Fuchsia-Debian DHCP Interoperability Testing

These tests exercise Fuchsia's DHCP client abilities when interacting with a Debian DHCP server.

The key pieces to this test are

1. The BUILD.gn file in this directory which defines all of the test dependencies.
2. The component manifest that describes the structure of the test setup.
3. The test program that constitutes the test.
   • Along with its manifest.

Build File Notes

• Any data files on which the test relies go under resources.
  • In the case of the dhcp_validity test, there is a config file for dhcpd and a bash script that runs on the Debian guest. Those need to be included in the resources section so that netemul can send them to the guest before test program runs.
• Component manifests for the binaries that constitute tests go under meta.
• Any binary targets that the test needs go under binaries.
  • The targets that generate these binaries need to be under deps.
• Tests go under tests.
  • Each test needs an empty binary.
  • Each item under tests needs a name that points to an empty binary and has an associated component manifest in the meta directory.

DHCP Validity Test Setup Notes

See meta/dhcp_validity_test.cmx.

Guest Creation

"guest": [
    {
        "files": {
            "data/dhcp_setup.sh": "/root/input/dhcp_setup.sh",
            "data/dhcpd.conf": "/etc/dhcp/dhcpd.conf"
            "data/dhcpd6.conf": "/etc/dhcp/dhcpd6.conf"
        },
        "label": "debian_guest",
        "networks": [
            "net"
        ],
        "url": "fuchsia-pkg://fuchsia.com/debian_guest#meta/debian_guest.cmx"
    }
],

• files contains a source to destination mapping for input files that should be transferred to the guest before the test starts.
  • These input files come from the resources section of the test_package.
• label defines the name of the guest that will be used to look up the guest during the test so that the test can control it.
• networks lists the ethertap networks to which the guest will be connected. Currently, the guest may only connect to a single network.
• url defines the type of guest VM will be launched for the test. Currently, only Debian guests are supported.

Test Programs Interacting With Guests

The test program configures dhcpd on the Debian guest and then waits for 30 seconds to ensure that netstack gets a DHCP address. dhcpd.conf and dhcp_setup.sh are pushed to the guest by netemul before the test runs. The test leverages the GuestDiscoveryService to get a handle to a GuestInteractionService that enables the transfer of files and execution of commands on the guest (see the helper library).

Using the same setup, the test program also configures dhcpd on the Debian guest to serve DHCPv6 requests. It then launches a DHCPv6 client in Fuchsia and expects it get a predefined list of DNS servers from dhcpd on the Debian guest.