bucket.go

package main

import (
	"crypto/tls"
	"crypto/x509"
	"io/ioutil"
	"net/http"
	"reflect"
	"strings"

	"github.com/pkg/errors"
	log "github.com/sirupsen/logrus"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/awserr"
	"github.com/aws/aws-sdk-go/aws/credentials"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/s3"
)

func checkS3Bucket(config S3Config) error {
	s3Transport := transportConfigS3(config)
	client := http.Client{Transport: s3Transport}
	s3Session := session.Must(session.NewSession(
		&aws.Config{
			Endpoint:         aws.String(config.url),
			Region:           aws.String(config.region),
			HTTPClient:       &client,
			S3ForcePathStyle: aws.Bool(true),
			DisableSSL:       aws.Bool(strings.HasPrefix(config.url, "http:")),
			Credentials:      credentials.NewStaticCredentials(config.accessKey, config.secretKey, ""),
		},
	))

	_, err := s3.New(s3Session).CreateBucket(&s3.CreateBucketInput{
		Bucket: aws.String(config.bucket),
	})
	log.Infoln(err)
	if err != nil {
		if aerr, ok := err.(awserr.Error); ok {
			if aerr.Code() != s3.ErrCodeBucketAlreadyOwnedByYou &&
				aerr.Code() != s3.ErrCodeBucketAlreadyExists {
				return errors.Errorf("Unexpected issue while creating bucket: %v", err)
			}
			return nil
		}
		return errors.New("Verifying bucket failed, check S3 configuration")
	}

	return nil
}

// transportConfigS3 is a helper method to setup TLS for the S3 client.
func transportConfigS3(config S3Config) http.RoundTripper {
	cfg := new(tls.Config)

	// Enforce TLS1.2 or higher
	cfg.MinVersion = 2

	// Read system CAs
	var systemCAs, _ = x509.SystemCertPool()
	if reflect.DeepEqual(systemCAs, x509.NewCertPool()) {
		log.Debug("creating new CApool")
		systemCAs = x509.NewCertPool()
	}
	cfg.RootCAs = systemCAs

	if config.cacert != "" {
		cacert, e := ioutil.ReadFile(config.cacert) // #nosec this file comes from our config
		if e != nil {
			log.Fatalf("failed to append %q to RootCAs: %v", cacert, e)
		}
		if ok := cfg.RootCAs.AppendCertsFromPEM(cacert); !ok {
			log.Debug("no certs appended, using system certs only")
		}
	}

	var trConfig http.RoundTripper = &http.Transport{
		TLSClientConfig:   cfg,
		ForceAttemptHTTP2: true}

	return trConfig
}