The Session

Before we can perform operations on an iRODS server, we need to connect to it using the Session object (see also API documentation). This object uses your irods_environment.json to connect to the iRODS server. All operations that need a connection will use the Session object.

Authentication with the iRODS server

There are two ways to create a Session.

Interactive authentication

The function ibridges.interactive.interactive_auth() will check in the .irods folder for the default irods_environment.json and will try to authenticate with the cached password. If the password does not exist, you will be interactively asked for a password. You can also pass a path to a specific irods_environment.json with the parameter irods_env_path and you can also pass a password with the parameter password:
```
from ibridges.interactive import interactive_auth

session = interactive_auth()
# or
session = interactive_auth(irods_env_path="/some/other/irods_environment.json")
```
Note

Upon successful authentication, the function will store an obfuscated password just like the iRODS icommands. Once you are authenticated you can create more sessions without providing your password again.
Authentication by environment and password

If your workflow does not allow you to provide your password interactively, you can instantiate a Session object with the following code:
```
from ibridges import Session
session = Session(irods_env="/path/to/irods_environment.json", password="YourPassword")
```
The irods_env can also be a python dictionary which contains all your connection details.

Note

The Session object is a context manager. Similar to opening files, we recommend using the Session object with a with statement.

with interactive_auth() as session:
        # Do stuff with the interactive session.

with Session(...) as session:
        # Do stuff with the session

The advantage is that at the end data operations, connections to the server will be automatically closed and not linger, regardless of whether the operations were successful or not.

Otherwise, you will have to close the connection manually using:

session.close()

The Session object

The Session does not only contain the connection to the iRODS server, but also some useful attributes:

print(session.username)
print(session.default_resc) # the resource to which data will be uploaded
print(session.zone)
print(session.server_version)
print(session.get_user_info()) # lists user type and groups
print(session.home) # default home for iRODS /zone/home/username

We will have a closer look at the Session.home below.

The Session home

The Session.home denotes your iRODS working path and can be referred to with ~. For any relative paths that are created using an IrodsPath, the path will be relative to the Session.home that you have set.

There are three ways to set the irods_home:

You can set the “irods_home” in the configuration file irods_environment.json
You can pass it as a parameter when creating the session
You can set it later by session.home = <YOUR_IRODS_PATH>

If you did not set any Session.home the home will default to /<zone_name>/home/<user name>.

Note

If the home collection does not exist, you might get some strange errors. Its existence can be checked with:

IrodsPath(session, session.home).collection_exists()

The Session cwd

Apart from the home collection, you can also set the current working collection (Session.cwd). By default this is not set, and it will be equal to your Session.home. To directly refer to your current working collection, you can use the . symbol in your ibridges.path.IrodsPath.