This software is beta

Bar was developed to solve one simple problem. Large BLOBs can be stored in working tree. But our developers do not need these BLOBs. Or they are need some of them.

We use git. Bar designed to to minor additions to the workflow. Also bar can work without git.

Consider the following scenario:

1. About 2TB of BLOBs in project.
2. All BLOBs should be under version control.
3. All blobs along are not needed locally.
4. Some staff do not have a clue about version control.
5. Some works under windows.
6. They need one-button solution.
7. Cry!
8. Use bar.

For now assume what bard is deployed and listening at :3001.

To set the bar in the repository use bar git-init command. Only one important flag "endpoint" is just HTTP endpoint of bard server.

$ bar git install --endpoint=localhost:3001

Bar-tracked BLOBs are defined by git attributes.

# .gitattributes
my/blobs    filter=bar

After that you can add, commit and push as usual. Bar will upload new and changed BLOBs to bard server on commit.

$ echo "test" > my/blobs/test.txt
$ git add -A
$ git commit -m "initial commit"  # <-- Here BLOBs will be uploaded
...

For this moment all is simple. To transform BLOBs to manifests use git bar squash:

$ git bar-squash
...

$ git status 
On branch master
nothing to commit, working directory clean

$ cat my/blobs/test.txt
BAR:MANIFEST

version 0.1.0
id 309a3490190131517180e3827398a665c1eef2b9b2b41108a08a59f4bb15d301
size 4


id 309a3490190131517180e3827398a665c1eef2b9b2b41108a08a59f4bb15d301
size 3
offset 0

Now BLOB transformed to manifest. Shadow is small text manifest describing BLOB. Bar installs own filter to git repo. This leverages git to store manifests in index.

$ git ls-files -s --cache my/blobs/test.txt
100644 c8c0b7267bf989a8d15c885dcdbafb10b60d244e 0	my/blobs/test.txt

$ git cat-file -p c8c0b7267bf989a8d15c885dcdbafb10b60d244e
BAR:MANIFEST
    
version 0.1.0
id 309a3490190131517180e3827398a665c1eef2b9b2b41108a08a59f4bb15d301
size 4


id 309a3490190131517180e3827398a665c1eef2b9b2b41108a08a59f4bb15d301
size 3
offset 0

To upload BLOBs without squashing them use git bar-up.

Also on checkout all non-existent BLOBs will be become stored as manifests. To get them back use git bar-down.

$ git bar-down my/blobs/test.txt
... 
$ git status
On branch master
nothing to commit, working directory clean
    
$ cat my/blobs/test.txt
test

To check status of bar-tracked BLOBs use git bar-ls

$ git bar-ls
NAME                BLOB    SYNC    ID                  SIZE
my/blobs/test.txt   yes     yes     309a349019013151    4

$ git bar-squash
$ git bar-ls
NAME                BLOB    SYNC    ID                  SIZE
my/blobs/test.txt   no      yes     309a349019013151    4

Many bar commands accepts optional [# path] parameters. path is git-like pattern for restrict bar to search files in tree relative to working directory. All patterns must use forward slashes ("/") in POSIX notation. Single asterisk ("*") matches any symbols to next slash. Double asterisks matches any symbols across slashes. To exclude path prepend it with explamation ("!"). All patterns are must match full path.

recursive/pattern/**
recursive/**/with.file
non/*/recursive
!excluded/**

With bar divert you can change specific files from inactive branch without touching other files in working tree.

$ git bar-divert other-branch my/pretty/dir "my pretty/file"
...

$ git bar-divert-finish
# or $ git bar-divert-abort to abort

To check divert status use bar divert status

$ git bar-divert-status

You can also push inactive branch:

$ git bar-divert-push other-branch

To install just grab latest binaries archive from releases and unpack somewhere to PATH.

$ bar server run \
    --bind-http=:3000 \
    --bind-rpc=:3001 \
    --storage=block:root=testdata \
    --endpoint=${HOSTNAME}:3001 \
    --endpoint-http=http://${HOSTNAME}:3000/v1 \
    --bin-dir=dist/bindir
DEBUG server.go:23: serving at http://0.0.0.0:3000/v1

Tricky part is bin-dir flag. Bar server has functionality to serve bar binaries by HTTP. Bar server searches binaries in bin-dir:

http://<bar-host>:<port>/v1/win/bar.exe -> bin-dir/windows

Bar doesn't require git to work. All git bar-* commands is just git aliases:

git bar-squash  ->  bar up --squash
git bar-up      ->  bar up
git bar-down    ->  bar down
git bar-ls      ->  bar ls

To use git infrastructure use up, down and ls with -git flag.

Specs is just filename->id maps. Specs can be exported and imported by bar spec export and bar spec import. Specs can be generated locally or uploaded to bard.

Under windows you can use one-button no-brain solution. Just go to HTTP host:port and follow instructions in browser.