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Sessions

A session holds the current Cumulocity settings and authentication to use for each command. For example, as session will contain the Cumulocity platform address, tenant, username and password. All of these settings are required in order to send REST requests to the platform.

The active session is controlled via an environment variable C8Y_SESSION. The environment variable just points to a JSON file which contains the Cumulocity settings.

A user can add any number of session that that want. They are then free to switch sessions at any time they want. For users with only one session, you could set the C8Y_SESSION environment variable to a file, however for users with multiple sessions, it is recommended to always to set the session when starting out.

caution

SSO (Single Sign On) is not currently supported due to a security mechanism on the platform side which makes any cli implementation impossible.

If you are an SSO user, then you will have to do one of the following before you can use go-c8y-cli:

  • Create a dedicated local user in Cumulocity IoT (via the Administration -> Users page)
  • Create a service user via the Application User interface (though only for advanced users whom already have a username/password, see the example)

If you are using a local Cumulocity IoT user, it recommended that you use TFA (Two-Factor Authentication) and use the "OAI-Secure" preferred login mode, which enables the usage of tokens (e.g. Bearer Authorization header), all of which is supported out of the box by go-c8y-cli.

Create a new session​

c8y sessions create \
    --host "mytenant.eu-latest.cumulocity.com"

You will be prompted for the username and password.

Create a session for a host with self-signed certificates​

If your Cumulocity host is using a self-signed certificate (which is usually the case if you are using the Cumulocity IoT Edge), then you may want to use the allowInsecure flag. This option ignores the SSL verification. It should only be used if you trust the host and you have no option available (e.g. importing the missing CA certificate to the operating system)!

c8y sessions create \
    --host "mytenant.eu-latest.cumulocity.com" \
    --allowInsecure

Alternatively you can allow insecure mode (i.e. disable SSL verification) for a single command by using the --insecure global flag.

c8y devices list --insecure

Activate a session (interactive)​

A helper is provided to set the session interactively by providing the user a list of configured sessions. The user will be prompted to select one of the listed sessions.

note

On some terminals, you need to hold shift+ArrowKey to navigate the list of sessions.

Alternatively, VIM style shortcuts "j" (down) and "k" (up) keys can be also used for navigation. Though this does not work when your using the interact search.

caution

set-session is not provided by c8y itself, and it is installed automatically for you if you following the installation guide

set-session
tip

You can also provide additional flags to set session, as these are passed directly to the underlying c8y sessions set command.

set-session --debug

Activate a session (manual)​

If you wish to manage your sessions manually, then you can set the C8Y_SESSION environment variable to an existing json session file.

export C8Y_SESSION=~/.cumulocity/my-settings01.json

Session file format​

A Cumulocity session file is simply a json file. Here is an example of the contents:

mysession.json
{
  "host": "https://mytenant.eu-latest.cumulocity.com",
  "tenant": "mytenant",
  "username": "myTestUser",
  "password": "sUp3rs3curEpassW0r5",
  "description": "My test Cumulocity tenant",
  "useTenantPrefix": false
}

You can edit this file manually to update your password, or to fix any mistakes made when entering your details.

The session file is read every time when a command is executed, so any changes will be read next time you use a command.

Optional properties:

By default the tenant prefix will be used in the basic authentication, however if you do not what this behavior, then you can add the useTenantPrefix property.

{
  "host": "https://mytenant.eu-latest.cumulocity.com",
  "tenant": "myTenant",
  "username": "myTestUser",
  "password": "sUp3rs3curEpassW0r5",
  "description": "My test Cumulocity tenant",
  "useTenantPrefix": false
}

All of the values in the sessions file, can also be overridden using environment variables. The configuration settings pages details how to modify them.

Continuous Integration usage (environment variables)​

Alternatively, the Cumulocity session can be controlled purely by environment variables.

Then the Cumulocity settings can be set by the following environment variables.

  • C8Y_HOST (example "https://cumulocity.com")
  • C8Y_TENANT (example "myTenant")
  • C8Y_USER
  • C8Y_PASSWORD
  • C8Y_SETTINGS_CI or CI

Switching sessions for a single command​

If you only need to set a session for a single session, then you can use the global --session argument. The name of the session should be the name of the file stored under your ~/.cumulocity/ folder (with or without the .json extension).

You can set the C8Y_SESSION_HOME environment variable to control where the sessions should be stored.

c8y devices list --session myother.tenant

Protection against accidental data loss​

The c8y cli tool provides a large number of commands which can be potentially destructive if used incorrectly. Therefore all commands which create, update and/or delete data are disabled by default, to protect against accidental usage.

The commands can be enabled per session or in global settings, however explicitly enabling it per session is the preferred method.

Ideally for production sessions, the settings should be left disabled to protect yourself against accidental data loss, especially if you have a large number of tenants, and are constantly switching between them.

The following shows how the functions can be controlled via session settings:

mysession.json
{
  "settings": {
    "mode.enableCreate": false,
    "mode.enableUpdate": false,
    "mode.enableDelete": false
  }
}

Enabling create/update/delete command temporarily​

When the commands are disabled in the session settings, they can be temporarily activated on the console by using the following command:

eval $( c8y settings update mode dev --shell auto )

The commands will remain enabled until the next time you call set-session.

Afterwards you can disable them again using:

eval $( c8y settings update mode prod --shell auto )

Using encryption in Cumulocity session files​

Encrypted password and cookies fields can be activated by adding the following fragment into the session file or your global settings.json file.

{
  "settings": {
    "encryption": {
      "enabled": true
    }
  }
}

When enabled the "password", and "authorization.cookies" fields will be encrypted using a passphrase chosen by the user. The passphrase should be something that is sufficiently complex and should not be stored on disk.

When the user sets the passphrase, a key file will be created within the Cumulocity session home folder, .key. This file will be used as a reference when comparing your passphrase to keep the passphrase constant across different sessions.

The user will be prompted for the passphrase if one is not already set, when activating a session.

Loss of passphrase (encryption key)​

If you forget your passphrase then all of the encrypted passwords will be unusable.

In such an event, then you need to remove the .key file within the Cumulocity session folder, and you will be prompted to re-enter your password when the session is re-activated using set-session.

rm ~/.cumulocity/.key

Manually settings password via the file​

{
    "$schema": "https://raw.githubusercontent.com/reubenmiller/go-c8y-cli/v2/tools/schema/session.schema.json",
    "host": "https://example.cumulocity.com",
    "tenant": "t12345",
    "username": "myuser@iot-user.com",
    "password": "{encrypted}65cd99f96f9fe681be286d6e573061053afac353faeb5b1220352ab57456f3ee852fa9078ead3846c982caad6c4dfd3be6fd0a9aba",
    "description": "",
    "settings": {
        "mode.enableUpdate": true
    }
}

Updating passwords​

Passwords can still be set as plain text in the session files, however the next time that you switch to the session using set-session, the password field will be encrypted. An field is marked as encrypted by starting with text {encrypted} followed by the encrypted string.

Advanced session commands​

The following shows some other ways how to manage sessions.

Setting a session without the helper​

If you have not installed the go-c8y-cli addons, then you cannot use the set-session helper function.

You need to switch sessions by calling the c8y binary directly and evaluating the environment variables returned by the command. Each shell handles this slightly different.

eval $( c8y sessions set --shell=auto )

# Set a session to an already known json path.
eval $( c8y sessions set --shell=auto --session "/my/path/session.json" )
info

set-session is a small helper function (for each supported shell) which wraps the call to c8y sessions set and sets the returned environment variables which are then read by subsequent calls to c8y.

Switching session for a single command​

A single command can be redirected to use another session by using the session <name> parameter. A full file path can be provided or just the file name for a file located in session directory defined by the C8Y_SESSION_HOME environment variable.

c8y devices list --session myothersession.json

Creating a session file manually​

Session files can also be manually created as each session is just a file. The file needs to be placed on the configured session folder.

You can check your where your session home folder is by running

c8y settings list --select session.home

# or if you want to write it to a variable
myhome=$( c8y settings list --select session.home --output csv )
Output
| session.home                            |
|-----------------------------------------|
| /workspaces/go-c8y-cli/.cumulocity      |

Then you can create the a file using your preferred text editor (i.e. vim, nano, VSCode)

# Using vim
vim ~/.cumulocity/my-manual-file.json
file: ~/.cumulocity/session1.json
{
    "host": "example01.cumulocity.eu-latest.com",
    "username": "hello.user@example.com",
    "password": "mys3cureP4assw!rd",
}

Cloning an existing session​

You can easily clone (copy) your activated session by running. The mode can also be changed when cloning the session.

c8y sessions clone --newName "customer-qual" --type "qual"
Output
✓ Cloned session file to /workspaces/go-c8y-cli/.cumulocity/customer-qual.json

Then switch to the cloned session

set-session "customer-qual"
tip

Cloning an existing session is convenient when you a group of tenants (i.e. dev, qual, prod) where the settings only differ by url and your password. So you can just clone it and then edit the file manually in your preferred text editor.

Remember it is best practice to use different passwords for different sessions!

Changing mode of the existing session until next set-session​

The mode can be updated on the existing profile using

Change mode until next set-session​

If you installed the addons then there are some helpers to set the mode temporarily until the session is changed.

set-c8ymode-dev

Changing the mode permanently​

c8y settings update mode dev