Symbolic Links

[mildred]

Symbolic links are not implemented. ipfs add -r on a directory containing a symlink to a directory will fail.

You can reproduce it using:

mkdir -p a/b
ln -s b a/c
touch a/b/c
ipfs add -r a

You get:

Error: Post http://127.0.0.1:5001/api/v0/add?encoding=json&r=true&stream-channels=true: read a/c: is a directory

I think I also got ipfs add -r to stop in the middle of adding because of that. At some point, it would just stop and not continue. Running stat, I found that it thought that the symlink to a directory was a file, and tried to read it:

open("root/ckeditor/plugins/openlink", O_RDONLY|O_CLOEXEC) = 5
read(5, 0xc208130000, 32768)            = -1 EISDIR (Is a directory)
epoll_wait(4, {}, 128, 0)               = 0
futex(0xf2e878, FUTEX_WAIT, 0, NULL)    = 0
futex(0xf2da30, FUTEX_WAKE, 1)          = 1
...

The normal sequence for a directory would be:

open("root/ckeditor/plugins/newpage/lang", O_RDONLY|O_CLOEXEC) = 5
getdents64(5, /* 68 entries */, 4096)   = 2160
getdents64(5, /* 0 entries */, 4096)    = 0
lstat("root/ckeditor/plugins/newpage/lang/fa.js", {st_mode=S_IFREG|0644, st_size=235, ...}) = 0
...

We should implement symbolic links in the unixfs protocol buffer object.

[mildred]

As far as ipfs add is concerned, we could do two things:

• follow symlinks as if they were the target file (this is what we do currently apart from the bug above)
• insert symlinks as such in the unixfs DAG

In any case, I think this should be configurable by a command line switch. Just like we have cp --no-dereference and cp --dereference

[jbenet]

Error: Post http://127.0.0.1:5001/api/v0/add?encoding=json&r=true&stream-channels=true: read a/c: is a directory

@mappum we shouldn't show that url in the error o/

Agreed with your analysis @mildred, as discussed in #620 let's:

• Default to inserting symlinks into unixfs (like git does)
• Option to follow symlinks. whatever is most common in other unix utils.

[daviddias]

@whyrusleeping Can we make getting symlinks working a priority?

[whyrusleeping]

@diasdavid sure thing.

[whyrusleeping]

Kachow!

[daviddias]

💥 :D