1
2ethsetupssh(8)               EFSFFCLIRG (Man Page)              ethsetupssh(8)
3
4
5

NAME

7       ethsetupssh
8
9
10
11       Creates SSH keys and configures them on all hosts so the system can use
12       SSH and SCP into all other hosts without a password prompt.  Typically,
13       during  cluster setup this tool enables the root user on the Management
14       Node to log into the other hosts (as root) using password-less SSH.
15

Syntax

17       ethsetupssh [-p|U] [-f  hostfile] [-h 'hosts'] [-u  user] [-S] [-R|P]
18

Options

20       --help
21
22                 Produces full help text.
23
24
25       -p
26
27                 Performs operation against all hosts in parallel.
28
29
30       -U
31
32                 Performs connect only (to enter in local hosts, known hosts).
33                 When run in this mode, the -S option is ignored.
34
35
36       -f hostfile
37
38                 Specifies the file with hosts in cluster.
39                 Default is /etc/eth-tools/hosts file.
40
41
42       -h hosts
43
44                 Specifies the list of hosts to set up.
45
46
47       -u user
48
49                 Specifies the user on remote system to allow this user to SSH
50                 to. Default is current user code for host(s).
51
52
53       -S
54
55                 Securely prompts for password for user on remote system.
56
57
58       -R
59
60                 Skips setup of SSH to local host.
61
62
63       -P
64
65                 Skips ping of host (for SSH to devices on Internet with ping
66                 firewalled).
67
68

Examples

70       ethsetupssh -S
71
72       ethsetupssh -U
73
74       ethsetupssh -h 'arwen elrond' -U
75
76       HOSTS='arwen elrond' ethsetupssh -U
77

Environment Variables

79       The following environment variables are also used by this command:
80
81       HOSTS_FILE
82
83                 File containing list of hosts, used in absence of -f and -h.
84
85
86       HOSTS
87
88                 List of hosts, used if -h option not supplied.
89
90
91       FF_MAX_PARALLEL
92
93                 When -p option is used, maximum concurrent operations.
94
95

Description

97       ethsetupssh provides an easy way to create SSH keys and distribute them
98       to  the  hosts in the cluster. Many of the FastFabric tools (as well as
99       many versions of MPI) require that SSH is set up for password-less  op‐
100       eration. Therefore, ethsetupssh is an important setup step.
101
102       This  tool  also  sets up SSH to the local host. This capability is re‐
103       quired by selected FastFabric Toolset commands and may be used by  some
104       applications (such as MPI).
105
106       ethsetupssh  has  two  modes  of operation. The mode is selected by the
107       presence or absence of the -U option. Typically, ethsetupssh  is  first
108       run without the -U option, then it may later be run with the -U option.
109

Host Initial Key Exchange

111       When  run  without  the -U option, ethsetupssh performs the initial key
112       exchange and enables password-less SSH and SCP. The  preferred  way  to
113       use  ethsetupssh  for  initial key exchange is with the -S option. This
114       requires that all hosts are configured with the same password  for  the
115       specified  "user"  (typically  root).  In  this  mode,  the password is
116       prompted for once and then SSH and SCP are  used  in  conjunction  with
117       that  password  to  complete  the  setup  for the hosts. This mode also
118       avoids the need to set up  rsh/rcp/rlogin  (which  can  be  a  security
119       risk).
120

Refreshing Local Systems Known Hosts

122       If  aspects  of  the  host  have changed, such as IP addresses, MAC ad‐
123       dresses, software installation, or server OS  reinstallation,  you  can
124       refresh  the  local  host's SSH known_hosts file by running ethsetupssh
125       with the -U option. This option does not transfer the keys, but instead
126       connects to each host to refresh the SSH keys. Existing entries for the
127       specified hosts are replaced within the local  known_hosts  file.  When
128       run  in  this mode, the -S option is ignored. This mode assumes SSH has
129       previously been set up for the hosts, as such no files are  transferred
130       to the specified hosts and no passwords should be required.
131
132
133
134Copyright(C) 2020-2022         Intel Corporation                ethsetupssh(8)