feat(api): add healthchecks to API

Author: Matthew Fisher

api/config.go

@@ -1,5 +1,11 @@
 package api
 
+import (
+	"bytes"
+	"fmt"
+	"text/template"
+)
+
 // ConfigSet is the definition of POST /v2/apps/<app id>/config/.
 type ConfigSet struct {
 	Values map[string]string `json:"values"`
@@ -12,14 +18,94 @@ type ConfigUnset struct {
 
 // Config is the structure of an app's config.
 type Config struct {
-	Owner    string                 `json:"owner,omitempty"`
-	App      string                 `json:"app,omitempty"`
-	Values   map[string]interface{} `json:"values,omitempty"`
-	Memory   map[string]interface{} `json:"memory,omitempty"`
-	CPU      map[string]interface{} `json:"cpu,omitempty"`
-	Tags     map[string]interface{} `json:"tags,omitempty"`
-	Registry map[string]interface{} `json:"registry,omitempty"`
-	Created  string                 `json:"created,omitempty"`
-	Updated  string                 `json:"updated,omitempty"`
-	UUID     string                 `json:"uuid,omitempty"`
+	Owner       string                  `json:"owner,omitempty"`
+	App         string                  `json:"app,omitempty"`
+	Values      map[string]interface{}  `json:"values,omitempty"`
+	Memory      map[string]interface{}  `json:"memory,omitempty"`
+	CPU         map[string]interface{}  `json:"cpu,omitempty"`
+	Healthcheck map[string]*Healthcheck `json:"healthcheck,omitempty"`
+	Tags        map[string]interface{}  `json:"tags,omitempty"`
+	Registry    map[string]interface{}  `json:"registry,omitempty"`
+	Created     string                  `json:"created,omitempty"`
+	Updated     string                  `json:"updated,omitempty"`
+	UUID        string                  `json:"uuid,omitempty"`
+}
+
+// Healthcheck is the structure for an application healthcheck.
+// Healthchecks only need to provide information about themselves.
+// All the information is pushed to the server and handled by kubernetes.
+type Healthcheck struct {
+	InitialDelaySeconds int             `json:"initialDelaySeconds"`
+	TimeoutSeconds      int             `json:"timeoutSeconds"`
+	PeriodSeconds       int             `json:"periodSeconds"`
+	SuccessThreshold    int             `json:"successThreshold"`
+	FailureThreshold    int             `json:"failureThreshold"`
+	Exec                *ExecProbe      `json:"exec,omitempty"`
+	HTTPGet             *HTTPGetProbe   `json:"httpGet,omitempty"`
+	TCPSocket           *TCPSocketProbe `json:"tcpSocket,omitempty"`
+}
+
+// String displays the HealthcheckHTTPGetProbe in a readable format.
+func (h Healthcheck) String() string {
+	var doc bytes.Buffer
+	tmpl, err := template.New("healthcheck").Parse(`Initial Delay (seconds): {{.InitialDelaySeconds}}
+Timeout (seconds): {{.TimeoutSeconds}}
+Period (seconds): {{.PeriodSeconds}}
+Success Threshold: {{.SuccessThreshold}}
+Failure Threshold: {{.FailureThreshold}}
+Exec Probe: {{or .Exec "N/A"}}
+HTTP GET Probe: {{or .HTTPGet "N/A"}}
+TCP Socket Probe: {{or .TCPSocket "N/A"}}`)
+	if err != nil { panic(err) }
+	err = tmpl.Execute(&doc, h)
+	if err != nil { panic(err) }
+	return doc.String()
+}
+
+// KVPair is a key/value pair used to parse values from
+// strings into a formal structure.
+type KVPair struct {
+	Key   string `json:"key"`
+	Value string `json:"value"`
+}
+
+func (k KVPair) String() string {
+	return k.Key+"="+k.Value
+}
+
+// ExecProbe executes a command within a Pod.
+type ExecProbe struct {
+	Command []string `json:"command"`
+}
+
+// String displays the ExecProbe in a readable format.
+func (e ExecProbe) String() string {
+	return fmt.Sprintf(`Command=%s`, e.Command)
+}
+
+// HTTPGetProbe performs an HTTP GET request to the Pod
+// with the given path, port and headers.
+type HTTPGetProbe struct {
+	Path        string    `json:"path,omitempty"`
+	Port        int       `json:"port"`
+	HTTPHeaders []*KVPair `json:"httpHeaders,omitempty"`
+}
+
+// String displays the HTTPGetProbe in a readable format.
+func (h HTTPGetProbe) String() string {
+	return fmt.Sprintf(`Path="%s" Port=%d HTTPHeaders=%s`,
+		h.Path,
+		h.Port,
+		h.HTTPHeaders)
+}
+
+// TCPSocketProbe attempts to open a socket connection to the
+// Pod on the given port.
+type TCPSocketProbe struct {
+	Port int `json:"port"`
+}
+
+// String displays the TCPSocketProbe in a readable format.
+func (t TCPSocketProbe) String() string {
+	return fmt.Sprintf("Port=%d", t.Port)
 }

api/config_test.go

@@ -0,0 +1,61 @@
+package api
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestHealthcheckString(t *testing.T) {
+	h := Healthcheck{}
+
+	expected := strings.TrimSpace(`Initial Delay (seconds): 0
+Timeout (seconds): 0
+Period (seconds): 0
+Success Threshold: 0
+Failure Threshold: 0
+Exec Probe: N/A
+HTTP GET Probe: N/A
+TCP Socket Probe: N/A`)
+
+	if strings.TrimSpace(h.String()) != expected {
+		t.Errorf("Expected:\n\n%s\n\nGot:\n\n%s", expected, h.String())
+	}
+
+	h.HTTPGet = &HTTPGetProbe{
+		Path: "/",
+		Port: 80,
+		HTTPHeaders: []*KVPair{{ Key: "X-DEIS-IS", Value: "AWESOME" }},
+	}
+
+	expected = strings.TrimSpace(`Initial Delay (seconds): 0
+Timeout (seconds): 0
+Period (seconds): 0
+Success Threshold: 0
+Failure Threshold: 0
+Exec Probe: N/A
+HTTP GET Probe: Path="/" Port=80 HTTPHeaders=[X-DEIS-IS=AWESOME]
+TCP Socket Probe: N/A`)
+
+	if strings.TrimSpace(h.String()) != expected {
+		t.Errorf("Expected:\n\n%s\n\nGot:\n\n%s", expected, h.String())
+	}
+
+	h.Exec = &ExecProbe{Command: []string{"echo", "hi"}}
+
+	h.TCPSocket = &TCPSocketProbe{
+		Port: 80,
+	}
+
+	expected = strings.TrimSpace(`Initial Delay (seconds): 0
+Timeout (seconds): 0
+Period (seconds): 0
+Success Threshold: 0
+Failure Threshold: 0
+Exec Probe: Command=[echo hi]
+HTTP GET Probe: Path="/" Port=80 HTTPHeaders=[X-DEIS-IS=AWESOME]
+TCP Socket Probe: Port=80`)
+
+	if strings.TrimSpace(h.String()) != expected {
+		t.Errorf("Expected:\n\n%s\n\nGot:\n\n%s", expected, h.String())
+	}
+}