Secure Client Access and Network Traffic
Legacy 'nms' references
Some commands, file paths, and configuration references still usenms
due to the ongoing transition from NGINX Management Suite (NMS) to NGINX Instance Manager (NIM). These will be updated in future releases.
Overview
This guide explains how to secure client connections to NGINX Instance Manager and protect traffic between NGINX Instance Manager and NGINX instances.
With NGINX Plus R33, telemetry data must be reported to a usage reporting endpoint, such as NGINX Instance Manager. This data validates subscription entitlements and tracks usage metrics. This guide also covers how to use the ssl_verify
directive to secure telemetry reporting through certificate verification.
Important:
Never expose your management server to the public internet. The settings in this guide reduce risk, but they can’t replace keeping your server inaccessible to unauthorized users.
See also:
- To learn how to secure traffic for NGINX Agent, see NGINX Agent TLS Settings.
- For details on NGINX Plus entitlement and usage reporting, see About subscription licenses.
NGINX Proxy SSL Termination
SSL termination is the process where SSL-encrypted traffic is decrypted at the proxy, in this case, NGINX Instance Manager. Once decrypted, the traffic can be sent to its destination unencrypted or re-encrypted, depending on the configuration.
To secure traffic between NGINX Plus instances and NGINX Instance Manager, you must configure an SSL certificate and key in the NGINX configuration. This setup applies to both NGINX Open Source and NGINX Plus. For more details, see the NGINX SSL Termination guide.
Starting with NGINX Plus R33, you must also enable ssl_verify
to verify the SSL certificate used by NGINX Instance Manager when reporting telemetry data. See the section on ssl_verify
and usage reporting for more details.
The example below shows how to set up SSL termination for NGINX Instance Manager:
/etc/nginx/conf.d/nms-http.conf
# Main external HTTPS server, needs port 443
server {
listen 443 ssl;
http2 on;
root /var/www/nms;
server_name _;
ssl_protocols TLSv1.1 TLSv1.2;
ssl_ciphers HIGH:!aNULL:!MD5;
ssl_session_cache shared:SSL:10m;
ssl_session_timeout 10m;
ssl_certificate /etc/nms/certs/manager-server.pem;
ssl_certificate_key /etc/nms/certs/manager-server.key;
ssl_client_certificate /etc/nms/certs/ca.pem;
Mutual Client Certificate Authentication Setup (mTLS)
Mutual TLS (mTLS) is a security method that uses client certificates to verify both the server and the client during communication. This ensures that both NGINX Instance Manager and NGINX Plus instances are securely authenticated, protecting your network from unauthorized access.
With mTLS, each NGINX instance has a unique client certificate that NGINX Instance Manager verifies before allowing communication. You can configure NGINX as a proxy to handle client certificates for this secure exchange.
Follow these steps to set up mTLS using a Public Key Infrastructure (PKI) system:
Certificate Authority (CA) Setup
-
Create a private Certificate Authority (CA):
- If you’re testing, you can generate the CA on the same machine as NGINX Instance Manager.
- For production environments, follow your organization’s security standards (these often require generating CAs on secure, offline machines).
-
Set up root and intermediate CAs:
- The root CA issues certificates to an intermediate CA. The intermediate CA, in turn, issues certificates for clients and servers. This layered setup adds extra security by ensuring that the root CA is only used for top-level tasks.
-
Issue Client and Server Certificates:
- The intermediate CA signs the certificate signing requests (CSRs) and issues certificates to NGINX clients and NGINX Instance Manager.
Generate Certificates
To generate the necessary certificates, follow these steps. You can modify these instructions to suit your specific environment.
-
Install OpenSSL (if it isn’t installed already).
-
Create the certificate generation script:
- Use the following example script to generate the certificates for your CA, server, and client. Save the script as
make_certs.sh
.
make_certs.sh
#!/bin/bash set -e make_ca() { echo "Creating Self-Signed Root CA certificate and key" openssl req \ -new \ -nodes \ -x509 \ -keyout ca.key \ -out ca.crt \ -config ca.cnf \ -extensions v3_req \ -days 1826 # 5 years } make_int() { echo "Creating Intermediate CA certificate and key" openssl req \ -new \ -nodes \ -keyout ca_int.key \ -out ca_int.csr \ -config ca-intermediate.cnf \ -extensions v3_req openssl req -in ca_int.csr -noout -verify openssl x509 \ -req \ -CA ca.crt \ -CAkey ca.key \ -CAcreateserial \ -in ca_int.csr \ -out ca_int.crt \ -extfile ca-intermediate.cnf \ -extensions v3_req \ -days 365 # 1 year openssl verify -CAfile ca.crt ca_int.crt echo "Creating CA chain" cat ca_int.crt ca.crt > ca.pem } make_server() { echo "Creating nginx-manger certificate and key" openssl req \ -new \ -nodes \ -keyout server.key \ -out server.csr \ -config server.cnf openssl req -in server.csr -noout -verify openssl x509 \ -req \ -CA ca_int.crt \ -CAkey ca_int.key \ -CAcreateserial \ -in server.csr \ -out server.crt \ -extfile server.cnf \ -extensions v3_req \ -days 365 # 1 year openssl verify -CAfile ca.pem server.crt } make_agent() { echo "Creating Agent certificate and key" openssl req \ -new \ -nodes \ -keyout agent.key \ -out agent.csr \ -config agent.cnf openssl req -in agent.csr -noout -verify openssl x509 \ -req \ -CA ca.crt \ -CAkey ca.key \ -CAcreateserial \ -in agent.csr \ -out agent.crt \ -extfile agent.cnf \ -extensions v3_req \ -days 365 # 1 year openssl verify -CAfile ca.pem agent.crt } # MAIN make_ca make_int make_server make_agent
- Use the following example script to generate the certificates for your CA, server, and client. Save the script as
-
Place the configuration files:
- Put the following OpenSSL
.cnf
files in the same directory as themake_certs.sh
script. These files are needed to configure the certificate authority and generate the appropriate certificates.
ca.cnf
[req] default_bits = 4096 distinguished_name = req_distinguished_name prompt = no default_md = sha256 req_extensions = v3_req # recommend changing these to your needs [req_distinguished_name] countryName = US stateOrProvinceName = California localityName = San Francisco organizationName = NGINX, Inc. commonName = nms-ca [v3_req] basicConstraints = critical, CA:true keyUsage = critical, keyCertSign, cRLSign subjectKeyIdentifier = hash
ca-intermediate.cnf
[req] default_bits = 4096 distinguished_name = req_distinguished_name prompt = no default_md = sha256 req_extensions = v3_req # recommend changing these to your needs [req_distinguished_name] countryName = US stateOrProvinceName = California localityName = San Francisco organizationName = NGINX, Inc. commonName = nms-int-ca [v3_req] basicConstraints = critical, CA:true keyUsage = critical, keyCertSign, cRLSign subjectKeyIdentifier = hash
server.cnf
[req] prompt = no default_bits = 4096 x509_extensions = v3_req req_extensions = v3_req default_md = sha256 distinguished_name = req_distinguished_name # recommend changing these to your needs [req_distinguished_name] countryName = US stateOrProvinceName = California localityName = San Francisco organizationName = NGINX, Inc. commonName = nginx-manager.example.com [v3_req] basicConstraints = CA:FALSE keyUsage = nonRepudiation, digitalSignature, keyEncipherment, keyAgreement extendedKeyUsage = critical, serverAuth subjectAltName = @alt_names # apply any DNS or IP SANs as needed [alt_names] DNS.1 = <NGINX-INSTANCE-MANAGER-FQDN> IP.1 = <NGINX-INSTANCE-MANAGER-IP>
agent.cnf
[req] prompt = no default_bits = 2048 x509_extensions = v3_req req_extensions = v3_req default_md = sha256 distinguished_name = req_distinguished_name # recommend changing these to your needs [req_distinguished_name] countryName = US stateOrProvinceName = California localityName = San Francisco organizationName = NGINX, Inc. commonName = agent.example.com [v3_req] basicConstraints = CA:FALSE keyUsage = nonRepudiation, digitalSignature, keyEncipherment, keyAgreement extendedKeyUsage = critical, clientAuth
- Put the following OpenSSL
-
Run the script:
- After saving the script, make it executable and run it to generate the certificates.
sudo chmod +x ./make_certs.sh sudo ./make_certs.sh
-
Copy the certificates to the NGINX instance:
- Once generated, copy the ca.pem, agent.crt, and agent.key files to the NGINX instance where the NGINX Agent certificates will be installed.
sudo mkdir -p /etc/nms/certs sudo cp ca.pem /etc/nms/certs/ sudo cp agent.crt /etc/nms/certs/ sudo cp agent.key /etc/nms/certs/
-
Modify the NGINX Agent configuration:
- Modify the
nginx-agent.conf
file to match the example below. The TLS options configure the NGINX Agent to use client certificate authentication with the NGINX proxy on NGINX Instance Manager. Theca.pem
file is included as the certificate authority that the agent will use to verify NGINX Instance Manager’s server certificate. - If the CA is trusted by the operating system, you can omit the ca option.
- Update the server host to match the NGINX Instance Manager address.
See Also:
For additional information about TLS configurations for the NGINX Agent, refer to the NGINX Agent TLS Settings topic./etc/nginx-agent/nginx-agent.conf
# # /etc/nginx-agent/nginx-agent.conf # # Configuration file for NGINX Agent. # # This file is to track agent configuration values that are meant to be statically set. There # are additional agent configuration values that are set via the API and agent install script # which can be found in /var/lib/nginx-agent/agent-dynamic.conf. # specify the server grpc port to connect to server: # host of the control plane host: <NGINX-INSTANCE-MANAGER-FQDN> grpcPort: 443 # provide servername overrides if using SNI metrics: "nginx-manager.example.com" command: "nginx-manager.example.com" # tls options tls: enable: true skip_verify: false cert: /etc/nms/certs/agent.crt key: /etc/nms/certs/agent.key ca: /etc/nms/certs/ca.pem log: # set log level (panic, fatal, error, info, debug, trace; default "info") level: info # set log path. if empty, don't log to file. path: /var/log/nginx-agent/ # data plane status message / 'heartbeat' nginx: # path of NGINX logs to exclude exclude_logs: "" dataplane: sync: enable: true # poll interval for data plane status status: poll_interval: 30s metrics: # specify the size of a buffer to build before sending metrics bulk_size: 20 # specify metrics poll interval report_interval: 1m collection_interval: 15s mode: aggregated # OSS NGINX default config path # path to aux file dirs can also be added config_dirs: "/etc/nginx:/usr/local/etc/nginx"
- Modify the
-
Copy
ca.pem
,server.crt
, andserver.key
to NGINX Instance Manager.sudo cp ca.pem /etc/nms/certs/ sudo cp server.crt /etc/nms/certs/ sudo cp server.key /etc/nms/certs/
-
Add a new server to NGINX proxy for gRPC in the NGINX Instance Manager configuration with the newly generated certificates, then reload the service.
- The
server_name
should match theserver.metrics
andserver.command
values innginx-agent.conf
. - You can remove
MetricsService
andCommander
locations from the existing server. - The new server will enforce mTLS communication between NGINX Agent and NGINX Instance Manager, while the previous server can continue serving static content for the web interface and API without mTLS requirements.
When
tls.skip_verify
is set tofalse
, NGINX Agent verifies the server’s certificate chain and hostname. Ensure theserver_name
in the configuration matches the Common Name (CN) or Subject Alternative Name (SAN) in the generated certificate.# gRPC HTTPS server, needs port 443 server { listen 443 ssl; http2 on; root /var/www/nms; server_name nginx-instance-manager.example.com; ssl_protocols TLSv1.1 TLSv1.2; ssl_ciphers HIGH:!aNULL:!MD5; ssl_session_cache shared:SSL:10m; ssl_session_timeout 10m; ssl_certificate /etc/nms/certs/server.crt; ssl_certificate_key /etc/nms/certs/server.key; ssl_client_certificate /etc/nms/certs/ca.pem; ssl_verify_client on; # gRPC service for metric ingestion location /f5.nginx.agent.sdk.MetricsService { include /etc/nms/nginx/errors-grpc.loc_conf; grpc_socket_keepalive on; grpc_read_timeout 5m; grpc_send_timeout 5m; client_body_timeout 10m; grpc_pass grpc://ingestion-grpc-service; } # gRPC service for DPM location /f5.nginx.agent.sdk.Commander { include /etc/nms/nginx/errors-grpc.loc_conf; grpc_socket_keepalive on; grpc_read_timeout 5m; grpc_send_timeout 5m; client_body_timeout 10m; grpc_pass grpc://dpm-grpc-service; }
- The
-
Reload NGINX proxy configuration:
- Apply the new settings by reloading NGINX proxy configuration.
sudo nginx -s reload
-
Restart NGINX Agent:
- Start or restart NGINX Agent to apply the changes.
sudo systemctl restart nginx-agent
Configure SSL verification for usage reporting with self-signed certificates
Version requirements
Usage reporting for NGINX Plus R33 or later in network-restricted environments requires NGINX Instance Manager version 2.18 or later.
See also: ngx_mgmt_module reference guide
For complete details about themgmt
module and directives, visit the Module ngx_mgmt_module reference guide.
Starting with NGINX Plus R33, NGINX Plus must report telemetry data to a usage reporting endpoint, like NGINX Instance Manager. This data is used to validate subscriptions and track usage metrics.
The ssl_verify
directive in the mgmt
block ensures that NGINX Plus connects to a trusted reporting endpoint by validating the server’s SSL certificate. This prevents communication with untrusted or malicious endpoints. By default, ssl_verify
is set to on
, so NGINX Plus will verify the certificate before sending telemetry data.
Why ssl_verify
is important
When ssl_verify
is enabled:
- NGINX Plus checks the SSL certificate presented by NGINX Instance Manager, preventing communication with untrusted endpoints.
- This ensures that telemetry data is securely transmitted and prevents man-in-the-middle (MITM) attacks.
If ssl_verify
fails (due to an untrusted certificate), telemetry reporting will not proceed, which can affect the validation of subscription entitlements and prevent NGINX Plus from functioning properly.
Trusting self-signed certificates
If NGINX Instance Manager uses a self-signed certificate, configure NGINX Plus to trust the certificate. Use the ssl_trusted_certificate
directive to specify a file with trusted CA certificates in the PEM format:
mgmt {
ssl_verify on;
ssl_trusted_certificate <file>;
}
Disabling ssl_verify
Although it’s recommended to keep ssl_verify
enabled for security reasons, you can disable it in certain cases, such as in testing environments or when using self-signed certificates. To disable ssl_verify
, set the directive to off
in the mgmt
block:
mgmt {
ssl_verify off;
}
Important:
Disablingssl_verify
bypasses SSL certificate verification, which reduces security and is not recommended for production environments.
Troubleshooting
If NGINX Agent and NGINX Instance Manager are having communication issues, follow these steps to troubleshoot:
-
Check access and error logs:
- Make sure access and error logging are enabled to capture detailed information about errors and request processing.
- By default, both logs are enabled in the
http
block of the main NGINX configuration file:
# nginx.conf http { ... access_log /var/log/nginx/access.log; error_log /var/log/nginx/error.log; ... }
-
Check the logs for certificate issues:
- Review the logs for any errors related to certificates. Ensure the server is using the correct certificates and Certificate Authority (CA).