Why does jenkins need sudo password when ssh account doesn't? - linux

My linux user account has the rights to run a particular sudo command without a password prompt. I am trying to implements jenkins to run this command. It is set up to ssh as my user account on the box with the Publish Over SSH plugin.
When I am in the box $USER shows the correct user, but when I try to run "sudo {command}" (which runs without password when I am using that box normally with my user) it requires password. What is causing this behavior?

Because it is configured to do so. There is file /etc/sudoers specifying these rules and there is respective manual page describing how does this file and the roles work. It is probably a good start to read.

Related

Make application available to all users

I am the sudo user (main_user) of my server (redhat8) and have many user accounts (user1, user2,....).
I can run installed application in server using main_user account but the other users are not able to execute the program or run the application.
** I have installed the applications/programs from main_user account which is not a root user but having sudo previlages.
What can be done to make the application and programs available to other users as well.
What I tried:
I have made alias in both ./bashrc and profile.d/all_user.sh, and source them but no luck.
You can implement sudo. First in /etc/sudoers file add line like:
user1,user2,user2 ALL=/path/to/the/program
If the users above are in specific group you can add something like:
%usergroup ALL=/path/to/the/program
And run the program like:
sudo -u main_user /path/to/the/program

Dropbear - cannot SSH when user's shell is redirected

I am running Linux on an embedded system with Buildroot+Dropbear. I am using systemd for init, if that matters.
Logging in via SSH works properly for root, but not as a regular user (gives "Permission denied, please try again."). The user's shell is redirected to a custom program with this entry in /etc/passwd:
admin:x:1000:1000:Custom user:/home/admin:/opt/customCLI
Logging in as the admin user works fine when the shell is /bin/sh. /opt/customCLI is a program I wrote that accepts a minimal set of commands.
Is there a way to support SSH logins directly to a custom program?
Add your program to /etc/shells
Some login tools will reject logins to users with unknown shells. This prevents the back door of using SSH to modify files or forward ports while being locked out with /usr/sbin/nologin or /bin/false.

aws ec2 ubuntu require my password

i want to build a project and failed because it requires root permission. When i change the user to root as "sudo -s", it prompted [sudo] password for ubuntu. As ec2 doesn't offer ubuntu password, it login with pem file. How can I login as root and create files? Thanks!
I fixed this by doing using "sudo" for a Ubuntu AWS EC2 SSH Login:
$ sudo passwd ubuntu
Instead of prompting me for:
"(current) UNIX password:"
It prompts now for:
"Enter new UNIX password:"
I hope this fixes some problems with ec2 ubuntu users!
I was surprised as well, when AWS ec2 ubuntu prompted me for a password.
[sudo] password for ubuntu:
In the end I just hit return without inserting anything and it worked.
If you want to run commands from your terminal interactively as root do it as follows:
sudo -i
If just want to run a single command do it as:
sudo some-command-goes-here
You will not be prompted for password in any of these scenario.
AWS doesn't grant root access by default to EC2 instances. This is an important security best practise. Users are supposed to open a ssh connection using the secure key/pair to login as ec2-user. Users are supposed to use the sudo command as ec2-user to obtain elevated privileges.

FTP From Local Desktop to Server As Sudo User

I have a file on my desktop that I need to FTP to a server. As I've been navigating this server, I need to login with initial credentials to access the box and then needed to run sudo -u [username] ksh to access the folder I need. (No password)
In Filezilla however, I only enter credentials once and therefore, don't have the option to sudo as the user and get permissions to the folder.
Am I going about this process wrong and if so, what's the usual way to do this?
There is no way to switch user on the ftp protocol. You need to know the correct credentials in the first place.
The closest you could come would be to ftp the files to a directory you do have access to, log in with a shell, and then move the files using shell commands after switching user.

How to reset Jenkins security settings from the command line?

Is there a way to reset all (or just disable the security settings) from the command line without a user/password as I have managed to completely lock myself out of Jenkins?
The simplest solution is to completely disable security - change true to false in /var/lib/jenkins/config.xml file.
<useSecurity>true</useSecurity>
A one-liner to achieve the same:
sed -i 's/<useSecurity>true<\/useSecurity>/<useSecurity>false<\/useSecurity>/g' /var/lib/jenkins/config.xml
Then just restart Jenkins:
sudo service jenkins restart
And then go to admin panel and set everything once again.
If you in case are running your Jenkins inside a Kubernetes pod and can not run service command, then you can just restart Jenkins by deleting the pod:
kubectl delete pod <jenkins-pod-name>
Once the command was issued, Kubernetes will terminate the old pod and start a new one.
One other way would be to manually edit the configuration file for your user (e.g. /var/lib/jenkins/users/username/config.xml) and update the contents of passwordHash:
<passwordHash>#jbcrypt:$2a$10$razd3L1aXndFfBNHO95aj.IVrFydsxkcQCcLmujmFQzll3hcUrY7S</passwordHash>
Once you have done this, just restart Jenkins and log in using this password:
test
The <passwordHash> element in users/<username>/config.xml will accept data of the format
salt:sha256("password{salt}")
So, if your salt is bar and your password is foo then you can produce the SHA256 like this:
echo -n 'foo{bar}' | sha256sum
You should get 7f128793bc057556756f4195fb72cdc5bd8c5a74dee655a6bfb59b4a4c4f4349 as the result. Take the hash and put it with the salt into <passwordHash>:
<passwordHash>bar:7f128793bc057556756f4195fb72cdc5bd8c5a74dee655a6bfb59b4a4c4f4349</passwordHash>
Restart Jenkins, then try logging in with password foo. Then reset your password to something else. (Jenkins uses bcrypt by default, and one round of SHA256 is not a secure way to store passwords. You'll get a bcrypt hash stored when you reset your password.)
I found the file in question located in /var/lib/jenkins called config.xml, modifying that fixed the issue.
In El-Capitan config.xml can not be found at
/var/lib/jenkins/
Its available in
~/.jenkins
then after that as other mentioned open the config.xml file and make the following changes
In this replace <useSecurity>true</useSecurity> with <useSecurity>false</useSecurity>
Remove <authorizationStrategy> and <securityRealm>
Save it and restart the jenkins(sudo service jenkins restart)
The answer on modifying was correct. Yet, I think it should be mentioned that /var/lib/jenkins/config.xml looks something like this if you have activated "Project-based Matrix Authorization Strategy". Deleting /var/lib/jenkins/config.xml and restarting jenkins also does the trick. I also deleted the users in /var/lib/jenkins/users to start from scratch.
<authorizationStrategy class="hudson.security.ProjectMatrixAuthorizationStrategy">
<permission>hudson.model.Computer.Configure:jenkins-admin</permission>
<permission>hudson.model.Computer.Connect:jenkins-admin</permission>
<permission>hudson.model.Computer.Create:jenkins-admin</permission>
<permission>hudson.model.Computer.Delete:jenkins-admin</permission>
<permission>hudson.model.Computer.Disconnect:jenkins-admin</permission>
<!-- if this is missing for your user and it is the only one, bad luck -->
<permission>hudson.model.Hudson.Administer:jenkins-admin</permission>
<permission>hudson.model.Hudson.Read:jenkins-admin</permission>
<permission>hudson.model.Hudson.RunScripts:jenkins-admin</permission>
<permission>hudson.model.Item.Build:jenkins-admin</permission>
<permission>hudson.model.Item.Cancel:jenkins-admin</permission>
<permission>hudson.model.Item.Configure:jenkins-admin</permission>
<permission>hudson.model.Item.Create:jenkins-admin</permission>
<permission>hudson.model.Item.Delete:jenkins-admin</permission>
<permission>hudson.model.Item.Discover:jenkins-admin</permission>
<permission>hudson.model.Item.Read:jenkins-admin</permission>
<permission>hudson.model.Item.Workspace:jenkins-admin</permission>
<permission>hudson.model.View.Configure:jenkins-admin</permission>
<permission>hudson.model.View.Create:jenkins-admin</permission>
<permission>hudson.model.View.Delete:jenkins-admin</permission>
<permission>hudson.model.View.Read:jenkins-admin</permission>
</authorizationStrategy>
We can reset the password while leaving security on.
The config.xml file in /var/lib/Jenkins/users/admin/ acts sort of like the /etc/shadow file Linux or UNIX-like systems or the SAM file in Windows, in the sense that it stores the hash of the account's password.
If you need to reset the password without logging in, you can edit this file and replace the old hash with a new one generated from bcrypt:
$ pip install bcrypt
$ python
>>> import bcrypt
>>> bcrypt.hashpw("yourpassword", bcrypt.gensalt(rounds=10, prefix=b"2a"))
'YOUR_HASH'
This will output your hash, with prefix 2a, the correct prefix for Jenkins hashes.
Now, edit the config.xml file:
...
<passwordHash>#jbcrypt:REPLACE_THIS</passwordHash>
...
Once you insert the new hash, reset Jenkins:
(if you are on a system with systemd):
sudo systemctl restart Jenkins
You can now log in, and you didn't leave your system open for a second.
To disable Jenkins security in simple steps in Linux, run these commands:
sudo ex +g/useSecurity/d +g/authorizationStrategy/d -scwq /var/lib/jenkins/config.xml
sudo /etc/init.d/jenkins restart
It will remove useSecurity and authorizationStrategy lines from your config.xml root config file and restart your Jenkins.
See also: Disable security at Jenkins website
After gaining the access to Jenkins, you can re-enable security in your Configure Global Security page by choosing the Access Control/Security Realm. After than don't forget to create the admin user.
To reset it without disabling security if you're using matrix permissions (probably easily adaptable to other login methods):
In config.xml, set disableSignup to false.
Restart Jenkins.
Go to the Jenkins web page and sign up with a new user.
In config.xml, duplicate one of the <permission>hudson.model.Hudson.Administer:username</permission> lines and replace username with the new user.
If it's a private server, set disableSignup back to true in config.xml.
Restart Jenkins.
Go to the Jenkins web page and log in as the new user.
Reset the password of the original user.
Log in as the original user.
Optional cleanup:
Delete the new user.
Delete the temporary <permission> line in config.xml.
No securities were harmed during this answer.
On the offchance you accidentally lock yourself out of Jenkins due to a permission mistake, and you dont have server-side access to switch to the jenkins user or root... You can make a job in Jenkins and add this to the Shell Script:
sed -i 's/<useSecurity>true/<useSecurity>false/' ~/config.xml
Then click Build Now and restart Jenkins (or the server if you need to!)
\.jenkins\secrets\initialAdminPassword
Copy the password from the initialAdminPassword file and paste it into the Jenkins.
1 first check location if you install war or Linux or windows based on that
for example if war under Linux and for admin user
/home/"User_NAME"/.jenkins/users/admin/config.xml
go to this tag after #jbcrypt:
<passwordHash>#jbcrypt:$2a$10$3DzCGLQr2oYXtcot4o0rB.wYi5kth6e45tcPpRFsuYqzLZfn1pcWK</passwordHash>
change this password using use any website for bcrypt hash generator
https://www.dailycred.com/article/bcrypt-calculator
make sure it start with $2a cause this one jenkens uses
In order to remove the by default security for jenkins in Windows OS,
You can traverse through the file Config.xml created inside /users/{UserName}/.jenkins.
Inside this file you can change the code from
<useSecurity>true</useSecurity>
To,
<useSecurity>false</useSecurity>
step-1 : go to the directory cd .jenkins/secrets then you will get a 'initialAdminPassword'.
step-2 : nano initialAdminPassword
you will get a password
changing the <useSecurity>true</useSecurity> to <useSecurity>false</useSecurity> will not be enough, you should remove <authorizationStrategy> and <securityRealm> elements too and restart your jenkins server by doing sudo service jenkins restart .
remember this, set <usesecurity> to false only may cause a problem for you, since these instructions are mentioned in thier official documentation here.
Jenkins over KUBENETES and Docker
In case of Jenkins over a container managed by a Kubernetes POD is a bit more complex since: kubectl exec PODID --namespace=jenkins -it -- /bin/bash will you allow to access directly to the container running Jenkins, but you will not have root access, sudo, vi and many commands are not available and therefore a workaround is needed.
Use kubectl describe pod [...] to find the node running your Pod and the container ID (docker://...)
SSH into the node
run docker exec -ti -u root -- /bin/bash to access the container with Root privileges
apt-get update
sudo apt-get install vim
The second difference is that the Jenkins configuration file are placed in a different path that corresponds to the mounting point of the persistent volume, i.e. /var/jenkins_home, this location might change in the future, check it running df.
Then disable security - change true to false in /var/jenkins_home/jenkins/config.xml file.
<useSecurity>false</useSecurity>
Now it is enough to restart the Jenkins, action that will cause the container and the Pod to die, it will created again in some seconds with the configuration updated (and all the chance like vi, update erased) thanks to the persistent volume.
The whole solution has been tested on Google Kubernetes Engine.
UPDATE
Notice that you can as well run ps -aux the password in plain text is shown even without root access.
jenkins#jenkins-87c47bbb8-g87nw:/$ps -aux
[...]
jenkins [..] -jar /usr/share/jenkins/jenkins.war --argumentsRealm.passwd.jenkins=password --argumentsRealm.roles.jenkins=admin
[...]
Easy way out of this is to use the admin psw to login with your admin user:
Change to root user: sudo su -
Copy the password: xclip -sel clip < /var/lib/jenkins/secrets/initialAdminPassword
Login with admin and press ctrl + v on password input box.
Install xclip if you don't have it:
$ sudo apt-get install xclip
Using bcrypt you can solve this issue. Extending the #Reem answer for someone who is trying to automate the process using bash and python.
#!/bin/bash
pip install bcrypt
yum install -y https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
yum -y install xmlstarlet
cat > /tmp/jenkinsHash.py <<EOF
import bcrypt
import sys
if not sys.argv[1]:
sys.exit(10)
plaintext_pwd=sys.argv[1]
encrypted_pwd=bcrypt.hashpw(sys.argv[1], bcrypt.gensalt(rounds=10, prefix=b"2a"))
isCorrect=bcrypt.checkpw(plaintext_pwd, encrypted_pwd)
if not isCorrect:
sys.exit(20);
print "{}".format(encrypted_pwd)
EOF
chmod +x /tmp/jenkinsHash.py
cd /var/lib/jenkins/users/admin*
pwd
while (( 1 )); do
echo "Waiting for Jenkins to generate admin user's config file ..."
if [[ -f "./config.xml" ]]; then
break
fi
sleep 10
done
echo "Admin config file created"
admin_password=$(python /tmp/jenkinsHash.py password 2>&1)
# Repalcing the new passowrd
xmlstarlet -q ed --inplace -u "/user/properties/hudson.security.HudsonPrivateSecurityRealm_-Details/passwordHash" -v '#jbcrypt:'"$admin_password" config.xml
# Restart
systemctl restart jenkins
sleep 10
I have kept password hardcoded here but it can be a user input depending upon the requirement. Also make sure to add that sleep otherwise any other command revolving around Jenkins will fail.
To very simply disable both security and the startup wizard, use the JAVA property:
-Djenkins.install.runSetupWizard=false
The nice thing about this is that you can use it in a Docker image such that your container will always start up immediately with no login screen:
# Dockerfile
FROM jenkins/jenkins:lts
ENV JAVA_OPTS -Djenkins.install.runSetupWizard=false
Note that, as mentioned by others, the Jenkins config.xml is in /var/jenkins_home in the image, but using sed to modify it from the Dockerfile fails, because (presumably) the config.xml doesn't exist until the server starts.
I will add some improvements based on the solution:
https://stackoverflow.com/a/51255443/5322871
On my scenario it was deployed with Swarm cluster with nfs volume, in order to perform the password reset I did the following:
Attach to the pod:
$ docker exec -it <pod-name> bash
Generate the hash password with python (do not forget to specify the letter b outside of your quoted password, the method hashpw requires a parameter in bytes):
$ pip install bcrypt
$ python
>>> import bcrypt
>>> bcrypt.hashpw(b"yourpassword", bcrypt.gensalt(rounds=10, prefix=b"2a"))
'YOUR_HASH'
Once inside the container find all the config.xml files:
$ find /var/ -type f -iname "config.xml"
Once identified, modify value of the field ( on my case the config.xml was in another location):
$ vim /var/jenkins_home/users/admin_9482805162890262115/config.xml
...
<passwordHash>#jbcrypt:YOUR_HASH</passwordHash>
...
Restart the service:
docker service scale <service-name>=0
docker service scale <service-name>=1
Hope this can be helpful for anybody.
I had a similar issue, and following reply from ArtB,
I found that my user didn't have the proper configurations. so what I did:
Note: manually modifying such XML files is risky. Do it at your own risk. Since I was already locked out, I didn't have much to lose. AFAIK Worst case I would have deleted the ~/.jenkins/config.xml file as prev post mentioned.
**> 1. ssh to the jenkins machine
cd ~/.jenkins (I guess that some installations put it under /var/lib/jenkins/config.xml, but not in my case )
vi config.xml, and under authorizationStrategy xml tag, add the below section (just used my username instead of "put-your-username")
restart jenkins. in my case as root service tomcat7 stop; ; service tomcat7 start
Try to login again. (worked for me)**
under
add:
<permission>hudson.model.Computer.Build:put-your-username</permission>
<permission>hudson.model.Computer.Configure:put-your-username</permission>
<permission>hudson.model.Computer.Connect:put-your-username</permission>
<permission>hudson.model.Computer.Create:put-your-username</permission>
<permission>hudson.model.Computer.Delete:put-your-username</permission>
<permission>hudson.model.Computer.Disconnect:put-your-username</permission>
<permission>hudson.model.Hudson.Administer:put-your-username</permission>
<permission>hudson.model.Hudson.ConfigureUpdateCenter:put-your-username</permission>
<permission>hudson.model.Hudson.Read:put-your-username</permission>
<permission>hudson.model.Hudson.RunScripts:put-your-username</permission>
<permission>hudson.model.Hudson.UploadPlugins:put-your-username</permission>
<permission>hudson.model.Item.Build:put-your-username</permission>
<permission>hudson.model.Item.Cancel:put-your-username</permission>
<permission>hudson.model.Item.Configure:put-your-username</permission>
<permission>hudson.model.Item.Create:put-your-username</permission>
<permission>hudson.model.Item.Delete:put-your-username</permission>
<permission>hudson.model.Item.Discover:put-your-username</permission>
<permission>hudson.model.Item.Read:put-your-username</permission>
<permission>hudson.model.Item.Workspace:put-your-username</permission>
<permission>hudson.model.Run.Delete:put-your-username</permission>
<permission>hudson.model.Run.Update:put-your-username</permission>
<permission>hudson.model.View.Configure:put-your-username</permission>
<permission>hudson.model.View.Create:put-your-username</permission>
<permission>hudson.model.View.Delete:put-your-username</permission>
<permission>hudson.model.View.Read:put-your-username</permission>
<permission>hudson.scm.SCM.Tag:put-your-username</permission>
Now, you can go to different directions. For example I had github oauth integration, so I could have tried to replace the authorizationStrategy with something like below:
Note:, It worked in my case because I had a specific github oauth plugin that was already configured. So it is more risky than the previous solution.
<authorizationStrategy class="org.jenkinsci.plugins.GithubAuthorizationStrategy" plugin="github-oauth#0.14">
<rootACL>
<organizationNameList class="linked-list">
<string></string>
</organizationNameList>
<adminUserNameList class="linked-list">
<string>put-your-username</string>
<string>username2</string>
<string>username3</string>
<string>username_4_etc_put_username_that_will_become_administrator</string>
</adminUserNameList>
<authenticatedUserReadPermission>true</authenticatedUserReadPermission>
<allowGithubWebHookPermission>false</allowGithubWebHookPermission>
<allowCcTrayPermission>false</allowCcTrayPermission>
<allowAnonymousReadPermission>false</allowAnonymousReadPermission>
</rootACL>
</authorizationStrategy>
Edit the file $JENKINS_HOME/config.xml and change de security configuration with this:
<authorizationStrategy class="hudson.security.AuthorizationStrategy$Unsecured"/>
After that restart Jenkins.
A lot of times you wont be having permissions to edit the config.xml file.
The simplest thing would be to take a back of config.xml and delete using sudo command.
Restart the jenkins using the command sudo /etc/init.d/jenkins restart
This will disable all the security in the Jenkins and the login option would disappear
For one who is using macOS, the new version just can be installed by homebrew. so for resting, this command line must be using:
brew services restart jenkins-lts
The directory where the file is located config.xml in windows
C:\Windows\System32\config\systemprofile\AppData\Local\Jenkins\.jenkins

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