# Salt SSH

Execute salt commands and states over ssh without installing a salt-minion.

## Getting Started

Salt SSH is very easy to use, simply set up a basic roster file of the systems to connect to and run `salt-ssh` commands in a similar way as standard `salt` commands.

- Salt ssh is considered production ready in version 2014.7.0

- Python is required on the remote system (unless using the `-r` option to send raw ssh commands). The python version requirement is the same as that for a standard Salt installation.

- On many systems, the `salt-ssh` executable will be in its own package, usually named `salt-ssh`

- The Salt SSH system does not supersede the standard Salt communication systems, it simply offers an SSH-based alternative that does not require ZeroMQ and a remote agent. Be aware that since all communication with Salt SSH is executed via SSH it is substantially slower than standard Salt with ZeroMQ.

- At the moment fileserver operations must be wrapped to ensure that the relevant files are delivered with the `salt-ssh` commands. The state module is an exception, which compiles the state run on the master, and in the process finds all the references to `salt://` paths and copies those files down in the same tarball as the state run. However, needed fileserver wrappers are still under development.

## Salt SSH Roster

The roster system in Salt allows for remote minions to be easily defined.

Note

See the SSH roster docs for more details.

Simply create the roster file, the default location is /etc/salt/roster:

    web1: 192.168.42.1

This is a very basic roster file where a Salt ID is being assigned to an IP address. A more elaborate roster can be created:

    web1:
      host: 192.168.42.1 # The IP addr or DNS hostname
      user: fred         # Remote executions will be executed as user fred
      passwd: foobarbaz  # The password to use for login, if omitted, keys are used
      sudo: True         # Whether to sudo to root, not enabled by default
    web2:
      host: 192.168.42.2

Note

sudo works only if NOPASSWD is set for user in /etc/sudoers: `fred ALL=(ALL) NOPASSWD: ALL`

## Deploy ssh key for salt-ssh

By default, salt-ssh will generate key pairs for ssh, the default path will be `/etc/salt/pki/master/ssh/salt-ssh.rsa`. The key generation happens when you run `salt-ssh` for the first time.

You can use ssh-copy-id, (the OpenSSH key deployment tool) to deploy keys to your servers.

    ssh-copy-id -i /etc/salt/pki/master/ssh/salt-ssh.rsa.pub user@server.demo.com

One could also create a simple shell script, named salt-ssh-copy-id.sh as follows:

    #!/bin/bash
    if [ -z $1 ]; then
       echo $0 user@host.com
       exit 0
    fi
    ssh-copy-id -i /etc/salt/pki/master/ssh/salt-ssh.rsa.pub $1

Note

Be certain to chmod +x salt-ssh-copy-id.sh.

    ./salt-ssh-copy-id.sh user@server1.host.com
    ./salt-ssh-copy-id.sh user@server2.host.com

Once keys are successfully deployed, salt-ssh can be used to control them.

Alternatively ssh agent forwarding can be used by setting the priv to agent-forwarding.

## Calling Salt SSH

Note

`salt-ssh` on target hosts without Python 3

The `salt-ssh` command requires at least python 3, which is not installed by default on some target hosts. An easy workaround in this situation is to use the `-r` option to run a raw shell command that installs python26:

    salt-ssh centos-5-minion -r 'yum -y install epel-release ; yum -y install python26'

Note

`salt-ssh` on systems with Python 3.x

Salt, before the 2017.7.0 release, does not support Python 3.x which is the default on for example the popular 16.04 LTS release of Ubuntu. An easy workaround for this scenario is to use the `-r` option similar to the example above:

    salt-ssh ubuntu-1604-minion -r 'apt update ; apt install -y python-minimal'

The `salt-ssh` command can be easily executed in the same way as a salt command:

    salt-ssh '*' test.version

Commands with `salt-ssh` follow the same syntax as the `salt` command.

The standard salt functions are available! The output is the same as `salt` and many of the same flags are available. Please see Salt SSH reference for all of the available options.

### Raw Shell Calls

By default `salt-ssh` runs Salt execution modules on the remote system, but `salt-ssh` can also execute raw shell commands:

    salt-ssh '*' -r 'ifconfig'

## States Via Salt SSH

The Salt State system can also be used with `salt-ssh`. The state system abstracts the same interface to the user in `salt-ssh` as it does when using standard `salt`. The intent is that Salt Formulas defined for standard `salt` will work seamlessly with `salt-ssh` and vice-versa.

The standard Salt States walkthroughs function by simply replacing `salt` commands with `salt-ssh`.

## Targeting with Salt SSH

Due to the fact that the targeting approach differs in salt-ssh, only glob and regex targets are supported as of this writing, the remaining target systems still need to be implemented.

Note

By default, Grains are settable through `salt-ssh`. By default, these grains will not be persisted across reboots.

See the "thin_dir" setting in Roster documentation for more details.

## Configuring Salt SSH

Salt SSH takes its configuration from a master configuration file. Normally, this file is in `/etc/salt/master`. If one wishes to use a customized configuration file, the `-c` option to Salt SSH facilitates passing in a directory to look inside for a configuration file named `master`.

### Minion Config

New in version 2015.5.1.

Minion config options can be defined globally using the master configuration option `ssh_minion_opts`. It can also be defined on a per-minion basis with the `minion_opts` entry in the roster.

## Running Salt SSH as non-root user

By default, Salt read all the configuration from /etc/salt/. If you are running Salt SSH with a regular user you have to modify some paths or you will get "Permission denied" messages. You have to modify two parameters: `pki_dir` and `cachedir`. Those should point to a full path writable for the user.

It's recommended not to modify /etc/salt for this purpose. Create a private copy of /etc/salt for the user and run the command with `-c /new/config/path`.

## Define CLI Options with Saltfile

If you are commonly passing in CLI options to `salt-ssh`, you can create a `Saltfile` to automatically use these options. This is common if you're managing several different salt projects on the same server.

So you can `cd` into a directory that has a `Saltfile` with the following YAML contents:

    salt-ssh:
      config_dir: path/to/config/dir
      ssh_log_file: salt-ssh.log
      ssh_max_procs: 30
      ssh_wipe: True

Instead of having to call `salt-ssh --config-dir=path/to/config/dir --max-procs=30 --wipe \* test.version` you can call `salt-ssh \* test.version`.

Boolean-style options should be specified in their YAML representation.

Note

The option keys specified must match the destination attributes for the options specified in the parser `salt.utils.parsers.SaltSSHOptionParser`. For example, in the case of the `--wipe` command line option, its `dest` is configured to be `ssh_wipe` and thus this is what should be configured in the `Saltfile`. Using the names of flags for this option, being `wipe: True` or `w: True`, will not work.

Note

For the Saltfile to be automatically detected it needs to be named Saltfile with a capital S and be readable by the user running salt-ssh.

At last you can create `~/.salt/Saltfile` and `salt-ssh` will automatically load it by default.

## Advanced options with salt-ssh

Salt's ability to allow users to have custom grains and custom modules is also applicable to using salt-ssh. This is done through first packing the custom grains into the thin tarball before it is deployed on the system.

For this to happen, the `config` file must be explicit enough to indicate where the custom grains are located on the machine like so:

    file_client: local
    file_roots:
      base:
        - /home/user/.salt
        - /home/user/.salt/_states
        - /home/user/.salt/_grains
    module_dirs:
      - /home/user/.salt
    pillar_roots:
      base:
        - /home/user/.salt/_pillar
    root_dir: /tmp/.salt-root

It's better to be explicit rather than implicit in this situation. This will allow urls all under salt:// to be resolved such as salt://_grains/custom_grain.py.

One can confirm this action by executing a properly setup salt-ssh minion with salt-ssh minion grains.items. During this process, a saltutil.sync_all is ran to discover the thin tarball and then consumed. Output similar to this indicates a successful sync with custom grains.

    local:
        ----------
        ...
        executors:
        grains:
            - grains.custom_grain
        log_handlers:
        ...

This is especially important when using a custom file_roots that differ from /etc/salt/.

Note

Please see https://docs.saltproject.io/en/latest/topics/grains/ for more information on grains and custom grains.

## Debugging salt-ssh

One common approach for debugging `salt-ssh` is to simply use the tarball that salt ships to the remote machine and call `salt-call` directly.

To determine the location of `salt-call`, simply run `salt-ssh` with the `-ltrace` flag and look for a line containing the string, `SALT_ARGV`. This contains the `salt-call` command that `salt-ssh` attempted to execute.

It is recommended that one modify this command a bit by removing the `-l quiet`, `--metadata` and `--output json` to get a better idea of what's going on the target system.

- Salt Rosters
  - How Rosters Work
    - Targets Data
    - ssh_pre_flight
    - ssh_pre_flight_args
    - Target Defaults
    - thin_dir
- SSH Ext Alternatives
  - auto_detect

## Different Python Versions

The 3001 release removed python 2 support in Salt. Even though this python 2 support is being dropped we have provided multiple ways to work around this with Salt-SSH. You can use the following options:

> - ssh_pre_flight

> - Using the Salt-SSH raw shell calls to install Python3.

> - Use an older version of Salt on the target host that still supports Python 2 using the feature SSH ext alternatives