litcli+rpcserver: session registration with config

We add command line flags to litcli in order to be able to submit
feature configurations when registering a session.

Author: bitromortac

cmd/litcli/autopilot.go

@@ -3,6 +3,8 @@ package main
 import (
 	"context"
 	"encoding/hex"
+	"encoding/json"
+	"fmt"
 	"strconv"
 	"strings"
 	"time"
@@ -39,8 +41,10 @@ var addAutopilotSessionCmd = cli.Command{
 	ShortName: "a",
 	Usage:     "Initialize an Autopilot session.",
 	Description: `
-	Initialize an Autopilot session.	
-	`,
+	Initialize an Autopilot session.
+
+	If set for any feature, configuration flags need to be repeated for each
+	feature that is registered, corresponding to the order of features.`,
 	Action: initAutopilotSession,
 	Flags: []cli.Flag{
 		labelFlag,
@@ -70,6 +74,15 @@ var addAutopilotSessionCmd = cli.Command{
 			Usage: "The hex encoded group ID of the session " +
 				"group to link this one to",
 		},
+		cli.StringSliceFlag{
+			Name: "feature-config",
+			Usage: `JSON-serialized configuration with the ` +
+				`expected format: {"version":0,` +
+				`"option1":"parameter1",` +
+				`"option2":"parameter2",...}. An empty ` +
+				`configuration is allowed with {} to use the ` +
+				`default configuration`,
+		},
 	},
 }
 
@@ -221,11 +234,36 @@ func initAutopilotSession(ctx *cli.Context) error {
 		}
 	}
 
+	features := ctx.StringSlice("feature")
+	configs := ctx.StringSlice("feature-config")
+	if len(configs) > 0 && len(features) != len(configs) {
+		return fmt.Errorf("number of features (%v) and configurations "+
+			"(%v) must match", len(features), len(configs))
+	}
+
 	featureMap := make(map[string]*litrpc.FeatureConfig)
-	for _, feature := range ctx.StringSlice("feature") {
+	for i, feature := range ctx.StringSlice("feature") {
+		var config []byte
+
+		// We allow empty configs, to signal the usage of the default
+		// configuration when the session is registered.
+		if len(configs) > 0 && configs[i] != "{}" {
+			// We expect the config to be a JSON dictionary, so we
+			// unmarshal it into a map to do a first validation.
+			var configMap map[string]interface{}
+			err := json.Unmarshal([]byte(configs[i]), &configMap)
+			if err != nil {
+				return fmt.Errorf("could not parse "+
+					"configuration for feature %v: %v",
+					feature, err)
+			}
+
+			config = []byte(configs[i])
+		}
+
 		featureMap[feature] = &litrpc.FeatureConfig{
 			Rules:  ruleMap,
-			Config: nil,
+			Config: config,
 		}
 	}
 

litrpc/lit-autopilot.swagger.json

@@ -592,6 +592,13 @@
           "type": "string",
           "format": "byte",
           "description": "The ID of the group of Session's that this Session is linked to. If this\nsession is not linked to any older Session, then this value will be the\nsame as the ID."
+        },
+        "feature_configs": {
+          "type": "object",
+          "additionalProperties": {
+            "type": "string"
+          },
+          "description": "Configurations for each individual feature mapping from the feature name to\na JSON-serialized configuration."
         }
       }
     },