Set user agent in getting HTTP status code

Close #8

src/configloader/HttpGetStatusCode.go

@@ -0,0 +1,28 @@
+package configloader
+
+import (
+    "net/http"
+)
+
+// Returns the HTTP status code for a url while sending requests using
+// a user-agent specific to the app.
+func HttpGetStatusCode(url string) (int, error) {
+
+    // create HTTP request
+    req, err := http.NewRequest("GET", url, nil)
+    if err != nil {
+        return 0, err
+    }
+
+    // set User-Agent header
+    req.Header.Set("User-Agent", "museum-digital-uploader")
+
+    resp, err := http.DefaultClient.Do(req)
+    if err != nil {
+        return 0, err
+    }
+    defer resp.Body.Close()
+
+    return resp.StatusCode, nil
+
+}

src/configloader/ValidateInstanceLink.go

@@ -3,7 +3,6 @@ package configloader
 import (
     "errors"
     "net/url"
-    "net/http"
     "strings"
 )
 
@@ -29,11 +28,11 @@ func ValidateInstanceLink(instanceUrl string) (string, error) {
         Host: parsed.Host,
         Path: "/musdb",
     }
-    resp, err := http.Get(musdbUrl.String())
+    statusCode, err := HttpGetStatusCode(musdbUrl.String())
 	if err != nil {
 		return "", err
 	}
-	if resp.StatusCode > 399 {
+	if statusCode > 399 {
         return "", errors.New("The museum-digital subdomain does not contain a musdb path")
 	}
 

src/configloader/ValidateInstitutionId.go

@@ -2,7 +2,6 @@ package configloader
 
 import (
     "errors"
-    "net/http"
     "strconv"
 )
 
@@ -16,12 +15,12 @@ func ValidateInstitutionId(institutionId int, instanceUrl string) (int, error) {
         return 0, errors.New("Institution ID cannot be negative")
     }
 
-    resp, err := http.Get(instanceUrl + "/institution/" + strconv.Itoa(institutionId))
+    statusCode, err := HttpGetStatusCode(instanceUrl + "/institution/" + strconv.Itoa(institutionId))
 	if err != nil {
 		return 0, err
 	}
 
-	if resp.StatusCode != 200 {
+	if statusCode != 200 {
         return 0, errors.New("The institution page does not respond with HTTP 200, the institution does not seem to exist")
 	}
 

src/configloader/configloader.go

@@ -9,6 +9,7 @@ import (
 
 type MDWebDavUploaderConfig struct {
     InstanceLink    string            `json:"instance"`
+    Username        string            `json:"username"`
     Mail            string            `json:"mail"`
     WebDavAuthToken string            `json:"token"`
     InstitutionId   int               `json:"institution_id"`