HTTP/2 Cleartext protocol (h2c) support for subgraph connections (#3852)

Fix #3535 The router can now connect to subgraphs over HTTP/2 Cleartext, which uses the HTTP/2 binary protocol directly over TCP without TLS. To activate it, set the `experimental_http2` option to `http2_only`. --------- Co-authored-by: Edward Huang <[email protected]> Co-authored-by: Jeremy Lempereur <[email protected]>
apollographql · Sep 25, 2023 · 7d45877 · 7d45877
1 parent 20b727b
commit 7d45877
Show file tree

Hide file tree

Showing 10 changed files with 293 additions and 74 deletions.
diff --git a/.changesets/feat_geal_h2c.md b/.changesets/feat_geal_h2c.md
@@ -0,0 +1,5 @@
+### HTTP/2 Cleartext protocol (h2c) support for subgraph connections ([Issue #3535](https://github.com/apollographql/router/issues/3535))
+
+The router can now connect to subgraphs over HTTP/2 Cleartext, which uses the HTTP/2 binary protocol directly over TCP without TLS. To activate it, set the `experimental_http2` option to `http2_only`.
+
+By [@Geal](https://github.com/Geal) in https://github.com/apollographql/router/pull/3852
diff --git a/apollo-router/src/configuration/metrics.rs b/apollo-router/src/configuration/metrics.rs
@@ -282,7 +282,7 @@ impl Metrics {
             opt.subgraph.rate_limit,
             "$[?(@.all.global_rate_limit || @.subgraphs..global_rate_limit)]",
             opt.subgraph.http2,
-            "$[?(@.all.experimental_enable_http2 == true || @.subgraphs..experimental_enable_http2 == true)]",
+            "$[?(@.all.experimental_http2 == 'enable' || @.all.experimental_http2 == 'http2only' || @.subgraphs..experimental_http2 == 'enable' || @.subgraphs..experimental_http2 == 'http2only')]",
             opt.subgraph.compression,
             "$[?(@.all.compression || @.subgraphs..compression)]",
             opt.subgraph.deduplicate_query,

diff --git a/apollo-router/src/configuration/migrations/0011-experimental-http2.yaml b/apollo-router/src/configuration/migrations/0011-experimental-http2.yaml
@@ -0,0 +1,25 @@
+description: Move experimental_enable_http2 to experimental_http2
+actions:
+  - type: change
+    path: traffic_shaping.all.experimental_enable_http2
+    from: true
+    to: enable
+  - type: change
+    path: traffic_shaping.all.experimental_enable_http2
+    from: false
+    to: disable
+  - type: move
+    from: traffic_shaping.all.experimental_enable_http2
+    to: traffic_shaping.all.experimental_http2
+
+  - type: change
+    path: traffic_shaping.subgraphs..experimental_enable_http2
+    from: true
+    to: enable
+  - type: change
+    path: traffic_shaping.subgraphs..experimental_enable_http2
+    from: false
+    to: disable
+  - type: move
+    from: traffic_shaping.subgraphs..experimental_enable_http2
+    to: traffic_shaping.subgraphs..experimental_http2
diff --git a/...r/src/configuration/snapshots/apollo_router__configuration__tests__schema_generation.snap b/...r/src/configuration/snapshots/apollo_router__configuration__tests__schema_generation.snap
@@ -5558,11 +5558,6 @@ expression: "&schema"
               "type": "boolean",
               "nullable": true
             },
-            "experimental_enable_http2": {
-              "description": "Enable HTTP2 for subgraphs",
-              "type": "boolean",
-              "nullable": true
-            },
             "experimental_entity_caching": {
               "description": "Enable entity caching",
               "type": "object",
@@ -5578,6 +5573,33 @@ expression: "&schema"
               "additionalProperties": false,
               "nullable": true
             },
+            "experimental_http2": {
+              "description": "Enable HTTP2 for subgraphs",
+              "oneOf": [
+                {
+                  "description": "Enable HTTP2 for subgraphs",
+                  "type": "string",
+                  "enum": [
+                    "enable"
+                  ]
+                },
+                {
+                  "description": "Disable HTTP2 for subgraphs",
+                  "type": "string",
+                  "enum": [
+                    "disable"
+                  ]
+                },
+                {
+                  "description": "Only HTTP2 is active",
+                  "type": "string",
+                  "enum": [
+                    "http2only"
+                  ]
+                }
+              ],
+              "nullable": true
+            },
             "experimental_retry": {
               "description": "Retry configuration",
               "type": "object",
@@ -5746,11 +5768,6 @@ expression: "&schema"
                 "type": "boolean",
                 "nullable": true
               },
-              "experimental_enable_http2": {
-                "description": "Enable HTTP2 for subgraphs",
-                "type": "boolean",
-                "nullable": true
-              },
               "experimental_entity_caching": {
                 "description": "Enable entity caching",
                 "type": "object",
@@ -5766,6 +5783,33 @@ expression: "&schema"
                 "additionalProperties": false,
                 "nullable": true
               },
+              "experimental_http2": {
+                "description": "Enable HTTP2 for subgraphs",
+                "oneOf": [
+                  {
+                    "description": "Enable HTTP2 for subgraphs",
+                    "type": "string",
+                    "enum": [
+                      "enable"
+                    ]
+                  },
+                  {
+                    "description": "Disable HTTP2 for subgraphs",
+                    "type": "string",
+                    "enum": [
+                      "disable"
+                    ]
+                  },
+                  {
+                    "description": "Only HTTP2 is active",
+                    "type": "string",
+                    "enum": [
+                      "http2only"
+                    ]
+                  }
+                ],
+                "nullable": true
+              },
               "experimental_retry": {
                 "description": "Retry configuration",
                 "type": "object",

diff --git a/...rc/configuration/snapshots/apollo_router__configuration__upgrade__test__change_field.snap b/...rc/configuration/snapshots/apollo_router__configuration__upgrade__test__change_field.snap
@@ -0,0 +1,14 @@
+---
+source: apollo-router/src/configuration/upgrade.rs
+expression: "apply_migration(&source_doc(),\n        &Migration::builder().action(Action::Change {\n                            path: \"obj.field1\".to_string(),\n                            from: Value::Number(1u64.into()),\n                            to: Value::String(\"a\".into()),\n                        }).description(\"change field1\").build()).expect(\"expected successful migration\")"
+---
+{
+  "obj": {
+    "field1": "a",
+    "field2": 2
+  },
+  "arr": [
+    "v1",
+    "v2"
+  ]
+}
diff --git a/apollo-router/src/configuration/testdata/metrics/traffic_shaping.router.yaml b/apollo-router/src/configuration/testdata/metrics/traffic_shaping.router.yaml
@@ -11,7 +11,7 @@ traffic_shaping:
     global_rate_limit:
       capacity: 100
       interval: 1s
-    experimental_enable_http2: true
+    experimental_http2: enable
     experimental_retry:
       ttl: 1s
       min_per_sec: 2

diff --git a/apollo-router/src/configuration/upgrade.rs b/apollo-router/src/configuration/upgrade.rs
@@ -38,6 +38,11 @@ enum Action {
         from: String,
         to: String,
     },
+    Change {
+        path: String,
+        from: Value,
+        to: Value,
+    },
 }
 
 const REMOVAL_VALUE: &str = "__PLEASE_DELETE_ME";
@@ -129,6 +134,17 @@ fn apply_migration(config: &Value, migration: &Migration) -> Result<Value, Confi
                     );
                 }
             }
+            Action::Change { path, from, to } => {
+                if !jsonpath_lib::select(config, &format!("$.{path} == {from}"))
+                    .unwrap_or_default()
+                    .is_empty()
+                {
+                    transformer_builder = transformer_builder.add_action(
+                        Parser::parse(&format!(r#"const({to})"#), path)
+                            .expect("migration must be valid"),
+                    );
+                }
+            }
         }
     }
     let transformer = transformer_builder
@@ -423,4 +439,20 @@ mod test {
         )
         .expect("expected successful migration"));
     }
+
+    #[test]
+    fn change_field() {
+        insta::assert_json_snapshot!(apply_migration(
+            &source_doc(),
+            &Migration::builder()
+                .action(Action::Change {
+                    path: "obj.field1".to_string(),
+                    from: Value::Number(1u64.into()),
+                    to: Value::String("a".into()),
+                })
+                .description("change field1")
+                .build(),
+        )
+        .expect("expected successful migration"));
+    }
 }
diff --git a/apollo-router/src/plugins/traffic_shaping/mod.rs b/apollo-router/src/plugins/traffic_shaping/mod.rs
@@ -73,7 +73,19 @@ struct Shaping {
     //  *experimental feature*: Enables request retry
     experimental_retry: Option<RetryConfig>,
     /// Enable HTTP2 for subgraphs
-    experimental_enable_http2: Option<bool>,
+    experimental_http2: Option<Http2Config>,
+}
+
+#[derive(PartialEq, Default, Debug, Clone, Deserialize, JsonSchema)]
+#[serde(rename_all = "lowercase")]
+pub(crate) enum Http2Config {
+    #[default]
+    /// Enable HTTP2 for subgraphs
+    Enable,
+    /// Disable HTTP2 for subgraphs
+    Disable,
+    /// Only HTTP2 is active
+    Http2Only,
 }
 
 impl Merge for Shaping {
@@ -94,10 +106,10 @@ impl Merge for Shaping {
                     .as_ref()
                     .or(fallback.experimental_retry.as_ref())
                     .cloned(),
-                experimental_enable_http2: self
-                    .experimental_enable_http2
+                experimental_http2: self
+                    .experimental_http2
                     .as_ref()
-                    .or(fallback.experimental_enable_http2.as_ref())
+                    .or(fallback.experimental_http2.as_ref())
                     .cloned(),
             },
         }
@@ -458,13 +470,13 @@ impl TrafficShaping {
         }
     }
 
-    pub(crate) fn enable_subgraph_http2(&self, service_name: &str) -> bool {
+    pub(crate) fn enable_subgraph_http2(&self, service_name: &str) -> Http2Config {
         Self::merge_config(
             self.config.all.as_ref(),
             self.config.subgraphs.get(service_name),
         )
-        .and_then(|config| config.shaping.experimental_enable_http2)
-        .unwrap_or(true)
+        .and_then(|config| config.shaping.experimental_http2)
+        .unwrap_or(Http2Config::Enable)
     }
 }
 
@@ -714,52 +726,55 @@ mod test {
         let config = serde_yaml::from_str::<Config>(
             r#"
         all:
-          experimental_enable_http2: false
+          experimental_http2: disable
         subgraphs: 
           products:
-            experimental_enable_http2: true
+            experimental_http2: enable
           reviews:
-            experimental_enable_http2: false
+            experimental_http2: disable
         router:
           timeout: 65s
         "#,
         )
         .unwrap();
 
-        assert!(TrafficShaping::merge_config(
-            config.all.as_ref(),
-            config.subgraphs.get("products")
-        )
-        .unwrap()
-        .shaping
-        .experimental_enable_http2
-        .unwrap());
-        assert!(!TrafficShaping::merge_config(
-            config.all.as_ref(),
-            config.subgraphs.get("reviews")
-        )
-        .unwrap()
-        .shaping
-        .experimental_enable_http2
-        .unwrap());
-        assert!(!TrafficShaping::merge_config(config.all.as_ref(), None)
-            .unwrap()
-            .shaping
-            .experimental_enable_http2
-            .unwrap());
+        assert!(
+            TrafficShaping::merge_config(config.all.as_ref(), config.subgraphs.get("products"))
+                .unwrap()
+                .shaping
+                .experimental_http2
+                .unwrap()
+                == Http2Config::Enable
+        );
+        assert!(
+            TrafficShaping::merge_config(config.all.as_ref(), config.subgraphs.get("reviews"))
+                .unwrap()
+                .shaping
+                .experimental_http2
+                .unwrap()
+                == Http2Config::Disable
+        );
+        assert!(
+            TrafficShaping::merge_config(config.all.as_ref(), None)
+                .unwrap()
+                .shaping
+                .experimental_http2
+                .unwrap()
+                == Http2Config::Disable
+        );
     }
 
     #[tokio::test]
     async fn test_enable_subgraph_http2() {
         let config = serde_yaml::from_str::<Config>(
             r#"
         all:
-          experimental_enable_http2: false
+          experimental_http2: disable
         subgraphs: 
           products:
-            experimental_enable_http2: true
+            experimental_http2: enable
           reviews:
-            experimental_enable_http2: false
+            experimental_http2: disable
         router:
           timeout: 65s
         "#,
@@ -770,9 +785,9 @@ mod test {
             .await
             .unwrap();
 
-        assert!(shaping_config.enable_subgraph_http2("products"));
-        assert!(!shaping_config.enable_subgraph_http2("reviews"));
-        assert!(!shaping_config.enable_subgraph_http2("this_doesnt_exist"));
+        assert!(shaping_config.enable_subgraph_http2("products") == Http2Config::Enable);
+        assert!(shaping_config.enable_subgraph_http2("reviews") == Http2Config::Disable);
+        assert!(shaping_config.enable_subgraph_http2("this_doesnt_exist") == Http2Config::Disable);
     }
 
     #[tokio::test(flavor = "multi_thread")]