TLS Security Migration Guide

Overview

Go Micro v6 verifies TLS certificates by default. This guide is for teams upgrading from v5, where TLS verification was disabled by default for backward compatibility.

Current Status (v6)

Default Behavior: TLS certificate verification is enabled by default (InsecureSkipVerify: false).

What changed from v5: v5 allowed MICRO_TLS_SECURE=true to opt into certificate verification. In v6, secure verification is the default and MICRO_TLS_SECURE is no longer used.

Development escape hatch: for local self-signed certificates only, set MICRO_TLS_INSECURE=true or provide an explicit insecure TLS config.

Migration Path from v5

1. Remove the old opt-in flag

Delete any use of the v5-only environment variable:

unset MICRO_TLS_SECURE

No replacement is required for production: verification is already on in v6.

2. Use the default secure config

Most services need no TLS-specific code. If you configure TLS explicitly, use a standard crypto/tls config with verification enabled:

import (
    "crypto/tls"
    "go-micro.dev/v6/broker"
)

// Create broker with certificate verification enabled.
b := broker.NewHttpBroker(
    broker.TLSConfig(&tls.Config{MinVersion: tls.VersionTLS12}),
)

3. Provide a custom trust root when needed

For private CAs, provide your own TLS configuration:

import (
    "crypto/tls"
    "crypto/x509"
    "go-micro.dev/v6/broker"
    "os"
)

// Load CA certificates
caCert, err := os.ReadFile("/path/to/ca-cert.pem")
if err != nil {
    log.Fatal(err)
}

caCertPool := x509.NewCertPool()
caCertPool.AppendCertsFromPEM(caCert)

// Create custom TLS config
tlsConfig := &tls.Config{
    RootCAs:    caCertPool,
    MinVersion: tls.VersionTLS12,
}

// Create broker with custom config
b := broker.NewHttpBroker(
    broker.TLSConfig(tlsConfig),
)

4. Use insecure mode only for local development

If a development environment still uses self-signed certificates that are not in your trust store, opt out explicitly:

export MICRO_TLS_INSECURE=true

or in code:

broker.TLSConfig(&tls.Config{InsecureSkipVerify: true, MinVersion: tls.VersionTLS12})

Do not use insecure mode in production.

Production Deployment Strategy

Rolling Upgrade Considerations

The default changed at the v6 major-version boundary. Before rolling v6 into a fleet that uses TLS, verify that:

1. All services present certificates trusted by their peers.
2. Private or self-signed CAs are installed consistently on every host.
3. Certificates include the DNS names or IP subject alternative names used by clients.
4. Any deliberate development-only insecure settings are excluded from production manifests.

Recommended Approach

1. Test in Staging with the same certificate chain and service names used in production.
2. Remove v5 flags such as MICRO_TLS_SECURE; they no longer control v6.
3. Monitor for Issues: watch for TLS handshake failures or certificate validation errors.
4. Use explicit insecure mode only in dev when a short-lived environment cannot yet provide trusted certificates.

Multi-Host/Multi-Process Considerations

Certificate Trust: With secure mode as the default, ensure:

1. All hosts trust the same root CAs.
2. Self-signed certificates are properly distributed if used.
3. Certificate validity periods are monitored.
4. Certificate chains are complete.

Service Mesh Alternative: Consider using a service mesh (Istio, Linkerd, etc.) for:

• Automatic mTLS between services
• Certificate management and rotation
• No application code changes required

Testing Your Migration

Verify Secure Mode is Active

package main

import (
    "crypto/tls"
    "fmt"
)

func main() {
    config := &tls.Config{MinVersion: tls.VersionTLS12}
    fmt.Printf("InsecureSkipVerify: %v (should be false)\n", config.InsecureSkipVerify)
}

Test Certificate Validation

Create a test service and verify it:

• Accepts valid certificates
• Rejects invalid/self-signed certificates (when not in CA)
• Properly validates certificate chains

Common Issues and Solutions

Issue: "x509: certificate signed by unknown authority"

Cause: The server certificate is not signed by a trusted CA

Solution:

1. Add the CA certificate to the trusted root CAs
2. Use a properly signed certificate
3. For development only: use MICRO_TLS_INSECURE=true or an explicit insecure TLS config

Issue: "x509: certificate has expired"

Cause: Server certificate has expired

Solution:

1. Renew the certificate
2. Implement certificate rotation
3. Monitor certificate expiry dates

Issue: Services can't communicate after upgrading to v6

Cause: Certificates that v5 accepted by default are now verified.

Solution:

1. Ensure all services use certificates from a trusted CA
2. Distribute CA certificates to all nodes
3. Verify certificate SANs match service addresses
4. Use insecure mode only as a temporary local-development workaround

Questions?

For issues or questions about TLS security migration, open an issue on GitHub or check the documentation at https://go-micro.dev/docs/.