Enhance info endpoint to include gateway version

Extend the health endpoint and add gateway version information

Resolves: #733
Signed-off-by: Edward Wilde <ewilde@gmail.com>

gateway/types/inforequest.go

@@ -0,0 +1,58 @@
+package types
+
+import (
+	"bytes"
+	"net/http"
+)
+
+// GatewayInfo provides information about the gateway and it's connected components
+type GatewayInfo struct {
+	Provider *ProviderInfo `json:"provider"`
+	Version  *VersionInfo  `json:"version"`
+}
+
+// ProviderInfo provides information about the configured provider
+type ProviderInfo struct {
+	Name          string       `json:"provider"`
+	Version       *VersionInfo `json:"version"`
+	Orchestration string       `json:"orchestration"`
+}
+
+// VersionInfo provides the commit message, sha and release version number
+type VersionInfo struct {
+	CommitMessage string `json:"commit_message,omitempty"`
+	SHA           string `json:"sha"`
+	Release       string `json:"release"`
+}
+
+// StringResponseWriter captures the handlers HTTP response in a buffer
+type StringResponseWriter struct {
+	body       *bytes.Buffer
+	headerCode int
+	header     http.Header
+}
+
+// NewStringResponseWriter create a new StringResponseWriter
+func NewStringResponseWriter() *StringResponseWriter {
+	return &StringResponseWriter{body: &bytes.Buffer{}, header: make(http.Header)}
+}
+
+// Header capture the Header information
+func (s StringResponseWriter) Header() http.Header {
+	return s.header
+}
+
+// Write captures the response data
+func (s StringResponseWriter) Write(data []byte) (int, error) {
+	return s.body.Write(data)
+}
+
+// WriteHeader captures the status code of the response
+func (s StringResponseWriter) WriteHeader(statusCode int) {
+	s.headerCode = statusCode
+}
+
+// Body returns the response body bytes
+func (s StringResponseWriter) Body() []byte {
+	return s.body.Bytes()
+}