package storage
import (
"encoding/xml"
"errors"
"fmt"
"io"
"net/http"
"net/url"
"strconv"
"time"
)
// Container represents an Azure container.
type Container struct {
bsc *BlobStorageClient
Name string `xml:"Name"`
Properties ContainerProperties `xml:"Properties"`
}
func (c *Container) buildPath() string {
return fmt.Sprintf("/%s", c.Name)
}
// ContainerProperties contains various properties of a container returned from
// various endpoints like ListContainers.
type ContainerProperties struct {
LastModified string `xml:"Last-Modified"`
Etag string `xml:"Etag"`
LeaseStatus string `xml:"LeaseStatus"`
LeaseState string `xml:"LeaseState"`
LeaseDuration string `xml:"LeaseDuration"`
}
// ContainerListResponse contains the response fields from
// ListContainers call.
//
// See https://msdn.microsoft.com/en-us/library/azure/dd179352.aspx
type ContainerListResponse struct {
XMLName xml.Name `xml:"EnumerationResults"`
Xmlns string `xml:"xmlns,attr"`
Prefix string `xml:"Prefix"`
Marker string `xml:"Marker"`
NextMarker string `xml:"NextMarker"`
MaxResults int64 `xml:"MaxResults"`
Containers []Container `xml:"Containers>Container"`
}
// BlobListResponse contains the response fields from ListBlobs call.
//
// See https://msdn.microsoft.com/en-us/library/azure/dd135734.aspx
type BlobListResponse struct {
XMLName xml.Name `xml:"EnumerationResults"`
Xmlns string `xml:"xmlns,attr"`
Prefix string `xml:"Prefix"`
Marker string `xml:"Marker"`
NextMarker string `xml:"NextMarker"`
MaxResults int64 `xml:"MaxResults"`
Blobs []Blob `xml:"Blobs>Blob"`
// BlobPrefix is used to traverse blobs as if it were a file system.
// It is returned if ListBlobsParameters.Delimiter is specified.
// The list here can be thought of as "folders" that may contain
// other folders or blobs.
BlobPrefixes []string `xml:"Blobs>BlobPrefix>Name"`
// Delimiter is used to traverse blobs as if it were a file system.
// It is returned if ListBlobsParameters.Delimiter is specified.
Delimiter string `xml:"Delimiter"`
}
// ListBlobsParameters defines the set of customizable
// parameters to make a List Blobs call.
//
// See https://msdn.microsoft.com/en-us/library/azure/dd135734.aspx
type ListBlobsParameters struct {
Prefix string
Delimiter string
Marker string
Include string
MaxResults uint
Timeout uint
}
func (p ListBlobsParameters) getParameters() url.Values {
out := url.Values{}
if p.Prefix != "" {
out.Set("prefix", p.Prefix)
}
if p.Delimiter != "" {
out.Set("delimiter", p.Delimiter)
}
if p.Marker != "" {
out.Set("marker", p.Marker)
}
if p.Include != "" {
out.Set("include", p.Include)
}
if p.MaxResults != 0 {
out.Set("maxresults", fmt.Sprintf("%v", p.MaxResults))
}
if p.Timeout != 0 {
out.Set("timeout", fmt.Sprintf("%v", p.Timeout))
}
return out
}
// ContainerAccessType defines the access level to the container from a public
// request.
//
// See https://msdn.microsoft.com/en-us/library/azure/dd179468.aspx and "x-ms-
// blob-public-access" header.
type ContainerAccessType string
// Access options for containers
const (
ContainerAccessTypePrivate ContainerAccessType = ""
ContainerAccessTypeBlob ContainerAccessType = "blob"
ContainerAccessTypeContainer ContainerAccessType = "container"
)
// ContainerAccessPolicy represents each access policy in the container ACL.
type ContainerAccessPolicy struct {
ID string
StartTime time.Time
ExpiryTime time.Time
CanRead bool
CanWrite bool
CanDelete bool
}
// ContainerPermissions represents the container ACLs.
type ContainerPermissions struct {
AccessType ContainerAccessType
AccessPolicies []ContainerAccessPolicy
}
// ContainerAccessHeader references header used when setting/getting container ACL
const (
ContainerAccessHeader string = "x-ms-blob-public-access"
)
// Create creates a blob container within the storage account
// with given name and access level. Returns error if container already exists.
//
// See https://msdn.microsoft.com/en-us/library/azure/dd179468.aspx
func (c *Container) Create() error {
resp, err := c.create()
if err != nil {
return err
}
defer readAndCloseBody(resp.body)
return checkRespCode(resp.statusCode, []int{http.StatusCreated})
}
// CreateIfNotExists creates a blob container if it does not exist. Returns
// true if container is newly created or false if container already exists.
func (c *Container) CreateIfNotExists() (bool, error) {
resp, err := c.create()
if resp != nil {
defer readAndCloseBody(resp.body)
if resp.statusCode == http.StatusCreated || resp.statusCode == http.StatusConflict {
return resp.statusCode == http.StatusCreated, nil
}
}
return false, err
}
func (c *Container) create() (*storageResponse, error) {
uri := c.bsc.client.getEndpoint(blobServiceName, c.buildPath(), url.Values{"restype": {"container"}})
headers := c.bsc.client.getStandardHeaders()
return c.bsc.client.exec(http.MethodPut, uri, headers, nil, c.bsc.auth)
}
// Exists returns true if a container with given name exists
// on the storage account, otherwise returns false.
func (c *Container) Exists() (bool, error) {
uri := c.bsc.client.getEndpoint(blobServiceName, c.buildPath(), url.Values{"restype": {"container"}})
headers := c.bsc.client.getStandardHeaders()
resp, err := c.bsc.client.exec(http.MethodHead, uri, headers, nil, c.bsc.auth)
if resp != nil {
defer readAndCloseBody(resp.body)
if resp.statusCode == http.StatusOK || resp.statusCode == http.StatusNotFound {
return resp.statusCode == http.StatusOK, nil
}
}
return false, err
}
// SetPermissions sets up container permissions as per https://msdn.microsoft.com/en-us/library/azure/dd179391.aspx
func (c *Container) SetPermissions(permissions ContainerPermissions, timeout int, leaseID string) error {
params := url.Values{
"restype": {"container"},
"comp": {"acl"},
}
if timeout > 0 {
params.Add("timeout", strconv.Itoa(timeout))
}
uri := c.bsc.client.getEndpoint(blobServiceName, c.buildPath(), params)
headers := c.bsc.client.getStandardHeaders()
if permissions.AccessType != "" {
headers[ContainerAccessHeader] = string(permissions.AccessType)
}
if leaseID != "" {
headers[headerLeaseID] = leaseID
}
body, length, err := generateContainerACLpayload(permissions.AccessPolicies)
headers["Content-Length"] = strconv.Itoa(length)
resp, err := c.bsc.client.exec(http.MethodPut, uri, headers, body, c.bsc.auth)
if err != nil {
return err
}
defer readAndCloseBody(resp.body)
if err := checkRespCode(resp.statusCode, []int{http.StatusOK}); err != nil {
return errors.New("Unable to set permissions")
}
return nil
}
// GetPermissions gets the container permissions as per https://msdn.microsoft.com/en-us/library/azure/dd179469.aspx
// If timeout is 0 then it will not be passed to Azure
// leaseID will only be passed to Azure if populated
func (c *Container) GetPermissions(timeout int, leaseID string) (*ContainerPermissions, error) {
params := url.Values{
"restype": {"container"},
"comp": {"acl"},
}
if timeout > 0 {
params.Add("timeout", strconv.Itoa(timeout))
}
uri := c.bsc.client.getEndpoint(blobServiceName, c.buildPath(), params)
headers := c.bsc.client.getStandardHeaders()
if leaseID != "" {
headers[headerLeaseID] = leaseID
}
resp, err := c.bsc.client.exec(http.MethodGet, uri, headers, nil, c.bsc.auth)
if err != nil {
return nil, err
}
defer resp.body.Close()
var ap AccessPolicy
err = xmlUnmarshal(resp.body, &ap.SignedIdentifiersList)
if err != nil {
return nil, err
}
return buildAccessPolicy(ap, &resp.headers), nil
}
func buildAccessPolicy(ap AccessPolicy, headers *http.Header) *ContainerPermissions {
// containerAccess. Blob, Container, empty
containerAccess := headers.Get(http.CanonicalHeaderKey(ContainerAccessHeader))
permissions := ContainerPermissions{
AccessType: ContainerAccessType(containerAccess),
AccessPolicies: []ContainerAccessPolicy{},
}
for _, policy := range ap.SignedIdentifiersList.SignedIdentifiers {
capd := ContainerAccessPolicy{
ID: policy.ID,
StartTime: policy.AccessPolicy.StartTime,
ExpiryTime: policy.AccessPolicy.ExpiryTime,
}
capd.CanRead = updatePermissions(policy.AccessPolicy.Permission, "r")
capd.CanWrite = updatePermissions(policy.AccessPolicy.Permission, "w")
capd.CanDelete = updatePermissions(policy.AccessPolicy.Permission, "d")
permissions.AccessPolicies = append(permissions.AccessPolicies, capd)
}
return &permissions
}
// Delete deletes the container with given name on the storage
// account. If the container does not exist returns error.
//
// See https://msdn.microsoft.com/en-us/library/azure/dd179408.aspx
func (c *Container) Delete() error {
resp, err := c.delete()
if err != nil {
return err
}
defer readAndCloseBody(resp.body)
return checkRespCode(resp.statusCode, []int{http.StatusAccepted})
}
// DeleteIfExists deletes the container with given name on the storage
// account if it exists. Returns true if container is deleted with this call, or
// false if the container did not exist at the time of the Delete Container
// operation.
//
// See https://msdn.microsoft.com/en-us/library/azure/dd179408.aspx
func (c *Container) DeleteIfExists() (bool, error) {
resp, err := c.delete()
if resp != nil {
defer readAndCloseBody(resp.body)
if resp.statusCode == http.StatusAccepted || resp.statusCode == http.StatusNotFound {
return resp.statusCode == http.StatusAccepted, nil
}
}
return false, err
}
func (c *Container) delete() (*storageResponse, error) {
uri := c.bsc.client.getEndpoint(blobServiceName, c.buildPath(), url.Values{"restype": {"container"}})
headers := c.bsc.client.getStandardHeaders()
return c.bsc.client.exec(http.MethodDelete, uri, headers, nil, c.bsc.auth)
}
// ListBlobs returns an object that contains list of blobs in the container,
// pagination token and other information in the response of List Blobs call.
//
// See https://msdn.microsoft.com/en-us/library/azure/dd135734.aspx
func (c *Container) ListBlobs(params ListBlobsParameters) (BlobListResponse, error) {
q := mergeParams(params.getParameters(), url.Values{
"restype": {"container"},
"comp": {"list"}},
)
uri := c.bsc.client.getEndpoint(blobServiceName, c.buildPath(), q)
headers := c.bsc.client.getStandardHeaders()
var out BlobListResponse
resp, err := c.bsc.client.exec(http.MethodGet, uri, headers, nil, c.bsc.auth)
if err != nil {
return out, err
}
defer resp.body.Close()
err = xmlUnmarshal(resp.body, &out)
return out, err
}
func generateContainerACLpayload(policies []ContainerAccessPolicy) (io.Reader, int, error) {
sil := SignedIdentifiers{
SignedIdentifiers: []SignedIdentifier{},
}
for _, capd := range policies {
permission := capd.generateContainerPermissions()
signedIdentifier := convertAccessPolicyToXMLStructs(capd.ID, capd.StartTime, capd.ExpiryTime, permission)
sil.SignedIdentifiers = append(sil.SignedIdentifiers, signedIdentifier)
}
return xmlMarshal(sil)
}
func (capd *ContainerAccessPolicy) generateContainerPermissions() (permissions string) {
// generate the permissions string (rwd).
// still want the end user API to have bool flags.
permissions = ""
if capd.CanRead {
permissions += "r"
}
if capd.CanWrite {
permissions += "w"
}
if capd.CanDelete {
permissions += "d"
}
return permissions
}
