Git clone LFS fails with dial tcp <IP>:<Port>: i/o timeout
Platform Notice: Data Center Only - This article only applies to Atlassian products on the Data Center platform.
Note that this KB was created for the Data Center version of the product. Data Center KBs for non-Data-Center-specific features may also work for Server versions of the product, however they have not been tested. Support for Server* products ended on February 15th 2024. If you are running a Server product, you can visit the Atlassian Server end of support announcement to review your migration options.
*Except Fisheye and Crucible
Problem
Cloning (or any other LFS server interactions) via SSH will fail if the Bitbucket Server has a misconfigured URL. An error message such as the following will be presented to the client:
Post http://<BITBUCKET_SERVER_URL>/scm/myproject/myrepo.git/info/lfs/objects/batch: dial tcp XXX.XXX.XXX.XX:YY: i/o timeoutCause
The command line client is unable to connect to the Bitbucket server instance because the URL is incorrect (i.e. mismatching between the <BITBUCKET_SERVER_URL> and the "Base URL").
Resolution
This occurs only via SSH, HTTP access is unaffected. This occurs because Git LFS does not actually support SSH; it does however permit that is configured with an SSH "remote" to, via SSH, contact the Bitbucket Server instance and request the HTTP/S URL and an authorisation token. The Bitbucket Server instance will reply with a URL that is based on the configured Base URL.
To resolve this see: Specifying the base URL for Bitbucket Server.
How do SSH remotes work?
The Git LFS Batch API does not directly support SSH, instead Bitbucket Server will redirect clients to a HTTP/S URL. So how does this work?
If using an SSH remote, the client (specifically the LFS filter) will make the following request via SSH for a download request:
git-lfs-authenticate myproject/myrepo.git download
The server will then respond with a JSON document, for example:
{
"header": {
"Authorization": "JWT <...JWT token...>"
},
"href": "https://bitbucket.example.com:7990/scm/myproject/myrepo.git/info/lfs"
}The Git LFS client will then POST a batch request via the returned URL.
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