public dashboards: insert default public dashboard config into database on save (#49131)

This PR adds endpoints for saving and retrieving a public dashboard configuration and and api endpoint to retrieve the public dashboard.

All of this is highly experimental and APIs will change. Notably, we will be removing isPublic from the dashboard model and moving it over to the public dashboard table in the next release.

Further context can be found here: https://github.com/grafana/grafana/pull/49131#issuecomment-1145456952

pkg/api/dashboard_public.go

@@ -0,0 +1,61 @@
+package api
+
+import (
+	"errors"
+	"net/http"
+
+	"github.com/grafana/grafana/pkg/api/response"
+	"github.com/grafana/grafana/pkg/models"
+	"github.com/grafana/grafana/pkg/services/dashboards"
+	"github.com/grafana/grafana/pkg/web"
+)
+
+// gets public dashboard
+func (hs *HTTPServer) GetPublicDashboard(c *models.ReqContext) response.Response {
+	dash, err := hs.dashboardService.GetPublicDashboard(c.Req.Context(), web.Params(c.Req)[":uid"])
+	if err != nil {
+		return handleDashboardErr(http.StatusInternalServerError, "Failed to get public dashboard", err)
+	}
+	return response.JSON(http.StatusOK, dash)
+}
+
+// gets public dashboard configuration for dashboard
+func (hs *HTTPServer) GetPublicDashboardConfig(c *models.ReqContext) response.Response {
+	pdc, err := hs.dashboardService.GetPublicDashboardConfig(c.Req.Context(), c.OrgId, web.Params(c.Req)[":uid"])
+	if err != nil {
+		return handleDashboardErr(http.StatusInternalServerError, "Failed to get public dashboard config", err)
+	}
+	return response.JSON(http.StatusOK, pdc)
+}
+
+// sets public dashboard configuration for dashboard
+func (hs *HTTPServer) SavePublicDashboardConfig(c *models.ReqContext) response.Response {
+	pdc := &models.PublicDashboardConfig{}
+	if err := web.Bind(c.Req, pdc); err != nil {
+		return response.Error(http.StatusBadRequest, "bad request data", err)
+	}
+
+	dto := dashboards.SavePublicDashboardConfigDTO{
+		OrgId:                 c.OrgId,
+		DashboardUid:          web.Params(c.Req)[":uid"],
+		PublicDashboardConfig: pdc,
+	}
+
+	pdc, err := hs.dashboardService.SavePublicDashboardConfig(c.Req.Context(), &dto)
+	if err != nil {
+		return handleDashboardErr(http.StatusInternalServerError, "Failed to save public dashboard configuration", err)
+	}
+
+	return response.JSON(http.StatusOK, pdc)
+}
+
+// util to help us unpack a dashboard err or use default http code and message
+func handleDashboardErr(defaultCode int, defaultMsg string, err error) response.Response {
+	var dashboardErr models.DashboardErr
+
+	if ok := errors.As(err, &dashboardErr); ok {
+		return response.Error(dashboardErr.StatusCode, dashboardErr.Error(), dashboardErr)
+	}
+
+	return response.Error(defaultCode, defaultMsg, err)
+}