phase1 opa pdp changes

For details on scope and implementation, please check.
https://lf-onap.atlassian.net/wiki/spaces/DW/pages/51150925/OPA+PDP
Code Coverage Total: 70.8%

Issue-ID: POLICY-5156
Change-Id: Ied07ee1596e9f447183fb715baaa68c704a9fe99
Signed-off-by: gururajarao79 <gb00566633@techmahindra.com>

1 files changed, 81 insertions, 0 deletions

diff --git a/api/register-handlers.go b/api/register-handlers.go
new file mode 100644
index 0000000..37028d2
--- /dev/null
+++ b/api/register-handlers.go
@@ -0,0 +1,81 @@
+// -
+//   ========================LICENSE_START=================================
+//   Copyright (C) 2024: Deutsche Telecom
+//
+//   Licensed under the Apache License, Version 2.0 (the "License");
+//   you may not use this file except in compliance with the License.
+//   You may obtain a copy of the License at
+//
+//        http://www.apache.org/licenses/LICENSE-2.0
+//
+//   Unless required by applicable law or agreed to in writing, software
+//   distributed under the License is distributed on an "AS IS" BASIS,
+//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//   See the License for the specific language governing permissions and
+//   limitations under the License.
+//   ========================LICENSE_END===================================
+
+// Package api provides HTTP handlers for the policy-opa-pdp service.
+// This package includes handlers for decision making, bundle serving, health checks, and readiness probes.
+// It also includes basic authentication middleware for securing certain endpoints.
+package api
+
+import (
+	"net/http"
+	"policy-opa-pdp/cfg"
+	"policy-opa-pdp/pkg/bundleserver"
+	"policy-opa-pdp/pkg/decision"
+	"policy-opa-pdp/pkg/healthcheck"
+	"policy-opa-pdp/pkg/metrics"
+)
+
+// RegisterHandlers registers the HTTP handlers for the service.
+func RegisterHandlers() {
+
+	// Handler for OPA decision making
+	opaDecisionHandler := http.HandlerFunc(decision.OpaDecision)
+	http.Handle("/policy/pdpx/v1/decision", basicAuth(opaDecisionHandler))
+
+	//This api is used internally by OPA-SDK
+	bundleServerHandler := http.HandlerFunc(bundleserver.GetBundle)
+	http.Handle("/opa/bundles/", bundleServerHandler)
+
+	// Handler for kubernetes readiness probe
+	readinessProbeHandler := http.HandlerFunc(readinessProbe)
+	http.Handle("/ready", readinessProbeHandler)
+
+	// Handler for health checks
+	healthCheckHandler := http.HandlerFunc(healthcheck.HealthCheckHandler)
+	http.HandleFunc("/policy/pdpx/v1/healthcheck", basicAuth(healthCheckHandler))
+
+	// Handler for statistics report
+	statisticsReportHandler := http.HandlerFunc(metrics.FetchCurrentStatistics)
+	http.HandleFunc("/policy/pdpx/v1/statistics", basicAuth(statisticsReportHandler))
+
+}
+
+// handles authentication
+func basicAuth(next http.HandlerFunc) http.HandlerFunc {
+	return func(res http.ResponseWriter, req *http.Request) {
+		user, pass, ok := req.BasicAuth()
+		if !ok || !validateCredentials(user, pass) {
+			res.Header().Set("WWW-Authenticate", `Basic realm="Restricted"`)
+			http.Error(res, "Unauthorized", http.StatusUnauthorized)
+			return
+		}
+		next(res, req)
+	}
+}
+
+// validates Credentials for http server
+func validateCredentials(username, password string) bool {
+	validUser := cfg.Username
+	validPass := cfg.Password
+	return username == validUser && password == validPass
+}
+
+// handles readiness probe endpoint
+func readinessProbe(res http.ResponseWriter, req *http.Request) {
+	res.WriteHeader(http.StatusOK)
+	res.Write([]byte("Ready"))
+}