Added remote SchemaSource type

apollo-federation-types/src/config/subgraph.rs

@@ -42,6 +42,10 @@ pub enum SchemaSource {
     File {
         file: Utf8PathBuf,
     },
+    Remote {
+        remote_url: Url,
+        headers: Option<HashMap<String, String>>,
+    },
     SubgraphIntrospection {
         subgraph_url: Url,
         introspection_headers: Option<HashMap<String, String>>,
@@ -59,6 +63,7 @@ pub enum SchemaSource {
 mod test_schema_source {
     use crate::config::SchemaSource;
     use serde_yaml::from_str;
+    use std::collections::HashMap;
 
     #[test]
     fn test_file() {
@@ -115,6 +120,41 @@ subgraph: my-subgraph
         assert_eq!(source, expected);
     }
 
+    #[test]
+    fn test_remote() {
+        let yaml = r#"
+remote_url: https://example.com/some/schema/v1.0.graphqls
+headers:
+    Authorization: ${env.AUTH_TOKEN}
+        "#;
+        let source: SchemaSource = from_str(yaml).unwrap();
+        let expected = SchemaSource::Remote {
+            remote_url: "https://example.com/some/schema/v1.0.graphqls"
+                .parse()
+                .unwrap(),
+            headers: Some(HashMap::from([(
+                "Authorization".to_string(),
+                "${env.AUTH_TOKEN}".to_string(),
+            )])),
+        };
+        assert_eq!(source, expected);
+    }
+
+    #[test]
+    fn test_remote_no_headers() {
+        let yaml = r#"
+remote_url: https://example.com/some/schema/v1.0.graphqls
+        "#;
+        let source: SchemaSource = from_str(yaml).unwrap();
+        let expected = SchemaSource::Remote {
+            remote_url: "https://example.com/some/schema/v1.0.graphqls"
+                .parse()
+                .unwrap(),
+            headers: None,
+        };
+        assert_eq!(source, expected);
+    }
+
     #[test]
     fn test_sdl() {
         let yaml = r#"