SSH public key log in suddenly stopped working (CENTOS 6) - ssh

I was testing a jenkins build job in which I was using ansible to scp a tarball to a number of servers. Below is the ansible yaml file:
- hosts: websocket_host
user: root
vars:
tarball: /data/websocket/jenkins/deployment/websocket_host/websocket.tgz
deploydir: /root
tasks:
- name: copy build to websocket server
action: copy src=$tarball dest=$deploydir/websocket.tgz
- name: untar build on websocket server
action: command tar xvfz $deploydir/websocket.tgz -C $deploydir
- name: restart websocket server
action: command /root/websocket/bin/websocket restart
The first two commands worked successfully with command /root/websocket/bin/websocket restart failing. I have since been able to log in (without a password) to any of the servers defined in my ansible host file for websocket_host. I have verified that all my permissions settings are correct on both the host and client machines. I have tested this from several client machines and they all now require me to enter a password to ssh. Yesterday I was able to ssh (via my public key) no problem. I am using the root user on the host machines and wonder if copying files to the /root directory caused this issue as it was the last command I was able to successfully run via a passwordless ssh session.

Turns out the Jenkins job changed ownership and group of my /root directory. The command: chown root.root /root fixes everything.

Related

Ansible unable to create folder on localhost with different user

I'm executing ansible playbook with appuser whereas I wish to create folder with user webuser on localhost.
ssh keys are setup for webuser on my localhost. So after login with appuser I can simply ssh webuser#localhost to switch user to webuser.
Note: I do not have sudo priveledges so I cannot sudo to switch to webuser from appuser.
Below is my playbook that is run with user appuser but needs to create a folder 04May2020 on localhost using webuser
- name: "Play 1"
hosts: localhost
remote_user: "webuser"
vars:
ansible_ssh_extra_args: -o StrictHostKeyChecking=no
ansible_ssh_private_key_file: /app/misc_automation/ssh_keys_id_rsa
tasks:
- name: create folder for today's print
file:
path: "/webWeb/htdocs/print/04May2020"
state: directory
remote_user: webuser
However, the output shows that the folder is created with appuser instead of webuser. See output showing ssh connectivity with appuser instead of webuser.
ansible-playbook /app/Ansible/playbook/print_oracle/print.yml -i /app/Ansible/playbook/print_oracle/allhosts.hosts -vvv
TASK [create folder for today] ***********************************
task path: /app/Ansible/playbook/print_oracle/print.yml:33
Using module file /usr/lib/python2.7/site-packages/ansible/modules/files/file.py
Pipelining is enabled.
<127.0.0.1> ESTABLISH LOCAL CONNECTION FOR USER: appuser
<127.0.0.1> EXEC /bin/sh -c '/usr/bin/python2 && sleep 0'
Can you please suggest if it is possible without sudo?
Putting all my comments together in a comprehensive answer.
<127.0.0.1> ESTABLISH LOCAL CONNECTION FOR USER: appuser
This is indicating that you are connecting to localhost through the local connection plugin, either because you explicitelly re-declared the host as such or because you are using the implicit localhost. From discussions, you are in the second situation.
When using the local connection plugin, as indicated in the above documentation, the remote_user is ignored. Trying to change the user has no effect as you can see in the below test run (user (u)ids changed):
# Check we are locally running as user1
$ id -a
uid=xxxx(user1) gid=yyy(group1) groups=yyy(group1)
# Running the same command through ansible returns the same result
$ ansible localhost -a 'id -a'
localhost | CHANGED | rc=0 >>
uid=xxxx(user1) gid=yyy(group1) groups=yyy(group1)
# Trying to change the remote user has no effect
$ ansible localhost -u whatever -a 'id -a'
localhost | CHANGED | rc=0 >>
uid=xxxx(user1) gid=yyy(group1) groups=yyy(group1)
Without changing your playbook and/or inventory, the only solution is to launch the playbook as the user who needs to create the directory.
Since you have ssh available, an other solution is to declare a new host that you will use only for this purpose, which will target the local IP through ssh. (Note: you can explicitly declare localhost like this but then all connections will go through ssh which might not be what you want to do).
Somewhere at the top of you inventory, add the line:
localssh ansible_host=127.0.0.1
And in your playbook, change
hosts: localssh
Now the connection to your local machine will go through ssh and the remote_user will be obeyed correctly.
One way you can try is by setting the ansible_connection to localhost. To do this, in the directory from which you are running ansible commands, create a host_vars directory. In that sub-directory, create a file named localhost, containing the line ansible_connection: smart

Is it possible to add an ssh key to the agent for a private repo in an ansible playbook?

I am using Ansible to provision a Vagrant environment. As part of the provisioning process, I need to connect from the currently-provisioning VM to a private external repository using an ssh key in order to use composer to pull in modules for an application. I've done a lot of reading on this before asking this question, but still can't seem to comprehend what's going on.
What I want to happen is:
As part of the playbook, on the Vagrant VM, I add the ssh key to the private repo to the ssh-agent
Using that private key, I am then able to use composer to require modules from the external source
I've read articles which highlight specifying the key in playbook execution. (E.g. ansible-play -u username --private-key play.yml) As far as I understand, this isn't for me, as I'm calling the playbook via Vagrant file. I've also read articles which mention ssh forwarding. (SSH Agent Forwarding with Ansible). Based on what I have read, this is what I've done:
On the VM being provisioned, I insert a known_hosts file which consists of the host entries of the machines which house the repos I need:
On the VM being provisioned, I have the following in ~/.ssh/config:
Host <VM IP>
ForwardAgent yes
I have the following entries in my ansible.cfg to support ssh forwarding:
[defaults]
transport = ssh
[ssh_connection]
ssh_args=-o ForwardAgent=yes -o ControlMaster=auto -o ControlPersist=60s -o ControlPath=/tmp/ansible-ssh-%h-%p-%r
[privilege_escalation]
pipelining = False
I have also added the following task to the playbook which tries to
use composer:
- name: Add ssh agent line to sudoers
become: true
lineinfile:
dest: /etc/sudoers
state: present
regexp: SSH_AUTH_SOCK
line: Defaults env_keep += "SSH_AUTH_SOCK"
I exit the ansible provisioner and add the private key on the provisioned VM to the agent via a shell provisioner (This is where I suspect I'm going wrong)
Then, I attempt to use composer, or call git via the command module. Like this, for example, to test:
- name: Test connection
command: ssh -T git#github.com
Finally, just in case I wasn't understanding ssh connection forwarding correctly, I assumed that what was supposed to happen was that I needed to first add the key to my local machine's agent, then forward that through to the provisioned VM to use to grab the repositories via composer. So I used ssh-add on my local machine before executing vagrant up and running the provisioner.
No matter what, though, I always get permission denied when I do this. I'd greatly appreciate some understanding as to what I may be missing in my understanding of how ssh forwarding should be working here, as well as any guidance for making this connection happen.
I'm not certain I understand your question correctly, but I often setup machines that connect to a private bitbucket repository in order to clone it. You don't need to (and shouldn't) use agent forwarding for that ("ssh forwarding" is unclear; there's "authentication agent forwarding" and "port forwarding", but you need neither in this case).
Just to be clear with terminology, you are running Ansible in your local machine, you are provisioning the controlled machine, and you want to ssh from the controlled machine to a third-party server.
What I do is I upload the ssh key to the controlled machine, in /root/.ssh (more generally $HOME/.ssh where $HOME is the home directory of the controlled machine user who will connect to the third-party server—in my case that's root). I don't use the names id_rsa and id_rsa.pub, because I don't want to touch the default keys of that user (these might have a different purpose; for example, I use them to backup the controlled machine). So this is the code:
- name: Install bitbucket aptiko_ro ssh key
copy:
dest: /root/.ssh/aptiko_ro_id_rsa
mode: 0600
content: "{{ aptiko_ro_ssh_key }}"
- name: Install bitbucket aptiko_ro ssh public key
copy:
dest: /root/.ssh/aptiko_ro_id_rsa.pub
content: "{{ aptiko_ro_ssh_pub_key }}"
Next, you need to tell the controlled machine ssh this: "When you connect to the third-party server, use key X instead of the default key, and logon as user Y". You tell it in this way:
- name: Install ssh config that uses aptiko_ro keys on bitbucket
copy:
dest: /root/.ssh/config
content: |
Host bitbucket.org
IdentityFile ~/.ssh/aptiko_ro_id_rsa
User aptiko_ro

How to use a public keypair .pem file for ansible playbooks?

I want to use a public aws keypair .pem file for running ansible playbooks. I want to do this without changing my ~/.ssh/id_rsa.pub and I can't create a new keypair from my current ~/.ssh/id_rsa.pub and apply it to the ec2 instances I am trying to change.
$ ansible --version
ansible 1.9.6
configured module search path = None
Here is my hosts file (note that my actual ip is replaced with 1.2.3.4). This is probably the issue since I need a way to set a public key variable and use that:
[all_servers:vars]
ansible_ssh_private_key_file = ./mykeypair.pem
[dashboard]
1.2.3.4 dashboard_domain=my.domain.info
Here is my playbook:
---
- hosts: dashboard
gather_facts: False
remote_user: ubuntu
tasks:
- name: ping
ping:
This is the command I am using to run it:
ansible-playbook -i ./hosts test.yml
It results in the following error:
fatal: [1.2.3.4] => SSH Error: Permission denied (publickey).
while connecting to 1.2.3.4:22
There is no problem with my keypair:
$ ssh -i mykeypair.pem ubuntu#1.2.3.4 'whoami'
ubuntu
What am I doing wrong?
Ok little mistakes I guess you can't have spaces in host file variables and need to define the group you are applying the vars to. This hosts file works with it all:
[dashboard:vars]
ansible_ssh_private_key_file=./mykeypair.pem
[dashboard]
1.2.3.4 dashboard_domain=my.domain.info
I have come across this and all what I had to do was to run the below
#ssh-agent bash
#ssh-add ~/.ssh/keypair.pem

Inject host's SSH keys into Docker Machine with Docker Compose

I am using Docker on Mac OS X with Docker Machine (with the default boot2docker machine), and I use docker-compose to setup my development environment.
Let's say that one of the containers is called "stack". Now what I want to do is call:
docker-composer run stack ssh user#stackoverflow.com
My public key (which has been added to stackoverflow.com and which will be used to authenticate me) is located on the host machine. I want this key to be available to the Docker Machine container so that I will be able to authenticate myself against stackoverflow using that key from within the container. Preferably without physically copying my key to Docker Machine.
Is there any way to do this? Also, if my key is password protected, is there any way to unlock it once so after every injection I will not have to manually enter the password?
You can add this to your docker-compose.yml (assuming your user inside container is root):
volumes:
- ~/.ssh:/root/.ssh
Also you can check for more advanced solution with ssh agent (I did not tried it myself)
WARNING: This feature seems to have limited support in Docker Compose and is more designed for Docker Swarm.
(I haven't checked to make sure, but) My current impression is that:
In Docker Compose secrets are just bind mount volumes, so there's no additional security compared to volumes
Ability to change secrets permissions with Linux host may be limited
See answer comments for more details.
Docker has a feature called secrets, which can be helpful here. To use it one could add the following code to docker-compose.yml:
---
version: '3.1' # Note the minimum file version for this feature to work
services:
stack:
...
secrets:
- host_ssh_key
secrets:
host_ssh_key:
file: ~/.ssh/id_rsa
Then the new secret file can be accessed in Dockerfile like this:
RUN mkdir ~/.ssh && ln -s /run/secrets/host_ssh_key ~/.ssh/id_rsa
Secret files won't be copied into container:
When you grant a newly-created or running service access to a secret, the decrypted secret is mounted into the container in an in-memory filesystem
For more details please refer to:
https://docs.docker.com/engine/swarm/secrets/
https://docs.docker.com/compose/compose-file/compose-file-v3/#secrets
If you're using OS X and encrypted keys this is going to be PITA. Here are the steps I went through figuring this out.
Straightforward approach
One might think that there’s no problem. Just mount your ssh folder:
...
volumes:
- ~/.ssh:/root/.ssh:ro
...
This should be working, right?
User problem
Next thing we’ll notice is that we’re using the wrong user id. Fine, we’ll write a script to copy and change the owner of ssh keys. We’ll also set ssh user in config so that ssh server knows who’s connecting.
...
volumes:
- ~/.ssh:/root/.ssh-keys:ro
command: sh -c ‘./.ssh-keys.sh && ...’
environment:
SSH_USER: $USER
...
# ssh-keys.sh
mkdir -p ~/.ssh
cp -r /root/.ssh-keys/* ~/.ssh/
chown -R $(id -u):$(id -g) ~/.ssh
cat <<EOF >> ~/.ssh/config
User $SSH_USER
EOF
SSH key passphrase problem
In our company we protect SSH keys using a passphrase. That wouldn’t work in docker since it’s impractical to enter a passphrase each time we start a container.
We could remove a passphrase (see example below), but there’s a security concern.
openssl rsa -in id_rsa -out id_rsa2
# enter passphrase
# replace passphrase-encrypted key with plaintext key:
mv id_rsa2 id_rsa
SSH agent solution
You may have noticed that locally you don’t need to enter a passphrase each time you need ssh access. Why is that?
That’s what SSH agent is for. SSH agent is basically a server which listens to a special file, unix socket, called “ssh auth sock”. You can see its location on your system:
echo $SSH_AUTH_SOCK
# /run/user/1000/keyring-AvTfL3/ssh
SSH client communicates with SSH agent through this file so that you’d enter passphrase only once. Once it’s unencrypted, SSH agent will store it in memory and send to SSH client on request.
Can we use that in Docker? Sure, just mount that special file and specify a corresponding environment variable:
environment:
SSH_AUTH_SOCK: $SSH_AUTH_SOCK
...
volumes:
- $SSH_AUTH_SOCK:$SSH_AUTH_SOCK
We don’t even need to copy keys in this case.
To confirm that keys are available we can use ssh-add utility:
if [ -z "$SSH_AUTH_SOCK" ]; then
echo "No ssh agent detected"
else
echo $SSH_AUTH_SOCK
ssh-add -l
fi
The problem of unix socket mount support in Docker for Mac
Unfortunately for OS X users, Docker for Mac has a number of shortcomings, one of which is its inability to share Unix sockets between Mac and Linux. There’s an open issue in D4M Github. As of February 2019 it’s still open.
So, is that a dead end? No, there is a hacky workaround.
SSH agent forwarding solution
Luckily, this issue isn’t new. Long before Docker there was a way to use local ssh keys within a remote ssh session. This is called ssh agent forwarding. The idea is simple: you connect to a remote server through ssh and you can use all the same remote servers there, thus sharing your keys.
With Docker for Mac we can use a smart trick: share ssh agent to the docker virtual machine using TCP ssh connection, and mount that file from virtual machine to another container where we need that SSH connection. Here’s a picture to demonstrate the solution:
First, we create an ssh session to the ssh server inside a container inside a linux VM through a TCP port. We use a real ssh auth sock here.
Next, ssh server forwards our ssh keys to ssh agent on that container. SSH agent has a Unix socket which uses a location mounted to Linux VM. I.e. Unix socket works in Linux. Non-working Unix socket file in Mac has no effect.
After that we create our useful container with an SSH client. We share the Unix socket file which our local SSH session uses.
There’s a bunch of scripts that simplifies that process:
https://github.com/avsm/docker-ssh-agent-forward
Conclusion
Getting SSH to work in Docker could’ve been easier. But it can be done. And it’ll likely to be improved in the future. At least Docker developers are aware of this issue. And even solved it for Dockerfiles with build time secrets. And there's a suggestion how to support Unix domain sockets.
You can forward SSH agent:
something:
container_name: something
volumes:
- $SSH_AUTH_SOCK:/ssh-agent # Forward local machine SSH key to docker
environment:
SSH_AUTH_SOCK: /ssh-agent
You can use multi stage build to build containers This is the approach you can take :-
Stage 1 building an image with ssh
FROM ubuntu as sshImage
LABEL stage=sshImage
ARG SSH_PRIVATE_KEY
WORKDIR /root/temp
RUN apt-get update && \
apt-get install -y git npm
RUN mkdir /root/.ssh/ &&\
echo "${SSH_PRIVATE_KEY}" > /root/.ssh/id_rsa &&\
chmod 600 /root/.ssh/id_rsa &&\
touch /root/.ssh/known_hosts &&\
ssh-keyscan github.com >> /root/.ssh/known_hosts
COPY package*.json ./
RUN npm install
RUN cp -R node_modules prod_node_modules
Stage 2: build your container
FROM node:10-alpine
RUN mkdir -p /usr/app
WORKDIR /usr/app
COPY ./ ./
COPY --from=sshImage /root/temp/prod_node_modules ./node_modules
EXPOSE 3006
CMD ["npm", "run", "dev"]
add env attribute in your compose file:
environment:
- SSH_PRIVATE_KEY=${SSH_PRIVATE_KEY}
then pass args from build script like this:
docker-compose build --build-arg SSH_PRIVATE_KEY="$(cat ~/.ssh/id_rsa)"
And remove the intermediate container it for security. This Will help you cheers.
Docker for Mac now supports mounting the ssh agent socket on macOS.

Vagrant ssh forward_agent without entering vagrant user password repeadley

I currently use Vagrant and Chef to provision a VM and setup my PHP based project. This includes running composer install which essentially does a git clone of a number of private repositories.
After setting up ssh agent forwarding as outlined in the docs and the answers here: How to use ssh agent forwarding with "vagrant ssh"? I have successfully got it working.
The problem I'm having is when ever I boot a VM, provision a VM or SSH into a VM I'm now asked for vagrants default password, see examples below:
==> web: Waiting for machine to boot. This may take a few minutes...
web: SSH address: 192.168.77.185:22
web: SSH username: vagrant
web: SSH auth method: private key
Text will be echoed in the clear. Please install the HighLine or Termios libraries to suppress echoed text.
vagrant#192.168.77.185's password:
Example 2
➜ vagrant git:(master) ✗ vagrant ssh
vagrant#192.168.77.185's password:
This is pretty inconvenient as I work across a number of projects, including destroying and creating some a number of times a day (Chef test kitchen). Is there anyway to automatically use my public key as well so I don't need to continually enter a password?
I ran into a similar issue recently after creating a new Vagrant box from scratch. The problem turned out to be old entries in ~/.ssh/known_hosts (on OS X).
Try the following (assumes OS X or linux):
ssh into your Vagrant machine
type ip addr or ifconfig or the like (depending on your OS)
take note of the IP addresses listed, including 127.0.0.1
on your host machine, run ssh-keygen -R {vm-ip-address} (make sure to include 127.0.0.1 and [127.0.0.1]) for the addresses in step 3
confirm the relevant entries have been removed from ~/.ssh/known_hosts
vagrant reload
vagrant ssh
Alternatively, you can just delete/move/rename the ~/.ssh/known_hosts file, though this will require reconfirming authenticity again for multiple machines you've already ssh'd to.
I hope that helps.
Reference: http://www.geekride.com/ssh-warning-remote-host-identification-has-changed/