[WIP] Micro Runtime (#947)

* Add Get() and GetOptions.

* Removed watcher. Outline of client. YAML templates

* Added default service and deployment templates and types

* Added API tests and cleaned up errors.

* Small refactoring. Template package is no more.

* Ripped out existing code in preparation to small rework

* Reshuffled the source code to make it organized better

* Create service and deployment in kubernetes runtime

* Major cleanup and refactoring of Kubernetes runtime

* Service now handles low level K8s API calls across both K8s deployment
an service API objects
* Runtime has a task queue that serves for queueing runtime action
requests
* General refactoring

* No need for Lock in k8s service

* Added kubernetes runtime env var to default deployment

* Enable running different versions of the same service

* Can't delete services through labels

* Proto cruft. Added runtime.CreateOptions implementation in proto

* Removed proxy service from default env variables

* Make service name mandatory param to Get method

* Get Delete changes from https://github.com/micro/go-micro/pull/945

* Replaced template files with global variables

* Validate service names before sending K8s API request

* Refactored Kubernetes API client. Fixed typos.

* Added client.Resource to make API resources more explicit in code

runtime/kubernetes/client/kubernetes.go

@@ -1,43 +1,132 @@
+// Package client provides an implementation of a restricted subset of kubernetes API client
 package client
 
+import (
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/micro/go-micro/util/log"
+)
+
+const (
+	// https://github.com/kubernetes/apimachinery/blob/master/pkg/util/validation/validation.go#L134
+	dns1123LabelFmt string = "[a-z0-9]([-a-z0-9]*[a-z0-9])?"
+)
+
+var (
+	// DefaultImage is default micro image
+	DefaultImage = "micro/micro"
+	// ServiceRegexp is used to validate service name
+	ServiceRegexp = regexp.MustCompile("^" + dns1123LabelFmt + "$")
+)
+
 // Kubernetes client
 type Kubernetes interface {
-	// UpdateDeployment patches deployment annotations with new metadata
-	UpdateDeployment(string, interface{}) error
-	// ListDeployments lists all micro deployments
-	ListDeployments(labels map[string]string) (*DeploymentList, error)
+	// Create creates new API resource
+	Create(*Resource) error
+	// Get queries API resrouces
+	Get(*Resource, map[string]string) error
+	// Update patches existing API object
+	Update(*Resource) error
+	// Delete deletes API resource
+	Delete(*Resource) error
+	// List lists API resources
+	List(*Resource) error
 }
 
-// Template is micro deployment template
-type Template struct {
-	Metadata *Metadata `json:"metadata,omitempty"`
+// DefaultService returns default micro kubernetes service definition
+func DefaultService(name, version string) *Service {
+	Labels := map[string]string{
+		"name":    name,
+		"version": version,
+		"micro":   "service",
+	}
+
+	svcName := name
+	if len(version) > 0 {
+		// API service object name joins name and version over "-"
+		svcName = strings.Join([]string{name, version}, "-")
+
+	}
+
+	Metadata := &Metadata{
+		Name:      svcName,
+		Namespace: "default",
+		Version:   version,
+		Labels:    Labels,
+	}
+
+	Spec := &ServiceSpec{
+		Type:     "ClusterIP",
+		Selector: Labels,
+		Ports: []ServicePort{{
+			name + "-port", 9090, "",
+		}},
+	}
+
+	return &Service{
+		Metadata: Metadata,
+		Spec:     Spec,
+	}
 }
 
-// Spec defines micro deployment spec
-type Spec struct {
-	Template *Template `json:"template,omitempty"`
-}
+// DefaultService returns default micro kubernetes deployment definition
+func DefaultDeployment(name, version string) *Deployment {
+	Labels := map[string]string{
+		"name":    name,
+		"version": version,
+		"micro":   "service",
+	}
 
-// Metadata defines api request metadata
-type Metadata struct {
-	Name        string            `json:"name,omitempty"`
-	Labels      map[string]string `json:"labels,omitempty"`
-	Annotations map[string]string `json:"annotations,omitempty"`
-}
+	// API deployment object name joins name and version over "="
+	depName := strings.Join([]string{name, version}, "-")
 
-// DeploymentList
-type DeploymentList struct {
-	Items []Deployment `json:"items"`
-}
+	Metadata := &Metadata{
+		Name:      depName,
+		Namespace: "default",
+		Version:   version,
+		Labels:    Labels,
+	}
 
-// Deployment is Kubernetes deployment
-type Deployment struct {
-	Metadata *Metadata `json:"metadata"`
-	Status   *Status   `json:"status"`
-}
+	// TODO: we need to figure out this version stuff
+	// might be worth adding Build to runtime.Service
+	buildTime, err := strconv.ParseInt(version, 10, 64)
+	if err == nil {
+		buildUnixTimeUTC := time.Unix(buildTime, 0)
+		Metadata.Annotations = map[string]string{
+			"build": buildUnixTimeUTC.Format(time.RFC3339),
+		}
+	} else {
+		log.Debugf("Runtime could not parse build: %v", err)
+	}
 
-// Status is Kubernetes deployment status
-type Status struct {
-	Replicas          int `json:"replicas"`
-	AvailableReplicas int `json:"availablereplicas"`
+	// TODO: change the image name here
+	Spec := &DeploymentSpec{
+		Replicas: 1,
+		Selector: &LabelSelector{
+			MatchLabels: Labels,
+		},
+		Template: &Template{
+			Metadata: Metadata,
+			PodSpec: &PodSpec{
+				Containers: []Container{{
+					Name:    name,
+					Image:   DefaultImage,
+					Env:     []EnvVar{},
+					Command: []string{"go", "run", "main.go"},
+					Ports: []ContainerPort{{
+						Name:          name + "-port",
+						ContainerPort: 8080,
+					}},
+				}},
+			},
+		},
+	}
+
+	return &Deployment{
+		Metadata: Metadata,
+		Spec:     Spec,
+	}
 }