tahoe-lafs/docs/frontends/CLI.rst

The Tahoe-LAFS CLI commands

1. Overview
2. CLI Command Overview
   1. Unicode Support
3. Node Management
4. Filesystem Manipulation
   1. Starting Directories
   2. Command Syntax Summary
   3. Command Examples
5. Storage Grid Maintenance
6. Debugging

Overview

Tahoe-LAFS provides a single executable named "tahoe", which can be used to create and manage client/server nodes, manipulate the filesystem, and perform several debugging/maintenance tasks.

This executable lives in the source tree at "bin/tahoe". Once you've done a build (by running "make" or "python setup.py build"), bin/tahoe can be run in-place: if it discovers that it is being run from within a Tahoe-LAFS source tree, it will modify sys.path as necessary to use all the source code and dependent libraries contained in that tree.

If you've installed Tahoe-LAFS (using "make install" or "python setup.py install", or by installing a binary package), then the tahoe executable will be available somewhere else, perhaps in /usr/bin/tahoe. In this case, it will use your platform's normal PYTHONPATH search path to find the Tahoe-LAFS code and other libraries.

CLI Command Overview

The "tahoe" tool provides access to three categories of commands.

• node management: create a client/server node, start/stop/restart it
• filesystem manipulation: list files, upload, download, unlink, rename
• debugging: unpack cap-strings, examine share files

To get a list of all commands, just run "tahoe" with no additional arguments. "tahoe --help" might also provide something useful.

Running "tahoe --version" will display a list of version strings, starting with the "allmydata" module (which contains the majority of the Tahoe-LAFS functionality) and including versions for a number of dependent libraries, like Twisted, Foolscap, pycryptopp, and zfec. "tahoe --version-and-path" will also show the path from which each library was imported.

On Unix systems, the shell expands filename wildcards ('*' and '?') before the program is able to read them, which may produce unexpected results for many tahoe comands. We recommend, if you use wildcards, to start the path with "./", for example "tahoe cp -r ./* somewhere:". This prevents the expanded filename from being interpreted as an option or as an alias, allowing filenames that start with a dash or contain colons to be handled correctly.

On Windows, a single letter followed by a colon is treated as a drive specification rather than an alias (and is invalid unless a local path is allowed in that context). Wildcards cannot be used to specify multiple filenames to tahoe on Windows.

Unicode Support

As of Tahoe-LAFS v1.7.0 (v1.8.0 on Windows), the tahoe tool supports non-ASCII characters in command lines and output. On Unix, the command-line arguments are assumed to use the character encoding specified by the current locale (usually given by the LANG environment variable).

If a name to be output contains control characters or characters that cannot be represented in the encoding used on your terminal, it will be quoted. The quoting scheme used is similar to POSIX shell quoting: in a "double-quoted" string, backslashes introduce escape sequences (like those in Python strings), but in a 'single-quoted' string all characters stand for themselves. This quoting is only used for output, on all operating systems. Your shell interprets any quoting or escapes used on the command line.

Node Management

"tahoe create-node [NODEDIR]" is the basic make-a-new-node command. It creates a new directory and populates it with files that will allow the "tahoe start" command to use it later on. This command creates nodes that have client functionality (upload/download files), web API services (controlled by the '[node]web.port' configuration), and storage services (unless --no-storage is specified).

NODEDIR defaults to ~/.tahoe/ , and newly-created nodes default to publishing a web server on port 3456 (limited to the loopback interface, at 127.0.0.1, to restrict access to other programs on the same host). All of the other "tahoe" subcommands use corresponding defaults (with the exception that "tahoe run" defaults to running a node in the current directory).

"tahoe create-client [NODEDIR]" creates a node with no storage service. That is, it behaves like "tahoe create-node --no-storage [NODEDIR]". (This is a change from versions prior to v1.6.0.)

"tahoe create-introducer [NODEDIR]" is used to create the Introducer node. This node provides introduction services and nothing else. When started, this node will produce a private/introducer.furl file, which should be published to all clients.

"tahoe create-key-generator [NODEDIR]" is used to create a special "key-generation" service, which allows a client to offload their RSA key generation to a separate process. Since RSA key generation takes several seconds, and must be done each time a directory is created, moving it to a separate process allows the first process (perhaps a busy web-API server) to continue servicing other requests. The key generator exports a FURL that can be copied into a node to enable this functionality.

"tahoe run [NODEDIR]" will start a previously-created node in the foreground.

"tahoe start [NODEDIR]" will launch a previously-created node. It will launch the node into the background, using the standard Twisted "twistd" daemon-launching tool. On some platforms (including Windows) this command is unable to run a daemon in the background; in that case it behaves in the same way as "tahoe run".

"tahoe stop [NODEDIR]" will shut down a running node.

"tahoe restart [NODEDIR]" will stop and then restart a running node. This is most often used by developers who have just modified the code and want to start using their changes.

Filesystem Manipulation

These commands let you exmaine a Tahoe-LAFS filesystem, providing basic list/upload/download/unlink/rename/mkdir functionality. They can be used as primitives by other scripts. Most of these commands are fairly thin wrappers around web-API calls, which are described in webapi.rst.

By default, all filesystem-manipulation commands look in ~/.tahoe/ to figure out which Tahoe-LAFS node they should use. When the CLI command makes web-API calls, it will use ~/.tahoe/node.url for this purpose: a running Tahoe-LAFS node that provides a web-API port will write its URL into this file. If you want to use a node on some other host, just create ~/.tahoe/ and copy that node's web-API URL into this file, and the CLI commands will contact that node instead of a local one.

These commands also use a table of "aliases" to figure out which directory they ought to use a starting point. This is explained in more detail below.

Starting Directories

As described in docs/architecture.rst, the Tahoe-LAFS distributed filesystem consists of a collection of directories and files, each of which has a "read-cap" or a "write-cap" (also known as a URI). Each directory is simply a table that maps a name to a child file or directory, and this table is turned into a string and stored in a mutable file. The whole set of directory and file "nodes" are connected together into a directed graph.

To use this collection of files and directories, you need to choose a starting point: some specific directory that we will refer to as a "starting directory". For a given starting directory, the "ls [STARTING_DIR]" command would list the contents of this directory, the "ls [STARTING_DIR]/dir1" command would look inside this directory for a child named "dir1" and list its contents, "ls [STARTING_DIR]/dir1/subdir2" would look two levels deep, etc.

Note that there is no real global "root" directory, but instead each starting directory provides a different, possibly overlapping perspective on the graph of files and directories.

Each Tahoe-LAFS node remembers a list of starting points, called "aliases", which are short Unicode strings that stand in for a directory read- or write- cap. They are stored (encoded as UTF-8) in the file NODEDIR/private/aliases . If you use the command line "tahoe ls" without any "[STARTING_DIR]" argument, then it will use the default alias, which is tahoe:, therefore "tahoe ls" has the same effect as "tahoe ls tahoe:". The same goes for the other commands that can reasonably use a default alias: get, put, mkdir, mv, and rm.

For backwards compatibility with Tahoe-LAFS v1.0, if the tahoe: alias is not found in ~/.tahoe/private/aliases, the CLI will use the contents of ~/.tahoe/private/root_dir.cap instead. Tahoe-LAFS v1.0 had only a single starting point, and stored it in this root_dir.cap file, so v1.1 and later will use it if necessary. However, once you've set a tahoe: alias with "tahoe set-alias", that will override anything in the old root_dir.cap file.

The Tahoe-LAFS CLI commands use the same path syntax as scp and rsync -- an optional ALIAS: prefix, followed by the pathname or filename. Some commands (like "tahoe cp") use the lack of an alias to mean that you want to refer to a local file, instead of something from the Tahoe-LAFS filesystem. [TODO] Another way to indicate this is to start the pathname with a dot, slash, or tilde.

When you're dealing a single starting directory, the tahoe: alias is all you need. But when you want to refer to something that isn't yet attached to the graph rooted at that starting directory, you need to refer to it by its capability. The way to do that is either to use its capability directory as an argument on the command line, or to add an alias to it, with the "tahoe add-alias" command. Once you've added an alias, you can use that alias as an argument to commands.

The best way to get started with Tahoe-LAFS is to create a node, start it, then use the following command to create a new directory and set it as your tahoe: alias:

tahoe create-alias tahoe

After that you can use "tahoe ls tahoe:" and "tahoe cp local.txt tahoe:", and both will refer to the directory that you've just created.

SECURITY NOTE: For users of shared systems

Another way to achieve the same effect as the above "tahoe create-alias" command is:

tahoe add-alias tahoe `tahoe mkdir`

However, command-line arguments are visible to other users (through the ps command or /proc filesystem, or the Windows Process Explorer tool), so if you are using a Tahoe-LAFS node on a shared host, your login neighbors will be able to see (and capture) any directory caps that you set up with the "tahoe add-alias" command.

The "tahoe create-alias" command avoids this problem by creating a new directory and putting the cap into your aliases file for you. Alternatively, you can edit the NODEDIR/private/aliases file directly, by adding a line like this:

fun: URI:DIR2:ovjy4yhylqlfoqg2vcze36dhde:4d4f47qko2xm5g7osgo2yyidi5m4muyo2vjjy53q4vjju2u55mfa

By entering the dircap through the editor, the command-line arguments are bypassed, and other users will not be able to see them. Once you've added the alias, no other secrets are passed through the command line, so this vulnerability becomes less significant: they can still see your filenames and other arguments you type there, but not the caps that Tahoe-LAFS uses to permit access to your files and directories.

Command Syntax Summary

tahoe add-alias ALIAS[:] DIRCAP

tahoe create-alias ALIAS[:]

tahoe list-aliases

tahoe mkdir

tahoe mkdir PATH

tahoe ls [PATH]

tahoe webopen [PATH]

tahoe put [--mutable] [FROMLOCAL|-]

tahoe put [--mutable] FROMLOCAL|- TOPATH

tahoe put [FROMLOCAL|-] mutable-file-writecap

tahoe get FROMPATH [TOLOCAL|-]

tahoe cp [-r] FROMPATH TOPATH

tahoe rm PATH

tahoe mv FROMPATH TOPATH

tahoe ln FROMPATH TOPATH

tahoe backup FROMLOCAL TOPATH

In these summaries, PATH, TOPATH or FROMPATH can be one of:

• [SUBDIRS/]FILENAME for a path relative to the default tahoe: alias;
• ALIAS:[SUBDIRS/]FILENAME for a path relative to another alias;
• DIRCAP/[SUBDIRS/]FILENAME or DIRCAP:./[SUBDIRS/]FILENAME for a path relative to a directory cap.

See CLI Command Overview above for information on using wildcards with local paths, and different treatment of colons between Unix and Windows.

FROMLOCAL or TOLOCAL is a path in the local filesystem.

Command Examples

tahoe add-alias ALIAS[:] DIRCAP

An example would be:

tahoe add-alias fun URI:DIR2:ovjy4yhylqlfoqg2vcze36dhde:4d4f47qko2xm5g7osgo2yyidi5m4muyo2vjjy53q4vjju2u55mfa

This creates an alias fun: and configures it to use the given directory cap. Once this is done, "tahoe ls fun:" will list the contents of this directory. Use "tahoe add-alias tahoe DIRCAP" to set the contents of the default tahoe: alias.

Since Tahoe-LAFS v1.8.2, the alias name can be given with or without the trailing colon.

On Windows, the alias should not be a single character, because it would be confused with the drive letter of a local path.

tahoe create-alias fun

This combines "tahoe mkdir" and "tahoe add-alias" into a single step.

tahoe list-aliases

This displays a table of all configured aliases.

tahoe mkdir

This creates a new empty unlinked directory, and prints its write-cap to stdout. The new directory is not attached to anything else.

tahoe mkdir subdir

tahoe mkdir /subdir

This creates a new empty directory and attaches it below the root directory of the default tahoe: alias with the name "subdir".

tahoe ls

tahoe ls /

tahoe ls tahoe:

tahoe ls tahoe:/

All four list the root directory of the default tahoe: alias.

tahoe ls subdir

This lists a subdirectory of your filesystem.

tahoe webopen

tahoe webopen tahoe:

tahoe webopen tahoe:subdir/

tahoe webopen subdir/

This uses the python 'webbrowser' module to cause a local web browser to open to the web page for the given directory. This page offers interfaces to add, download, rename, and unlink files and subdirectories in that directory. If no alias or path is given, this command opens the root directory of the default tahoe: alias.

tahoe put file.txt

tahoe put ./file.txt

tahoe put /tmp/file.txt

tahoe put ~/file.txt

These upload the local file into the grid, and prints the new read-cap to stdout. The uploaded file is not attached to any directory. All one-argument forms of "tahoe put" perform an unlinked upload.

tahoe put -

tahoe put

These also perform an unlinked upload, but the data to be uploaded is taken from stdin.

tahoe put file.txt uploaded.txt

tahoe put file.txt tahoe:uploaded.txt

These upload the local file and add it to your tahoe: root with the name "uploaded.txt".

tahoe put file.txt subdir/foo.txt

tahoe put - subdir/foo.txt

tahoe put file.txt tahoe:subdir/foo.txt

tahoe put file.txt DIRCAP/foo.txt

tahoe put file.txt DIRCAP/subdir/foo.txt

These upload the named file and attach them to a subdirectory of the given root directory, under the name "foo.txt". When a directory write-cap is given, you can use either / (as shown above) or :./ to separate it from the following path. When the source file is named "-", the contents are taken from stdin.

tahoe put file.txt --mutable

Create a new (SDMF) mutable file, fill it with the contents of file.txt, and print the new write-cap to stdout.

tahoe put file.txt MUTABLE-FILE-WRITECAP

Replace the contents of the given mutable file with the contents of file.txt and print the same write-cap to stdout.

tahoe cp file.txt tahoe:uploaded.txt

tahoe cp file.txt tahoe:

tahoe cp file.txt tahoe:/

tahoe cp ./file.txt tahoe:

These upload the local file and add it to your tahoe: root with the name "uploaded.txt".

tahoe cp tahoe:uploaded.txt downloaded.txt

tahoe cp tahoe:uploaded.txt ./downloaded.txt

tahoe cp tahoe:uploaded.txt /tmp/downloaded.txt

tahoe cp tahoe:uploaded.txt ~/downloaded.txt

This downloads the named file from your tahoe: root, and puts the result on your local filesystem.

tahoe cp tahoe:uploaded.txt fun:stuff.txt

This copies a file from your tahoe: root to a different directory, set up earlier with "tahoe add-alias fun DIRCAP" or "tahoe create-alias fun".

tahoe unlink uploaded.txt

tahoe unlink tahoe:uploaded.txt

This unlinks a file from your tahoe: root (that is, causes there to no longer be an entry uploaded.txt in the root directory that points to it). Note that this does not delete the file from the grid. For backward compatibility, tahoe rm is accepted as a synonym for tahoe unlink.

tahoe mv uploaded.txt renamed.txt

tahoe mv tahoe:uploaded.txt tahoe:renamed.txt

These rename a file within your tahoe: root directory.

tahoe mv uploaded.txt fun:

tahoe mv tahoe:uploaded.txt fun:

tahoe mv tahoe:uploaded.txt fun:uploaded.txt

These move a file from your tahoe: root directory to the directory set up earlier with "tahoe add-alias fun DIRCAP" or "tahoe create-alias fun".

tahoe backup ~ work:backups

This command performs a full versioned backup of every file and directory underneath your "~" home directory, placing an immutable timestamped snapshot in e.g. work:backups/Archives/2009-02-06_04:00:05Z/ (note that the timestamp is in UTC, hence the "Z" suffix), and a link to the latest snapshot in work:backups/Latest/ . This command uses a small SQLite database known as the "backupdb", stored in ~/.tahoe/private/backupdb.sqlite, to remember which local files have been backed up already, and will avoid uploading files that have already been backed up (except occasionally that will randomly upload them again if it has been awhile since had last been uploaded, just to make sure that the copy of it on the server is still good). It compares timestamps and filesizes when making this comparison. It also re-uses existing directories which have identical contents. This lets it run faster and reduces the number of directories created.

If you reconfigure your client node to switch to a different grid, you should delete the stale backupdb.sqlite file, to force "tahoe backup" to upload all files to the new grid.

The fact that "tahoe backup" checks timestamps on your local files and skips ones that don't appear to have been changed is one of the major differences between "tahoe backup" and "tahoe cp -r". The other major difference is that "tahoe backup" keeps links to all of the versions that have been uploaded to the grid, so you can navigate among old versions stored in the grid. In contrast, "tahoe cp -r" unlinks the previous version from the grid directory and links the new version into place, so unless you have a link to the older version stored somewhere else, you'll never be able to get back to it.

tahoe backup --exclude=*~ ~ work:backups

Same as above, but this time the backup process will ignore any filename that will end with '~'. --exclude will accept any standard Unix shell-style wildcards, as implemented by the Python fnmatch module. You may give multiple --exclude options. Please pay attention that the pattern will be matched against any level of the directory tree; it's still impossible to specify absolute path exclusions.

tahoe backup --exclude-from=/path/to/filename ~ work:backups

--exclude-from is similar to --exclude, but reads exclusion patterns from /path/to/filename, one per line.

tahoe backup --exclude-vcs ~ work:backups

This command will ignore any file or directory name known to be used by version control systems to store metadata. The excluded names are:

• CVS
• RCS
• SCCS
• .git
• .gitignore
• .cvsignore
• .svn
• .arch-ids
• {arch}
• =RELEASE-ID
• =meta-update
• =update
• .bzr
• .bzrignore
• .bzrtags
• .hg
• .hgignore
• _darcs

Storage Grid Maintenance

tahoe manifest tahoe:

tahoe manifest --storage-index tahoe:

tahoe manifest --verify-cap tahoe:

tahoe manifest --repair-cap tahoe:

tahoe manifest --raw tahoe:

This performs a recursive walk of the given directory, visiting every file and directory that can be reached from that point. It then emits one line to stdout for each object it encounters.

The default behavior is to print the access cap string (like URI:CHK:.. or URI:DIR2:..), followed by a space, followed by the full path name.

If --storage-index is added, each line will instead contain the object's storage index. This (string) value is useful to determine which share files (on the server) are associated with this directory tree. The --verify-cap and --repair-cap options are similar, but emit a verify-cap and repair-cap, respectively. If --raw is provided instead, the output will be a JSON-encoded dictionary that includes keys for pathnames, storage index strings, and cap strings. The last line of the --raw output will be a JSON encoded deep-stats dictionary.

tahoe stats tahoe:

This performs a recursive walk of the given directory, visiting every file and directory that can be reached from that point. It gathers statistics on the sizes of the objects it encounters, and prints a summary to stdout.

Debugging

For a list of all debugging commands, use "tahoe debug". For more detailed help on any of these commands, use "tahoe debug COMMAND --help".

"tahoe debug find-shares STORAGEINDEX NODEDIRS.." will look through one or more storage nodes for the share files that are providing storage for the given storage index.

"tahoe debug catalog-shares NODEDIRS.." will look through one or more storage nodes and locate every single share they contain. It produces a report on stdout with one line per share, describing what kind of share it is, the storage index, the size of the file is used for, etc. It may be useful to concatenate these reports from all storage hosts and use it to look for anomalies.

"tahoe debug dump-share SHAREFILE" will take the name of a single share file (as found by "tahoe find-shares") and print a summary of its contents to stdout. This includes a list of leases, summaries of the hash tree, and information from the UEB (URI Extension Block). For mutable file shares, it will describe which version (seqnum and root-hash) is being stored in this share.

"tahoe debug dump-cap CAP" will take any Tahoe-LAFS URI and unpack it into separate pieces. The most useful aspect of this command is to reveal the storage index for any given URI. This can be used to locate the share files that are holding the encoded+encrypted data for this file.

"tahoe debug repl" will launch an interactive Python interpreter in which the Tahoe-LAFS packages and modules are available on sys.path (e.g. by using 'import allmydata'). This is most useful from a source tree: it simply sets the PYTHONPATH correctly and runs the Python executable.

"tahoe debug corrupt-share SHAREFILE" will flip a bit in the given sharefile. This can be used to test the client-side verification/repair code. Obviously, this command should not be used during normal operation.

"tahoe debug trial [OPTIONS] [TESTSUITE]" will run the tests specified by TESTSUITE (defaulting to the whole Tahoe test suite), using Twisted Trial.