Matt Keeler afa1cc98d1
Implement data filtering of some endpoints (#5579)
Fixes: #4222 

# Data Filtering

This PR will implement filtering for the following endpoints:

## Supported HTTP Endpoints

- `/agent/checks`
- `/agent/services`
- `/catalog/nodes`
- `/catalog/service/:service`
- `/catalog/connect/:service`
- `/catalog/node/:node`
- `/health/node/:node`
- `/health/checks/:service`
- `/health/service/:service`
- `/health/connect/:service`
- `/health/state/:state`
- `/internal/ui/nodes`
- `/internal/ui/services`

More can be added going forward and any endpoint which is used to list some data is a good candidate.

## Usage

When using the HTTP API a `filter` query parameter can be used to pass a filter expression to Consul. Filter Expressions take the general form of:

```
<selector> == <value>
<selector> != <value>
<value> in <selector>
<value> not in <selector>
<selector> contains <value>
<selector> not contains <value>
<selector> is empty
<selector> is not empty
not <other expression>
<expression 1> and <expression 2>
<expression 1> or <expression 2>
```

Normal boolean logic and precedence is supported. All of the actual filtering and evaluation logic is coming from the [go-bexpr](https://github.com/hashicorp/go-bexpr) library

## Other changes

Adding the `Internal.ServiceDump` RPC endpoint. This will allow the UI to filter services better.
2019-04-16 12:00:15 -04:00

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3.4 KiB
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# Objx
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[![GoDoc](https://godoc.org/github.com/stretchr/objx?status.svg)](https://godoc.org/github.com/stretchr/objx)
Objx - Go package for dealing with maps, slices, JSON and other data.
Get started:
- Install Objx with [one line of code](#installation), or [update it with another](#staying-up-to-date)
- Check out the API Documentation http://godoc.org/github.com/stretchr/objx
## Overview
Objx provides the `objx.Map` type, which is a `map[string]interface{}` that exposes a powerful `Get` method (among others) that allows you to easily and quickly get access to data within the map, without having to worry too much about type assertions, missing data, default values etc.
### Pattern
Objx uses a preditable pattern to make access data from within `map[string]interface{}` easy. Call one of the `objx.` functions to create your `objx.Map` to get going:
m, err := objx.FromJSON(json)
NOTE: Any methods or functions with the `Must` prefix will panic if something goes wrong, the rest will be optimistic and try to figure things out without panicking.
Use `Get` to access the value you're interested in. You can use dot and array
notation too:
m.Get("places[0].latlng")
Once you have sought the `Value` you're interested in, you can use the `Is*` methods to determine its type.
if m.Get("code").IsStr() { // Your code... }
Or you can just assume the type, and use one of the strong type methods to extract the real value:
m.Get("code").Int()
If there's no value there (or if it's the wrong type) then a default value will be returned, or you can be explicit about the default value.
Get("code").Int(-1)
If you're dealing with a slice of data as a value, Objx provides many useful methods for iterating, manipulating and selecting that data. You can find out more by exploring the index below.
### Reading data
A simple example of how to use Objx:
// Use MustFromJSON to make an objx.Map from some JSON
m := objx.MustFromJSON(`{"name": "Mat", "age": 30}`)
// Get the details
name := m.Get("name").Str()
age := m.Get("age").Int()
// Get their nickname (or use their name if they don't have one)
nickname := m.Get("nickname").Str(name)
### Ranging
Since `objx.Map` is a `map[string]interface{}` you can treat it as such. For example, to `range` the data, do what you would expect:
m := objx.MustFromJSON(json)
for key, value := range m {
// Your code...
}
## Installation
To install Objx, use go get:
go get github.com/stretchr/objx
### Staying up to date
To update Objx to the latest version, run:
go get -u github.com/stretchr/objx
### Supported go versions
We support the lastest two major Go versions, which are 1.8 and 1.9 at the moment.
## Contributing
Please feel free to submit issues, fork the repository and send pull requests!