Minio Go Client API Reference Slack

Initialize Minio Client object.

Minio

package main

import (
    "fmt"

    "github.com/minio/minio-go"
)

func main() {
        // Use a secure connection.
        ssl := true

        // Initialize minio client object.
        minioClient, err := minio.New("play.minio.io:9000", "Q3AM3UQ867SPQQA43P2F", "zuf+tfteSlswRu7BJ86wekitnifILbZam1KYY3TG", ssl)
        if err != nil {
                fmt.Println(err)
                return
        }
}

AWS S3

package main

import (
    "fmt"

    "github.com/minio/minio-go"
)

func main() {
        // Use a secure connection.
        ssl := true

        // Initialize minio client object.
        s3Client, err := minio.New("s3.amazonaws.com", "YOUR-ACCESSKEYID", "YOUR-SECRETACCESSKEY", ssl)
        if err != nil {
                fmt.Println(err)
                return
        }
}
Bucket operations Object operations Encrypted Object operations Presigned operations Bucket Policy/Notification Operations Client custom settings
MakeBucket GetObject NewSymmetricKey PresignedGetObject SetBucketPolicy SetAppInfo
ListBuckets PutObject NewAsymmetricKey PresignedPutObject GetBucketPolicy SetCustomTransport
BucketExists CopyObject GetEncryptedObject PresignedPostPolicy ListBucketPolicies TraceOn
RemoveBucket StatObject PutObjectStreaming SetBucketNotification TraceOff
ListObjects RemoveObject PutEncryptedObject GetBucketNotification SetS3TransferAccelerate
ListObjectsV2 RemoveObjects NewSSEInfo RemoveAllBucketNotification
ListIncompleteUploads RemoveIncompleteUpload ListenBucketNotification
FPutObject
FGetObject
ComposeObject
NewSourceInfo
NewDestinationInfo

1. Constructor

New(endpoint, accessKeyID, secretAccessKey string, ssl bool) (*Client, error)

Initializes a new client object.

Parameters

Param Type Description
endpoint string S3 compatible object storage endpoint
accessKeyID string Access key for the object storage
secretAccessKey string Secret key for the object storage
ssl bool If 'true' API requests will be secure (HTTPS), and insecure (HTTP) otherwise

NewWithRegion(endpoint, accessKeyID, secretAccessKey string, ssl bool, region string) (*Client, error)

Initializes minio client, with region configured. Unlike New(), NewWithRegion avoids bucket-location lookup operations and it is slightly faster. Use this function when if your application deals with single region.

Parameters

Param Type Description
endpoint string S3 compatible object storage endpoint
accessKeyID string Access key for the object storage
secretAccessKey string Secret key for the object storage
ssl bool If 'true' API requests will be secure (HTTPS), and insecure (HTTP) otherwise
region string Region for the object storage

2. Bucket operations

MakeBucket(bucketName, location string) error

Creates a new bucket.

Parameters

Param Type Description
bucketName string Name of the bucket
location string Region where the bucket is to be created. Default value is us-east-1. Other valid values are listed below. Note: When used with minio server, use the region specified in its config file (defaults to us-east-1).
us-east-1
us-west-1
us-west-2
eu-west-1
eu-central-1
ap-southeast-1
ap-northeast-1
ap-southeast-2
sa-east-1

Example

err := minioClient.MakeBucket("mybucket", "us-east-1")
if err != nil {
    fmt.Println(err)
    return
}
fmt.Println("Successfully created mybucket.")

ListBuckets() ([]BucketInfo, error)

Lists all buckets.

Param Type Description
bucketList []BucketInfo Lists of all buckets
Param Type Description
bucket.Name string Name of the bucket
bucket.CreationDate time.Time Date of bucket creation

Example

buckets, err := minioClient.ListBuckets()
    if err != nil {
    fmt.Println(err)
    return
}
for _, bucket := range buckets {
    fmt.Println(bucket)
}

BucketExists(bucketName string) (found bool, err error)

Checks if a bucket exists.

Parameters

Param Type Description
bucketName string Name of the bucket

Return Values

Param Type Description
found bool Indicates whether bucket exists or not
err error Standard Error

Example

found, err := minioClient.BucketExists("mybucket")
if err != nil {
    fmt.Println(err)
    return
}
if found {
    fmt.Println("Bucket found")
}

RemoveBucket(bucketName string) error

Removes a bucket.

Parameters

Param Type Description
bucketName string Name of the bucket

Example

err := minioClient.RemoveBucket("mybucket")
if err != nil {
    fmt.Println(err)
    return
}

ListObjects(bucketName, prefix string, recursive bool, doneCh chan struct{}) <-chan ObjectInfo

Lists objects in a bucket.

Parameters

Param Type Description
bucketName string Name of the bucket
objectPrefix string Prefix of objects to be listed
recursive bool true indicates recursive style listing and false indicates directory style listing delimited by '/'.
doneCh chan struct{} A message on this channel ends the ListObjects iterator.

Return Value

Param Type Description
chan ObjectInfo chan ObjectInfo Read channel for all objects in the bucket, the object is of the format listed below:
Param Type Description
objectInfo.Key string Name of the object
objectInfo.Size int64 Size of the object
objectInfo.ETag string MD5 checksum of the object
objectInfo.LastModified time.Time Time when object was last modified
// Create a done channel to control 'ListObjects' go routine.
doneCh := make(chan struct{})

// Indicate to our routine to exit cleanly upon return.
defer close(doneCh)

isRecursive := true
objectCh := minioClient.ListObjects("mybucket", "myprefix", isRecursive, doneCh)
for object := range objectCh {
    if object.Err != nil {
        fmt.Println(object.Err)
        return
    }
    fmt.Println(object)
}

ListObjectsV2(bucketName, prefix string, recursive bool, doneCh chan struct{}) <-chan ObjectInfo

Lists objects in a bucket using the recommended listing API v2

Parameters

Param Type Description
bucketName string Name of the bucket
objectPrefix string Prefix of objects to be listed
recursive bool true indicates recursive style listing and false indicates directory style listing delimited by '/'.
doneCh chan struct{} A message on this channel ends the ListObjectsV2 iterator.

Return Value

Param Type Description
chan ObjectInfo chan ObjectInfo Read channel for all the objects in the bucket, the object is of the format listed below:
Param Type Description
objectInfo.Key string Name of the object
objectInfo.Size int64 Size of the object
objectInfo.ETag string MD5 checksum of the object
objectInfo.LastModified time.Time Time when object was last modified
// Create a done channel to control 'ListObjectsV2' go routine.
doneCh := make(chan struct{})

// Indicate to our routine to exit cleanly upon return.
defer close(doneCh)

isRecursive := true
objectCh := minioClient.ListObjectsV2("mybucket", "myprefix", isRecursive, doneCh)
for object := range objectCh {
    if object.Err != nil {
        fmt.Println(object.Err)
        return
    }
    fmt.Println(object)
}

ListIncompleteUploads(bucketName, prefix string, recursive bool, doneCh chan struct{}) <- chan ObjectMultipartInfo

Lists partially uploaded objects in a bucket.

Parameters

Param Type Description
bucketName string Name of the bucket
prefix string Prefix of objects that are partially uploaded
recursive bool true indicates recursive style listing and false indicates directory style listing delimited by '/'.
doneCh chan struct{} A message on this channel ends the ListenIncompleteUploads iterator.

Return Value

Param Type Description
chan ObjectMultipartInfo chan ObjectMultipartInfo Emits multipart objects of the format listed below:

Return Value

Param Type Description
multiPartObjInfo.Key string Name of incompletely uploaded object
multiPartObjInfo.UploadID string Upload ID of incompletely uploaded object
multiPartObjInfo.Size int64 Size of incompletely uploaded object

Example

// Create a done channel to control 'ListObjects' go routine.
doneCh := make(chan struct{})

// Indicate to our routine to exit cleanly upon return.
defer close(doneCh)

isRecursive := true // Recursively list everything at 'myprefix'
multiPartObjectCh := minioClient.ListIncompleteUploads("mybucket", "myprefix", isRecursive, doneCh)
for multiPartObject := range multiPartObjectCh {
    if multiPartObject.Err != nil {
        fmt.Println(multiPartObject.Err)
        return
    }
    fmt.Println(multiPartObject)
}

3. Object operations

GetObject(bucketName, objectName string) (*Object, error)

Returns a stream of the object data. Most of the common errors occur when reading the stream.

Parameters

Param Type Description
bucketName string Name of the bucket
objectName string Name of the object

Return Value

Param Type Description
object *minio.Object minio.Object represents object reader. It implements io.Reader, io.Seeker, io.ReaderAt and io.Closer interfaces.

Example

object, err := minioClient.GetObject("mybucket", "photo.jpg")
if err != nil {
    fmt.Println(err)
    return
}
localFile, err := os.Create("/tmp/local-file.jpg")
if err != nil {
    fmt.Println(err)
    return
}
if _, err = io.Copy(localFile, object); err != nil {
    fmt.Println(err)
    return
}

FGetObject(bucketName, objectName, filePath string) error

Downloads and saves the object as a file in the local filesystem.

Parameters

Param Type Description
bucketName string Name of the bucket
objectName string Name of the object
filePath string Path to download object to

Example

err := minioClient.FGetObject("mybucket", "photo.jpg", "/tmp/photo.jpg")
if err != nil {
    fmt.Println(err)
    return
}

PutObject(bucketName, objectName string, reader io.Reader, contentType string) (n int, err error)

Uploads objects that are less than 64MiB in a single PUT operation. For objects that are greater than 64MiB in size, PutObject seamlessly uploads the object as parts of 64MiB or more depending on the actual file size. The max upload size for an object is 5TB.

Parameters

Param Type Description
bucketName string Name of the bucket
objectName string Name of the object
reader io.Reader Any Go type that implements io.Reader
contentType string Content type of the object

Example

file, err := os.Open("my-testfile")
if err != nil {
    fmt.Println(err)
    return
}
defer file.Close()

n, err := minioClient.PutObject("mybucket", "myobject", file, "application/octet-stream")
if err != nil {
    fmt.Println(err)
    return
}

PutObjectStreaming(bucketName, objectName string, reader io.Reader) (n int, err error)

Uploads an object as multiple chunks keeping memory consumption constant. It is similar to PutObject in how objects are broken into multiple parts. Each part in turn is transferred as multiple chunks with constant memory usage. However resuming previously failed uploads from where it was left is not supported.

Parameters

Param Type Description
bucketName string Name of the bucket
objectName string Name of the object
reader io.Reader Any Go type that implements io.Reader

Example

file, err := os.Open("my-testfile")
if err != nil {
    fmt.Println(err)
    return
}
defer file.Close()

n, err := minioClient.PutObjectStreaming("mybucket", "myobject", file)
if err != nil {
    fmt.Println(err)
    return
}

CopyObject(dst DestinationInfo, src SourceInfo) error

Create or replace an object through server-side copying of an existing object. It supports conditional copying, copying a part of an object and server-side encryption of destination and decryption of source. See the SourceInfo and DestinationInfo types for further details.

To copy multiple source objects into a single destination object see the ComposeObject API.

Parameters

Param Type Description
dst DestinationInfo Argument describing the destination object
src SourceInfo Argument describing the source object

Example

// Use-case 1: Simple copy object with no conditions, etc
// Source object
src := minio.NewSourceInfo("my-sourcebucketname", "my-sourceobjectname", nil)

// Destination object
dst, err := minio.NewDestinationInfo("my-bucketname", "my-objectname", nil, nil)
if err != nil {
    fmt.Println(err)
    return
}

// Copy object call
err = s3Client.CopyObject(dst, src)
if err != nil {
    fmt.Println(err)
    return
}

// Use-case 2: Copy object with copy-conditions, and copying only part of the source object.
// 1. that matches a given ETag
// 2. and modified after 1st April 2014
// 3. but unmodified since 23rd April 2014
// 4. copy only first 1MiB of object.

// Source object
src := minio.NewSourceInfo("my-sourcebucketname", "my-sourceobjectname", nil)

// Set matching ETag condition, copy object which matches the following ETag.
src.SetMatchETagCond("31624deb84149d2f8ef9c385918b653a")

// Set modified condition, copy object modified since 2014 April 1.
src.SetModifiedSinceCond(time.Date(2014, time.April, 1, 0, 0, 0, 0, time.UTC))

// Set unmodified condition, copy object unmodified since 2014 April 23.
src.SetUnmodifiedSinceCond(time.Date(2014, time.April, 23, 0, 0, 0, 0, time.UTC))

// Set copy-range of only first 1MiB of file.
src.SetRange(0, 1024*1024-1)

// Destination object
dst, err := minio.NewDestinationInfo("my-bucketname", "my-objectname", nil, nil)
if err != nil {
    fmt.Println(err)
    return
}

// Copy object call
err = s3Client.CopyObject(dst, src)
if err != nil {
    fmt.Println(err)
    return
}

ComposeObject(dst DestinationInfo, srcs []SourceInfo) error

Create an object by concatenating a list of source objects using
server-side copying.

Parameters

Param Type Description
dst minio.DestinationInfo Struct with info about the object to be created.
srcs []minio.SourceInfo Slice of struct with info about source objects to be concatenated in order.

Example

// Prepare source decryption key (here we assume same key to
// decrypt all source objects.)
decKey := minio.NewSSEInfo([]byte{1, 2, 3}, "")

// Source objects to concatenate. We also specify decryption
// key for each
src1 := minio.NewSourceInfo("bucket1", "object1", decKey)
src1.SetMatchETag("31624deb84149d2f8ef9c385918b653a")

src2 := minio.NewSourceInfo("bucket2", "object2", decKey)
src2.SetMatchETag("f8ef9c385918b653a31624deb84149d2")

src3 := minio.NewSourceInfo("bucket3", "object3", decKey)
src3.SetMatchETag("5918b653a31624deb84149d2f8ef9c38")

// Create slice of sources.
srcs := []minio.SourceInfo{src1, src2, src3}

// Prepare destination encryption key
encKey := minio.NewSSEInfo([]byte{8, 9, 0}, "")

// Create destination info
dst := minio.NewDestinationInfo("bucket", "object", encKey, nil)
err = s3Client.ComposeObject(dst, srcs)
if err != nil {
    log.Println(err)
    return
}

log.Println("Composed object successfully.")

NewSourceInfo(bucket, object string, decryptSSEC *SSEInfo) SourceInfo

Construct a SourceInfo object that can be used as the source for server-side copying operations like CopyObject and ComposeObject. This object can be used to set copy-conditions on the source.

Parameters

Param Type Description
bucket string Name of the source bucket
object string Name of the source object
decryptSSEC *minio.SSEInfo Decryption info for the source object (nil without encryption)

Example

// No decryption parameter.
src := NewSourceInfo("bucket", "object", nil)

// With decryption parameter.
decKey := NewSSEKey([]byte{1,2,3}, "")
src := NewSourceInfo("bucket", "object", decKey)

NewDestinationInfo(bucket, object string, encryptSSEC *SSEInfo, userMeta map[string]string) (DestinationInfo, error)

Construct a DestinationInfo object that can be used as the destination object for server-side copying operations like CopyObject and ComposeObject.

Parameters

Param Type Description
bucket string Name of the destination bucket
object string Name of the destination object
encryptSSEC *minio.SSEInfo Encryption info for the source object (nil without encryption)
userMeta map[string]string User metadata to be set on the destination. If nil, with only one source, user-metadata is copied from source.

Example

// No encryption parameter.
dst, err := NewDestinationInfo("bucket", "object", nil, nil)

// With encryption parameter.
encKey := NewSSEKey([]byte{1,2,3}, "")
dst, err := NewDecryptionInfo("bucket", "object", encKey, nil)

FPutObject(bucketName, objectName, filePath, contentType string) (length int64, err error)

Uploads contents from a file to objectName.

FPutObject uploads objects that are less than 64MiB in a single PUT operation. For objects that are greater than the 64MiB in size, FPutObject seamlessly uploads the object in chunks of 64MiB or more depending on the actual file size. The max upload size for an object is 5TB.

Parameters

Param Type Description
bucketName string Name of the bucket
objectName string Name of the object
filePath string Path to file to be uploaded
contentType string Content type of the object

Example

n, err := minioClient.FPutObject("mybucket", "myobject.csv", "/tmp/otherobject.csv", "application/csv")
if err != nil {
    fmt.Println(err)
    return
}

StatObject(bucketName, objectName string) (ObjectInfo, error)

Gets metadata of an object.

Parameters

Param Type Description
bucketName string Name of the bucket
objectName string Name of the object

Return Value

Param Type Description
objInfo ObjectInfo Object stat information
Param Type Description
objInfo.LastModified time.Time Time when object was last modified
objInfo.ETag string MD5 checksum of the object
objInfo.ContentType string Content type of the object
objInfo.Size int64 Size of the object

Example

objInfo, err := minioClient.StatObject("mybucket", "photo.jpg")
if err != nil {
    fmt.Println(err)
    return
}
fmt.Println(objInfo)

RemoveObject(bucketName, objectName string) error

Removes an object.

Parameters

Param Type Description
bucketName string Name of the bucket
objectName string Name of the object
err := minioClient.RemoveObject("mybucket", "photo.jpg")
if err != nil {
    fmt.Println(err)
    return
}

RemoveObjects(bucketName string, objectsCh chan string) errorCh chan minio.RemoveObjectError

Removes a list of objects obtained from an input channel. The call sends a delete request to the server up to 1000 objects at a time.
The errors observed are sent over the error channel.

Parameters

Param Type Description
bucketName string Name of the bucket
objectsCh chan string Prefix of objects to be removed

Return Values

Param Type Description
errorCh _chan minio.RemoveObjectError Channel of errors observed during deletion.
errorCh := minioClient.RemoveObjects("mybucket", objectsCh)
for e := range errorCh {
    fmt.Println("Error detected during deletion: " + e.Err.Error())
}

RemoveIncompleteUpload(bucketName, objectName string) error

Removes a partially uploaded object.

Parameters

Param Type Description
bucketName string Name of the bucket
objectName string Name of the object

Example

err := minioClient.RemoveIncompleteUpload("mybucket", "photo.jpg")
if err != nil {
    fmt.Println(err)
    return
}

4. Encrypted object operations

NewSymmetricKey(key []byte) *minio.SymmetricKey

Parameters

Param Type Description
key string Name of the bucket

Return Value

Param Type Description
symmetricKey *minio.SymmetricKey minio.SymmetricKey represents a symmetric key structure which can be used to encrypt and decrypt data.
symKey := minio.NewSymmetricKey([]byte("my-secret-key-00"))

NewAsymmetricKey(privateKey []byte, publicKey[]byte) (*minio.AsymmetricKey, error)

Parameters

Param Type Description
privateKey []byte Private key data
publicKey []byte Public key data

Return Value

Param Type Description
asymmetricKey *minio.AsymmetricKey represents an asymmetric key structure which can be used to encrypt and decrypt data.
err error encountered errors.
privateKey, err := ioutil.ReadFile("private.key")
if err != nil {
    log.Fatal(err)
}

publicKey, err := ioutil.ReadFile("public.key")
if err != nil {
    log.Fatal(err)
}

// Initialize the asymmetric key
asymmetricKey, err := minio.NewAsymmetricKey(privateKey, publicKey)
if err != nil {
    log.Fatal(err)
}

GetEncryptedObject(bucketName, objectName string, encryptMaterials minio.EncryptionMaterials) (io.ReadCloser, error)

Returns the decrypted stream of the object data based of the given encryption materiels. Most of the common errors occur when reading the stream.

Parameters

Param Type Description
bucketName string Name of the bucket
objectName string Name of the object
encryptMaterials minio.EncryptionMaterials The module to decrypt the object data

Return Value

Param Type Description
stream io.ReadCloser Returns the deciphered object reader, caller should close after reading.
err _error Returns errors.

Example

// Generate a master symmetric key
key := minio.NewSymmetricKey("my-secret-key-00")

// Build the CBC encryption material
cbcMaterials, err := NewCBCSecureMaterials(key)
if err != nil {
    t.Fatal(err)
}

object, err := minioClient.GetEncryptedObject("mybucket", "photo.jpg", cbcMaterials)
if err != nil {
    fmt.Println(err)
    return
}
defer object.Close()

localFile, err := os.Create("/tmp/local-file.jpg")
if err != nil {
    fmt.Println(err)
    return
}

if _, err = io.Copy(localFile, object); err != nil {
    fmt.Println(err)
    return
}

PutEncryptedObject(bucketName, objectName string, reader io.Reader, encryptMaterials minio.EncryptionMaterials, metadata map[string][]string, progress io.Reader) (n int, err error)

Encrypt and upload an object.

Parameters

Param Type Description
bucketName string Name of the bucket
objectName string Name of the object
reader io.Reader Any Go type that implements io.Reader
encryptMaterials minio.EncryptionMaterials The module that encrypts data
metadata map[string][]string Object metadata to be stored
progress io.Reader A reader to update the upload progress

Example

// Load a private key
privateKey, err := ioutil.ReadFile("private.key")
if err != nil {
    log.Fatal(err)
}

// Load a public key
publicKey, err := ioutil.ReadFile("public.key")
if err != nil {
    log.Fatal(err)
}

// Build an asymmetric key
key, err := NewAssymetricKey(privateKey, publicKey)
if err != nil {
    log.Fatal(err)
}

// Build the CBC encryption module
cbcMaterials, err := NewCBCSecureMaterials(key)
if err != nil {
    t.Fatal(err)
}

// Open a file to upload
file, err := os.Open("my-testfile")
if err != nil {
    fmt.Println(err)
    return
}
defer file.Close()

// Upload the encrypted form of the file
n, err := minioClient.PutEncryptedObject("mybucket", "myobject", file, encryptMaterials, nil, nil)
if err != nil {
    fmt.Println(err)
    return
}

NewSSEInfo(key []byte, algo string) SSEInfo

Create a key object for use as encryption or decryption parameter in operations involving server-side-encryption with customer provided key (SSE-C).

Parameters

Param Type Description
key []byte Byte-slice of the raw, un-encoded binary key
algo string Algorithm to use in encryption or decryption with the given key. Can be empty (defaults to AES256)

Example

// Key for use in encryption/decryption
keyInfo := NewSSEInfo([]byte{1,2,3}, "")

5. Presigned operations

PresignedGetObject(bucketName, objectName string, expiry time.Duration, reqParams url.Values) (*url.URL, error)

Generates a presigned URL for HTTP GET operations. Browsers/Mobile clients may point to this URL to directly download objects even if the bucket is private. This presigned URL can have an associated expiration time in seconds after which it is no longer operational. The default expiry is set to 7 days.

Parameters

Param Type Description
bucketName string Name of the bucket
objectName string Name of the object
expiry time.Duration Expiry of presigned URL in seconds
reqParams url.Values Additional response header overrides supports response-expires, response-content-type, response-cache-control, response-content-disposition.

Example

// Set request parameters for content-disposition.
reqParams := make(url.Values)
reqParams.Set("response-content-disposition", "attachment; filename=\"your-filename.txt\"")

// Generates a presigned url which expires in a day.
presignedURL, err := minioClient.PresignedGetObject("mybucket", "myobject", time.Second * 24 * 60 * 60, reqParams)
if err != nil {
    fmt.Println(err)
    return
}

PresignedPutObject(bucketName, objectName string, expiry time.Duration) (*url.URL, error)

Generates a presigned URL for HTTP PUT operations. Browsers/Mobile clients may point to this URL to upload objects directly to a bucket even if it is private. This presigned URL can have an associated expiration time in seconds after which it is no longer operational. The default expiry is set to 7 days.

NOTE: you can upload to S3 only with specified object name.

Parameters

Param Type Description
bucketName string Name of the bucket
objectName string Name of the object
expiry time.Duration Expiry of presigned URL in seconds

Example

// Generates a url which expires in a day.
expiry := time.Second * 24 * 60 * 60 // 1 day.
presignedURL, err := minioClient.PresignedPutObject("mybucket", "myobject", expiry)
if err != nil {
    fmt.Println(err)
    return
}
fmt.Println(presignedURL)

PresignedPostPolicy(PostPolicy) (*url.URL, map[string]string, error)

Allows setting policy conditions to a presigned URL for POST operations. Policies such as bucket name to receive object uploads, key name prefixes, expiry policy may be set.

Create policy :

policy := minio.NewPostPolicy()

Apply upload policy restrictions:

policy.SetBucket("mybucket")
policy.SetKey("myobject")
policy.SetExpires(time.Now().UTC().AddDate(0, 0, 10)) // expires in 10 days

// Only allow 'png' images.
policy.SetContentType("image/png")

// Only allow content size in range 1KB to 1MB.
policy.SetContentLengthRange(1024, 1024*1024)

// Get the POST form key/value object:

url, formData, err := minioClient.PresignedPostPolicy(policy)
if err != nil {
    fmt.Println(err)
    return
}

POST your content from the command line using curl:

fmt.Printf("curl ")
for k, v := range formData {
    fmt.Printf("-F %s=%s ", k, v)
}
fmt.Printf("-F file=@/etc/bash.bashrc ")
fmt.Printf("%s\n", url)

6. Bucket policy/notification operations

SetBucketPolicy(bucketname, objectPrefix string, policy policy.BucketPolicy) error

Set access permissions on bucket or an object prefix.

Importing github.com/minio/minio-go/pkg/policy package is needed.

Parameters

Param Type Description
bucketName string Name of the bucket
objectPrefix string Name of the object prefix
policy policy.BucketPolicy Policy can be one of the following,
policy.BucketPolicyNone
policy.BucketPolicyReadOnly
policy.BucketPolicyReadWrite
policy.BucketPolicyWriteOnly

Return Values

Param Type Description
err error Standard Error

Example

err := minioClient.SetBucketPolicy("mybucket", "myprefix", policy.BucketPolicyReadWrite)
if err != nil {
    fmt.Println(err)
    return
}

GetBucketPolicy(bucketName, objectPrefix string) (policy.BucketPolicy, error)

Get access permissions on a bucket or a prefix.

Importing github.com/minio/minio-go/pkg/policy package is needed.

Parameters

Param Type Description
bucketName string Name of the bucket
objectPrefix string Prefix matching objects under the bucket

Return Values

Param Type Description
bucketPolicy policy.BucketPolicy string that contains: none, readonly, readwrite, or writeonly
err error Standard Error

Example

bucketPolicy, err := minioClient.GetBucketPolicy("mybucket", "")
if err != nil {
    fmt.Println(err)
    return
}
fmt.Println("Access permissions for mybucket is", bucketPolicy)

ListBucketPolicies(bucketName, objectPrefix string) (map[string]BucketPolicy, error)

Get access permissions rules associated to the specified bucket and prefix.

Parameters

Param Type Description
bucketName string Name of the bucket
objectPrefix string Prefix matching objects under the bucket

Return Values

Param Type Description
bucketPolicies map[string]BucketPolicy Map of object resource paths and their permissions
err error Standard Error

Example

bucketPolicies, err := minioClient.ListBucketPolicies("mybucket", "")
if err != nil {
    fmt.Println(err)
    return
}
for resource, permission := range bucketPolicies {
    fmt.Println(resource, " => ", permission)
}

GetBucketNotification(bucketName string) (BucketNotification, error)

Get all notification configurations related to the specified bucket.

Parameters

Param Type Description
bucketName string Name of the bucket

Return Values

Param Type Description
bucketNotification BucketNotification structure which holds all notification configurations
err error Standard Error

Example

bucketNotification, err := minioClient.GetBucketNotification("mybucket")
if err != nil {
    log.Fatalf("Failed to get bucket notification configurations for mybucket - %v", err)
}
for _, topicConfig := range bucketNotification.TopicConfigs {
    for _, e := range topicConfig.Events {
        fmt.Println(e + " event is enabled")
    }
}

SetBucketNotification(bucketName string, bucketNotification BucketNotification) error

Set a new bucket notification on a bucket.

Parameters

Param Type Description
bucketName string Name of the bucket
bucketNotification BucketNotification Represents the XML to be sent to the configured web service

Return Values

Param Type Description
err error Standard Error

Example

topicArn := NewArn("aws", "sns", "us-east-1", "804605494417", "PhotoUpdate")

topicConfig := NewNotificationConfig(topicArn)
topicConfig.AddEvents(minio.ObjectCreatedAll, minio.ObjectRemovedAll)
lambdaConfig.AddFilterPrefix("photos/")
lambdaConfig.AddFilterSuffix(".jpg")

bucketNotification := BucketNotification{}
bucketNotification.AddTopic(topicConfig)
err := c.SetBucketNotification(bucketName, bucketNotification)
if err != nil {
    fmt.Println("Unable to set the bucket notification: " + err)
}

RemoveAllBucketNotification(bucketName string) error

Remove all configured bucket notifications on a bucket.

Parameters

Param Type Description
bucketName string Name of the bucket

Return Values

Param Type Description
err error Standard Error

Example

err := c.RemoveAllBucketNotification(bucketName)
if err != nil {
    fmt.Println("Unable to remove bucket notifications.", err)
}

ListenBucketNotification(bucketName, prefix, suffix string, events []string, doneCh <-chan struct{}) <-chan NotificationInfo

ListenBucketNotification API receives bucket notification events through the
notification channel. The returned notification channel has two fields
'Records' and 'Err'.

NOTE: Notification channel is closed at the first occurrence of an error.

Parameters

Param Type Description
bucketName string Bucket to listen notifications on
prefix string Object key prefix to filter notifications for
suffix string Object key suffix to filter notifications for
events []string Enables notifications for specific event types
doneCh chan struct{} A message on this channel ends the ListenBucketNotification iterator

Return Values

Param Type Description
chan NotificationInfo chan Read channel for all notifications on bucket
NotificationInfo object Notification object represents events info
notificationInfo.Records []NotificationEvent Collection of notification events
notificationInfo.Err error Carries any error occurred during the operation

Example

// Create a done channel to control 'ListenBucketNotification' go routine.
doneCh := make(chan struct{})

// Indicate a background go-routine to exit cleanly upon return.
defer close(doneCh)

// Listen for bucket notifications on "mybucket" filtered by prefix, suffix and events.
for notificationInfo := range minioClient.ListenBucketNotification("YOUR-BUCKET", "PREFIX", "SUFFIX", []string{
    "s3:ObjectCreated:*",
    "s3:ObjectAccessed:*",
    "s3:ObjectRemoved:*",
    }, doneCh) {
    if notificationInfo.Err != nil {
        log.Fatalln(notificationInfo.Err)
    }
    log.Println(notificationInfo)
}

7. Client custom settings

SetAppInfo(appName, appVersion string)

Adds application details to User-Agent.

Parameters

Param Type Description
appName string Name of the application performing the API requests.
appVersion string Version of the application performing the API requests.

Example

// Set Application name and version to be used in subsequent API requests.
minioClient.SetAppInfo("myCloudApp", "1.0.0")

SetCustomTransport(customHTTPTransport http.RoundTripper)

Overrides default HTTP transport. This is usually needed for debugging
or for adding custom TLS certificates.

Parameters

Param Type Description
customHTTPTransport http.RoundTripper Custom transport e.g, to trace API requests and responses for debugging purposes.

TraceOn(outputStream io.Writer)

Enables HTTP tracing. The trace is written to the io.Writer
provided. If outputStream is nil, trace is written to os.Stdout.

Parameters

Param Type Description
outputStream io.Writer HTTP trace is written into outputStream.

TraceOff()

Disables HTTP tracing.

SetS3TransferAccelerate(acceleratedEndpoint string)

Set AWS S3 transfer acceleration endpoint for all API requests hereafter.
NOTE: This API applies only to AWS S3 and ignored with other S3 compatible object storage services.

Parameters

Param Type Description
acceleratedEndpoint string Set to new S3 transfer acceleration endpoint.

8. Explore Further