feat(proxy-wasm) new 'request.is_subrequest' property

Introduce a new request property `request.is_subrequest` to indicate
whether the current request is a subrequest of an existing request
(e.g. in slicing scenarios).

Note: although the property uses the `request.*` prefix, this is not an
Envoy-supported attribute.

See #658.

Co-Authored-By: Thibault Charbonnier <[email protected]>

Author: dev-null-undefined

docs/PROXY_WASM.md

@@ -712,6 +712,7 @@ implementation state in ngx_wasm_module:
 `request.size`                              | :heavy_check_mark: | :x:                 | Maps to [ngx.content_length](https://nginx.org/en/docs/http/ngx_http_core_module.html#content_length).
 `request.total_size`                        | :heavy_check_mark: | :x:                 | Maps to [ngx.request_length](https://nginx.org/en/docs/http/ngx_http_core_module.html#request_length).
 `request.headers.*`                         | :heavy_check_mark: | :x:                 | Returns the value of any request header, e.g. `request.headers.date`.
+`request.is_subrequest`                     | :heavy_check_mark: | :x:                 | An ngx_wasm_module extension indicating whether the current request is a subrequest as a `"true"/"false"` string.
 *Response properties*                       |                    |
 `response.code`                             | :heavy_check_mark: | :x:                 | Maps to [ngx.status](https://nginx.org/en/docs/http/ngx_http_core_module.html#status).
 `response.size`                             | :heavy_check_mark: | :x:                 | Maps to [ngx.body_bytes_sent](https://nginx.org/en/docs/http/ngx_http_core_module.html#body_bytes_sent).

src/common/proxy_wasm/ngx_proxy_wasm_properties.c

@@ -41,15 +41,22 @@ static const char             *ngx_prefix = "ngx.";
 static const size_t            ngx_prefix_len = 4;
 
 
+static const char             *host_prefix =
+                                  NGX_WASM_HOST_PROPERTY_NAMESPACE_STR ".";
+static size_t                  host_prefix_len;
+
+
+#ifdef NGX_WASM_HTTP
+static ngx_str_t               str_on  = ngx_string("true");
+static ngx_str_t               str_off = ngx_string("false");
+#endif
+
+
 static ngx_hash_init_t         pwm2ngx_init;
 static ngx_hash_combined_t     pwm2ngx_hash;
 static ngx_hash_keys_arrays_t  pwm2ngx_keys;
 
 
-static const char  *host_prefix = NGX_WASM_HOST_PROPERTY_NAMESPACE_STR ".";
-static size_t       host_prefix_len;
-
-
 typedef struct {
     ngx_str_node_t   sn;
     ngx_str_t        value;
@@ -171,6 +178,37 @@ get_request_time(ngx_proxy_wasm_ctx_t *pwctx, ngx_str_t *path,
 }
 
 
+static ngx_int_t
+get_request_header(ngx_proxy_wasm_ctx_t *pwctx, ngx_str_t *path,
+    ngx_str_t *value)
+{
+    ngx_str_t   name;
+
+    name.data = (u_char *) (path->data + request_headers_prefix_len);
+    name.len = path->len - request_headers_prefix_len;
+
+    return get_map_value(pwctx, &name, value,
+                         NGX_PROXY_WASM_MAP_HTTP_REQUEST_HEADERS);
+}
+
+
+static ngx_int_t
+is_subrequest(ngx_proxy_wasm_ctx_t *pwctx, ngx_str_t *path,
+    ngx_str_t *value)
+{
+    ngx_str_t                *result;
+    ngx_http_wasm_req_ctx_t  *rctx = pwctx->data;
+    ngx_http_request_t       *r = rctx->r;
+
+    result = r != r->main ? &str_on : &str_off;
+
+    value->data = result->data;
+    value->len = result->len;
+
+    return NGX_OK;
+}
+
+
 static ngx_int_t
 get_upstream_address(ngx_proxy_wasm_ctx_t *pwctx, ngx_str_t *path,
     ngx_str_t *value)
@@ -243,20 +281,6 @@ get_upstream_port(ngx_proxy_wasm_ctx_t *pwctx, ngx_str_t *path,
 }
 
 
-static ngx_int_t
-get_request_header(ngx_proxy_wasm_ctx_t *pwctx, ngx_str_t *path,
-    ngx_str_t *value)
-{
-    ngx_str_t   name;
-
-    name.data = (u_char *) (path->data + request_headers_prefix_len);
-    name.len = path->len - request_headers_prefix_len;
-
-    return get_map_value(pwctx, &name, value,
-                         NGX_PROXY_WASM_MAP_HTTP_REQUEST_HEADERS);
-}
-
-
 static ngx_int_t
 get_response_header(ngx_proxy_wasm_ctx_t *pwctx, ngx_str_t *path,
     ngx_str_t *value)
@@ -313,9 +337,6 @@ get_connection_mtls(ngx_proxy_wasm_ctx_t *pwctx, ngx_str_t *path,
     static ngx_str_t  verify_p = ngx_string("ngx.ssl_client_verify");
     static ngx_str_t  verify_e = ngx_string("SUCCESS");
 
-    static ngx_str_t  mtls_on  = ngx_string("true");
-    static ngx_str_t  mtls_off = ngx_string("false");
-
     if (!pwctx->mtls.len) {
         rc = ngx_proxy_wasm_properties_get_ngx(pwctx, &https_p, &https_v);
         if (rc != NGX_OK) {
@@ -331,7 +352,7 @@ get_connection_mtls(ngx_proxy_wasm_ctx_t *pwctx, ngx_str_t *path,
              && ngx_str_eq(verify_v.data, verify_v.len,
                            verify_e.data, verify_e.len);
 
-        result = on ? &mtls_on : &mtls_off;
+        result = on ? &str_on : &str_off;
 
         pwctx->mtls.data = ngx_pnalloc(pwctx->pool, result->len);
         if (pwctx->mtls.data == NULL) {
@@ -472,6 +493,9 @@ static pwm2ngx_mapping_t  pw2ngx[] = {
     { ngx_string("request.headers.*"),
       ngx_null_string,
       &get_request_header, NULL },
+    { ngx_string("request.is_subrequest"),
+      ngx_null_string,
+      &is_subrequest, NULL },
 
     /* Response properties */
 

t/03-proxy_wasm/hfuncs/117-proxy_properties_get.t

@@ -19,6 +19,7 @@ our $request_properties = join(',', qw(
     request.duration
     request.size
     request.total_size
+    request.is_subrequest
 ));
 
 plan_tests(5);
@@ -63,7 +64,8 @@ request\.protocol: HTTP\/1\.1 at RequestHeaders
 request\.query: special_arg\=true\&special_arg2\=false at RequestHeaders
 request\.duration: \d+\.\d+ at RequestHeaders
 request\.size: 5 at RequestHeaders
-request\.total_size: 187 at RequestHeaders/
+request\.total_size: 187 at RequestHeaders
+request\.is_subrequest: false at RequestHeaders/
 --- no_error_log
 [error]
 [crit]
@@ -151,7 +153,8 @@ request.method: GET at OnHttpCallResponse
 request.time: \d+\.\d+ at OnHttpCallResponse
 request.protocol: HTTP\/1\.1 at OnHttpCallResponse
 request.query: hello\=world at OnHttpCallResponse
-request.total_size: [1-9]+[0-9]+ at OnHttpCallResponse/
+request.total_size: [1-9]+[0-9]+ at OnHttpCallResponse
+request.is_subrequest: false at OnHttpCallResponse/
 --- no_error_log
 [error]
 [crit]
@@ -667,7 +670,32 @@ qr/"response.code_details" property not supported
 
 
 
-=== TEST 15: proxy_wasm - get_property() - unknown property on: request_headers
+=== TEST 15: proxy_wasm - get_property() - request.is_subrequest on: request_headers
+--- load_nginx_modules: ngx_http_echo_module
+--- wasm_modules: hostcalls
+--- config
+    location /t {
+        echo_subrequest GET '/sub';
+    }
+
+    location /sub {
+        proxy_wasm hostcalls 'on=request_headers \
+                              test=/t/log/properties \
+                              name=request.is_subrequest';
+        echo ok;
+    }
+--- response_body
+ok
+--- grep_error_log eval: qr/request\.is_subrequest: (true|false) at \w+/
+--- grep_error_log_out eval
+qr/request\.is_subrequest: true at RequestHeaders/
+--- no_error_log
+[error]
+[crit]
+
+
+
+=== TEST 16: proxy_wasm - get_property() - unknown property on: request_headers
 --- wasm_modules: hostcalls
 --- load_nginx_modules: ngx_http_echo_module
 --- config
@@ -686,7 +714,7 @@ qr/\[info\] .*? property not found: nonexistent_property,/
 
 
 
-=== TEST 16: proxy_wasm - get_property() request.* - not available on: tick (isolation: global)
+=== TEST 17: proxy_wasm - get_property() request.* - not available on: tick (isolation: global)
 --- skip_hup
 --- wasm_modules: hostcalls
 --- load_nginx_modules: ngx_http_echo_module
@@ -709,7 +737,7 @@ qr/\[info\] .*? property not found: nonexistent_property,/
 
 
 
-=== TEST 17: proxy_wasm - get_property() response.* - not available on: tick (isolation: global)
+=== TEST 18: proxy_wasm - get_property() response.* - not available on: tick (isolation: global)
 --- skip_hup
 --- wasm_modules: hostcalls
 --- load_nginx_modules: ngx_http_echo_module
@@ -732,7 +760,7 @@ qr/\[info\] .*? property not found: nonexistent_property,/
 
 
 
-=== TEST 18: proxy_wasm - get_property() upstream.* - not available on: tick (isolation: global)
+=== TEST 19: proxy_wasm - get_property() upstream.* - not available on: tick (isolation: global)
 --- skip_hup
 --- wasm_modules: hostcalls
 --- load_nginx_modules: ngx_http_echo_module
@@ -755,7 +783,7 @@ qr/\[info\] .*? property not found: nonexistent_property,/
 
 
 
-=== TEST 19: proxy_wasm - get_property() upstream.* - not available on: configure (isolation: global)
+=== TEST 20: proxy_wasm - get_property() upstream.* - not available on: configure (isolation: global)
 --- skip_hup
 --- wasm_modules: hostcalls
 --- load_nginx_modules: ngx_http_echo_module

t/lib/proxy-wasm-tests/hostcalls/src/filter.rs

@@ -44,6 +44,7 @@ impl Context for TestHttp {
                     "request.protocol",
                     "request.query",
                     "request.total_size",
+                    "request.is_subrequest",
                 ];
 
                 for property in properties {