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TLS certificates

Interacting with services that require TLS certificates is a common issue when working with containers. You can create one or more on-the-fly certificates in order to communicate with your services.

Testcontainers for Go uses a library to generate certificates on-the-fly. This library is called tlscert.


In the following example we are going to start an HTTP server with a self-signed certificate. It exposes one single handler that will return a simple message when accessed. The example will also create a client that will connect to the server using the generated certificate, demonstrating how to use the generated certificate to communicate with a service.

caCert := tlscert.SelfSignedFromRequest(tlscert.Request{
    Name:              "ca",
    SubjectCommonName: "Cockroach Test CA",
    Host:              "localhost,",
    IsCA:              true,
    ValidFor:          time.Hour,
if caCert == nil {
    return nil, fmt.Errorf("failed to generate CA certificate")
nodeCert := tlscert.SelfSignedFromRequest(tlscert.Request{
    Name:              "node",
    SubjectCommonName: "node",
    Host:              "localhost,",
    IPAddresses:       []net.IP{net.IPv4(127, 0, 0, 1), net.IPv6loopback},
    ValidFor:          time.Hour,
    Parent:            caCert, // using the CA certificate as parent
if nodeCert == nil {
    return nil, fmt.Errorf("failed to generate node certificate")