![Mizu: The API Traffic Viewer for Kubernetes](assets/mizu-logo.svg)

# The API Traffic Viewer for Kubernetes

A simple-yet-powerful API traffic viewer for Kubernetes to help you troubleshoot and debug your microservices. Think TCPDump and Chrome Dev Tools combined

![Simple UI](assets/mizu-ui.png)

## Features

- Simple and powerful CLI
- Real-time view of all HTTP requests, REST and gRPC API calls
- No installation or code instrumentation
- Works completely on premises

## Download

Download Mizu for your platform and operating system

### Latest Stable Release

* for MacOS - Intel 
```
curl -Lo mizu \
https://github.com/up9inc/mizu/releases/latest/download/mizu_darwin_amd64 \
&& chmod 755 mizu
```
 
* for Linux - Intel 64bit
```
curl -Lo mizu \
https://github.com/up9inc/mizu/releases/latest/download/mizu_linux_amd64 \
&& chmod 755 mizu
``` 

SHA256 checksums are available on the [Releases](https://github.com/up9inc/mizu/releases) page

### Development (unstable) Build
Pick one from the [Releases](https://github.com/up9inc/mizu/releases) page

## Prerequisites
1. Set `KUBECONFIG` environment variable to your Kubernetes configuration. If this is not set, Mizu assumes that configuration is at `${HOME}/.kube/config`
2. `mizu` assumes user running the command has permissions to create resources (such as pods, services, namespaces) on your Kubernetes cluster (no worries - `mizu` resources are cleaned up upon termination)

For detailed list of k8s permissions see [PERMISSIONS](PERMISSIONS.md) document


## How to Run

1. Find pods you'd like to tap to in your Kubernetes cluster
2. Run `mizu tap` or `mizu tap PODNAME`  
3. Open browser on `http://localhost:8899/mizu` **or** as instructed in the CLI
4. Watch the API traffic flowing
5. Type ^C to stop

## Examples

Run `mizu help` for usage options

To tap all pods in current namespace - 
``` 
 $ kubectl get pods 
 NAME                            READY   STATUS    RESTARTS   AGE
 carts-66c77f5fbb-fq65r          2/2     Running   0          20m
 catalogue-5f4cb7cf5-7zrmn       2/2     Running   0          20m
 front-end-649fc5fd6-kqbtn       2/2     Running   0          20m
 ..

 $ mizu tap
 +carts-66c77f5fbb-fq65r
 +catalogue-5f4cb7cf5-7zrmn
 +front-end-649fc5fd6-kqbtn
 Web interface is now available at http://localhost:8899
 ^C
```


To tap specific pod - 
```bash
 $ kubectl get pods 
 NAME                            READY   STATUS    RESTARTS   AGE
 front-end-649fc5fd6-kqbtn       2/2     Running   0          7m
 ..

 $ mizu tap front-end-649fc5fd6-kqbtn
 +front-end-649fc5fd6-kqbtn
 Web interface is now available at http://localhost:8899
 ^C
```

To tap multiple pods using regex - 
```bash
 $ kubectl get pods 
 NAME                            READY   STATUS    RESTARTS   AGE
 carts-66c77f5fbb-fq65r          2/2     Running   0          20m
 catalogue-5f4cb7cf5-7zrmn       2/2     Running   0          20m
 front-end-649fc5fd6-kqbtn       2/2     Running   0          20m
 ..

 $ mizu tap "^ca.*"
 +carts-66c77f5fbb-fq65r
 +catalogue-5f4cb7cf5-7zrmn
 Web interface is now available at http://localhost:8899
 ^C
```

## Configuration

Mizu can work with config file which should be stored in ${HOME}/.mizu/config.yaml (macOS: ~/.mizu/config.yaml) <br />
In case no config file found, defaults will be used <br />
In case of partial configuration defined, all other fields will be used with defaults <br />
You can always override the defaults or config file with CLI flags

To get the default config params run `mizu config` <br />
To generate a new config file with default values use `mizu config -r`

### Telemetry

By default, mizu reports usage telemetry. It can be disabled by adding a line of `telemetry: false` in the `${HOME}/.mizu/config.yaml` file


## Advanced Usage

### Namespace-Restricted Mode

Some users have permission to only manage resources in one particular namespace assigned to them
By default `mizu tap` creates a new namespace `mizu` for all of its Kubernetes resources. In order to instead install
Mizu in an existing namespace, set the `mizu-resources-namespace` config option

If `mizu-resources-namespace` is set to a value other than the default `mizu`, Mizu will operate in a
Namespace-Restricted mode. It will only tap pods in `mizu-resources-namespace`. This way Mizu only requires permissions
to the namespace set by `mizu-resources-namespace`. The user must set the tapped namespace to the same namespace by
using the `--namespace` flag or by setting `tap.namespaces` in the config file

Setting `mizu-resources-namespace=mizu` resets Mizu to its default behavior

### User agent filtering

User-agent filtering (like health checks) - can be configured using command-line options:

```shell
$ mizu tap "^ca.*" --set ignored-user-agents=kube-probe --set ignored-user-agents=prometheus
+carts-66c77f5fbb-fq65r
+catalogue-5f4cb7cf5-7zrmn
Web interface is now available at http://localhost:8899
^C

```
Any request that contains `User-Agent` header with one of the specified values (`kube-probe` or `prometheus`) will not be captured

### API Rules validation

This feature allows you to define set of simple rules, and test the API against them.
Such validation may test response for specific JSON fields, headers, etc.

Please see [API RULES](docs/POLICY_RULES.md) page for more details and syntax.

