allow using {{ .URL }} inside "routes" section in plugin.json

[Slach]

What is this feature?
Detail description is #80856

Why do we need this feature?

Looks like current implementation contains bug

Who is this feature for?

For plugin developers which can't store all settings into jsonData
and try to use standard @grafana/ui DataSourceHttpSettings component

For plugin developers when data source destination server doesn't allow additional path in proxyfied request URL.

Which issue(s) does this PR fix?:

Fixes #80856

Special notes for your reviewer:

Please check that:

• It works as expected from a user's perspective.
• If this is a pre-GA feature, it is behind a feature toggle.
• The docs are updated, and if this is a notable improvement, it's added to our What's New doc.

[Slach]

@wbrowne @andresmgot @oshirohugo could you sugget how to pass Changelog Check and Milestone Check? It looks like manual approve

[CLAassistant]

All committers have signed the CLA.

[andresmgot]

It seems there is a specific test that prevents the request from being modified at all:

https://github.com/grafana/grafana/blob/main/pkg/api/pluginproxy/ds_proxy_test.go#L151-L159

This was introduced here: #27653 which seemed to be only interested in keeping the Host and Schema but also protected the Path. Seems unnecessary but do you know if this may break anything @marefr ?

[Slach]

@andresmgot i can't figure out
why test-backend failed, but no-one test failed here - https://drone.grafana.net/grafana/grafana/155812/1/7

[andresmgot]

@andresmgot i can't figure out why test-backend failed, but no-one test failed here - https://drone.grafana.net/grafana/grafana/155812/1/7

It did fail, you need to expand the logs:

--- FAIL: TestDataSourceProxy_routeRule (0.65s)
    --- FAIL: TestDataSourceProxy_routeRule/Plugin_with_routes (0.00s)
        --- FAIL: TestDataSourceProxy_routeRule/Plugin_with_routes/When_matching_route_path_with_no_url (0.00s)
            ds_proxy_test.go:158: 
                	Error Trace:	/drone/src/pkg/api/pluginproxy/ds_proxy_test.go:158
                	Error:      	Not equal: 
                	            	expected: "http://localhost/asd"
                	            	actual  : "http://localhost"
                	            	
                	            	Diff:
                	            	--- Expected
                	            	+++ Actual
                	            	@@ -1 +1 @@
                	            	-http://localhost/asd
                	            	+http://localhost
                	Test:       	TestDataSourceProxy_routeRule/Plugin_with_routes/When_matching_route_path_with_no_url
FAIL
coverage: 65.8% of statements
FAIL	github.com/grafana/grafana/pkg/api/pluginproxy	0.935s

[Slach]

@andresmgot thanks for logs
so, what will we do?
should I expand template data to allow pass URL or should i change test behavior?

[Slach]

@andresmgot @marefr I implemented allowing to use {{ .URL }} instead of changing behavior with proxyPath.
Please review it.

[andresmgot]

LGTM, do you mind adding a test to cover this use case? You can add the following:

--- a/pkg/api/pluginproxy/ds_proxy_test.go
+++ b/pkg/api/pluginproxy/ds_proxy_test.go
@@ -158,6 +158,36 @@ func TestDataSourceProxy_routeRule(t *testing.T) {
                        assert.Equal(t, "http://localhost/asd", req.URL.String())
                })
 
+               t.Run("When matching route path and has setting url", func(t *testing.T) {
+                       ctx, req := setUp()
+                       proxy, err := setupDSProxyTest(t, ctx, ds, routes, "api/common/some/method")
+                       require.NoError(t, err)
+                       proxy.matchedRoute = &plugins.Route{
+                               Path: "api/common",
+                               URL:  "{{.URL}}",
+                               Headers: []plugins.Header{
+                                       {Name: "x-header", Content: "my secret {{.SecureJsonData.key}}"},
+                               },
+                               URLParams: []plugins.URLParam{
+                                       {Name: "{{.JsonData.queryParam}}", Content: "{{.SecureJsonData.key}}"},
+                               },
+                       }
+
+                       dsInfo := DSInfo{
+                               ID:       ds.ID,
+                               Updated:  ds.Updated,
+                               JSONData: jd,
+                               DecryptedSecureJSONData: map[string]string{
+                                       "key": "123",
+                               },
+                               URL: "https://dynamic.grafana.com",
+                       }
+                       ApplyRoute(proxy.ctx.Req.Context(), req, proxy.proxyPath, proxy.matchedRoute, dsInfo, proxy.cfg)
+
+                       assert.Equal(t, "https://dynamic.grafana.com/some/method?apiKey=123", req.URL.String())
+                       assert.Equal(t, "my secret 123", req.Header.Get("x-header"))
+               })
+

[Slach]

@andresmgot test added, thanks for suggestion

[Slach]

@andresmgot hot to approve continuous-integration/drone/pr github workflow ?

[andresmgot]

hi @Slach, can you merge the latest main here to deal with the CI issues?

[Slach]

merge and rebase, done
@andresmgot

[andresmgot]

Thank you for the contribution.