feat: Support API requests

* Support auth from Authorization header * First cookies will be checked, if not found, Auth header will be checked * If any of them are successful, headers will be forwarded for client reqs Signed-off-by: Mahendra Paipuri <[email protected]>
mahendrapaipuri · Apr 18, 2024 · a151d11 · a151d11
1 parent 3f56681
commit a151d11
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Showing 6 changed files with 60 additions and 29 deletions.
diff --git a/pkg/plugin/app.go b/pkg/plugin/app.go
@@ -49,7 +49,7 @@ type App struct {
 	httpClient       *http.Client
 	grafanaAppUrl    string
 	config           *Config
-	newGrafanaClient func(client *http.Client, grafanaAppURL string, cookie string, variables url.Values, layout string, panels string) GrafanaClient
+	newGrafanaClient func(client *http.Client, grafanaAppURL string, headers http.Header, variables url.Values, layout string, panels string) GrafanaClient
 	newReport        func(logger log.Logger, grafanaClient GrafanaClient, config *ReportConfig) (Report, error)
 }
 

diff --git a/pkg/plugin/client.go b/pkg/plugin/client.go
@@ -23,21 +23,21 @@ type grafanaClient struct {
 	url              string
 	getDashEndpoint  func(dashUID string) string
 	getPanelEndpoint func(dashUID string, vals url.Values) string
-	cookies          string
+	headers          http.Header
 	queryParams      url.Values
 	layout           string
 	dashboardMode    string
 }
 
 var getPanelRetrySleepTime = time.Duration(10) * time.Second
 
-// NewClient creates a new Grafana Client. If cookies is the non-empty string,
-// cookie will be forwarded in the requests.
+// NewClient creates a new Grafana Client. Cookies and Authorization headers, if found,
+// will be forwarded in the requests
 // queryParams are Grafana template variable url values of the form var-{name}={value}, e.g. var-host=dev
 func NewGrafanaClient(
 	client *http.Client,
 	grafanaAppURL string,
-	cookie string,
+	headers http.Header,
 	queryParams url.Values,
 	layout string,
 	dashboardMode string,
@@ -60,13 +60,25 @@ func NewGrafanaClient(
 		grafanaAppURL,
 		getDashEndpoint,
 		getPanelEndpoint,
-		cookie,
+		headers,
 		queryParams,
 		layout,
 		dashboardMode,
 	}
 }
 
+// Add auth specific header to request
+func (g grafanaClient) forwardAuthHeader(r *http.Request) *http.Request {
+	// If incoming request has cookies formward them
+	// If cookie is not foun, try Authorization header that is used in API requests
+	if g.headers.Get(backend.CookiesHeaderName) != "" {
+		r.Header.Set(backend.CookiesHeaderName, g.headers.Get(backend.CookiesHeaderName))
+	} else if g.headers.Get("Authorization") != "" {
+		r.Header.Set("Authorization", g.headers.Get("Authorization"))
+	}
+	return r
+}
+
 func (g grafanaClient) GetDashboard(dashUID string) (Dashboard, error) {
 	dashURL := g.getDashEndpoint(dashUID)
 
@@ -76,10 +88,8 @@ func (g grafanaClient) GetDashboard(dashUID string) (Dashboard, error) {
 		return Dashboard{}, fmt.Errorf("error creating request for %s: %v", dashURL, err)
 	}
 
-	// If incoming request has cookies formward them
-	if g.cookies != "" {
-		req.Header.Set(backend.CookiesHeaderName, g.cookies)
-	}
+	// Forward auth headers
+	req = g.forwardAuthHeader(req)
 
 	// Make request
 	resp, err := g.client.Do(req)
@@ -113,10 +123,8 @@ func (g grafanaClient) GetPanelPNG(p Panel, dashUID string, t TimeRange) (io.Rea
 		return nil, fmt.Errorf("error creating request for %s: %v", panelURL, err)
 	}
 
-	// Forward cookies from incoming request
-	if g.cookies != "" {
-		req.Header.Set(backend.CookiesHeaderName, g.cookies)
-	}
+	// Forward auth headers
+	req = g.forwardAuthHeader(req)
 
 	// Make request
 	resp, err := g.client.Do(req)

diff --git a/pkg/plugin/client_test.go b/pkg/plugin/client_test.go
@@ -7,6 +7,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/grafana/grafana-plugin-sdk-go/backend"
 	. "github.com/smartystreets/goconvey/convey"
 )
 
@@ -20,19 +21,26 @@ func init() {
 func TestGrafanaClientFetchesDashboard(t *testing.T) {
 	Convey("When fetching a Dashboard", t, func() {
 		requestURI := ""
+		requestCookie := ""
 		ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 			requestURI = r.RequestURI
+			requestCookie = r.Header.Get(backend.CookiesHeaderName)
 			w.Write([]byte(`{"dashboard": {"title": "foo"}}`))
 		}))
 		defer ts.Close()
 
 		Convey("When using the Grafana client", func() {
-			grf := NewGrafanaClient(&testClient, ts.URL, "", url.Values{}, "simple", "default")
+			headers := http.Header{}
+			headers.Add(backend.CookiesHeaderName, "cookie")
+			grf := NewGrafanaClient(&testClient, ts.URL, headers, url.Values{}, "simple", "default")
 			grf.GetDashboard("rYy7Paekz")
 
 			Convey("It should use the v5 dashboards endpoint", func() {
 				So(requestURI, ShouldEqual, "/api/dashboards/uid/rYy7Paekz")
 			})
+			Convey("It should use cookie", func() {
+				So(requestCookie, ShouldEqual, "cookie")
+			})
 		})
 
 	})
@@ -49,7 +57,8 @@ func TestGrafanaClientFetchesPanelPNG(t *testing.T) {
 		}))
 		defer ts.Close()
 
-		cookies := "1234"
+		headers := http.Header{}
+		headers.Add("Authorization", "token")
 		variables := url.Values{}
 		variables.Add("var-host", "servername")
 		variables.Add("var-port", "adapter")
@@ -59,7 +68,7 @@ func TestGrafanaClientFetchesPanelPNG(t *testing.T) {
 			pngEndpoint string
 		}{
 			"client": {
-				NewGrafanaClient(&testClient, ts.URL, cookies, variables, "simple", "default"),
+				NewGrafanaClient(&testClient, ts.URL, headers, variables, "simple", "default"),
 				"/render/d-solo/testDash/_",
 			},
 		}
@@ -85,7 +94,7 @@ func TestGrafanaClientFetchesPanelPNG(t *testing.T) {
 			})
 
 			Convey("The client should insert auth token should in request header", func() {
-				So(requestHeaders.Get("Cookie"), ShouldContainSubstring, cookies)
+				So(requestHeaders.Get("Authorization"), ShouldEqual, "token")
 			})
 
 			Convey("The client should pass variables in the request parameters", func() {
@@ -104,7 +113,7 @@ func TestGrafanaClientFetchesPanelPNG(t *testing.T) {
 			pngEndpoint string
 		}{
 			"client": {
-				NewGrafanaClient(&testClient, ts.URL, cookies, variables, "grid", "default"),
+				NewGrafanaClient(&testClient, ts.URL, headers, variables, "grid", "default"),
 				"/render/d-solo/testDash/_",
 			},
 		}
@@ -138,7 +147,7 @@ func TestGrafanaClientFetchPanelPNGErrorHandling(t *testing.T) {
 		}))
 		defer ts.Close()
 
-		grf := NewGrafanaClient(&testClient, ts.URL, "", url.Values{}, "simple", "default")
+		grf := NewGrafanaClient(&testClient, ts.URL, http.Header{}, url.Values{}, "simple", "default")
 
 		_, err := grf.GetPanelPNG(
 			Panel{44, "singlestat", "title", GridPos{0, 0, 0, 0}},
@@ -157,7 +166,7 @@ func TestGrafanaClientFetchPanelPNGErrorHandling(t *testing.T) {
 		}))
 		defer ts.Close()
 
-		grf := NewGrafanaClient(&testClient, ts.URL, "", url.Values{}, "simple", "default")
+		grf := NewGrafanaClient(&testClient, ts.URL, http.Header{}, url.Values{}, "simple", "default")
 
 		_, err := grf.GetPanelPNG(
 			Panel{44, "singlestat", "title", GridPos{0, 0, 0, 0}},

diff --git a/pkg/plugin/resources.go b/pkg/plugin/resources.go
@@ -9,7 +9,6 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/grafana/grafana-plugin-sdk-go/backend"
 	"github.com/grafana/grafana-plugin-sdk-go/backend/log"
 	"github.com/grafana/grafana-plugin-sdk-go/backend/resource/httpadapter"
 )
@@ -150,15 +149,11 @@ func (a *App) handleReport(w http.ResponseWriter, req *http.Request) {
 		}
 	}
 
-	// Get current user cookie and we will use this cookie in API request to get
-	// dashboard JSON models and panel PNGs
-	cookie := req.Header.Get(backend.CookiesHeaderName)
-
 	// Make a new Grafana client to get dashboard JSON model and Panel PNGs
 	grafanaClient := a.newGrafanaClient(
 		a.httpClient,
 		a.grafanaAppUrl,
-		cookie,
+		req.Header,
 		variables,
 		layout,
 		dashboardMode,

diff --git a/pkg/plugin/resources_test.go b/pkg/plugin/resources_test.go
@@ -56,9 +56,9 @@ func TestReportResource(t *testing.T) {
 	Convey("When the report handler is called", t, func() {
 		var clientVars url.Values
 		// mock new grafana client function to capture and validate its input parameters
-		app.newGrafanaClient = func(client *http.Client, url string, cookie string, variables url.Values, layout string, panels string) GrafanaClient {
+		app.newGrafanaClient = func(client *http.Client, url string, headers http.Header, variables url.Values, layout string, panels string) GrafanaClient {
 			clientVars = variables
-			return NewGrafanaClient(&testClient, url, "", clientVars, "simple", "default")
+			return NewGrafanaClient(&testClient, url, http.Header{}, clientVars, "simple", "default")
 		}
 		//mock new report function to capture and validate its input parameters
 		var repDashName string

diff --git a/src/README.md b/src/README.md
@@ -190,6 +190,8 @@ to set these values.
 
 ## Using plugin
 
+### Using Grafana web UI
+
 The prerequisite is the user must have at least `Viewer` role on the dashboard that they 
 want to create a PDF report. After the user authenticates with Grafana, creating a 
 dashboard report is done by visiting the following end point
@@ -221,6 +223,23 @@ Following steps will configure a dashboard link to create PDF report for that da
 Now there should be link in the right top corner of dashboard named `Report` and clicking
 this link will create a new PDF report of the dashboard.
 
+### Using Grafana API
+
+The plugin can generate reports programmatically using Grafana API by using 
+[Grafana service accounts](https://grafana.com/docs/grafana/latest/administration/service-accounts/).
+
+Once a service account is created with appropriate permissions by following 
+[Grafana docs](https://grafana.com/docs/grafana/latest/administration/service-accounts/#to-create-a-service-account), 
+generate an [API token](https://grafana.com/docs/grafana/latest/administration/service-accounts/#add-a-token-to-a-service-account-in-grafana) 
+from the service account. Once the token has been generated, reports can be created using
+
+```
+$ curl --output=report.pdf -H "Authorization: Bearer <supersecrettoken>" "https://example.grafana.com/api/plugins/mahendrapaipuri-dashboardreporter-app/resources/report?dashUid=<UID of dashboard>"
+```
+
+The above example shows on how to generate report using `curl` but this can be done with
+any HTTP client of your favorite programming language.
+
 ## Examples
 
 Here are the example reports that are generated out of the test dashboards