moby--moby/vendor/github.com/RackSec/srslog/README.md

148 lines
3.9 KiB
Markdown

[![Build Status](https://travis-ci.org/RackSec/srslog.svg?branch=master)](https://travis-ci.org/RackSec/srslog)
# srslog
Go has a `syslog` package in the standard library, but it has the following
shortcomings:
1. It doesn't have TLS support
2. [According to bradfitz on the Go team, it is no longer being maintained.](https://github.com/golang/go/issues/13449#issuecomment-161204716)
I agree that it doesn't need to be in the standard library. So, I've
followed Brad's suggestion and have made a separate project to handle syslog.
This code was taken directly from the Go project as a base to start from.
However, this _does_ have TLS support.
# Usage
Basic usage retains the same interface as the original `syslog` package. We
only added to the interface where required to support new functionality.
Switch from the standard library:
```
import(
//"log/syslog"
syslog "github.com/RackSec/srslog"
)
```
You can still use it for local syslog:
```
w, err := syslog.Dial("", "", syslog.LOG_ERR, "testtag")
```
Or to unencrypted UDP:
```
w, err := syslog.Dial("udp", "192.168.0.50:514", syslog.LOG_ERR, "testtag")
```
Or to unencrypted TCP:
```
w, err := syslog.Dial("tcp", "192.168.0.51:514", syslog.LOG_ERR, "testtag")
```
But now you can also send messages via TLS-encrypted TCP:
```
w, err := syslog.DialWithTLSCertPath("tcp+tls", "192.168.0.52:514", syslog.LOG_ERR, "testtag", "/path/to/servercert.pem")
```
And if you need more control over your TLS configuration :
```
pool := x509.NewCertPool()
serverCert, err := ioutil.ReadFile("/path/to/servercert.pem")
if err != nil {
return nil, err
}
pool.AppendCertsFromPEM(serverCert)
config := tls.Config{
RootCAs: pool,
}
w, err := DialWithTLSConfig(network, raddr, priority, tag, &config)
```
(Note that in both TLS cases, this uses a self-signed certificate, where the
remote syslog server has the keypair and the client has only the public key.)
And then to write log messages, continue like so:
```
if err != nil {
log.Fatal("failed to connect to syslog:", err)
}
defer w.Close()
w.Alert("this is an alert")
w.Crit("this is critical")
w.Err("this is an error")
w.Warning("this is a warning")
w.Notice("this is a notice")
w.Info("this is info")
w.Debug("this is debug")
w.Write([]byte("these are some bytes"))
```
If you need further control over connection attempts, you can use the DialWithCustomDialer
function. To continue with the DialWithTLSConfig example:
```
netDialer := &net.Dialer{Timeout: time.Second*5} // easy timeouts
realNetwork := "tcp" // real network, other vars your dail func can close over
dial := func(network, addr string) (net.Conn, error) {
// cannot use "network" here as it'll simply be "custom" which will fail
return tls.DialWithDialer(netDialer, realNetwork, addr, &config)
}
w, err := DialWithCustomDialer("custom", "192.168.0.52:514", syslog.LOG_ERR, "testtag", dial)
```
Your custom dial func can set timeouts, proxy connections, and do whatever else it needs before returning a net.Conn.
# Generating TLS Certificates
We've provided a script that you can use to generate a self-signed keypair:
```
pip install cryptography
python script/gen-certs.py
```
That outputs the public key and private key to standard out. Put those into
`.pem` files. (And don't put them into any source control. The certificate in
the `test` directory is used by the unit tests, and please do not actually use
it anywhere else.)
# Running Tests
Run the tests as usual:
```
go test
```
But we've also provided a test coverage script that will show you which
lines of code are not covered:
```
script/coverage --html
```
That will open a new browser tab showing coverage information.
# License
This project uses the New BSD License, the same as the Go project itself.
# Code of Conduct
Please note that this project is released with a Contributor Code of Conduct.
By participating in this project you agree to abide by its terms.