Merge pull request #1420 from datawire/story/regex_rewrite_nits

Regex rewrite nits.

docs/topics/using/rewrites.md

@@ -8,56 +8,68 @@ There are two approaches for rewriting: `rewrite` for simpler scenarios and `reg
 
 ## `rewrite`
 
+By default, the `prefix` is rewritten to `/`, so e.g., if we map `/backend-api/` to the service `service1`, then
 
-By default, the `prefix` is rewritten to `/`, so e.g., if we map `/prefix1/` to the service `service1`, then
+<code>
+http://ambassador.example.com<span style="color:red">/backend-api/</span><span style="color:green">foo/bar</span>
+</code>
+
+* ```prefix```: <span style="color:red">/backend-api/</span> which rewrites to <span style="color:red">/</span> by default.
+* ```rewrite```: <span style="color:red">/</span>
+* ```remainder```: <span style="color:green">foo/bar</span>
 
-```shell
-http://ambassador.example.com/prefix1/foo/bar
-```
 
 would effectively be written to
 
-```shell
-http://service1/foo/bar
-```
+<code>
+http://service1<span style="color:red">/</span><span style="color:green">foo/bar</span>
+</code>
 
-when it was handed to `service1`.
+* ```prefix```: was <span style="color:red">/backend-api/</span>
+* ```rewrite```: <span style="color:red">/</span> (by default)
 
-You can change the rewriting: for example, if you choose to rewrite the prefix as `/v1/` in this example, the final target would be:
+You can change the rewriting: for example, if you choose to rewrite the prefix as <span style="color:red">/v1/</span> in this example, the final target would be:
 
-```shell
-http://service1/v1/foo/bar
-```
+
+<code>
+http://service1<span style="color:red">/v1/</span><span style="color:green">foo/bar</span>
+</code>
+
+* ```prefix```: was <span style="color:red">/backend-api/</span> 
+* ```rewrite```: <span style="color:red">/v1/</span>
 
 And, of course, you can choose to rewrite the prefix to the prefix itself, so that
 
-```shell
-http://ambassador.example.com/prefix1/foo/bar
-```
+<code>
+http://ambassador.example.com<span style="color:red">/backend-api/</span><span style="color:green">foo/bar</span>
+</code>
+
+* ```prefix```: <span style="color:red">/backend-api/</span>
+* ```rewrite```: <span style="color:red">/backend-api/</span>
 
 would be "rewritten" as:
 
-```shell
-http://service1/prefix1/foo/bar
-```
+<code>
+http://service1<span style="color:red">/backend-api/</span><span style="color:green">foo/bar</span>
+</code>
 
-Ambassador Edge Stack can be configured to not change the prefix as it forwards a request to the upstream service. To do that, specify an empty `rewrite` directive:
+Ambassador can be configured to not change the prefix as it forwards a request to the upstream service. To do that, specify an empty `rewrite` directive:
 
 - `rewrite: ""`
 
 ## `regex_rewrite`
 
-In some cases, a portion of URL needs to be extracted before making the upstream service URL. For example, suppose that when a request is made to `leaderboards/v1/12345/find`, the target URL must be rewritten as `game/12345`. We can do this as follows:
+In some cases, a portion of URL needs to be extracted before making the upstream service URL. For example, suppose that when a request is made to `foo/12345/list`, the target URL must be rewritten as `bar/12345`. We can do this as follows:
 
 ```shell
-prefix: /leaderboards/
+prefix: /foo/
 regex_rewrite:
-    pattern: 'leaderboards/v1/([0-9]*)/find'
-    substitution: '/game/\1'
+    pattern: '/foo/([0-9]*)/list'
+    substitution: '/bar/\1'
 ```
 
 `([0-9]*)` can be replaced with `(\d)` for simplicity.
 
 More than one group can be captured in the `pattern` to be referenced by `\2`, `\3` and `\n` in the `substitution` section.
 
-For more information on how rewrite and prefix can be configured, see [Mappings](../mappings).
+For more information on how `Mapping` can be configured, see [Mappings](../mappings).

python/tests/t_regexrewrite_forwarding.py

@@ -18,8 +18,8 @@ def config(self):
 prefix: /foo/
 service: http://{self.target.path.fqdn}
 regex_rewrite:
-    pattern: "foo/baz"
-    substitution: "baz/foo"
+    pattern: "/foo/baz"
+    substitution: "/baz/foo"
 """)
 
     def queries(self):
@@ -37,29 +37,29 @@ class RegexRewriteForwardingWithExtractAndSubstituteTest(AmbassadorTest):
     target: ServiceType
 
     def init(self):
-        self.target = HTTP(name="lboards")
+        self.target = HTTP(name="foo")
 
     def config(self):
         yield self.target, self.format(r"""
 ---
 apiVersion: ambassador/v2
 kind:  Mapping
 name:  regex_rewrite_mapping
-prefix: /leaderboards/
+prefix: /foo/
 service: http://{self.target.path.fqdn}
 regex_rewrite:
-    pattern: "leaderboards/v1/([0-9]*)/find"
-    substitution: "game/\\1"
+    pattern: "/foo/([0-9]*)/list"
+    substitution: "/bar/\\1"
 """)
 
     def queries(self):
-        yield Query(self.url("leaderboards/v1/123456789/find"), expected=200)
-        yield Query(self.url("leaderboards/v1/987654321/find"), expected=200)
-        yield Query(self.url("leaderboardddddds/v1/123456789/find"), expected=404)
-        yield Query(self.url("leaderboards/v1/"), expected=200)
+        yield Query(self.url("foo/123456789/list"), expected=200)
+        yield Query(self.url("foo/987654321/list"), expected=200)
+        yield Query(self.url("fooooo/123456789/list"), expected=404)
+        yield Query(self.url("foo/"), expected=200)
 
     def check(self):
-        assert self.results[0].backend.request.headers['x-envoy-original-path'][0] == f'/leaderboards/v1/123456789/find'
-        assert self.results[0].backend.request.url.path == "/game/123456789"
-        assert self.results[1].backend.request.headers['x-envoy-original-path'][0] == f'/leaderboards/v1/987654321/find'
-        assert self.results[1].backend.request.url.path == "/game/987654321"
+        assert self.results[0].backend.request.headers['x-envoy-original-path'][0] == f'/foo/123456789/list'
+        assert self.results[0].backend.request.url.path == "/bar/123456789"
+        assert self.results[1].backend.request.headers['x-envoy-original-path'][0] == f'/foo/987654321/list'
+        assert self.results[1].backend.request.url.path == "/bar/987654321"