error:" ln: failed to create symbolic link ‘./sys/kernel/config/nvmt’: Operation not permitted" even with root access - permissions

I am trying to setup NVMe over Fabrics using post "https://community.mellanox.com/s/article/howto-configure-nvme-over-fabrics".
I could reach step 10, but when I try to create the soft link according to step 10 as a root user, I am getting error:
ln: failed to create symbolic link ‘./sys/kernel/config/nvmt/subsystems’: Operation not permitted
why creating soft link in /sys/kernel/config as a root user is not possible?
is there any way to get this to work?

Having the same issue, I found that in my case the problem was with the OFED driver.
When trying to run the ln -s command, I would see in dmesg the error:
nvmet: transport type 1 not supported
Following this answer, I reinstalled OFED with the option --with-nvmf, and that allowed setting NVMeoF properly.

Are you including the initial period ('./') in the path? That would say from the current location.

I had similar problem and the reason turned out to be that the directory to be linked must be created BEFORE creating the link. I checked the instructions you are referring to, it seems that they have been updated.
The step you are referring to seems to be step 9 now:
ln -s /sys/kernel/config/nvmet/subsystems/nvme-subsystem-name /sys/kernel/config/nvmet/ports/1/subsystems/nvme-subsystem-name
This will only work if both /sys/kernel/config/nvmet/subsystems/nvme-subsystem-name and /sys/kernel/config/nvmet/ports/1/subsystems/nvme-subsystem-name already exist. Now, I don't see the latter folder being created anywhere, so I would try creating that folder:
mkdir -p /sys/kernel/config/nvmet/ports/1/subsystems/nvme-subsystem-name
The -p option enables mkdir to create all the missing directories in the given path if they are missing, so you can directly type mkdir -p a/b/c instead of first mkdir a, then mkdir a/b, then mkdir a/b/c.

Related

How to use podman's ssh build flag?

I have been using the docker build --ssh flag to give builds access to my keys from ssh-agent.
When I try the same thing with podman it does not work. I am working on macOS Monterey 12.0.1. Intel chip. I have also reproduced this on Ubuntu and WSL2.
❯ podman --version
podman version 3.4.4
This is an example Dockerfile:
FROM python:3.10
RUN mkdir -p -m 0600 ~/.ssh \
&& ssh-keyscan github.com >> ~/.ssh/known_hosts
RUN --mount=type=ssh git clone git#github.com:ruarfff/a-private-repo-of-mine.git
When I run DOCKER_BUILDKIT=1 docker build --ssh default . it works i.e. the build succeeds, the repo is cloned and the ssh key is not baked into the image.
When I run podman build --ssh default . the build fails with:
git#github.com: Permission denied (publickey).
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
Error: error building at STEP "RUN --mount=type=ssh git clone git#github.com:ruarfff/a-private-repo-of-mine.git": error while running runtime: exit status 128
I have just begun playing around with podman. Looking at the docs, that flag does appear to be supported. I have tried playing around with the format a little, specifying the id directly for example but no variation of specifying the flag or the mount has worked so far. Is there something about how podman works that I may be missing that explains this?
Adding this line as suggested in the comments:
RUN --mount=type=ssh ssh-add -l
Results in this error:
STEP 4/5: RUN --mount=type=ssh ssh-add -l
Could not open a connection to your authentication agent.
Error: error building at STEP "RUN --mount=type=ssh ssh-add -l": error while running runtime: exit status 2
Edit:
I belive this may have something to do with this issue in buildah. A fix has been merged but has not been released yet as far as I can see.
The error while running runtime: exit status 2 does not to me appear to be necessarily related to SSH or --ssh for podman build. It's hard to say really, and I've successfully used --ssh like you are trying to do, with some minor differences that I can't relate to the error.
I am also not sure ssh-add being run as part of building the container is what you really meant to do -- if you want it to talk to an agent, you need to have two environment variables being exported from the environment in which you run ssh-add, these define where to find the agent to talk to and are as follows:
SSH_AUTH_SOCK, specifying the path to a socket file that a program uses to communicate with the agent
SSH_AGENT_PID, specifying the PID of the agent
Again, without these two variables present in the set of exported environment variables, the agent is not discoverable and might as well not exist at all so ssh-add will fail.
Since your agent is probably running as part of the set of processes to which your podman build also belongs to, at the minimum the PID denoted by SSH_AGENT_PID should be valid in that namespace (meaning it's normally invalid in the set of processes that container building is isolated to, so defining the variable as part of building the container would be a mistake). Similar story with SSH_AUTH_SOCK -- the path to the socket file dumped by starting the agent program, would not normally refer to a file that exists in the mount namespace of the container being built.
Now, you can run both the agent and ssh-add as part of building a container, but ssh-add reads keys from ~/.ssh and if you had key files there as part of the container image being built you wouldn't need --ssh in the first place, would you?
The value of --ssh lies in allowing you to transfer your authority to talk to remote services defined through your keys on the host, to the otherwise very isolated container building procedure, through use of nothing else but an SSH agent designed for this very purpose. That removes the need to do things like copying key files into the container. They (keys) should also normally not be part of the built container, especially if they were only to be used during building. The agent, on the other hand, runs on the host, securely encapsulates the keys you add to it, and since the host is where you'd have your keys that's where you're supposed to run ssh-add at to add them to the agent.

SSH opening file error - no idea why

Running Debian Linux - newest version.
cp /included/filename /usr/bin/
It gives me error "cannot stat '/included/filename': No such file or directory
I don't get why there should be an error. I am doing it as superuser.
From your latest comment i conclude you got the paths mixed up. If you want to copy the file install.sh located under /usr/bin/included/ you would need to do
cp /usr/bin/included/install.sh /usr/bin/
to make something similar to your provided command work, id assume you are in /usr/bin and the first argument needs to be a relative one
cd /usr/bin
cp ./included/install.sh /usr/bin/
Please provide more information on what you are trying to do and provide realworld example code.

at command in ubuntu apache error 'You do not have permission to use at'

I am pretty new at php and ubuntu. I have 2 servers set up, one for development and one for staging. On the dev machine I can use the at command without a problem, but on staging I get a permissions error. The at.deny (and at.allow) files are identical, so it must be another permissions issue.
Any clues?
I see that on the staging server I can only use at command as root. How can I fix this to be able to use the at command as www-data? Again... I checked the at.allow and at.deny files ... they are not the problem here.
1) Check if you have file /etc/at.allow.
If it exists - just add your user in new line.
If not exists - try to find your user in /etc/at.deny and remove/comment it.
2) Restart "at" daemon:
sudo atd restart
3) Check:
at -l
or
sudo -u myuser at -l
The error should not be output.

I m trying to integrate ldap with devstack and when i did ./stack.sh i got this localrc: line 9: KEYSTONE_IDENTITY_BACKEND: command not found

localrc file
ADMIN_PASSWORD=password2 MYSQL_PASSWORD=password2
RABBIT_PASSWORD=password2 SERVICE_PASSWORD=password2
SERVICE_TOKEN=token2
ENABLED_SERVICES=key,n-api,n-crt,n-obj,n-cpu,n-net,n-cond,cinder,c-sch,c-api,c-vol,n-sch,n-novnc,n-xvnc,n-cauth,horizon,mysql,rabbit,ldap
KEYSTONE_IDENTITY_BACKEND=ldap
KEYSTONE_CLEAR_LDAP=yes LDAP_PASSWORD=9632
I followed this website(http://www.ibm.com/developerworks/cloud/library/cl-ldap-keystone/)
I am assuming the above snippet is from a file written in shell script. Your example looks Ok.
I checked the link you provided and noted that the line you say failed is written in the IBM example as:
KEYSTONE_IDENTITY_BACKEND = ldap
Which is not legal sh (or bash) and would cause the error message you described.
KEYSTONE_IDENTITY_BACKEND = ldap
-bash: KEYSTONE_IDENTITY_BACKEND: command not found
I suspect you copied and pasted the bad example from the link into your localrc file, which caused the error you saw, but somehow when you wrote the SO question, you corrected the mistake by removing the spaces around the "=".
Edit: Investigation
;TLDR
Create a file in the root of the devstack repo, devstack/local.conf with the contents:
[[local|localrc]]
ADMIN_PASSWORD=password2
MYSQL_PASSWORD=password2
RABBIT_PASSWORD=password2
SERVICE_PASSWORD=password2
SERVICE_TOKEN=token2
ENABLED_SERVICES=key,n-api,n-crt,n-obj,n-cpu,n-net,n-cond,cinder,c-sch,c-api,c-vol,n-sch,n-novnc,n-xvnc,n-cauth,horizon,mysql,rabbit,ldap
KEYSTONE_IDENTITY_BACKEND=ldap
KEYSTONE_CLEAR_LDAP=yes
LDAP_PASSWORD=9632
Full Description
I installed devstack on Centos7 (using the Devstack Quick Start Guide):
git clone https://git.openstack.org/openstack-dev/devstack
cd devstack
./stack.sh
I entered passwords as prompted, but eventually it failed with the error:
Error: pg_config executable not found.
Please add the directory containing pg_config to the PATH
or specify the full executable path with the option:
python setup.py build_ext --pg-config /path/to/pg_config build ...
or with the pg_config option in 'setup.cfg'.
I traced the problem to a limited PATH in the sudoers entry, and because my postgreSQL install is in a non-standard location, I linked pg_config into /usr/local/bin and ran stack.sh again:
sudo ln -s /usr/pgsql-9.3/bin/pg_config /usr/local/bin/pg_config
./stack.sh
(You probably won't have to do this if Postgres is in a standard location).
Install took a long time -
This is your host IP address: 192.168.200.181
This is your host IPv6 address: ::1
Horizon is now available at http://192.168.200.181/dashboard
Keystone is serving at http://192.168.200.181/identity/
The default users are: admin and demo
The password: 12345678
2016-07-17 18:16:32.834 | WARNING:
2016-07-17 18:16:32.834 | Using lib/neutron-legacy is deprecated, and it will be removed in the future
2016-07-17 18:16:32.834 | stack.sh completed in 1447 seconds.
I killed the devstack session and did it all again with a clean git repo and with a localrc file.
./unstack.sh
cd ..
git clone https://git.openstack.org/openstack-dev/devstack
cd devstack
cat << __EOF > local.conf
[[local|localrc]]
ADMIN_PASSWORD=password2
MYSQL_PASSWORD=password2
RABBIT_PASSWORD=password2
SERVICE_PASSWORD=password2
SERVICE_TOKEN=token2
ENABLED_SERVICES=key,n-api,n-crt,n-obj,n-cpu,n-net,n-cond,cinder,c-sch,c-api,c-vol,n-sch,n-novnc,n-xvnc,n-cauth,horizon,mysql,rabbit,ldap
KEYSTONE_IDENTITY_BACKEND=ldap
KEYSTONE_CLEAR_LDAP=yes
LDAP_PASSWORD=9632
__EOF
./stack.sh
This time there were no password prompts, so the local config was definitely read.

scp command - transfer folder over ssh

I have a Arduino Yun and want setup the server for Yun.
So what I want is to copy a folder that contain a py file and a index.html to my Yun
I used mac terminal to do this operation
the command looks like this
scp -r /Users/gudi/Desktop/LobsterHeartRate root#192.168.240.1:/mnt/sda1
and then terminal asked for the password
after I typed, it shows
scp: /mnt/sda1/LobsterHeartRate: Not a directory
I didn't type /mnt/sda1/LobsterHeartRate why it shows this error
Your code
scp -r /Users/gudi/Desktop/LobsterHeartRate root#192.168.240.1:/mnt/sda1
requires that the remote directory /mnt/sda1 exists. This looks like it is not true in your case. Check it using ssh root#192.168.240.1 ls /mnt/sda1.
scp is simple tool and it does not allow you to rename directories on the fly and the target directory must exists. You might try
scp -r /Users/gudi/Desktop/LobsterHeartRate root#192.168.240.1:/mnt/
ssh root#192.168.240.1 mv /mnt/LobsterHeartRate /mnt/sda1
or so, if it will suit your needs. But copying more files, rsync is usually more suitable. Check its manual page and give it a try next time.
As #Jens Höpken notes, your post is a bit sparse. But trying to read between the lines of your post I suspect that LobsterHeartRate is a DIRECTORY on your local system but a FILE named LobsterHeartRate in your target system. This might be happening right at the top of the directory tree, or perhaps you have directories/files of the same name further down the tree. scp -rv might help resolve any confusions here.
Beware: scp -r resolves symbolic links. If you want to preserve symlinks you need to do something else. For historic reasons I use the following, though cpio with a find front-end opens up interesting possibilities for fine-grained file selections.
( cd /Users/gudi/Desktop && tar -cf - LobsterHeartRate ) |
ssh root#192.168.240.1 'cd /mnt/sda1 && tar -xf -'
For a safe "dry run" you could change the -xf to a -tf. The && chains are required to prevent bad things from happening if any prior command fails.
Disclaimer: any debugging is left as an exercise for the student.