.CooldownPeriodSeconds = ptr.To(300)
+	}
+
+	if autoscaling.MinQuantity == nil {
+		autoscaling.MinQuantity = ptr.To(replicas)
+	}
+
+	if autoscaling.MaxQuantity == nil {
+		defaultValue := math.Max(float64(replicas), float64(*autoscaling.MinQuantity))
+		autoscaling.MaxQuantity = ptr.To(int(defaultValue))
+	}
+
+	if autoscaling.PollingIntervalSeconds == nil {
+		autoscaling.PollingIntervalSeconds = ptr.To(30)
+	}
+
+	if len(autoscaling.Triggers) == 0 {
+		return FormationAutoscaling{}, false, nil
+	}
+
+	return autoscaling, true, nil
+}

plugins/app-json/go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
 	github.com/spf13/pflag v1.0.5
 	golang.org/x/sync v0.6.0
+	k8s.io/utils v0.0.0-20240102154912-e7106e64919e
 )
 
 require (

plugins/app-json/go.sum

@@ -4,8 +4,9 @@ github.com/codegangsta/inject v0.0.0-20150114235600-33e0aa1cb7c0 h1:sDMmm+q/3+Bu
 github.com/codegangsta/inject v0.0.0-20150114235600-33e0aa1cb7c0/go.mod h1:4Zcjuz89kmFXt9morQgcfYZAYZ5n8WHjt81YYWIwtTM=
 github.com/codeskyblue/go-sh v0.0.0-20190412065543-76bd3d59ff27 h1:HHUr4P/aKh4quafGxDT9LDasjGdlGkzLbfmmrlng3kA=
 github.com/codeskyblue/go-sh v0.0.0-20190412065543-76bd3d59ff27/go.mod h1:VQx0hjo2oUeQkQUET7wRwradO6f+fN5jzXgB/zROxxE=
-github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/fatih/color v1.16.0 h1:zmkK9Ngbjj+K0yRhTVONQh1p/HknKYSlNT+vZCzyokM=
 github.com/fatih/color v1.16.0/go.mod h1:fL2Sau1YI5c0pdGEVCbKQbLXB6edEj1ZgiY4NijnWvE=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
@@ -95,3 +96,5 @@ gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+k8s.io/utils v0.0.0-20240102154912-e7106e64919e h1:eQ/4ljkx21sObifjzXwlPKpdGLrCfRziVtos3ofG/sQ=
+k8s.io/utils v0.0.0-20240102154912-e7106e64919e/go.mod h1:OLgZIPagt7ERELqWJFomSt595RzquPNLL48iOWgYOg0=