mt-aws-glacier
==============
Perl Multithreaded multipart sync to Amazon Glacier service.

## Intro

Amazon Glacier is an archive/backup service with very low storage price. However with some caveats in usage and archive retrieval prices.
[Read more about Amazon Glacier][amazon glacier]

*mt-aws-glacier* is a client application for Amazon Glacier, written in Perl programming language, for *nix.

[amazon glacier]:http://aws.amazon.com/glacier/

## Version

* Version 1.100 (See [ChangeLog][mt-aws glacier changelog] or follow [@mtglacier](https://twitter.com/mtglacier) for updates)  [![Build Status](https://travis-ci.org/vsespb/mt-aws-glacier.png?branch=master)](https://travis-ci.org/vsespb/mt-aws-glacier)

[mt-aws glacier changelog]:https://github.com/vsespb/mt-aws-glacier/blob/master/ChangeLog

## Contents

* [Features](#features)

* [Important bugs/missing features](#important-bugsmissing-features)

* [Production readiness](#production-readiness)

* [Installation/System requirements](#installationsystem-requirements)

	* [Installation via OS package manager](#installation-via-os-package-manager)

	* [Manual installation](#manual-installation)

	* [Installation via CPAN](#or-installation-via-cpan)

	* [Installation general instructions, troubleshooting, edge cases and misc instructions](#installation-general-instructions-troubleshooting-edge-cases-and-misc-instructions)

* [Warnings ( MUST READ )](#warnings--must-read-)

* [Help/contribute this project](#helpcontribute-this-project)

* [Usage](#usage)

* [Restoring journal](#restoring-journal)

* [Journal concept](#journal-concept)

* [Specification for some commands](#specification-for-some-commands)

	* [sync](#sync)

	* [restore](#restore)

	* [restore-completed](#restore-completed)

	* [upload-file](#upload-file)

	* [other commands](#other-commands)

* [File selection options](#file-selection-options)

* [Additional command line options](#additional-command-line-options)

* [Configuring Character Encodings](#configuring-character-encodings)

* [Limitations](#limitations)

* [See also](#see-also)

* [Minimum Amazon Glacier permissions](#minimum-amazon-glacier-permissions)



## Features

* Does not use any existing Amazon Glacier library, so can be flexible in implementing advanced features
* Amazon Glacier Multipart upload
* Multi-segment download (using HTTP Range header)
* Multithreaded upload/download
* Multipart+Multithreaded download/upload
* Multithreaded archive retrieval, deletion and download
* TreeHash validation while downloading
* Tracking of all uploaded files with a local journal file (opened for write in append mode only)
* Checking integrity of local files using journal
* Ability to limit number of archives to retrieve
* File selection options for all commands (using flexible rules with wildcard support)
* Full synchronization to Amazon Glacier - new file uploaded, modified files can be replaced, deletions can be propogated
* File name and modification times are stored as Glacier metadata ([metadata format for developers][mt-aws-glacier Amazon Glacier meta-data format specification])
* Ability to re-create journal file from Amazon Glacier metadata
* Full UTF-8 support (and full single-byte encoding support for *BSD systems)
* Multipart/multithreaded upload from STDIN
* User selectable HTTPS support. Currently defaults to plaintext HTTP
* Vault creation and deletion
* STS/IAM security tokens support

[mt-aws-glacier Amazon Glacier meta-data format specification]:https://github.com/vsespb/mt-aws-glacier/blob/master/lib/App/MtAws/MetaData.pm

## Important bugs/missing features

* Only multipart upload implemented, no plain upload
* Mac OS X filesystem treated as case-sensitive

## Production readiness

* After **one year** since first public version released, beta testing was finished and version 1.xxx released. Current project status is **non-beta**, **stable**.

## Installation/System requirements

Script is made for Unix OS. Tested under Linux. Should work under other POSIX OSes (*BSD, Solaris). Lightly tested under Mac OS X.
Will NOT work under Windows/Cygwin. Minimum Perl version required is 5.8.8 (pretty old, AFAIK there are no supported distributions with older Perls)

### Installation via OS package manager

NOTE: If you've used manual installation before, please remove previously installed `mtglacier` executable from your path.

NOTE: If you've used CPAN installation before, please remove previously installed module, ([cpanm] is capable to do that)

##### Ubuntu 12.04+

Can be installed/updated via PPA  [vsespb/mt-aws-glacier](https://launchpad.net/~vsespb/+archive/mt-aws-glacier):

1.	`sudo add-apt-repository ppa:vsespb/mt-aws-glacier`

	(GPG key id/fingerprint would be **D2BFA5E4** and **D7F1BC2238569FC447A8D8249E86E8B2D2BFA5E4**)

2.	`sudo apt-get update`
3.	`sudo apt-get install libapp-mtaws-perl`

That's it.

##### Debian 7 (Wheezy), Debian 8 (Jessie)

Can be installed/updated via custom repository

1.	`wget -O - https://mt-aws.com/vsespb.gpg.key | sudo apt-key add -`

	(this will add GPG key 2C00 B003 A56C 5F2A 75C4 4BF8 2A6E 0307 **D0FF 5699**)

2. Add repository


		echo "deb http://dl.mt-aws.com/debian/current $(lsb_release -sc) main"|sudo tee /etc/apt/sources.list.d/mt-aws.list


3.	`sudo apt-get update`
4.	`sudo apt-get install libapp-mtaws-perl`

That's it.

##### Debian 6 (Squeeze)

Can be installed/updated via custom repository

1.	`wget -O - http://mt-aws.com/vsespb.gpg.key | sudo apt-key add -`

	(this will add GPG key 2C00 B003 A56C 5F2A 75C4 4BF8 2A6E 0307 **D0FF 5699**)

2. Add repository


		echo "deb http://dl.mt-aws.com/debian/current $(lsb_release -sc) main"|sudo tee /etc/apt/sources.list.d/mt-aws.list


3.	`sudo apt-get update`
4.	`sudo apt-get install libapp-mtaws-perl`


	(To use HTTPS you also need:)

5. `sudo apt-get install build-essential libssl-dev`

6. install/update `LWP::UserAgent` and `LWP::Protocol::https` using [cpanm]


### Manual installation

#### Install prerequisites

###### Ubuntu 12.04+, Debian 7

`sudo apt-get install libwww-perl libjson-xs-perl`

###### RHEL/CentOS 5

1. `sudo yum install perl-Digest-SHA`
2. `sudo yum groupinstall "Development Tools"`
3. `sudo yum install openssl-devel`
4. Install `JSON::XS`, `LWP::UserAgent` and `LWP::Protocol::https` using [cpanm]

You also can install `mtglacier` prerequisites without CPAN if you have [EPEL](http://fedoraproject.org/wiki/EPEL) repository enabled and if you don't need HTTPS:

`sudo yum install perl-Digest-SHA perl-JSON-XS perl-libwww-perl`

###### RHEL/CentOS 6

1. `sudo yum install perl-core perl-CGI`
2. `sudo yum groupinstall "Development Tools"`
3. `sudo yum install openssl-devel`
4. Install `JSON::XS`, `LWP::UserAgent` and `LWP::Protocol::https` using [cpanm]

You also can install `mtglacier` prerequisites without CPAN if you have [EPEL](http://fedoraproject.org/wiki/EPEL) repository enabled and if you don't need HTTPS:

`sudo yum install perl-core perl-CGI perl-JSON-XS perl-libwww-perl`

###### Debian 6

`sudo apt-get install libwww-perl libjson-xs-perl`

To use HTTPS you also need:

1. `sudo apt-get install build-essential libssl-dev`

3. install/update `LWP::UserAgent` and `LWP::Protocol::https` using [cpanm]

###### Fedora 18+

`sudo yum install perl-core perl-CGI perl-JSON-XS perl-libwww-perl perl-LWP-Protocol-https`

###### SUSE Linux Enterprise Server 11

1. `sudo zypper install perl-libwww-perl libopenssl-devel`
2. `sudo zypper install --type pattern Basis-Devel`
3. Upgrade openssl to (at least) `0.9.8r` (to check version use `openssl version`), can be found [here](http://download.opensuse.org/repositories/security:/fips/) (more info here [RT#81575](https://rt.cpan.org/Public/Bug/Display.html?id=81575))
4. Update `ExtUtils::MakeMaker` via [cpanm]
5. Install `LWP::UserAgent`, `LWP::Protocol::https`, `JSON::XS` using [cpanm]

###### Amazon Linux 2013.03

`sudo yum install perl-core perl-JSON-XS perl-libwww-perl perl-LWP-Protocol-https`

###### MacOS X

Install the following packages:

`p5-libwww-perl p5-json-XS`

#### Install mt-aws-glacier

	git clone https://github.com/vsespb/mt-aws-glacier.git

(or just download and unzip `https://github.com/vsespb/mt-aws-glacier/archive/master.zip` )

After that you can execute `mtglacier` script (found in root of repository) from any directory, or create a symlink to it - it will find other package files by itself
(don't forget to remove it later, if you decide to switch to CPAN install)

### *OR* Installation via CPAN

		cpan -i App::MtAws

That's it.


### Installation general instructions, troubleshooting, edge cases and misc instructions

##### In general you need the following perl modules to run *mt-aws-glacier*:

* **LWP::UserAgent** (or Debian package **libwww-perl** or RPM package **perl-libwww-perl** or MacPort **p5-libwww-perl**)
* **JSON::XS** (or Debian package **libjson-xs-perl** or RPM package **perl-JSON-XS** or MacPort **p5-json-XS**)

##### Other notes

1. for old Perl < 5.9.3 (i.e. *CentOS 5.x*), install also **Digest::SHA** (or Debian package **libdigest-sha-perl** or RPM package **perl-Digest-SHA**)

2. Some distributions with old Perl stuff (examples: *Ubuntu 10.04*, *CentOS 5/6*) to use HTTPS you need to upgrade **LWP::Protocol::https** to version 6+ via CPAN.

3. *Fedora*, *CentOS 6* etc [decoupled](http://www.nntp.perl.org/group/perl.perl5.porters/2009/08/msg149747.html) Perl,
so package named `perl`, which is a part of default installation, is not actually real, full Perl, which is misleading.
`perl-core` is looks much more like a real Perl (I [hope](https://bugzilla.redhat.com/show_bug.cgi?id=985791) so)

4. On newer RHEL distributions (some *Fedora* versions) you need install **perl-LWP-Protocol-https** to use HTTPS.

5. To inistall `perl-JSON-XS` RPM package on RHEL5/6 you need to enable [EPEL](http://fedoraproject.org/wiki/EPEL) repository

6. If you've used manual installation before "CPAN" installation, it's probably better to remove previously installed `mtglacier` executable from your path.

7. CPAN distribution of *mt-aws-glacier* has a bit more dependencies than manual installation, as it requires additional modules for testsuite.

8. New releases of *mt-aws-glacier* usually appear on CPAN within a ~week after official release.

9. On *Fedora*, *CentOS 6 minimal* you need to install `perl-core`, `perl-CPAN`, `perl-CGI` before trying to install via CPAN

10. For some distributions with old Perl stuff (examples: *CentOS 5/6*) you need to update CPAN and Module::Build first: `cpan -i CPAN`, `cpan -i Module::Build`

11. CPAN tool asks too many questions during install (but ignores important errors). You can avoid it by running `cpan` command and configuring it like this:

		o conf build_requires_install_policy yes
		o conf prerequisites_policy follow
		o conf halt_on_failure on
		o conf commit
		exit

12. Instead system `cpan` tool you might want to try [`cpanm`](http://search.cpan.org/perldoc?App%3A%3Acpanminus) - it's a bit easier to install and configure.

13. Installation of **LWP::Protocol::https** requires C header files ( `yum groupinstall "Development Tools"` for RHEL or `build-essential` for Debian ) and OpenSSL dev library (`openssl-devel` RPM or `libssl-dev` DEB).

[cpanm]:http://search.cpan.org/perldoc?App%3A%3Acpanminus

## Warnings ( *MUST READ* )

* When playing with Glacier make sure you will be able to delete all your archives, it's impossible to delete archive
or non-empty vault in amazon console now. Also make sure you have read _all_ Amazon Glacier pricing/faq.

* Read Amazon Glacier pricing [FAQ][Amazon Glacier faq] again, really. Beware of retrieval fee.

* Before using this program, you should read Amazon Glacier documentation and understand, in general, Amazon Glacier workflows and entities. This documentation
does not define any new layer of abstraction over Amazon Glacier entities.

* With low "partsize" option you pay a bit more (Amazon charges for each upload request)

* For backup created with older versions (0.7x) of mt-aws-glacier, Journal file **required to restore backup**.

* Use a **Journal file** only with **same vault** ( more info [here](#what-is-journal) and [here](#how-to-maintain-a-relation-between-my-journal-files-and-my-vaults) and [here](https://github.com/vsespb/mt-aws-glacier/issues/50))

* When work with CD-ROM/CIFS/other non-Unix/non-POSIX filesystems, you might need set `leaf-optimization` to `0`

* Please read [ChangeLog][mt-aws glacier changelog] when upgrading to new version, and especially when downgrading.
(See "Compatibility" sections when downgrading)

* Zero length files and empty directories are ignored (as Amazon Glacier does not support it)

* See other [limitations](#limitations)

[Amazon Glacier faq]:http://aws.amazon.com/glacier/faqs/#How_will_I_be_charged_when_retrieving_large_amounts_of_data_from_Amazon_Glacier
[mt-aws glacier changelog]:https://github.com/vsespb/mt-aws-glacier/blob/master/ChangeLog

## Help/contribute this project

* If you like *mt-aws-glacier*, and registered on GitHub, please **Star** it on GitHUb, this way you'll help promote the project.
* Please report any bugs or issues (using GitHub issues). Well, any feedback is welcomed.
* If you want to contribute to the source code, please contact me first and describe what you want to do

## Usage

1. Create a directory containing files to backup. Example `/data/backup`
2. Create config file, say, glacier.cfg

		key=YOURKEY
		secret=YOURSECRET
		# region: eu-west-1, us-east-1 etc
		region=us-east-1
		# protocol=http (default) or https
		protocol=http

	(you can skip any config option and specify it directly in command line)
3. Create a vault in specified region, using Amazon Console (`myvault`) or using mtglacier

		./mtglacier create-vault myvault --config=glacier.cfg

	(note that Amazon Glacier does not return error if vault already exists etc)

4. Choose a filename for the Journal, for example, `journal.log`
5. Sync your files

		./mtglacier sync --config=glacier.cfg --dir /data/backup --vault=myvault --journal=journal.log --concurrency=3

6. Add more files and sync again
7. Check that your local files not modified since last sync

		./mtglacier check-local-hash --config=glacier.cfg --dir /data/backup --journal=journal.log

8. Delete some files from your backup location
9. Initiate archive restore job on Amazon side

		./mtglacier restore --config=glacier.cfg --dir /data/backup --vault=myvault --journal=journal.log --max-number-of-files=10

10. Wait 4+ hours for Amazon Glacier to complete archive retrieval
11. Download restored files back to backup location

		./mtglacier restore-completed --config=glacier.cfg --dir /data/backup --vault=myvault --journal=journal.log

12. Delete all your files from vault

		./mtglacier purge-vault --config=glacier.cfg --vault=myvault --journal=journal.log

13. Wait ~ 24-48 hours and you can try deleting your vault

		./mtglacier delete-vault myvault --config=glacier.cfg

	(note: currently Amazon Glacier does not return error if vault is not exists)

## Restoring journal

In case you lost your journal file, you can restore it from Amazon Glacier metadata

1. Run retrieve-inventory command. This will request Amazon Glacier to prepare vault inventory.

		./mtglacier retrieve-inventory --config=glacier.cfg --vault=myvault

2. Wait 4+ hours for Amazon Glacier to complete inventory retrieval (also note that you will get only ~24h old inventory..)

3. Download inventory and export it to new journal (this sometimes can be pretty slow even if inventory is small, wait a few minutes):

		./mtglacier download-inventory --config=glacier.cfg --vault=myvault --new-journal=new-journal.log


For files created by mt-aws-glacier version 0.8x and higher original filenames will be restored. For other files archive_id will be used as filename. See Amazon Glacier metadata format for mt-aws-glacier here: [Amazon Glacier metadata format used by mt-aws glacier][Amazon Glacier metadata format used by mt-aws glacier]

[Amazon Glacier metadata format used by mt-aws glacier]:https://github.com/vsespb/mt-aws-glacier/blob/master/lib/App/MtAws/MetaData.pm

## Journal concept

#### What is Journal

Journal is a file in local filesystem, which contains list of all files, uploaded to Amazon Glacier.
Strictly saying, this file contains a list of operations (list of records), performed with Amazon Glacier vault. Main operations are:
file creation, file deletion and file retrieval.

Create operation records contains: *local filename* (relative to transfer root - `--dir`), file *size*, file last *modification time* (in 1 second resolution), file *TreeHash* (Amazon
hashing algorithm, based on SHA256), file upload time, and Amazon Glacier *archive id*

Delete operation records contains *local filename* and corresponding Amazon Glacier *archive id*

Having such list of operation, we can, any time reconstruct list of files, that are currently stored in Amazon Glacier.

As you see Journal records don't contain Amazon Glacier *region*, *vault*, file permissions, last access times and other filesystem metadata.

Thus you should always use a separate Journal file for each Amazon Glacier *vault*. Also, file metadata (except filename and file *modification time*) will
be lost, if you restore files from Amazon Glacier.

#### Some Journal features

* It's a text file. You can parse it with `grep` `awk` `cut`, `tail` etc, to extract information in case you need perform some advanced stuff, that `mtglacier` can't do (NOTE: make sure you know what you're doing ).

	To view only some files:

		grep Majorca Photos.journal

	To view only creation records:

		grep CREATED Photos.journal | wc -l

	To compare only important fields of two journals

		cut journal -f 4,5,6,7,8 |sort > journal.cut
		cut new-journal -f 4,5,6,7,8 |sort > new-journal.cut
		diff journal.cut new-journal.cut

* Each text line in a file represent one record

* It's an append-only file. File opened in append-only mode, and new records only added to the end. This guarantees that
you can recover Journal file to previous state in case of bug in program/crash/some power/filesystem issues. You can even use `chattr +a` to set append-only protection to the Journal.

* As Journal file is append-only, it's easy to perform incremental backups of it

#### Why Journal is a file in local filesystem file, but not in online Cloud storage (like Amazon S3 or Amazon DynamoDB)?

Journal is needed to restore backup, and we can expect that if you need to restore a backup, that means that you lost your filesystem, together with Journal.

However Journal also needed to perform *new backups* (`sync` command), to determine which files are already in Glacier and which are not. And also to checking local file integrity (`check-local-hash` command).
Actually, usually you perform new backups every day. And you restore backups (and loose your filesystem) very rare.

So fast (local) journal is essential to perform new backups fast and cheap (important for users who backups thousands or millions of files).

And if you lost your journal, you can restore it from Amazon Glacier (see `retrieve-inventory` command). Also it's recommended to backup your journal
to another backup system (Amazon S3 ? Dropbox ?) with another tool, because retrieving inventory from Amazon Glacier is pretty slow.

Also some users might want to backup *same* files from *multiple* different locations. They will need *synchronization* solution for journal files.

Anyway I think problem of putting Journals into cloud can be automated and solved with 3 lines bash script..

#### How to maintain a relation between my journal files and my vaults?

1. You can name journal with same name as your vault. Example: Vault name is `Photos`. Journal file name is `Photos.journal`. Or `eu-west-1-Photos.journal`

2. (Almost) Any command line option can be used in config file, so you can create `myphotos.cfg` with following content:

		key=YOURKEY
		secret=YOURSECRET
		protocol=http
		region=us-east-1
		vault=Photos
		journal=/home/me/.glacier/photos.journal

#### Why Journal does not contain region/vault information?

Keeping journal/vault in config does looks to me more like a Unix way. It can be a bit danger, but easier to maintain, because:

1. Let's imaging I decided to put region/vault into Journal. There are two options:

	a. Put it into beginning of the file, before journal creation.

	b. Store same region/vault in each record of the file. It looks like a waste of disk space.

	Option (a) looks better. So this way journal will contain something like

		region=us-east-1
		vault=Photos

	in the beginning. But same can be achieved by putting same lines to the config file (see previous question)

2. Also, putting vault/region to journal will make command line options `--vault` and `--region` useless
for general commands and will require to add another command (something like `create-journal-file`)

3. There is a possibility to use different *account id* in Amazon Glacier (i.e. different person's account). It's not supported yet in `mtglacier`,
but when it will, I'll have to store *account id* together with *region*/*vault*. Also default *account id* is '-' (means 'my account'). If one wish to use same
vault from a different Amazon Glacier account, he'll have to change '-' to real account id. So need to have ability to edit *account id*.
And *region/vault* information does not have sense without account.

4. Some users can have different permissions for different vaults, so they needs to maintain `key`/`secret`/`account_id` `region/vault` `journal` relation in same place
(this only can be config file, because involves `secret`)

5. Amazon might allow renaming of vaults or moving it across regions, in the future.

6. Currently journal consists of independent records, so can be split to separate records using `grep`, or several
journals can be merged using `cat` (but be careful if doing that)

7. In the future, there can be other features and options added, such as compression/encryption, which might require to decide again where to put new attributes for it.

8. Usually there is different policy for backing up config files and journal files (modifiable). So if you loose your journal file, you won't be sure which config corresponds to which *vault* (and journal file
can be restored from a *vault*)

9. It's better to keep relation between *vault* and transfer root (`--dir` option) in one place, such as config file.

#### Why Journal (and metadata stored in Amazon Glacier) does not contain file's metadata (like permissions)?

If you want to store permissions, put your files to archives before backup to Amazon Glacier. There are lot's of different possible things to store as file metadata information,
most of them are not portable. Take a look on archives file formats - different formats allows to store different metadata.

It's possible that in the future `mtglacier` will support some other metadata things.

## Specification for some commands

### `sync`

Propagates current local filesystem state to Amazon Glacier server.

`sync` accepts one or several of the following mode options: `--new`, `--replace-modified`, `--delete-removed`

If none of three above mode options provided, `--new` is implied (basically for backward compatibility).

1. `--new`

	Uploads files, which exist in local filesystem (and have non-zero size), but not exist in Amazon Glacier (i.e. in Journal)

2. `--replace-modified`

	Uploads modified files (i.e. which exist in local filesystem and in Amazon Glacier). After file gets successfully uploaded,
	previous version of file is deleted. Logic of detection of modified files controlled by `--detect` option.

3. `--delete-removed`

	Deletes files, which exist in Amazon Glacier, but missing in local filesystem (or have zero size) , from Amazon Glacier.

4. `--detect`

	Controls how `--replace-modified` detect modified files. Possible values are: `treehash`, `mtime`, `mtime-or-treehash`, `mtime-and-treehash`,
	`always-positive`, `size-only`.
	Default value is `mtime-and-treehash`

	File is always considered modified if its *size changed* (but not zero)

	 1. `treehash` - calculates TreeHash checksum for file and compares with one in Journal. If checksum does not match - file is modified.

	 2. `mtime` - compares file last modification time in local filesystem and in journal, if it differs - file is modified.

	 3. `mtime-or-treehash` - compares file last modification time, if it differs - file is modified. If it matches - compares TreeHash.

	 4. `mtime-and-treehash` - compares file last modification time, if it differs - compares TreeHash. If modification time is not changed, file
	 treated as not-modified, treehash not checked.

	 5. `always-positive` - always treat files as modified, Modification time and TreeHash are ignored. Probably makes some sense only with `--filter` options.

	 6. `size-only` - treat files as modified only if size differs

	NOTE: default mode for detect is `mtime-and-treehash`, it's more performance wise (treehash checked only for files with modification time changed),
	but `mtime-or-treehash` and `treehash` are more safe in case you're not sure which programs change your files and how.

	NOTE: `mtime-or-treehash` is mnemonic for *File is modified if mtime differs OR treehash differs*
	`mtime-and-treehash`  is mnemonic for  *File is modified if mtime differs AND treehash differs*. Words
	*AND* and *OR* means here logical operators with [short-circuit evaluation](http://en.wikipedia.org/wiki/Short-circuit_evaluation)
	i.e. with `mtime-and-treehash` treehash never checked if mtime not differs. And with `mtime-or-treehash` treehash never checked if mtime differs.

NOTE: files with zero sizes are not supported by Amazon Glacier API, thus considered non-existing for consistency, for all `sync` modes.

NOTE: `sync` does not upload empty directories, there is no such thing as directory in Amazon Glacier.

NOTE: With `--dry-run` option TreeHash will not be calculated, instead *Will VERIFY treehash and upload...* message will be displayed.

NOTE: TreeHash calculation performed in parallel, so some of workers (defined with `--concurrency`) might be busy calculating treehash instead
of network IO.

### `restore`

Initiate Amazon Glacier RETRIEVE oparation for files listed in Journal, which don't *exist* on local filesystem and for
which RETRIEVE was not initiated during last 24 hours (that information obtained from *Journal* too - each retrieval logged
into journal together with timestamp)

### `restore-completed`

Donwloads files, listed in Journal, which don't *exist* on local filesystem, and which were previously
RETRIEVED (using `restore` command) and now available for download (i.e. in a ~4hours after retrieve).
Unlike `restore` command, list of retrieved files is requested from Amazon Glacier servers at runtime using API, not from
journal.

Data downloaded to unique temporary files (created in same directory as destination file). Temp files renamed to real files
only when download successfully finished. In case program terminated with error or after Ctrl-C, temp files with unfinished
downloads removed.

If `segment-size` specified (greater than 0) and particular file size in megabytes is larger than `segment-size`,
download for this file performed in multiple segments, i.e. using HTTP `Range:` header (each of size `segment-size` MiB, except last,
which can be smaller). Segments are downloaded in parallel (and different segments from different files can
be downloaded at same time).

Only values that are power of two supported for `segment-size` now.

Currenly if download breaks due to network problem, no resumption is performed, download of file or of current segment
started from beginning.

In case multi-segment downloads, TreeHash reported by Amazon Glacier for each segment is compared with actual TreeHash, calculated for segment at runtime.
In case of mismatch error is thrown and process stopped. Final TreeHash for whole file not checked yet.

In case full-file downloads, TreeHash reported by Amazon Glacier for whole file is compared with one calculated runtime and with one found in Journal file,
in case of mismatch, error is thrown and process stopped.

Unlike `partsize` option, `segment-size` does not allocate buffers in memory of the size specified, so you can use large `segment-size`.

### `upload-file`

Uploads a single file into Amazon Glacier. File will be tracked with Journal (just like when using `sync` command).

There are several possible combinations of options for `upload-file`:

1. **--filename** and **--dir**

	_Uploads what_: a file, pointed by `filename`.

	_Filename in Journal and Amazon Glacier metadata_: A relative path from `dir` to `filename`

		./mtglacier upload-file --config=glacier.cfg --vault=myvault --journal=journal.log --dir /data/backup --filename=/data/backup/dir1/myfile

	(this will upload content of `/data/backup/dir1/myfile` to Amazon Glacier and use `dir1/myfile` as filename for Journal )

		./mtglacier upload-file --config=glacier.cfg --vault=myvault --journal=journal.log --dir data/backup --filename=data/backup/dir1/myfile

	(Let's assume current directory is `/home`. Then this will upload content of `/home/data/backup/dir1/myfile` to Amazon Glacier and use `dir1/myfile` as filename for Journal)

	(NOTE: file `filename` should be inside directory `dir`)

2. **--filename** and  **--set-rel-filename**

	_Uploads what_: a file, pointed by `filename`.

	_Filename in Journal and Amazon Glacier metadata_: As specified in `set-rel-filename`

		./mtglacier upload-file --config=glacier.cfg --vault=myvault --journal=journal.log --filename=/tmp/myfile --set-rel-filename a/b/c

	(this will upload content of `/tmp/myfile` to Amazon Glacier and use `a/b/c` as filename for Journal )

	(NOTE: `set-rel-filename` should be a _relative_ filename i.e. must not start with `/`)

3. **--stdin**, **--set-rel-filename** and **--check-max-file-size**

	_Uploads what_: a file, read from STDIN

	_Filename in Journal and Amazon Glacier metadata_: As specified in `set-rel-filename`

	Also, as file size is not known until the very end of upload, need to be sure that file will not exceed 10 000 parts limit, and you must
	specify `check-max-file-size` -- maximum possible size of file (in Megabytes), that you can expect. What this option do is simply throw error
	if `check-max-file-size`/`partsize` > 10 000 parts (in that case it's recommended to adjust `partsize`). That's all. I remind that you can put this (and
	any other option to config file)


		./mtglacier upload-file --config=glacier.cfg --vault=myvault --journal=journal.log --stdin --set-rel-filename path/to/file --check-max-file-size=131

	(this will upload content of file read from STDIN to Amazon Glacier and use `path/to/file` as filename for Journal. )

	(NOTE: `set-rel-filename` should be a _relative_ filename i.e. must not start with `/`)


NOTES:

1. In the current version of mtglacier you are disallowed to store multiple versions of same file. I.e. upload multiple files with same relative filename
to a single Amazon Glacier vault and single Journal. Simple file versioning will be implemented in the future versions.

2. You can use other optional options with this command (`concurrency`, `partsize`)

### Other commands

See [usage](#usage) for examples of use of the following commands: `purge-vault`, `check-local-hash`, `create-vault`, `delete-vault`.

See [Restoring journal](#restoring-journal) for `retrieve-inventory`, `download-inventory` commands.

## File selection options

`filter`, `include`, `exclude` options allow you to construct a list of RULES to select only certain files for the operation.
Can be used with commands: `sync`, `purge-vault`, `restore`, `restore-completed ` and `check-local-hash`

+ **--filter**

	Adds one or several RULES to the list of rules. One filter value can contain multiple rules, it has same effect as multiple filter values with one
	RULE each.

		--filter='RULE1 RULE2' --filter 'RULE3'

	is same as

		--filter 'RULE1 RULE2 RULE3'


	RULES should be a sequence of PATTERNS, followed by '+' or '-' and separated by a spaces. There can be a space between '+'/'-' and PATTERN.

		RULES: [+-]PATTERN [+-]PATTERN ...


	'+' means INCLUDE PATTERN, '-' means EXCLUDE PATTERN


	NOTES:

		1. If RULES contain spaces or wildcards, you must quote it when running `mtglacier` from Shell (Example: `mtglacier ... --filter -tmp/` but `mtglacier --filter '-log/ -tmp/'`)


		2. Although, PATTERN can contain spaces, you cannot use if, because RULES separated by a space(s).


		3. PATTERN can be empty (Example: `--filter +data/ --filter -` - excludes everything except any directory with name `data`, last pattern is empty)


		4. Unlike other options, `filter`, `include` and `exclude` cannot be used in config file (in order to avoid mess with order of rules)


+ **--include**

	Adds an INCLUDE PATTERN to list of rules (Example: `--include /data/ --filter '+/photos/ -'` - include only photos and data directories)

+ **--exclude**

	Adds an EXCLUDE PATTERN to list of rules (Example: `--exclude /data/` - include everything except /data and subdirectories)

	NOTES:

		1. You can use spaces in PATTERNS here (Example: `--exclude '/my documents/'` - include everything except "/my documents" and subdirectories)


+ **How PATTERNS work**

+ 1)  If the pattern starts with a '/' then it is anchored to a particular spot in the hierarchy of files, otherwise it is matched against the final
component of the filename.

		`/tmp/myfile` - matches only `/tmp/myfile`. But `tmp/myfile` - matches `/tmp/myfile` and `/home/john/tmp/myfile`

+ 2) If the pattern ends with a '/' then it will only match a directory and all files/subdirectories inside this directory. It won't match regular file.
Note that if directory is empty, it won't be synchronized to Amazon Glacier, as it does not support directories

		`log/` - matches only directory `log`, but not a file `log`

+ 3) If pattern does not end with a '/', it won't match directory (directories are not supported by Amazon Glacier, so it makes no sense to match a directory
without subdirectories). However if, in future versions, we find a way to store empty directories in Amazon Glacier, this behavior may change.

		`log` - matches only file `log`, but not a directory `log` nor files inside it

+ 4) if the pattern contains a '/' (not counting a trailing '/') then it is matched against the full pathname, including any leading directories.
Otherwise it is matched only against the final component of the filename.

		`myfile` - matches `myfile` in any directory (i.e. matches both `/home/ivan/myfile` and `/data/tmp/myfile`), but it does not match
		`/tmp/myfile/myfile1`. While `tmp/myfile` matches `/data/tmp/myfile` and `/tmp/myfile/myfile1`

+ 5) Wildcard '*' matches zero or more characters, but it stops at slashes.

		`/tmp*/file` matches `/tmp/file`, `/tmp1/file`, `/tmp2/file` but not `tmp1/x/file`

+ 6) Wildcard '**' matches anything, including slashes.

		`/tmp**/file` matches `/tmp/file`, `/tmp1/file`, `/tmp2/file`, `tmp1/x/file` and `tmp1/x/y/z/file`

+ 7) When wildcard '**' meant to be a separated path component (i.e. surrounded with slashes/beginning of line/end of line), it matches 0 or more subdirectories.

		`/foo/**/bar` matches `foo/bar` and `foo/x/bar`. Also `**/file` matches `/file` and `x/file`

+ 8) Wildcard '?' matches any (exactly one) character except a slash ('/').

		`??.txt` matches `11.txt`, `xy.txt` but not `abc.txt`

+ 9) if PATTERN is empty, it matches anything.

		`mtglacier ... --filter '+data/ -'` - Last pattern is empty string (followed by '-')

+ 10) If PATTERN is started with '!' it only match when rest of pattern (i.e. without '!') does not match.

		`mtglacier ... --filter '-!/data/ +*.gz' -` - include only `*.gz` files inside `data/` directory.

+ **How rules are processed**

+ 1) File's relative filename (relative to `--dir` root) is checked against rules in the list. Once filename match PATTERN, file is included or excluded depending on the kind of PATTERN matched.
No other rules checked after first match.

		`--filter '+*.txt -file.txt'` File `file.txt` is INCLUDED, it matches 1st pattern, so 2nd pattern is ignored

+ 2) If no rules matched - file is included (default rule is INCLUDE rule).

		`--filter '+*.jpeg'` File `file.txt` is INCLUDED, as it does not match any rules

+ 3) When we process both local files and Journal filelist (sync, restore commands), rule applied to BOTH sides.

+ 4) When traverse directory tree, (in contrast to behavior of some tools, like _Rsync_), if a directory (and all subdirectories) match exclude pattern,
directory tree is not pruned, traversal go into the directory. So this will work fine (it will include `/tmp/data/a/b/c`, but exclude all other files in `/tmp/data`):

		--filter '+/tmp/data/a/b/c -/tmp/data/ +'

+ 5) In some cases, to reduce disk IO, directory traversal into excluded directory can be stopped.
This only can happen when `mtglacier` absolutely sure that it won't break behavior (4) described above.
Currently it's guaranteed that traversal stop only in case when:

+ A directory match EXCLUDE rule without '!' prefix, ending with '/' or '**', or empty rule

+ AND there are no INCLUDE rules before this EXCLUDE RULE

		`--filter '-*.tmp -/media/ -/proc/ +*.jpeg'` - system '/proc' and huge '/media' directory is not traversed.

+ 6) Non-ASCII characters in PATTERNS are supported.

## Additional command line options
NOTE: Any command line option can be used in config file as well.

1. `concurrency` (with `sync`, `upload-file`, `restore`, `restore-completed` commands) - number of parallel upload streams to run. (default 4)

		--concurrency=4

2. `partsize` (with `sync`, `upload-file` command) - size of file chunk to upload at once, in Megabytes. (default 16)

		--partsize=16

3. `segment-size` (with `restore-completed` command) - size of download segment, in MiB  (default: none)

	If `segment-size` specified (greater than zero), and file size in megabytes is larger than `segment-size`, download performed in
	multiple segments.

	If omited or zero, multi-segment download is disabled (i.e this is default)

	`segment-size` should be power of two.

4. `max-number-of-files` (with `sync` or `restore` commands) - limit number of files to sync/restore. Program will finish when reach this limit.

		--max-number-of-files=100

5. `key/secret/region/vault/protocol` - you can override any option from config

6. `dry-run` (with `sync`, `purge-vault`, `restore`, `restore-completed ` and even `check-local-hash` commands) - do not perform actual work, print what will happen instead.

		--dry-run

6. `leaf-optimization` (only `sync` command). `0` - disable. `1` - enable (default).
Similar to [find][find] (coreutils tools) `-noleaf` option and [File::Find][File::Find] `$dont_use_nlink` option.
When disabled number of hardlinks to directory is ignored during file tree traversal. This slow down file search, but more
compatible with (some) CIFS/CD-ROM filesystems.
For more information see [find][find] and [File::Find][File::Find] manuals.

7. `token` (all commands which connect Amazon Glacier API) - a STS/IAM security token, described in [Amazon STS/IAM Using Temporary Security Credentials to Access AWS]

[Amazon STS/IAM Using Temporary Security Credentials to Access AWS]:http://docs.aws.amazon.com/STS/latest/UsingSTS/UsingTokens.html
[find]:http://unixhelp.ed.ac.uk/CGI/man-cgi?find
[File::Find]:http://search.cpan.org/perldoc?File%3A%3AFind

8. `timeout` (all commands which connect Amazon Glacier API)

	Sets the timeout value in seconds, default value is 180 seconds. Request to Amazon Glacier is retried, if if no activity
	on the connection to the server is observed for `timeout` seconds. This means that the time it takes for the complete whole
	request might be longer.

9. `follow` (only `sync` command)

	Follow symbolic links during directory traversal. This option hits performance and increases memory usage. Similar to `find -L`

## Configuring Character Encodings

Autodetection of locale/encodings not implemented yet, but currently there is ability to tune encodings manually.

Below 4 options, that can be used in config file and in command line.

1. `terminal-encoding` - Encoding of your terminal (STDOUT/STDERR for system messages)

2. `filenames-encoding` - Encoding of filenames in filesystem.

	Under most *nix filesystems filenames stored as byte sequences, not characters. So in theory application is responsible for managing encodings.

3. `config-encoding` - Encoding of your config file (`glacier.cfg` in examples above)

4. `journal-encoding` - Encoding to be used for Journal file (when reading and writing journal specified with `--journal` and `--new-journal` options)


Default value for all options is 'UTF-8'. Under Linux and Mac OS X you usually don't need to change encodings.
Under *BSD systems often single-byte encodings are used. Most likely yo'll need to change `terminal-encoding` and `filenames-encoding`. Optionaly you can also
change `config-encoding` and `journal-encoding`.

Notes:

* Before switching `config-encoding` and `journal-encoding` you are responsible for transcoding file content of config and journal files manually.

* You are responsible for encoding compatibility. For example Don't try to work with UTF-8 journal with non-Cyrilic characters and KOI8-R (Cyrilic) filesystem.

* Don't try to use UTF-16 for *nix filesystem. It's not ASCII compatible and contains \x00 bytes, which can't be stored in filesystem.

* Don't use `UTF8` - it does not validate data, use `UTF-8` (one with a dash) instead.

* To get list of encodings installed with your Perl run:

		perl -MEncode -e 'print join qq{\n}, Encode->encodings(q{:all})'

* Config file name (specified with `--config`) can be in any encoding (it's used as is) Of course it will work only if your terminal encoding match your
filesystem encoding or if your config file name consists of ASCII-7bit characters only.

* Additional information about encoding support in Perl programming language: [CPAN module Encode::Supported](http://search.cpan.org/perldoc?Encode%3A%3ASupported)

* Amazon Glacier metadata (on Amazon servers) is always stored in UTF-8. No way to override it. You can use Journal in any encoding with same
metdata without problems and you can dump metadata to journals with different encodings (using `download-inventory` command)

* See also [convmv tool](http://www.j3e.de/linux/convmv/man/)

## Limitations

* Only support filenames, which consist of octets, that can be mapped to a valid character sequence in desired encoding (i.e. filename
which are made of random bytes/garbage is not supported. usually it's not a problem).

* Filenames with CR (Carriage return, code 0x0D) LF (Line feed, code 0x0A) and TAB (0x09) are not supported (usually not a problem too).

* Length of relative filenames. Currently limit is about 700 ASCII characters or 350 2-byte UTF-8 character (.. or 230 3-byte characters).

(NOTE: if above requirements are not met, error will be thrown)

* Memory usage (for 'sync') formula is ~ min(NUMBER_OF_FILES_TO_SYNC, max-number-of-files) + partsize*concurrency

* With high partsize*concurrency there is a risk of getting network timeouts HTTP 408/500.


## Test/Play with it

1. create empty dir MYDIR
2. Set vault name inside `cycletest.sh`
3. Run

		./cycletest.sh init MYDIR
		./cycletest.sh retrieve MYDIR
		./cycletest.sh restore MYDIR

* OR

		./cycletest.sh init MYDIR
		./cycletest.sh purge MYDIR

## See also

* Amazon Glacier Perl library on CPAN - see [Net::Amazon::Glacier][Amazon Glacier API CPAN module - Net::Amazon::Glacier] by *Tim Nordenfur*
* Amazon Glacier TreeHash CPAN module [Net::Amazon::TreeHash][Amazon Glacier TreeHash CPAN module - Net::Amazon::TreeHash] (copied from `mtglacier` code)
* [Amazon Glacier development forum][Amazon Glacier development forum]

[Amazon Glacier API CPAN module - Net::Amazon::Glacier]:https://metacpan.org/module/Net::Amazon::Glacier
[Amazon Glacier TreeHash CPAN module - Net::Amazon::TreeHash]:https://metacpan.org/module/Net::Amazon::TreeHash
[Amazon Glacier development forum]:https://forums.aws.amazon.com/forum.jspa?forumID=140


## Minimum Amazon Glacier permissions:

Something like this (including permissions to create/delete vaults):

	{
	"Statement": [
		{
		"Effect": "Allow",
		"Resource":["arn:aws:glacier:eu-west-1:*:vaults/test1",
			"arn:aws:glacier:us-east-1:*:vaults/test1",
			"arn:aws:glacier:eu-west-1:*:vaults/test2",
			"arn:aws:glacier:eu-west-1:*:vaults/test3"],
			"Action":["glacier:UploadArchive",
			  "glacier:InitiateMultipartUpload",
			  "glacier:UploadMultipartPart",
			  "glacier:UploadPart",
			  "glacier:DeleteArchive",
			  "glacier:ListParts",
			  "glacier:InitiateJob",
			  "glacier:ListJobs",
			  "glacier:GetJobOutput",
			  "glacier:ListMultipartUploads",
			  "glacier:CompleteMultipartUpload"]
		},
		{
			"Effect": "Allow",
			"Resource":["arn:aws:glacier:eu-west-1:*",
			  "arn:aws:glacier:us-east-1:*"],
			"Action":["glacier:CreateVault",
			  "glacier:DeleteVault"]
		}
		]
	}


#### EOF

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