UYUNI SD: Validate HTTP config

Related-to #12810

Signed-off-by: Jayapriya Pai <janantha@redhat.com>

config/config_test.go

@@ -1893,6 +1893,10 @@ var expectedErrors = []struct {
 		filename: "uyuni_no_server.bad.yml",
 		errMsg:   "Uyuni SD configuration requires server host",
 	},
+	{
+		filename: "uyuni_token_file.bad.yml",
+		errMsg:   "at most one of bearer_token & bearer_token_file must be configured",
+	},
 	{
 		filename: "ionos_datacenter.bad.yml",
 		errMsg:   "datacenter id can't be empty",

config/testdata/uyuni_token_file.bad.yml

@@ -0,0 +1,8 @@
+scrape_configs:
+  - job_name: uyuni
+    uyuni_sd_configs:
+      - server: "server"
+        username: "username"
+        password: "password"
+        bearer_token: foo
+        bearer_token_file: foo

discovery/uyuni/uyuni.go

@@ -146,7 +146,7 @@ func (c *SDConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	if c.Password == "" {
 		return errors.New("Uyuni SD configuration requires a password")
 	}
-	return nil
+	return c.HTTPClientConfig.Validate()
 }
 
 func login(rpcclient *xmlrpc.Client, user, pass string, duration int) (string, error) {