[State] Feat: write current and desired state

Author: MeNsaaH

README.md

@@ -31,11 +31,28 @@ cp config/config.example.yaml config/config.yaml
 # One time run
 go run main.go --config ../config/config.yaml
 
-# Web Dashboard
+# TODO Web Dashboard
 go run main.go web --config ../config/config.yaml
 ```
 
-using [air](https://github.com/cosmtrek/air) with autoreload UI features
+## Installation
+### Using go
 ```bash
-    air -c .air.toml
+go get -u github.com/mensaah/reka
+```
+
+## Usage
+
+Reka loads default config from $HOME/.reka.yaml if --config param is not passed.
+Copy `config/config.example.yaml` to `config/config.yaml` and make all necessary changes
+
+```bash
+cp config/config.example.yaml config/config.yaml
+# Run reka using configuration. Stops stoppable resources, resume resumable resources and terminate
+# resources dues for termination
+reka --config ../config/config.yaml
+
+# KABOOOOOM
+# everything gone
+reka nuke --config ../config/config.yaml
 ```

cmd/root.go

@@ -17,13 +17,13 @@ package cmd
 
 import (
 	"fmt"
-	"log"
 	"os"
 	"unsafe"
 
 	"github.com/spf13/cobra"
 
 	homedir "github.com/mitchellh/go-homedir"
+	log "github.com/sirupsen/logrus"
 	"github.com/spf13/viper"
 
 	"github.com/mensaah/reka/config"
@@ -40,7 +40,7 @@ var (
 	cfg          *config.Config
 	providers    []*provider.Provider
 	backend      state.Backender
-	currentState state.State
+	currentState *state.State
 )
 
 // rootCmd represents the base command when called without any subcommands
@@ -91,7 +91,7 @@ func initConfig() {
 
 	// If a config file is found, read it in.
 	if err := viper.ReadInConfig(); err == nil {
-		fmt.Println("Using config file:", viper.ConfigFileUsed())
+		log.Info("Using config file:", viper.ConfigFileUsed())
 	}
 
 	// Load Config and Defaults
@@ -108,10 +108,8 @@ func initConfig() {
 	// Initialize Provider objects
 	providers = initProviders()
 	backend = state.InitBackend()
-	currentState = make(state.State)
 }
 
-// TODO Add logger to Providers during configuration
 func initProviders() []*provider.Provider {
 	var providers []*provider.Provider
 	for _, p := range config.GetProviders() {
@@ -135,25 +133,43 @@ func initProviders() []*provider.Provider {
 }
 
 // Refresh current status of resources from Providers
+// TODO Reconcile state so that new resources are added to desired states and former resources removed
 func refreshResources(providers []*provider.Provider) {
+	// currentState is the state stored in backend
+	currentState = backend.GetState()
+
+	currentState.Current = make(state.ProvidersState)
 	for _, provider := range providers {
 		allResources := provider.GetAllResources()
-		currentState[provider.Name] = allResources
-
-		// stoppableResources := provider.GetStoppableResources(allResources)
-		// fmt.Println("Stoppable Resources: ", stoppableResources)
-		// errs := provider.StopResources(stoppableResources)
-		// fmt.Println("Errors Stopping Resources: ", errs)
-
-		// resumableResources := provider.GetResumableResources(allResources)
-		// fmt.Println("Resumable Resources: ", resumableResources)
-		// errs = provider.ResumeResources(resumableResources)
-		// fmt.Println("Errors Resuming Resources: ", errs)
-
-		destroyableResources := provider.GetDestroyableResources(allResources)
-		fmt.Println("Destroyable Resources: ", destroyableResources)
-		// errs = provider.DestroyResources(destroyableResources)
-		// fmt.Println("Errors Destroying Resources: ", errs)
+		currentState.Current[provider.Name] = allResources
+	}
+
+	// Add new resources to desired state if they don't already exists
+	for k, v := range currentState.Current {
+		if m, ok := currentState.Desired[k]; ok || currentState.Desired[k] == nil {
+			log.Error(m)
+			// TODO Return difference between two Resources object
+			continue
+		}
+		currentState.Desired[k] = v
 	}
-	backend.WriteState(&currentState)
+
+	backend.WriteState(currentState)
+}
+
+func reapResources() {
+	// stoppableResources := provider.GetStoppableResources(allResources)
+	// fmt.Println("Stoppable Resources: ", stoppableResources)
+	// errs := provider.StopResources(stoppableResources)
+	// fmt.Println("Errors Stopping Resources: ", errs)
+
+	// resumableResources := provider.GetResumableResources(allResources)
+	// fmt.Println("Resumable Resources: ", resumableResources)
+	// errs = provider.ResumeResources(resumableResources)
+	// fmt.Println("Errors Resuming Resources: ", errs)
+
+	// destroyableResources := provider.GetDestroyableResources(allResources)
+	// fmt.Println("Destroyable Resources: ", destroyableResources)
+	// errs = provider.DestroyResources(destroyableResources)
+	// fmt.Println("Errors Destroying Resources: ", errs)
 }

provider/aws/ec2_types.go

@@ -14,7 +14,7 @@ var ec2Manager resource.Manager
 
 const (
 	// Name of resource
-	ec2Name = "EC2"
+	ec2Name = "ec2"
 	// LongName descriptive name for resource
 	ec2LongName = "Elastic Compute Cloud"
 )

provider/aws/eip_types.go

@@ -12,7 +12,7 @@ var eipManager resource.Manager
 
 const (
 	// Name of resource
-	eipName = "EIP"
+	eipName = "eip"
 	// LongName descriptive name for resource
 	eipLongName = "Elastic IP"
 )

provider/aws/eks_types.go

@@ -14,7 +14,7 @@ var eksManager resource.Manager
 
 const (
 	// Name of resource
-	eksName = "EKS"
+	eksName = "eks"
 	// LongName descriptive name for resource
 	eksLongName = "Elastic Compute Cloud"
 

provider/aws/s3_types.go

@@ -9,7 +9,7 @@ import (
 
 const (
 	// Name of resource
-	s3Name = "S3"
+	s3Name = "s3"
 	// LongName descriptive name for resource
 	s3LongName = "Simple Storage Service"
 )

state/backend.go

@@ -15,7 +15,7 @@ type Backender interface {
 
 // Reader is the interface for state types that can return state resources
 type Reader interface {
-	Get() *State
+	GetState() *State
 }
 
 // Writer is the interface for state types that can write to state files
@@ -31,8 +31,10 @@ func InitBackend() Backender {
 	switch cfg.StateBackend.Type {
 	default:
 		log.Debugf("using Local State at %s", cfg.StateBackend.Path)
+		s := NewEmptyState()
 		backend = LocalBackend{
-			Path: cfg.StateBackend.Path,
+			Path:  cfg.StateBackend.Path,
+			state: &s,
 		}
 	}
 	return backend

state/local.go

@@ -16,11 +16,11 @@ type LocalBackend struct {
 	Path  string
 }
 
-// Get returns state from local source
-func (s LocalBackend) Get() *State {
-	if s.state.empty() {
+// GetState returns state from local source
+func (s LocalBackend) GetState() *State {
+	if s.state.Empty() {
 		if _, err := os.Stat(s.Path); os.IsNotExist(err) {
-			s.state = &State{}
+			log.Debugf("State file not found, using empty state")
 			return s.state
 		}
 		stateFile, err := os.Open(s.Path)

state/state.go

@@ -8,21 +8,49 @@ import (
 var backend Backender
 var cfg *config.Config
 
-// State object: Represents a reka state consisting of resources
-// aws: {
+// ProvidersState represents state for providers
+//   {
+//    aws: {
 // 		s3: [ Resource1, Resource2 ]
+//    }
+//  }
+type ProvidersState map[string]provider.Resources
+
+// State object: Represents a reka state consisting of current and desired state
+// Desired state is used for resumption of resources. It stores the attributes of the resource to resume to
+// for resources that need extra info like size of node pool to resize to
+// current: {
+//    aws: {
+// 		s3: [ Resource1, Resource2 ]
+//    }
+// }
+// desired: {
+//    aws: {
+// 		s3: [ Resource1, Resource2 ]
+//    }
 // }
-type State map[string]provider.Resources
+// State object stores state for both current and desired states
+// of resources
+type State struct {
+	Current ProvidersState
+	Desired ProvidersState
+}
 
-func (s *State) diff(st *State) State {
-	return Diff(s, st)
+func (s *State) diff() State {
+	return Diff(s.Desired, s.Current)
 }
 
-func (s State) empty() bool {
-	return len(s) == 0
+// Empty checks if state is empty
+func (s State) Empty() bool {
+	return len(s.Current) == 0 && len(s.Desired) == 0
 }
 
 // Diff returns the difference in between two states
-func Diff(previous, current *State) State {
+func Diff(previous, current ProvidersState) State {
 	return State{}
 }
+
+// NewEmptyState gets a new empty state
+func NewEmptyState() State {
+	return State{Desired: make(ProvidersState), Current: make(ProvidersState)}
+}