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https://github.com/raphink/narcissus
Map configuration files to Go structures using Augeas
https://github.com/raphink/narcissus
augeas configuration configuration-management golang golang-library parser parsing
Last synced: 2 days ago
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Map configuration files to Go structures using Augeas
- Host: GitHub
- URL: https://github.com/raphink/narcissus
- Owner: raphink
- License: apache-2.0
- Created: 2016-08-11T07:24:58.000Z (about 8 years ago)
- Default Branch: master
- Last Pushed: 2020-05-24T20:56:17.000Z (over 4 years ago)
- Last Synced: 2024-05-02T00:59:24.984Z (5 months ago)
- Topics: augeas, configuration, configuration-management, golang, golang-library, parser, parsing
- Language: Go
- Homepage:
- Size: 115 KB
- Stars: 7
- Watchers: 2
- Forks: 0
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- Funding: .github/FUNDING.yml
- License: LICENSE
Awesome Lists containing this project
README
Narcissus: edit configuration files as go structs
=================================================
[](https://godoc.org/github.com/raphink/narcissus)
[](https://travis-ci.org/raphink/narcissus)
[](https://coveralls.io/r/raphink/narcissus?branch=master)
[](https://goreportcard.com/report/github.com/raphink/narcissus)
This go package aims to provide reflection for the [Augeas](http://augeas.net) library.
This allows to turn Augeas lenses into Go structs for easy parsing and
modification of configuration files.
## Example
```go
import (
"log"
"honnef.co/go/augeas"
"github.com/raphink/narcissus"
)
func main() {
aug, err := augeas.New("/", "", augeas.None)
if err != nil {
log.Fatal("Failed to create Augeas handler")
}
n := narcissus.New(&aug)
user := n.NewPasswdUser("raphink")
if err != nil {
log.Fatalf("Failed to retrieve user: %v" err)
}
log.Printf("UID=%v", user.UID)
// Modify UID
user.UID = 42
err = n.Write(user)
if err != nil {
log.Fatalf("Failed to save user: %v", err)
}
}
```
## Available types
### Fstab
* [`Fstab`](https://godoc.org/github.com/raphink/narcissus#Fstab) maps a whole `/etc/fstab` file
* [`FstabEntry`](https://godoc.org/github.com/raphink/narcissus#FstabEntry) maps a single `/etc/fstab` entry
### Hosts
* [`Hosts`](https://godoc.org/github.com/raphink/narcissus#Hosts) maps a whole `/etc/hosts` file
* [`Host`](https://godoc.org/github.com/raphink/narcissus#Host) maps a single `/etc/hosts` entry
### Passwd
* [`Passwd`](https://godoc.org/github.com/raphink/narcissus#Passwd) maps a whole `/etc/passwd` file
* [`PasswdUser`](https://godoc.org/github.com/raphink/narcissus#PasswdUser) maps a single `/etc/passwd` entry
### Services
* [`Services`](https://godoc.org/github.com/raphink/narcissus#Services) maps a whole `/etc/services` file
* [`Service`](https://godoc.org/github.com/raphink/narcissus#Service) maps a single `/etc/services` entry
## Mapping your own structures
```go
import (
"log"
"honnef.co/go/augeas"
"github.com/raphink/narcissus"
)
type group struct {
augeasPath string
Name string `narcissus:".,value-from-label"`
Password string `narcissus:"password"`
GID int `narcissus:"gid"`
Users []string `narcissus:"user"`
}
func main() {
aug, err := augeas.New("/", "", augeas.None)
if err != nil {
log.Fatal("Failed to create Augeas handler")
}
n := narcissus.New(&aug)
group := &group{
augeasPath: "/files/etc/group/docker",
}
err = n.Parse(group)
if err != nil {
log.Fatalf("Failed to retrieve group: %v", err)
}
log.Printf("GID=%v", group.GID)
log.Printf("Users=%v", strings.Join(group.Users, ","))
}
```
## Tag values
The `narcissus` tag accepts multiple comma separated values. The first value in
the list is the relative path where the field is mapped in the Augeas tree.
Other possible (optional) values are:
* `value-from-label`: get field value from the node label instead of its value;
* `seq` (slice field only): will treat field as a seq entry in the Augeas tree;
* `key-from-value` (map field only): get the key from the node label instead
of its value;
* `purge` (map field only): purge all unknown keys in the map.
## Fields
Described structures have special fields to specify parameters for Augeas.
* `augeasPath` (mandatory): the path to the structure in the Augeas tree;
* `augeasFile` (optional): let Augeas load only this file. If `augeasLens` is
not specified, Augeas will use the default lens for the file if available;
* `augeasLens` (optional): if `augeasFile` is set (ignored otherwise),
specifies which lens to use to parse the file. This is required when parsing
a file at a non-standard location.
Each of these fields can be specified in one of two ways:
* by using the `default` tag with a default value for the field, e.g.
```go
type group struct {
augeasPath string `default:"/files/etc/group/root"`
}
```
* by specifying a value for the instance in the structure field, e.g.
```go
myGroup := group {
augeasPath: "/files/etc/group/docker",
}
```