Files
onix/pkg/plugin/implementation/router/router.go
2025-03-27 11:28:45 +05:30

233 lines
7.1 KiB
Go

package router
import (
"context"
"encoding/json"
"fmt"
"net/url"
"os"
"path"
"strings"
definition "github.com/beckn/beckn-onix/pkg/plugin/definition"
"gopkg.in/yaml.v3"
)
// Config holds the configuration for the Router plugin.
type Config struct {
RoutingConfig string `json:"routingConfig"`
}
// RoutingConfig represents the structure of the routing configuration file.
type routingConfig struct {
RoutingRules []routingRule `yaml:"routingRules"`
}
// Router implements Router interface.
type Router struct {
rules map[string]map[string]map[string]*definition.Route // domain -> version -> endpoint -> route
}
// RoutingRule represents a single routing rule.
type routingRule struct {
Domain string `yaml:"domain"`
Version string `yaml:"version"`
TargetType string `yaml:"targetType"` // "url", "msgq", "bpp", or "bap"
Target target `yaml:"target,omitempty"`
Endpoints []string `yaml:"endpoints"`
}
// Target contains destination-specific details.
type target struct {
URL string `yaml:"url,omitempty"` // URL for "url" or gateway endpoint for "bpp"/"bap"
PublisherID string `yaml:"publisherId,omitempty"` // For "msgq" type
}
// TargetType defines possible target destinations.
const (
targetTypeURL = "url" // Route to a specific URL
targetTypeMSGQ = "msgq" // Route to a message queue
targetTypeBPP = "bpp" // Route to a BPP endpoint
targetTypeBAP = "bap" // Route to a BAP endpoint
)
// New initializes a new Router instance with the provided configuration.
// It loads and validates the routing rules from the specified YAML file.
// Returns an error if the configuration is invalid or the rules cannot be loaded.
func New(ctx context.Context, config *Config) (*Router, func() error, error) {
// Check if config is nil
if config == nil {
return nil, nil, fmt.Errorf("config cannot be nil")
}
router := &Router{
rules: make(map[string]map[string]map[string]*definition.Route),
}
// Load rules at bootup
if err := router.loadRules(config.RoutingConfig); err != nil {
return nil, nil, fmt.Errorf("failed to load routing rules: %w", err)
}
return router, nil, nil
}
// LoadRules reads and parses routing rules from the YAML configuration file.
func (r *Router) loadRules(configPath string) error {
if configPath == "" {
return fmt.Errorf("routingConfig path is empty")
}
data, err := os.ReadFile(configPath)
if err != nil {
return fmt.Errorf("error reading config file at %s: %w", configPath, err)
}
var config routingConfig
if err := yaml.Unmarshal(data, &config); err != nil {
return fmt.Errorf("error parsing YAML: %w", err)
}
// Validate rules
if err := validateRules(config.RoutingRules); err != nil {
return fmt.Errorf("invalid routing rules: %w", err)
}
// Build the optimized rule map
for _, rule := range config.RoutingRules {
// Initialize domain map if not exists
if _, ok := r.rules[rule.Domain]; !ok {
r.rules[rule.Domain] = make(map[string]map[string]*definition.Route)
}
// Initialize version map if not exists
if _, ok := r.rules[rule.Domain][rule.Version]; !ok {
r.rules[rule.Domain][rule.Version] = make(map[string]*definition.Route)
}
// Add all endpoints for this rule
for _, endpoint := range rule.Endpoints {
var route *definition.Route
switch rule.TargetType {
case targetTypeMSGQ:
route = &definition.Route{
TargetType: rule.TargetType,
PublisherID: rule.Target.PublisherID,
}
case targetTypeURL:
route = &definition.Route{
TargetType: rule.TargetType,
URL: rule.Target.URL,
}
case targetTypeBPP, targetTypeBAP:
route = &definition.Route{
TargetType: rule.TargetType,
URL: rule.Target.URL, // Fallback URL if URI not provided in request
}
}
fmt.Print(r.rules)
r.rules[rule.Domain][rule.Version][endpoint] = route
}
}
return nil
}
// validateRules performs basic validation on the loaded routing rules.
func validateRules(rules []routingRule) error {
for _, rule := range rules {
// Ensure domain, version, and TargetType are present
if rule.Domain == "" || rule.Version == "" || rule.TargetType == "" {
return fmt.Errorf("invalid rule: domain, version, and targetType are required")
}
// Validate based on TargetType
switch rule.TargetType {
case targetTypeURL:
if rule.Target.URL == "" {
return fmt.Errorf("invalid rule: url is required for targetType 'url'")
}
if _, err := url.ParseRequestURI(rule.Target.URL); err != nil {
return fmt.Errorf("invalid URL in rule: %w", err)
}
case targetTypeMSGQ:
if rule.Target.PublisherID == "" {
return fmt.Errorf("invalid rule: publisherID is required for targetType 'msgq'")
}
case targetTypeBPP, targetTypeBAP:
// No target validation needed for bpp/bap, as they use URIs from the request body
continue
default:
return fmt.Errorf("invalid rule: unknown targetType '%s'", rule.TargetType)
}
}
return nil
}
// Route determines the routing destination based on the request context.
func (r *Router) Route(ctx context.Context, url *url.URL, body []byte) (*definition.Route, error) {
// Parse the body to extract domain and version
var requestBody struct {
Context struct {
Domain string `json:"domain"`
Version string `json:"version"`
BPPURI string `json:"bpp_uri,omitempty"`
BAPURI string `json:"bap_uri,omitempty"`
} `json:"context"`
}
if err := json.Unmarshal(body, &requestBody); err != nil {
return nil, fmt.Errorf("error parsing request body: %w", err)
}
// Extract the endpoint from the URL
endpoint := path.Base(url.Path)
// Lookup route in the optimized map
domainRules, ok := r.rules[requestBody.Context.Domain]
if !ok {
return nil, fmt.Errorf("no routing rules found for domain %s", requestBody.Context.Domain)
}
versionRules, ok := domainRules[requestBody.Context.Version]
if !ok {
return nil, fmt.Errorf("no routing rules found for domain %s version %s", requestBody.Context.Domain, requestBody.Context.Version)
}
route, ok := versionRules[endpoint]
if !ok {
return nil, fmt.Errorf("endpoint '%s' is not supported for domain %s and version %s in routing config",
endpoint, requestBody.Context.Domain, requestBody.Context.Version)
}
// Handle BPP/BAP routing with request URIs
switch route.TargetType {
case targetTypeBPP:
uri := strings.TrimSpace(requestBody.Context.BPPURI)
target := strings.TrimSpace(route.URL)
if len(uri) != 0 {
target = uri
}
if len(target) == 0 {
return nil, fmt.Errorf("could not determine destination for endpoint '%s': neither request contained a BPP URI nor was a default URL configured in routing rules", endpoint)
}
route = &definition.Route{
TargetType: route.TargetType,
URL: target,
}
case targetTypeBAP:
uri := strings.TrimSpace(requestBody.Context.BAPURI)
target := strings.TrimSpace(route.URL)
if len(uri) != 0 {
target = uri
}
if len(target) == 0 {
return nil, fmt.Errorf("could not determine destination for endpoint '%s': neither request contained a BAP URI nor was a default URL configured in routing rules", endpoint)
}
route = &definition.Route{
TargetType: route.TargetType,
URL: target,
}
}
return route, nil
}