Write files to CVMFS

Table of contents
[Write files to CVMFS]
- [Access privileges]

Modifications to SBND area in CVMFS are performed interacting as user cvmfssbnd on the server oasiscfs.fnal.gov.
A file README in the home directory in there contains instructions that may be more up to date than these ones.

These are the suggested operations, optimised for "the less time in oasiscfs.fnal.gov, the better":

get a Kerberos ticket as usual:
```
kinit -R "${USER}@FNAL.GOV" || kinit "${USER}@FNAL.GOV"
```
(this is just a trick so that it renews if available, otherwise it asks for a password and creates a new one)
copy the files you want to store in CVMFS into oasiscfs.fnal.gov (you need to [be authorised]:
```
scp sbnd_data-01.00.00-noarch.tar.bz2 cvmfssbnd@oasiscfs.fnal.gov:
```
will copy all the files (in this case, a single sbnd_data-01.00.00-noarch.tar.bz2) into the home directory of cvmfssbnd
log in oasiscfs.fnal.gov (you need to [be authorised]:
```
ssh cvmfssbnd@oasiscfs.fnal.gov
```

start the CVMFS update session:

cvmfs_server transaction sbnd.opensciencegrid.org

do what it takes to modify the CVMFS area at /cvmfs/sbnd.opensciencegrid.org: copy files, move files, expand files, edit files...
```
tar xvvf sbnd_data-01.00.00-noarch.tar.bz2 -C /cvmfs/sbnd.opensciencegrid.org/products/sbnd
```
close and "publish" the update wit a tag string and a message; make sure you are not in the CVMFS directory:
```
cd
cvmfs_server publish -m "Published sbnd_data 1.0.0" -a 1.0 sbnd.opensciencegrid.org
```
will create a new tag 1.0, with a meaningful description. A tag can be also created after publication, with cvmfs_server tag -m "Published sbnd_data 1.0.0" -a 1.0 sbnd.opensciencegrid.org (same effect as before). To see all tags, issue cvmfs_server tag -l sbnd.opensciencegrid.org (-l is optional).
log out

You can try and check the directory /cvmfs/sbnd.opensciencegrid.org/products/sbnd (and note that on GPVM the directory /cvmfs/sbnd.opensciencegrid.org might not show with a ls /cvmfs, but it will automatically appear the first time it is requested), but it takes some time for the CVMFS server to propagate the change to the world.

Access privileges

A few SBND people are allowed to log as cvmfssbnd on oasiscfs.fnal.gov, and these people can add a few others. If you are a blesseduser, the access command is:\

kinit blesseduser@FNAL.GOV
ssh cvmfssbnd@oasiscfs.fnal.gov

As of October 2021, these people are blessed:

To add a user to the list, his/her Kerberos principal must be added to .k5login file in the home directory of cvmfssbnd.
Since January 2018, we can freely edit the list of authorised people and we are responsible of the maintenance of that list.

A "backup file" showing how this file looks like is attached to this wiki page (k5login-201801165{.attachment}).
The actual file is at oasiscfs.fnal.gov:~cvmfssbnd/.k5login (the ownership cvmfssbnd:cvmfs and the access mode 0600 must be preserved).