# amazon-vpc-cni-plugins

## Included tests

There are two different kinds of tests that are included with this repository, unit tests and end to end tests.

## Basic setup

There is some tooling that needs to be in place for the tests to be able to run, the basics are listed below

- Git - you can install either the `build-essential` meta package on Debian based distros or the package group called `'Development Tools'` on RHEL based distros and that will get you `git`. Otherwise, you can install Git separately as well.
- Make - the above meta package/package group will also include `make` but it can also be installed separately.
- Go - go can be installed from the golang website; the tests are confirmed working on Go version 1.19
- `iptables` - in case the tests are being run in a minimal environment, `iptables` can be obtained from the default package manager for the distro; it is likely that it is already installed on the system

For the end to end tests, a successful build is also required. A build can be triggered by running `make build`.

## Networking setup

The tests commonly reference network interfaces called `eth1` and `eth2`. It is encouraged that tests be run in an environment where `eth1` and `eth2` do not exist and are not being used for any critical workloads because the state of these interfaces will be modified by the tests.

Accordingly, a dummy `eth1` interface can be created by running `ip link add eth1 type dummy`. Likewise for the `eth2` interface. Elevated privilege (`sudo`) might be necessary to run the commands. The existing interfaces can be checked at any time using `ip link show` and the dummy interfaces can be cleaned up by running `ip link delete eth1` and `ip link delete eth2`. The cleanup commands might also require elevated privileges.

The pretest step in the [e2e.yaml](.github/workflows/e2e.yaml) does this exactly, brings up (enables) the interface, and also (optionally) sets the [MTU](https://en.wikipedia.org/wiki/Maximum_transmission_unit) to match the MTU value that we commonly set for AWS networking interfaces.

This does mean that the tests will only run on Linux distros that support creating dummy interfaces via the [`ip`](https://man7.org/linux/man-pages/man8/ip.8.html) command.

## Running

The unit tests can be run using `make unit-test` and the end to end tests can be run using `make e2e-test`.

There are also some specific Make targets included to help with more directed testing. These are included in the table below

| Target                         | Description                                                   |
| ------------------------------ | ------------------------------------------------------------- |
| `appmesh-unit-test`            | Run only the `aws-appmesh` plugin unit tests                  |
| `ecs-serviceconnect-unit-test` | Run only the `ecs-serviceconnect` plugin unit tests           |
| `vpc-branch-eni-e2e-tests`     | Run only the `vpc-branch-eni` plugin end to end tests         |
| `vpc-tunnel-e2e-tests`         | Run only the `vpc-tunnel` plugin end to end tests             |
| `appmesh-e2e-tests`            | Run only the `aws-appmesh` plugin end to end tests            |
| `ecs-serviceconnect-e2e-test`  | Run only the `ecs-serviceconnect` plugin end to end tests     |

## Debugging

If you're running VS Code, here is a sample `launch.json` that can help set up debugging for the tests. This uses the [`vscode-go`](https://github.com/golang/vscode-go) extension.

Something to note is that since these tests run with elevated privileges, it is always a good idea to not stop a test in the middle of execution because it might leave behind resources and/or configuration that needs cleaned up.

The computed CNI path input is a prompt from VSCode that gives users the chance to modify the path where all the CNI plugin binaries reside. By default, it is `<workspace_folder>/build/<os>_<arch>`. The default build path assumes linux on x86_64 architecture but it can be changed via this prompt.

```json
{
  // Use IntelliSense to learn about possible attributes.
  // Hover to view descriptions of existing attributes.
  // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Debug e2e test",
      "type": "go",
      "request": "launch",
      "mode": "auto",
      "program": "${fileDirname}",
      "asRoot": true,
      "console": "integratedTerminal",
      "buildFlags": "-tags=e2e_test",
      "env": {
        "CNI_PATH": "${input:computedCniPath}"
      }
    }
  ],
  "inputs": [
    {
      "id": "computedCniPath",
      "description": "Optional, the path to the CNI plugin build in case the OS or the arch are different.",
      "type": "promptString",
      "default": "${workspaceFolder}${pathSeparator}build${pathSeparator}linux_amd64"
    }
  ]
}
```