-
Notifications
You must be signed in to change notification settings - Fork 44
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
1 parent
510fa2d
commit e934433
Showing
51 changed files
with
2,206 additions
and
2,148 deletions.
There are no files selected for viewing
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
Loading
Sorry, something went wrong. Reload?
Sorry, we cannot display this file.
Sorry, this file is invalid so it cannot be displayed.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
|
@@ -3,33 +3,57 @@ | |
### Setting up password-less kerberos token | ||
|
||
In order for the kerberos token to be refreshed automatically, it must be possible to do so without a password. | ||
Therefore, we create a keytab (similar to a private ssh key) on lxplus using the keytab utility. After starting it by typing `ktutil`, type the following three lines into the prompt and confirm the first two steps with your password. | ||
Therefore, we create a keytab (similar to a private ssh key) on lxplus using the provided `cern-get-keytab` utility. Note it will prompt for your password, in order to generate the keytab. | ||
|
||
{% callout "The old way" %} | ||
|
||
The former recipe was to start `ktutil`, then type the following three lines into the prompt and confirm the first two steps with your password. | ||
```bash | ||
add_entry -password -p [email protected] -k 1 -e arcfour-hmac-md5 | ||
add_entry -password -p [email protected] -k 1 -e aes256-cts | ||
wkt USERNAME.keytab | ||
cern-get-keytab --user USERNAME --keytab USERNAME.keytab | ||
``` | ||
and close the `ktutil` prompt with `Ctrl+D`. | ||
This will create a file called USERNAME.keytab in the current directory. It is strongly recommended to store this file in a directory to which only you have access as anyone who obtains a copy of this file can use it to obtain tokens in your name. | ||
This would create a file called USERNAME.keytab in the current directory. | ||
Since [OTG0077802](https://cern.service-now.com/service-portal?id=outage&n=OTG0077802), this recipe no longer works, and you will have to create a new keytab using these updated instructions. | ||
|
||
{% endcallout %} | ||
|
||
CERN [provides](https://cern.service-now.com/service-portal?id=kb_article&n=KB0003405) a shortcut command on lxplus9 (it will not work properly on lxplus7, though you can still use the created keytab from lxplus7 or lxplus8), which will prompt you for your password: | ||
```bash | ||
cern-get-keytab --keytab ~/private/$USER.keytab --user --login $USER | ||
``` | ||
This will create a file called `$USER.keytab` (where `$USER` is your username) in the directory `~/private/`. By default, on lxplus, only `$USER` has access to this directory; anyone who can access this file can use it to obtain tokens in your name, so be careful if you decide to move it to a different directory. | ||
|
||
**NOTE** that the domain name `CERN.CH` has to be all uppercase, while the `USERNAME` should match your case-sensitive CERN username. | ||
To test if the keytab works: | ||
```bash | ||
kdestroy; kinit -kt ~/private/$USER.keytab $USER; klist | ||
``` | ||
This should display information about a ticket cache. | ||
|
||
### Making use of the keytab | ||
This keytab file can now be used to obtain kerberos tokens without having to type a password: | ||
```bash | ||
kinit -k -t USERNAME.keytab USERNAME@CERN.CH | ||
kinit -k -t ~/private/$USER.keytab $USER@CERN.CH | ||
``` | ||
where `-k` tells `kinit` to use a keytab file and `-t USERNAME.keytab` where this keytab actually is. | ||
where `-k` tells `kinit` to use a keytab file and `-t ~/private/$USER.keytab` where this keytab actually is. | ||
### Using k5reauth to automatically refresh your kerberos token | ||
To create a permanent session of `tmux` or `screen`, the `k5reauth` command is used, which by default creates a new shell and attaches it as a child to itself and keeps renewing the kerberos token for its children. `k5reauth` can start processes other than a new shell by specifying the program you want to start as an argument | ||
```bash | ||
k5reauth -f -i 3600 -p .... -- <command> | ||
``` | ||
To start `screen` or `tmux` run: | ||
```bash | ||
k5reauth -f -i 3600 -p USERNAME -k /path/to/USERNAME.keytab -- tmux new-session -s NAME | ||
k5reauth -f -i 3600 -p $USER -k ~/private/$USER.keytab -- tmux new-session -s NAME | ||
``` | ||
which will create a `tmux` session whose kerberos token is refreshed automatically every 3600 seconds. | ||
|
||
This is not enough to actually get a persistent session. From inside the `tmux` session, run: | ||
```bash | ||
kinit [email protected] | ||
``` | ||
which will create a `tmux` session whose kerberos token is refreshed automatically every 3600 seconds. When attaching back to the process, a simple | ||
Make a note of which lxplus machine you are on. Then, detach the session (<kbd>^B D</kbd> by default) and log out. Finally, log back into the same machine, attach the session using `tmux a`, and run `kinit [email protected]` again. | ||
Now, you should have a persistent tmux session on the machine you logged in to. | ||
|
||
When attaching back to the process in the future, a simple | ||
```bash | ||
tmux attach-session -t NAME | ||
``` | ||
|
@@ -43,13 +67,14 @@ You will almost certainly want to use an alias or function to access this comman | |
```bash | ||
ktmux(){ | ||
if [[ -z "$1" ]]; then #if no argument passed | ||
k5reauth -f -i 3600 -p USERNAME -k /path/to/USERNAME.keytab -- tmux new-session | ||
k5reauth -f -i 3600 -p $USER -k ~/private/$USER.keytab -- tmux new-session | ||
else #pass the argument as the tmux session name | ||
k5reauth -f -i 3600 -p USERNAME -k /path/to/USERNAME.keytab -- tmux new-session -s $1 | ||
k5reauth -f -i 3600 -p $USER -k ~/private/$USER.keytab -- tmux new-session -s $1 | ||
fi | ||
} | ||
``` | ||
You could then start a tmux session named “Test” using | ||
```bash | ||
ktmux Test | ||
``` | ||
Note that you will still have to follow the rest of the recipe (`kinit`, detach, log out, log in, attach, `kinit`) manually to get a persistent session. |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.