Nick Craig-Wood 4824837eed azureblob: allow anonymous access for public resources

See: https://forum.rclone.org/t/azure-blob-public-resources/46882

2024-07-18 11:13:29 +01:00

27 KiB

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title	description	versionIntroduced
Microsoft Azure Blob Storage	Rclone docs for Microsoft Azure Blob Storage	v1.38

{{< icon "fab fa-windows" >}} Microsoft Azure Blob Storage

Paths are specified as remote:container (or remote: for the lsd command.) You may put subdirectories in too, e.g. remote:container/path/to/dir.

Configuration

Here is an example of making a Microsoft Azure Blob Storage configuration. For a remote called remote. First run:

 rclone config

This will guide you through an interactive setup process:

No remotes found, make a new one?
n) New remote
s) Set configuration password
q) Quit config
n/s/q> n
name> remote
Type of storage to configure.
Choose a number from below, or type in your own value
[snip]
XX / Microsoft Azure Blob Storage
   \ "azureblob"
[snip]
Storage> azureblob
Storage Account Name
account> account_name
Storage Account Key
key> base64encodedkey==
Endpoint for the service - leave blank normally.
endpoint> 
Remote config
--------------------
[remote]
account = account_name
key = base64encodedkey==
endpoint = 
--------------------
y) Yes this is OK
e) Edit this remote
d) Delete this remote
y/e/d> y

See all containers

rclone lsd remote:

Make a new container

rclone mkdir remote:container

List the contents of a container

rclone ls remote:container

Sync /home/local/directory to the remote container, deleting any excess files in the container.

rclone sync --interactive /home/local/directory remote:container

--fast-list

This remote supports --fast-list which allows you to use fewer transactions in exchange for more memory. See the rclone docs for more details.

Modification times and hashes

The modification time is stored as metadata on the object with the mtime key. It is stored using RFC3339 Format time with nanosecond precision. The metadata is supplied during directory listings so there is no performance overhead to using it.

If you wish to use the Azure standard LastModified time stored on the object as the modified time, then use the --use-server-modtime flag. Note that rclone can't set LastModified, so using the --update flag when syncing is recommended if using --use-server-modtime.

MD5 hashes are stored with blobs. However blobs that were uploaded in chunks only have an MD5 if the source remote was capable of MD5 hashes, e.g. the local disk.

Performance

When uploading large files, increasing the value of --azureblob-upload-concurrency will increase performance at the cost of using more memory. The default of 16 is set quite conservatively to use less memory. It maybe be necessary raise it to 64 or higher to fully utilize a 1 GBit/s link with a single file transfer.

Restricted filename characters

In addition to the default restricted characters set the following characters are also replaced:

Character	Value	Replacement
/	0x2F	／
\	0x5C	＼

File names can also not end with the following characters. These only get replaced if they are the last character in the name:

Character	Value	Replacement
.	0x2E	．

Invalid UTF-8 bytes will also be replaced, as they can't be used in JSON strings.

Authentication

There are a number of ways of supplying credentials for Azure Blob Storage. Rclone tries them in the order of the sections below.

Env Auth

If the env_auth config parameter is true then rclone will pull credentials from the environment or runtime.

It tries these authentication methods in this order:

Environment Variables
Managed Service Identity Credentials
Azure CLI credentials (as used by the az tool)

These are described in the following sections

Env Auth: 1. Environment Variables

If env_auth is set and environment variables are present rclone authenticates a service principal with a secret or certificate, or a user with a password, depending on which environment variable are set. It reads configuration from these variables, in the following order:

Service principal with client secret
- AZURE_TENANT_ID: ID of the service principal's tenant. Also called its "directory" ID.
- AZURE_CLIENT_ID: the service principal's client ID
- AZURE_CLIENT_SECRET: one of the service principal's client secrets
Service principal with certificate
- AZURE_TENANT_ID: ID of the service principal's tenant. Also called its "directory" ID.
- AZURE_CLIENT_ID: the service principal's client ID
- AZURE_CLIENT_CERTIFICATE_PATH: path to a PEM or PKCS12 certificate file including the private key.
- AZURE_CLIENT_CERTIFICATE_PASSWORD: (optional) password for the certificate file.
- AZURE_CLIENT_SEND_CERTIFICATE_CHAIN: (optional) Specifies whether an authentication request will include an x5c header to support subject name / issuer based authentication. When set to "true" or "1", authentication requests include the x5c header.
User with username and password
- AZURE_TENANT_ID: (optional) tenant to authenticate in. Defaults to "organizations".
- AZURE_CLIENT_ID: client ID of the application the user will authenticate to
- AZURE_USERNAME: a username (usually an email address)
- AZURE_PASSWORD: the user's password
Workload Identity
- AZURE_TENANT_ID: Tenant to authenticate in.
- AZURE_CLIENT_ID: Client ID of the application the user will authenticate to.
- AZURE_FEDERATED_TOKEN_FILE: Path to projected service account token file.
- AZURE_AUTHORITY_HOST: Authority of an Azure Active Directory endpoint (default: login.microsoftonline.com).

Env Auth: 2. Managed Service Identity Credentials

When using Managed Service Identity if the VM(SS) on which this program is running has a system-assigned identity, it will be used by default. If the resource has no system-assigned but exactly one user-assigned identity, the user-assigned identity will be used by default.

If the resource has multiple user-assigned identities you will need to unset env_auth and set use_msi instead. See the use_msi section.

Env Auth: 3. Azure CLI credentials (as used by the az tool)

Credentials created with the az tool can be picked up using env_auth.

For example if you were to login with a service principal like this:

az login --service-principal -u XXX -p XXX --tenant XXX

Then you could access rclone resources like this:

rclone lsf :azureblob,env_auth,account=ACCOUNT:CONTAINER

rclone lsf --azureblob-env-auth --azureblob-account=ACCOUNT :azureblob:CONTAINER

Which is analogous to using the az tool:

az storage blob list --container-name CONTAINER --account-name ACCOUNT --auth-mode login

Account and Shared Key

This is the most straight forward and least flexible way. Just fill in the account and key lines and leave the rest blank.

SAS URL

This can be an account level SAS URL or container level SAS URL.

To use it leave account and key blank and fill in sas_url.

An account level SAS URL or container level SAS URL can be obtained from the Azure portal or the Azure Storage Explorer. To get a container level SAS URL right click on a container in the Azure Blob explorer in the Azure portal.

If you use a container level SAS URL, rclone operations are permitted only on a particular container, e.g.

rclone ls azureblob:container

You can also list the single container from the root. This will only show the container specified by the SAS URL.

$ rclone lsd azureblob:
container/

Note that you can't see or access any other containers - this will fail

rclone ls azureblob:othercontainer

Container level SAS URLs are useful for temporarily allowing third parties access to a single container or putting credentials into an untrusted environment such as a CI build server.

Service principal with client secret

If these variables are set, rclone will authenticate with a service principal with a client secret.

tenant: ID of the service principal's tenant. Also called its "directory" ID.
client_id: the service principal's client ID
client_secret: one of the service principal's client secrets

The credentials can also be placed in a file using the service_principal_file configuration option.

Service principal with certificate

If these variables are set, rclone will authenticate with a service principal with certificate.

tenant: ID of the service principal's tenant. Also called its "directory" ID.
client_id: the service principal's client ID
client_certificate_path: path to a PEM or PKCS12 certificate file including the private key.
client_certificate_password: (optional) password for the certificate file.
client_send_certificate_chain: (optional) Specifies whether an authentication request will include an x5c header to support subject name / issuer based authentication. When set to "true" or "1", authentication requests include the x5c header.

NB client_certificate_password must be obscured - see rclone obscure.

User with username and password

If these variables are set, rclone will authenticate with username and password.

tenant: (optional) tenant to authenticate in. Defaults to "organizations".
client_id: client ID of the application the user will authenticate to
username: a username (usually an email address)
password: the user's password

Microsoft doesn't recommend this kind of authentication, because it's less secure than other authentication flows. This method is not interactive, so it isn't compatible with any form of multi-factor authentication, and the application must already have user or admin consent. This credential can only authenticate work and school accounts; it can't authenticate Microsoft accounts.

NB password must be obscured - see rclone obscure.

Managed Service Identity Credentials

If use_msi is set then managed service identity credentials are used. This authentication only works when running in an Azure service. env_auth needs to be unset to use this.

However if you have multiple user identities to choose from these must be explicitly specified using exactly one of the msi_object_id, msi_client_id, or msi_mi_res_id parameters.

If none of msi_object_id, msi_client_id, or msi_mi_res_id is set, this is is equivalent to using env_auth.

Anonymous

If you want to access resources with public anonymous access then set account only. You can do this without making an rclone config:

rclone lsf :azureblob,account=ACCOUNT:CONTAINER

{{< rem autogenerated options start" - DO NOT EDIT - instead edit fs.RegInfo in backend/azureblob/azureblob.go then run make backenddocs" >}}

Standard options

Here are the Standard options specific to azureblob (Microsoft Azure Blob Storage).

--azureblob-account

Azure Storage Account Name.

Set this to the Azure Storage Account Name in use.

Leave blank to use SAS URL or Emulator, otherwise it needs to be set.

If this is blank and if env_auth is set it will be read from the environment variable AZURE_STORAGE_ACCOUNT_NAME if possible.

Properties:

Config: account
Env Var: RCLONE_AZUREBLOB_ACCOUNT
Type: string
Required: false

--azureblob-env-auth

Read credentials from runtime (environment variables, CLI or MSI).

See the authentication docs for full info.

Properties:

Config: env_auth
Env Var: RCLONE_AZUREBLOB_ENV_AUTH
Type: bool
Default: false

--azureblob-key

Storage Account Shared Key.

Leave blank to use SAS URL or Emulator.

Properties:

Config: key
Env Var: RCLONE_AZUREBLOB_KEY
Type: string
Required: false

--azureblob-sas-url

SAS URL for container level access only.

Leave blank if using account/key or Emulator.

Properties:

Config: sas_url
Env Var: RCLONE_AZUREBLOB_SAS_URL
Type: string
Required: false

--azureblob-tenant

ID of the service principal's tenant. Also called its directory ID.

Set this if using

Service principal with client secret
Service principal with certificate
User with username and password

Properties:

Config: tenant
Env Var: RCLONE_AZUREBLOB_TENANT
Type: string
Required: false

--azureblob-client-id

The ID of the client in use.

Set this if using

Service principal with client secret
Service principal with certificate
User with username and password

Properties:

Config: client_id
Env Var: RCLONE_AZUREBLOB_CLIENT_ID
Type: string
Required: false

--azureblob-client-secret

One of the service principal's client secrets

Set this if using

Service principal with client secret

Properties:

Config: client_secret
Env Var: RCLONE_AZUREBLOB_CLIENT_SECRET
Type: string
Required: false

--azureblob-client-certificate-path

Path to a PEM or PKCS12 certificate file including the private key.

Set this if using

Service principal with certificate

Properties:

Config: client_certificate_path
Env Var: RCLONE_AZUREBLOB_CLIENT_CERTIFICATE_PATH
Type: string
Required: false

--azureblob-client-certificate-password

Password for the certificate file (optional).

Optionally set this if using

Service principal with certificate

And the certificate has a password.

NB Input to this must be obscured - see rclone obscure.

Properties:

Config: client_certificate_password
Env Var: RCLONE_AZUREBLOB_CLIENT_CERTIFICATE_PASSWORD
Type: string
Required: false

Advanced options

Here are the Advanced options specific to azureblob (Microsoft Azure Blob Storage).

--azureblob-client-send-certificate-chain

Send the certificate chain when using certificate auth.

Specifies whether an authentication request will include an x5c header to support subject name / issuer based authentication. When set to true, authentication requests include the x5c header.

Optionally set this if using

Service principal with certificate

Properties:

Config: client_send_certificate_chain
Env Var: RCLONE_AZUREBLOB_CLIENT_SEND_CERTIFICATE_CHAIN
Type: bool
Default: false

--azureblob-username

User name (usually an email address)

Set this if using

User with username and password

Properties:

Config: username
Env Var: RCLONE_AZUREBLOB_USERNAME
Type: string
Required: false

--azureblob-password

The user's password

Set this if using

User with username and password

NB Input to this must be obscured - see rclone obscure.

Properties:

Config: password
Env Var: RCLONE_AZUREBLOB_PASSWORD
Type: string
Required: false

--azureblob-service-principal-file

Path to file containing credentials for use with a service principal.

Leave blank normally. Needed only if you want to use a service principal instead of interactive login.

$ az ad sp create-for-rbac --name "<name>" \
  --role "Storage Blob Data Owner" \
  --scopes "/subscriptions/<subscription>/resourceGroups/<resource-group>/providers/Microsoft.Storage/storageAccounts/<storage-account>/blobServices/default/containers/<container>" \
  > azure-principal.json

See "Create an Azure service principal" and "Assign an Azure role for access to blob data" pages for more details.

It may be more convenient to put the credentials directly into the rclone config file under the client_id, tenant and client_secret keys instead of setting service_principal_file.

Properties:

Config: service_principal_file
Env Var: RCLONE_AZUREBLOB_SERVICE_PRINCIPAL_FILE
Type: string
Required: false

--azureblob-use-msi

Use a managed service identity to authenticate (only works in Azure).

When true, use a managed service identity to authenticate to Azure Storage instead of a SAS token or account key.

If the VM(SS) on which this program is running has a system-assigned identity, it will be used by default. If the resource has no system-assigned but exactly one user-assigned identity, the user-assigned identity will be used by default. If the resource has multiple user-assigned identities, the identity to use must be explicitly specified using exactly one of the msi_object_id, msi_client_id, or msi_mi_res_id parameters.

Properties:

Config: use_msi
Env Var: RCLONE_AZUREBLOB_USE_MSI
Type: bool
Default: false

--azureblob-msi-object-id

Object ID of the user-assigned MSI to use, if any.

Leave blank if msi_client_id or msi_mi_res_id specified.

Properties:

Config: msi_object_id
Env Var: RCLONE_AZUREBLOB_MSI_OBJECT_ID
Type: string
Required: false

--azureblob-msi-client-id

Object ID of the user-assigned MSI to use, if any.

Leave blank if msi_object_id or msi_mi_res_id specified.

Properties:

Config: msi_client_id
Env Var: RCLONE_AZUREBLOB_MSI_CLIENT_ID
Type: string
Required: false

--azureblob-msi-mi-res-id

Azure resource ID of the user-assigned MSI to use, if any.

Leave blank if msi_client_id or msi_object_id specified.

Properties:

Config: msi_mi_res_id
Env Var: RCLONE_AZUREBLOB_MSI_MI_RES_ID
Type: string
Required: false

--azureblob-use-emulator

Uses local storage emulator if provided as 'true'.

Leave blank if using real azure storage endpoint.

Properties:

Config: use_emulator
Env Var: RCLONE_AZUREBLOB_USE_EMULATOR
Type: bool
Default: false

--azureblob-endpoint

Endpoint for the service.

Leave blank normally.

Properties:

Config: endpoint
Env Var: RCLONE_AZUREBLOB_ENDPOINT
Type: string
Required: false

--azureblob-upload-cutoff

Cutoff for switching to chunked upload (<= 256 MiB) (deprecated).

Properties:

Config: upload_cutoff
Env Var: RCLONE_AZUREBLOB_UPLOAD_CUTOFF
Type: string
Required: false

--azureblob-chunk-size

Upload chunk size.

Note that this is stored in memory and there may be up to "--transfers" * "--azureblob-upload-concurrency" chunks stored at once in memory.

Properties:

Config: chunk_size
Env Var: RCLONE_AZUREBLOB_CHUNK_SIZE
Type: SizeSuffix
Default: 4Mi

--azureblob-upload-concurrency

Concurrency for multipart uploads.

This is the number of chunks of the same file that are uploaded concurrently.

If you are uploading small numbers of large files over high-speed links and these uploads do not fully utilize your bandwidth, then increasing this may help to speed up the transfers.

In tests, upload speed increases almost linearly with upload concurrency. For example to fill a gigabit pipe it may be necessary to raise this to 64. Note that this will use more memory.

Note that chunks are stored in memory and there may be up to "--transfers" * "--azureblob-upload-concurrency" chunks stored at once in memory.

Properties:

Config: upload_concurrency
Env Var: RCLONE_AZUREBLOB_UPLOAD_CONCURRENCY
Type: int
Default: 16

--azureblob-list-chunk

Size of blob list.

This sets the number of blobs requested in each listing chunk. Default is the maximum, 5000. "List blobs" requests are permitted 2 minutes per megabyte to complete. If an operation is taking longer than 2 minutes per megabyte on average, it will time out ( source ). This can be used to limit the number of blobs items to return, to avoid the time out.

Properties:

Config: list_chunk
Env Var: RCLONE_AZUREBLOB_LIST_CHUNK
Type: int
Default: 5000

--azureblob-access-tier

Access tier of blob: hot, cool, cold or archive.

Archived blobs can be restored by setting access tier to hot, cool or cold. Leave blank if you intend to use default access tier, which is set at account level

If there is no "access tier" specified, rclone doesn't apply any tier. rclone performs "Set Tier" operation on blobs while uploading, if objects are not modified, specifying "access tier" to new one will have no effect. If blobs are in "archive tier" at remote, trying to perform data transfer operations from remote will not be allowed. User should first restore by tiering blob to "Hot", "Cool" or "Cold".

Properties:

Config: access_tier
Env Var: RCLONE_AZUREBLOB_ACCESS_TIER
Type: string
Required: false

--azureblob-archive-tier-delete

Delete archive tier blobs before overwriting.

Archive tier blobs cannot be updated. So without this flag, if you attempt to update an archive tier blob, then rclone will produce the error:

can't update archive tier blob without --azureblob-archive-tier-delete

With this flag set then before rclone attempts to overwrite an archive tier blob, it will delete the existing blob before uploading its replacement. This has the potential for data loss if the upload fails (unlike updating a normal blob) and also may cost more since deleting archive tier blobs early may be chargable.

Properties:

Config: archive_tier_delete
Env Var: RCLONE_AZUREBLOB_ARCHIVE_TIER_DELETE
Type: bool
Default: false

--azureblob-disable-checksum

Don't store MD5 checksum with object metadata.

Normally rclone will calculate the MD5 checksum of the input before uploading it so it can add it to metadata on the object. This is great for data integrity checking but can cause long delays for large files to start uploading.

Properties:

Config: disable_checksum
Env Var: RCLONE_AZUREBLOB_DISABLE_CHECKSUM
Type: bool
Default: false

--azureblob-memory-pool-flush-time

How often internal memory buffer pools will be flushed. (no longer used)

Properties:

Config: memory_pool_flush_time
Env Var: RCLONE_AZUREBLOB_MEMORY_POOL_FLUSH_TIME
Type: Duration
Default: 1m0s

--azureblob-memory-pool-use-mmap

Whether to use mmap buffers in internal memory pool. (no longer used)

Properties:

Config: memory_pool_use_mmap
Env Var: RCLONE_AZUREBLOB_MEMORY_POOL_USE_MMAP
Type: bool
Default: false

--azureblob-encoding

The encoding for the backend.

See the encoding section in the overview for more info.

Properties:

Config: encoding
Env Var: RCLONE_AZUREBLOB_ENCODING
Type: Encoding
Default: Slash,BackSlash,Del,Ctl,RightPeriod,InvalidUtf8

--azureblob-public-access

Public access level of a container: blob or container.

Properties:

Config: public_access
Env Var: RCLONE_AZUREBLOB_PUBLIC_ACCESS
Type: string
Required: false
Examples:
- ""
  - The container and its blobs can be accessed only with an authorized request.
  - It's a default value.
- "blob"
  - Blob data within this container can be read via anonymous request.
- "container"
  - Allow full public read access for container and blob data.

--azureblob-directory-markers

Upload an empty object with a trailing slash when a new directory is created

Empty folders are unsupported for bucket based remotes, this option creates an empty object ending with "/", to persist the folder.

This object also has the metadata "hdi_isfolder = true" to conform to the Microsoft standard.

Properties:

Config: directory_markers
Env Var: RCLONE_AZUREBLOB_DIRECTORY_MARKERS
Type: bool
Default: false

--azureblob-no-check-container

If set, don't attempt to check the container exists or create it.

This can be useful when trying to minimise the number of transactions rclone does if you know the container exists already.

Properties:

Config: no_check_container
Env Var: RCLONE_AZUREBLOB_NO_CHECK_CONTAINER
Type: bool
Default: false

--azureblob-no-head-object

If set, do not do HEAD before GET when getting objects.

Properties:

Config: no_head_object
Env Var: RCLONE_AZUREBLOB_NO_HEAD_OBJECT
Type: bool
Default: false

--azureblob-delete-snapshots

Set to specify how to deal with snapshots on blob deletion.

Properties:

Config: delete_snapshots
Env Var: RCLONE_AZUREBLOB_DELETE_SNAPSHOTS
Type: string
Required: false
Choices:
- ""
  - By default, the delete operation fails if a blob has snapshots
- "include"
  - Specify 'include' to remove the root blob and all its snapshots
- "only"
  - Specify 'only' to remove only the snapshots but keep the root blob.

--azureblob-description

Description of the remote.

Properties:

Config: description
Env Var: RCLONE_AZUREBLOB_DESCRIPTION
Type: string
Required: false

Custom upload headers

You can set custom upload headers with the --header-upload flag.

Cache-Control
Content-Disposition
Content-Encoding
Content-Language
Content-Type

Eg --header-upload "Content-Type: text/potato"

Limitations

MD5 sums are only uploaded with chunked files if the source has an MD5 sum. This will always be the case for a local to azure copy.

rclone about is not supported by the Microsoft Azure Blob storage backend. Backends without this capability cannot determine free space for an rclone mount or use policy mfs (most free space) as a member of an rclone union remote.

See List of backends that do not support rclone about and rclone about

Azure Storage Emulator Support

You can run rclone with the storage emulator (usually azurite).

To do this, just set up a new remote with rclone config following the instructions in the introduction and set use_emulator in the advanced settings as true. You do not need to provide a default account name nor an account key. But you can override them in the account and key options. (Prior to v1.61 they were hard coded to azurite's devstoreaccount1.)

Also, if you want to access a storage emulator instance running on a different machine, you can override the endpoint parameter in the advanced settings, setting it to http(s)://<host>:<port>/devstoreaccount1 (e.g. http://10.254.2.5:10000/devstoreaccount1).

27 KiB Raw Blame History

{{< icon "fab fa-windows" >}} Microsoft Azure Blob Storage

Configuration

--fast-list

Modification times and hashes

Performance

Restricted filename characters

Authentication

Env Auth

Env Auth: 1. Environment Variables

Env Auth: 2. Managed Service Identity Credentials

Env Auth: 3. Azure CLI credentials (as used by the az tool)

Account and Shared Key

SAS URL

Service principal with client secret

Service principal with certificate

User with username and password

Managed Service Identity Credentials

Anonymous

Standard options

--azureblob-account

--azureblob-env-auth

--azureblob-key

--azureblob-sas-url

--azureblob-tenant

--azureblob-client-id

--azureblob-client-secret

--azureblob-client-certificate-path

--azureblob-client-certificate-password

Advanced options

--azureblob-client-send-certificate-chain

--azureblob-username

--azureblob-password

--azureblob-service-principal-file

--azureblob-use-msi

--azureblob-msi-object-id

--azureblob-msi-client-id

--azureblob-msi-mi-res-id

--azureblob-use-emulator

--azureblob-endpoint

--azureblob-upload-cutoff

--azureblob-chunk-size

--azureblob-upload-concurrency

--azureblob-list-chunk

--azureblob-access-tier

--azureblob-archive-tier-delete

--azureblob-disable-checksum

--azureblob-memory-pool-flush-time

--azureblob-memory-pool-use-mmap

--azureblob-encoding

--azureblob-public-access

--azureblob-directory-markers

--azureblob-no-check-container

--azureblob-no-head-object

--azureblob-delete-snapshots

--azureblob-description

Custom upload headers

Limitations

Azure Storage Emulator Support

27 KiB

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