Transforming Custom LDAP Attributes for Genesys Cloud SCIM Provisioning in Go

What You Will Build

• One sentence: The code ingests raw LDAP directory records, applies a YAML-driven mapping to transform multi-valued attributes into Genesys Cloud SCIM extension fields, and emits RFC 7643-compliant JSON payloads.
• One sentence: This implementation targets the Genesys Cloud REST API v2 SCIM endpoint /api/v2/scim/v2/users.
• One sentence: The tutorial uses Go 1.21+ with standard library HTTP clients and gopkg.in/yaml.v3 for configuration parsing.

Prerequisites

• OAuth client type: Confidential client registered in Genesys Cloud Admin Console
• Required OAuth scope: scim:admin
• API version: Genesys Cloud REST API v2
• Language/runtime: Go 1.21+
• External dependencies: gopkg.in/yaml.v3 for configuration parsing, standard library net/http, encoding/json, net/url, sync, time

Authentication Setup

Genesys Cloud uses OAuth 2.0 client credentials grant for service-to-service authentication. The middleware must fetch an access token before issuing SCIM requests. Token caching prevents unnecessary authentication calls, and the cache must expire slightly before the actual token lifetime to avoid 401 errors during payload construction.

package main

import (
	"context"
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"net/url"
	"sync"
	"time"
)

type TokenCache struct {
	mu      sync.Mutex
	token   string
	expires time.Time
}

func (tc *TokenCache) GetToken(ctx context.Context, clientID, clientSecret, baseURI string) (string, error) {
	tc.mu.Lock()
	defer tc.mu.Unlock()

	// Return cached token if it remains valid for at least 60 seconds
	if tc.token != "" && time.Now().Before(tc.expires.Add(-time.Minute)) {
		return tc.token, nil
	}

	form := url.Values{}
	form.Set("grant_type", "client_credentials")
	form.Set("scope", "scim:admin")

	req, err := http.NewRequestWithContext(ctx, http.MethodPost, fmt.Sprintf("%s/oauth/token", baseURI), strings.NewReader(form.Encode()))
	if err != nil {
		return "", fmt.Errorf("failed to create token request: %w", err)
	}

	req.SetBasicAuth(clientID, clientSecret)
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	client := &http.Client{Timeout: 15 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		return "", fmt.Errorf("token request failed: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return "", fmt.Errorf("oauth token request returned %d", resp.StatusCode)
	}

	var tokenResp struct {
		AccessToken string `json:"access_token"`
		ExpiresIn   int    `json:"expires_in"`
	}
	if err := json.NewDecoder(resp.Body).Decode(&tokenResp); err != nil {
		return "", fmt.Errorf("failed to decode token response: %w", err)
	}

	tc.token = tokenResp.AccessToken
	tc.expires = time.Now().Add(time.Duration(tokenResp.ExpiresIn) * time.Second)
	log.Printf("OAuth token refreshed. Expires in %d seconds", tokenResp.ExpiresIn)
	return tc.token, nil
}

The scim:admin scope grants permission to create, update, and delete users via the SCIM endpoint. The cache mutex ensures thread-safe access when multiple goroutines provision users concurrently. The 60-second buffer prevents edge cases where network latency causes a request to arrive after token expiration.

Implementation

Step 1: Configuration-Driven Transformer Setup

LDAP directories export multi-valued attributes as delimited strings or raw arrays. Genesys Cloud SCIM extensions require strict JSON typing. Strings must remain strings, and multi-valued attributes must be JSON arrays. A YAML configuration file drives the transformation without hardcoding field names.

Create a file named scim-mapping.yaml:

ldap_to_scim:
  customDepartment:
    scim_path: "urn:ietf:params:scim:schemas:extension:genesys:2.0:User/departments"
    multi_valued: true
    delimiter: ","
  customManagerID:
    scim_path: "urn:ietf:params:scim:schemas:extension:genesys:2.0:User/managerId"
    multi_valued: false
    delimiter: ""
  customCostCenter:
    scim_path: "urn:ietf:params:scim:schemas:extension:genesys:2.0:User/costCenters"
    multi_valued: true
    delimiter: "|"

Load the configuration and parse LDAP records into a normalized map:

import (
	"gopkg.in/yaml.v3"
	"os"
)

type MappingRule struct {
	ScimPath    string `yaml:"scim_path"`
	MultiValued bool   `yaml:"multi_valued"`
	Delimiter   string `yaml:"delimiter"`
}

type TransformConfig struct {
	LdapToScim map[string]MappingRule `yaml:"ldap_to_scim"`
}

func LoadConfig(path string) (*TransformConfig, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return nil, fmt.Errorf("failed to read config: %w", err)
	}

	var cfg TransformConfig
	if err := yaml.Unmarshal(data, &cfg); err != nil {
		return nil, fmt.Errorf("failed to parse config: %w", err)
	}
	return &cfg, nil
}

The configuration explicitly declares whether an attribute is multi-valued and which delimiter separates values in the LDAP export. This eliminates guesswork during runtime and allows non-developers to update mappings without touching Go code.

Step 2: SCIM Payload Construction and Extension Mapping

RFC 7643 requires SCIM payloads to include a schemas array listing the core schema and any extension schemas. Genesys Cloud uses urn:ietf:params:scim:schemas:extension:genesys:2.0:User for custom fields. The transformer must extract the target field name from the SCIM path, apply delimiter splitting, deduplicate values, and enforce correct JSON types.

import (
	"strings"
	"time"
)

func buildScimPayload(record map[string]any, cfg *TransformConfig) (map[string]any, error) {
	payload := map[string]any{
		"schemas": []string{
			"urn:ietf:params:scim:schemas:core:2.0:User",
			"urn:ietf:params:scim:schemas:extension:genesys:2.0:User",
		},
	}

	// Map standard SCIM fields from LDAP record
	if u, ok := record["userName"].(string); ok {
		payload["userName"] = u
	}
	if n, ok := record["name"].(string); ok {
		parts := strings.Fields(n)
		payload["name"] = map[string]any{
			"formatted":  n,
			"familyName": parts[len(parts)-1],
			"givenName":  parts[0],
		}
	}
	if e, ok := record["email"].(string); ok {
		payload["emails"] = []map[string]any{
			{"value": e, "primary": true, "type": "work"},
		}
	}

	extKey := "urn:ietf:params:scim:schemas:extension:genesys:2.0:User"
	extData := make(map[string]any)

	for ldapAttr, rule := range cfg.LdapToScim {
		rawVal, exists := record[ldapAttr]
		if !exists {
			continue
		}

		// Extract field name from the SCIM path (last segment after the final slash)
		pathParts := strings.Split(rule.ScimPath, "/")
		fieldName := pathParts[len(pathParts)-1]

		switch v := rawVal.(type) {
		case string:
			if rule.MultiValued && v != "" {
				vals := strings.Split(v, rule.Delimiter)
				cleaned := make([]string, 0, len(vals))
				seen := make(map[string]bool)
				for _, item := range vals {
					item = strings.TrimSpace(item)
					if item != "" && !seen[item] {
						cleaned = append(cleaned, item)
						seen[item] = true
					}
				}
				extData[fieldName] = cleaned
			} else {
				extData[fieldName] = strings.TrimSpace(v)
			}
		case []string:
			if rule.MultiValued {
				extData[fieldName] = v
			} else {
				extData[fieldName] = strings.Join(v, rule.Delimiter)
			}
		default:
			return nil, fmt.Errorf("unsupported type for attribute %s: %T", ldapAttr, rawVal)
		}
	}

	payload[extKey] = extData
	return payload, nil
}

The transformer handles three critical edge cases. First, it trims whitespace from delimited values to prevent SCIM validation failures. Second, it deduplicates array entries to avoid duplicate resource warnings. Third, it extracts the field name dynamically from the scim_path configuration value, allowing the same transformer to support multiple extension schemas if Genesys introduces new ones in the future.

Step 3: HTTP POST to Genesys Cloud SCIM API

The final step serializes the payload to JSON and POSTs it to /api/v2/scim/v2/users. Genesys Cloud enforces strict rate limits. The middleware must parse the Retry-After header on 429 responses and implement exponential backoff as a fallback. The request must include the Authorization header, Content-Type: application/json, and Accept: application/json.

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"strconv"
	"time"
)

type ScimClient struct {
	client  *http.Client
	baseURI string
	cache   *TokenCache
}

func NewScimClient(baseURI string, clientID, clientSecret string) *ScimClient {
	return &ScimClient{
		client: &http.Client{Timeout: 30 * time.Second},
		baseURI: baseURI,
		cache: &TokenCache{},
	}
}

func (sc *ScimClient) ProvisionUser(ctx context.Context, payload map[string]any) error {
	token, err := sc.cache.GetToken(ctx, os.Getenv("GENESYS_CLIENT_ID"), os.Getenv("GENESYS_CLIENT_SECRET"), sc.baseURI)
	if err != nil {
		return fmt.Errorf("authentication failed: %w", err)
	}

	jsonData, err := json.Marshal(payload)
	if err != nil {
		return fmt.Errorf("payload serialization failed: %w", err)
	}

	maxRetries := 3
	for attempt := 0; attempt <= maxRetries; attempt++ {
		req, err := http.NewRequestWithContext(ctx, http.MethodPost, fmt.Sprintf("%s/api/v2/scim/v2/users", sc.baseURI), bytes.NewBuffer(jsonData))
		if err != nil {
			return fmt.Errorf("request creation failed: %w", err)
		}

		req.Header.Set("Authorization", "Bearer "+token)
		req.Header.Set("Content-Type", "application/json")
		req.Header.Set("Accept", "application/json")

		resp, err := sc.client.Do(req)
		if err != nil {
			return fmt.Errorf("HTTP request failed: %w", err)
		}

		body, _ := io.ReadAll(resp.Body)
		resp.Body.Close()

		switch resp.StatusCode {
		case http.StatusCreated:
			log.Printf("User provisioned successfully. ID: %s", extractSCIMID(body))
			return nil
		case http.StatusUnauthorized:
			// Invalidate cache and retry once
			sc.cache.mu.Lock()
			sc.cache.token = ""
			sc.cache.mu.Unlock()
			token, err = sc.cache.GetToken(ctx, os.Getenv("GENESYS_CLIENT_ID"), os.Getenv("GENESYS_CLIENT_SECRET"), sc.baseURI)
			if err != nil {
				return fmt.Errorf("token refresh failed: %w", err)
			}
			continue
		case http.StatusForbidden:
			return fmt.Errorf("403 forbidden: missing scim:admin scope or insufficient permissions")
		case http.StatusTooManyRequests:
			if attempt == maxRetries {
				return fmt.Errorf("max retries exceeded for 429 rate limit")
			}
			wait := parseRetryAfter(resp.Header.Get("Retry-After"))
			if wait == 0 {
				wait = time.Duration(1<<uint(attempt)) * time.Second
			}
			log.Printf("Rate limited. Retrying in %v", wait)
			time.Sleep(wait)
			continue
		case http.StatusBadRequest:
			return fmt.Errorf("400 bad request: %s", string(body))
		default:
			return fmt.Errorf("unexpected status %d: %s", resp.StatusCode, string(body))
		}
	}
	return fmt.Errorf("provisioning failed after retries")
}

func parseRetryAfter(header string) time.Duration {
	if header == "" {
		return 0
	}
	if secs, err := strconv.Atoi(header); err == nil {
		return time.Duration(secs) * time.Second
	}
	// Fallback to RFC 7231 date parsing if needed
	return 0
}

func extractSCIMID(body []byte) string {
	var resp map[string]any
	if json.Unmarshal(body, &resp) == nil {
		if id, ok := resp["id"].(string); ok {
			return id
		}
	}
	return "unknown"
}

The client implements a complete request lifecycle. It fetches the token, serializes the payload, handles 401 cache invalidation, respects the Retry-After header for 429 responses, and logs the SCIM id on success. The meta object is intentionally omitted from the POST payload because Genesys Cloud generates it automatically upon creation.

Complete Working Example

The following script combines authentication, configuration loading, payload transformation, and API provisioning into a single executable module. Replace the environment variables with your OAuth client credentials.

package main

import (
	"context"
	"encoding/json"
	"fmt"
	"log"
	"os"
	"strings"
	"sync"
	"time"

	"gopkg.in/yaml.v3"
)

// TokenCache, MappingRule, TransformConfig, ScimClient definitions from previous sections go here
// (Include all types and methods from Authentication Setup and Implementation steps)

func main() {
	ctx := context.Background()

	baseURI := os.Getenv("GENESYS_BASE_URI")
	if baseURI == "" {
		baseURI = "https://api.mypurecloud.com"
	}

	cfg, err := LoadConfig("scim-mapping.yaml")
	if err != nil {
		log.Fatalf("Config load failed: %v", err)
	}

	sc := NewScimClient(baseURI, os.Getenv("GENESYS_CLIENT_ID"), os.Getenv("GENESYS_CLIENT_SECRET"))

	// Simulate LDAP export record
	ldapRecord := map[string]any{
		"userName": "jdoe@example.com",
		"name":     "John Doe",
		"email":    "jdoe@example.com",
		"customDepartment": "Engineering, Sales, Engineering", // Multi-valued with duplicates
		"customManagerID":  "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
		"customCostCenter": "CC-101|CC-202|CC-101",
	}

	payload, err := buildScimPayload(ldapRecord, cfg)
	if err != nil {
		log.Fatalf("Payload construction failed: %v", err)
	}

	prettyJSON, _ := json.MarshalIndent(payload, "", "  ")
	fmt.Println("Generated SCIM Payload:")
	fmt.Println(string(prettyJSON))

	if err := sc.ProvisionUser(ctx, payload); err != nil {
		log.Fatalf("Provisioning failed: %v", err)
	}
}

Run the script with go run main.go. The output displays the RFC 7643-compliant JSON payload before sending it to Genesys Cloud. The multi-valued LDAP attributes are split, deduplicated, and cast to JSON arrays. The extension schema key is properly formatted.

Common Errors & Debugging

Error: 401 Unauthorized

• What causes it: The OAuth token expired during payload construction or network latency delayed the request past the token lifetime.
• How to fix it: Implement cache invalidation on 401 responses. The provided ProvisionUser method detects 401, clears the cached token, and retries once with a fresh token.
• Code showing the fix: The case http.StatusUnauthorized block in ProvisionUser locks the cache mutex, resets the token string, and calls GetToken before retrying.

Error: 403 Forbidden

• What causes it: The OAuth client lacks the scim:admin scope, or the service account does not have SCIM provisioning permissions in the Genesys Cloud Admin Console.
• How to fix it: Navigate to Admin > Security > OAuth 2.0 Clients, select your client, and verify scim:admin is checked. Ensure the associated service account has the SCIM Administrator role.
• Code showing the fix: Verify the form.Set("scope", "scim:admin") line in the token request. Do not use user:read or user:write for SCIM endpoints.

Error: 429 Too Many Requests

• What causes it: The middleware exceeds Genesys Cloud rate limits, typically 60 requests per minute per tenant for SCIM operations.
• How to fix it: Parse the Retry-After header. If the header is missing, apply exponential backoff. Throttle concurrent goroutines using golang.org/x/time/rate.
• Code showing the fix: The parseRetryAfter function extracts the header value. The retry loop sleeps for the specified duration or falls back to 1 << attempt seconds.

Error: 400 Bad Request (SCIM Schema Validation)

• What causes it: Multi-valued attributes are sent as strings instead of JSON arrays, or the schemas array is missing the extension URI.
• How to fix it: Ensure the multi_valued: true configuration flag triggers array casting. Verify the schemas array includes both urn:ietf:params:scim:schemas:core:2.0:User and urn:ietf:params:scim:schemas:extension:genesys:2.0:User.
• Code showing the fix: The buildScimPayload function checks rule.MultiValued and assigns extData[fieldName] = cleaned (a []string) instead of a single string.

Official References

• Genesys Cloud SCIM API Documentation
• Genesys Cloud OAuth 2.0 Client Credentials Flow
• RFC 7643: SCIM Core Schema
• Genesys Cloud Go SDK (Community Maintained)