Salt rosters are pluggable systems added in Salt 0.17.0 to facilitate the
The roster system was created because
salt-ssh needs a means to
identify which systems need to be targeted for execution.
The Roster System is not needed or used in standard Salt because the master does not need to be initially aware of target systems, since the Salt Minion checks itself into the master.
Since the roster system is pluggable, it can be easily augmented to attach to
any existing systems to gather information about what servers are presently
available and should be attached to by
salt-ssh. By default the roster
file is located at /etc/salt/roster.
The roster system compiles a data structure internally referred to as
targets is a list of target systems and attributes about how
to connect to said systems. The only requirement for a roster module in Salt
is to return the
targets data structure.
The information which can be stored in a roster
target is the following:
<Salt ID>: # The id to reference the target system with host: # The IP address or DNS name of the remote host user: # The user to log in as passwd: # The password to log in with # Optional parameters port: # The target system's ssh port number sudo: # Boolean to run command via sudo sudo_user: # Str: Set this to execute Salt as a sudo user other than root. # This user must be in the same system group as the remote user # that is used to login and is specified above. Alternatively, # the user must be a super-user. tty: # Boolean: Set this option to True if sudo is also set to # True and requiretty is also set on the target system priv: # File path to ssh private key, defaults to salt-ssh.rsa # The priv can also be set to agent-forwarding to not specify # a key, but use ssh agent forwarding timeout: # Number of seconds to wait for response when establishing # an SSH connection minion_opts: # Dictionary of minion opts thin_dir: # The target system's storage directory for Salt # components. Defaults to /tmp/salt-<hash>. cmd_umask: # umask to enforce for the salt-call command. Should be in # octal (so for 0o077 in YAML you would do 0077, or 63)
The roster_defaults dictionary in the master config is used to set the default login variables for minions in the roster so that the same arguments do not need to be passed with commandline arguments.
roster_defaults: user: daniel sudo: True priv: /root/.ssh/id_rsa tty: True
Salt needs to upload a standalone environment to the target system, and this defaults to /tmp/salt-<hash>. This directory will be cleaned up per normal systems operation.
If you need a persistent Salt environment, for instance to set persistent grains, this value will need to be changed.