Add endpoints for ifql function suggestions

Co-authored-by: Brandon Farmer <bthesorceror@gmail.com>
Co-authored-by: Andrew Watkins <andrew.watkinz@gmail.com>

Gopkg.toml

@@ -72,6 +72,9 @@ required = ["github.com/kevinburke/go-bindata","github.com/gogo/protobuf/proto",
   name = "github.com/influxdata/influxdb"
   version = "~1.1.0"
 
+[[constraint]]
+  name = "github.com/influxdata/ifql"
+  revision = "master"
 
 [[constraint]]
   name = "github.com/influxdata/kapacitor"

Makefile

@@ -124,3 +124,6 @@ clean:
 
 ctags:
 	ctags -R --languages="Go" --exclude=.git --exclude=ui .
+
+lint:
+	cd ui && yarn prettier

server/ifql.go

@@ -0,0 +1,41 @@
+package server
+
+import (
+	"net/http"
+
+	"github.com/bouk/httprouter"
+	"github.com/influxdata/ifql"
+)
+
+// SuggestionsResponse provides a list of available IFQL functions
+type SuggestionsResponse struct {
+	Functions []string `json:"funcs"`
+}
+
+// SuggestionResponse provides the parameters available for a given IFQL function
+type SuggestionResponse struct {
+	Params map[string]string `json:"params"`
+}
+
+// IFQLSuggestions returns a list of available IFQL functions for the IFQL Builder
+func (s *Service) IFQLSuggestions(w http.ResponseWriter, r *http.Request) {
+	completer := ifql.DefaultCompleter()
+	names := completer.FunctionNames()
+	res := SuggestionsResponse{Functions: names}
+
+	encodeJSON(w, http.StatusOK, res, s.Logger)
+}
+
+// IFQLSuggestion returns the function parameters for the requested function
+func (s *Service) IFQLSuggestion(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+	name := httprouter.GetParamFromContext(ctx, "name")
+	completer := ifql.DefaultCompleter()
+
+	res, err := completer.FunctionSuggestion(name)
+	if err != nil {
+		Error(w, http.StatusNotFound, err.Error(), s.Logger)
+	}
+
+	encodeJSON(w, http.StatusOK, SuggestionResponse(res), s.Logger)
+}

server/links.go

@@ -5,6 +5,11 @@ import (
 	"net/url"
 )
 
+type getIFQLLinksResponse struct {
+	Self        string `json:"self"`
+	Suggestions string `json:"suggestions"`
+}
+
 type getConfigLinksResponse struct {
 	Self string `json:"self"` // Location of the whole global application configuration
 	Auth string `json:"auth"` // Location of the auth section of the global application configuration

server/mux.go

@@ -156,6 +156,9 @@ func NewMux(opts MuxOpts, service Service) http.Handler {
 	router.PATCH("/chronograf/v1/sources/:id", EnsureEditor(service.UpdateSource))
 	router.DELETE("/chronograf/v1/sources/:id", EnsureEditor(service.RemoveSource))
 
+	router.GET("/chronograf/v1/ifql/suggestions", EnsureViewer(service.IFQLSuggestions))
+	router.GET("/chronograf/v1/ifql/suggestions/:name", EnsureViewer(service.IFQLSuggestion))
+
 	// Source Proxy to Influx; Has gzip compression around the handler
 	influx := gziphandler.GzipHandler(http.HandlerFunc(EnsureViewer(service.Influx)))
 	router.Handler("POST", "/chronograf/v1/sources/:id/proxy", influx)

server/routes.go

@@ -44,6 +44,7 @@ type getRoutesResponse struct {
 	Auth          []AuthRoute              `json:"auth"`             // Location of all auth routes.
 	Logout        *string                  `json:"logout,omitempty"` // Location of the logout route for all auth routes
 	ExternalLinks getExternalLinksResponse `json:"external"`         // All external links for the client to use
+	IFQL          getIFQLLinksResponse     `json:"ifql"`
 }
 
 // AllRoutes is a handler that returns all links to resources in Chronograf server, as well as
@@ -94,6 +95,10 @@ func (a *AllRoutes) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			StatusFeed:  &a.StatusFeed,
 			CustomLinks: customLinks,
 		},
+		IFQL: getIFQLLinksResponse{
+			Self:        "/chronograf/v1/ifql",
+			Suggestions: "/chronograf/v1/ifql/suggestions",
+		},
 	}
 
 	// The JSON response will have no field present for the LogoutLink if there is no logout link.