Add Fargate provider config loader

providers/aws/config.go

@@ -0,0 +1,142 @@
+package aws
+
+import (
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/virtual-kubelet/virtual-kubelet/providers"
+	"github.com/virtual-kubelet/virtual-kubelet/providers/aws/fargate"
+
+	"github.com/BurntSushi/toml"
+	"k8s.io/apimachinery/pkg/api/resource"
+)
+
+const (
+	// Provider configuration defaults.
+	// https://docs.aws.amazon.com/AmazonECS/latest/developerguide/platform_versions.html
+	defaultPlatformVersion         = "LATEST"
+	defaultClusterName             = "default"
+	defaultAssignPublicIPv4Address = false
+	defaultOperatingSystem         = providers.OperatingSystemLinux
+
+	// Default resource capacity advertised by Fargate provider.
+	// These are intentionally low to prevent any accidental overuse.
+	defaultCPUCapacity     = "20"
+	defaultMemoryCapacity  = "40Gi"
+	defaultStorageCapacity = "40Gi"
+	defaultPodCapacity     = "20"
+
+	// Minimum resource capacity advertised by Fargate provider.
+	// These values correspond to the minimum Fargate task size.
+	minCPUCapacity    = "250m"
+	minMemoryCapacity = "512Mi"
+	minPodCapacity    = "1"
+)
+
+// ProviderConfig represents the contents of the provider configuration file.
+type providerConfig struct {
+	Region                  string
+	ClusterName             string
+	Subnets                 []string
+	SecurityGroups          []string
+	AssignPublicIPv4Address bool
+	PlatformVersion         string
+	OperatingSystem         string
+	CPU                     string
+	Memory                  string
+	Storage                 string
+	Pods                    string
+}
+
+// loadConfigFile loads the given Fargate provider configuration file.
+func (p *FargateProvider) loadConfigFile(filePath string) error {
+	f, err := os.Open(filePath)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	err = p.loadConfig(f)
+	return err
+}
+
+// loadConfigStream loads the given Fargate provider TOML configuration stream.
+func (p *FargateProvider) loadConfig(r io.Reader) error {
+	var config providerConfig
+	var q resource.Quantity
+
+	// Set defaults for optional fields.
+	config.ClusterName = defaultClusterName
+	config.AssignPublicIPv4Address = defaultAssignPublicIPv4Address
+	config.PlatformVersion = defaultPlatformVersion
+	config.OperatingSystem = defaultOperatingSystem
+	config.CPU = defaultCPUCapacity
+	config.Memory = defaultMemoryCapacity
+	config.Storage = defaultStorageCapacity
+	config.Pods = defaultPodCapacity
+
+	// Read the user-supplied configuration.
+	_, err := toml.DecodeReader(r, &config)
+	if err != nil {
+		return err
+	}
+
+	// Validate aggregate configuration.
+	if config.Region == "" {
+		return fmt.Errorf("Region is a required field")
+	}
+	if !fargate.FargateRegions.Include(config.Region) {
+		return fmt.Errorf(
+			"Fargate is available only in regions %v and not available in %v",
+			fargate.FargateRegions.Names(), config.Region)
+	}
+	if config.Subnets == nil || len(config.Subnets) == 0 {
+		return fmt.Errorf("Subnets is a required field")
+	}
+	if config.SecurityGroups == nil {
+		config.SecurityGroups = []string{}
+	}
+	if config.OperatingSystem != providers.OperatingSystemLinux {
+		return fmt.Errorf("Fargate does not support operating system %v", config.OperatingSystem)
+	}
+
+	// Validate advertised capacity.
+	if q, err = resource.ParseQuantity(config.CPU); err != nil {
+		return fmt.Errorf("Invalid CPU value %v", config.CPU)
+	}
+	if q.Cmp(resource.MustParse(minCPUCapacity)) == -1 {
+		return fmt.Errorf("CPU value %v is less than the minimum %v", config.CPU, minCPUCapacity)
+	}
+	if q, err = resource.ParseQuantity(config.Memory); err != nil {
+		return fmt.Errorf("Invalid memory value %v", config.Memory)
+	}
+	if q.Cmp(resource.MustParse(minMemoryCapacity)) == -1 {
+		return fmt.Errorf("Memory value %v is less than the minimum %v", config.Memory, minMemoryCapacity)
+	}
+	if q, err = resource.ParseQuantity(config.Storage); err != nil {
+		return fmt.Errorf("Invalid storage value %v", config.Storage)
+	}
+	if q, err = resource.ParseQuantity(config.Pods); err != nil {
+		return fmt.Errorf("Invalid pods value %v", config.Pods)
+	}
+	if q.Cmp(resource.MustParse(minPodCapacity)) == -1 {
+		return fmt.Errorf("Pod value %v is less than the minimum %v", config.Pods, minPodCapacity)
+	}
+
+	// Populate provider fields.
+	p.region = config.Region
+	p.subnets = config.Subnets
+	p.securityGroups = config.SecurityGroups
+
+	p.clusterName = config.ClusterName
+	p.assignPublicIPv4Address = config.AssignPublicIPv4Address
+	p.platformVersion = config.PlatformVersion
+	p.operatingSystem = config.OperatingSystem
+	p.capacity.cpu = config.CPU
+	p.capacity.memory = config.Memory
+	p.capacity.storage = config.Storage
+	p.capacity.pods = config.Pods
+
+	return nil
+}