Docker Per-Container Disk Quota on Bind Mounted Volumes - wordpress

I am trying to create a simple hosting platform for my clients. I am deploying all of my apps via docker on a VPS behind nginx-proxy. For wordpress applications I want to be able to limit disk-space so that my clients do not use too much and affect other applications. I bind mount all volumes to a single directory so that I can back-up easily with cron.
I've change the file system to overlay2 and am on centos 7.
[root#my-ip ~]# docker info
Server:
Containers: 12
Running: 12
Paused: 0
Stopped: 0
Images: 11
Server Version: 19.03.1
Storage Driver: overlay2
Backing Filesystem: xfs
Supports d_type: true
Native Overlay Diff: true
When I run a wordpress container with the --storage-opt size=10G I get the following error:
docker: Error response from daemon: --storage-opt is supported only for overlay over xfs with 'pquota' mount option.
This is an example of the bind mount I am using:
-v /DOCKER_VOLUMES/wordpress/appname/www/html:/var/www/html
How do I fix this? Can you please provide a full list of instructions to enable it?

from the Docs:
This (size) will allow to set the container rootfs size to 120G at creation time. This option is only available for the devicemapper, btrfs, overlay2, windowsfilter and zfs graph drivers. For the devicemapper, btrfs, windowsfilter and zfs graph drivers, user cannot pass a size less than the Default BaseFS Size. For the overlay2 storage driver, the size option is only available if the backing fs is xfs and mounted with the pquota mount option. Under these conditions, user can pass any size less than the backing fs size.
so the pquota should be enabled on your system
you can edit the file /etc/default/grub like so, and restart your machine:
GRUB_CMDLINE_LINUX_DEFAULT="rootflags=uquota,pquota"
and try to rerun your command with --storage-opt size=10G

Related

Mosquitto: Starting in local only mode

I have a virtual machine that is supposed to be the host, which can receive and send data. The first picture is the error that I'm getting on my main machine (from which I'm trying to send data from). The second picture is the mosquitto log on my virtual machine. Also I'm using the default config, which as far as I know can't cause these problems, at least from what I have seen from other examples. I have very little understanding on how all of this works, so any help is appreciated.
What I have tried on the host machine:
Disabling Windows defender
Adding firewall rules for "mosquitto.exe"
Installing mosquitto on a linux machine
Starting with the release of Mosquitto version 2.0.0 (you are running v2.0.2) the default config will only bind to localhost as a move to a more secure default posture.
If you want to be able to access the broker from other machines you will need to explicitly edit the config files to either add a new listener that binds to the external IP address (or 0.0.0.0) or add a bind entry for the default listener.
By default it will also only allow anonymous connections (without username/password) from localhost, to allow anonymous from remote add:
allow_anonymous true
More details can be found in the 2.0 release notes here
You have to run with
mosquitto -c mosquitto.conf
mosquitto.conf, which exists in the folder same with execution file exists (C:\Program Files\mosquitto etc.), have to include following line.
listener 1883 ip_address_of_the_machine(192.168.1.1 etc.)
By default, the Mosquitto broker will only accept connections from clients on the local machine (the server hosting the broker).
Therefore, a custom configuration needs to be used with your instance of Mosquitto in order to accept connections from remote clients.
On your Windows machine, run a text editor as administrator and paste the following text:
listener 1883
allow_anonymous true
This creates a listener on port 1883 and allows anonymous connections. By default the number of connections is infinite. Save the file to "C:\Program Files\Mosquitto" using a file name with the ".conf" extension such as "your_conf_file.conf".
Open a terminal window and navigate to the mosquitto directory. Run the following command:
mosquitto -v -c your_conf_file.conf
where
-c : specify the broker config file.
-v : verbose mode - enable all logging types. This overrides
any logging options given in the config file.
I found I had to add, not only bind_address ip_address but also had to set allow_anonymous true before devices could connect successfully to MQTT. Of course I understand that a better option would be to set user and password on each device. But that's a next step after everything actually works in the minimum configuration.
For those who use mosquitto with homebrew on Mac.
Adding these two lines to /opt/homebrew/Cellar/mosquitto/2.0.15/etc/mosquitto/mosquitto.conf fixed my issue.
allow_anonymous true
listener 1883
you can run it with the included 'no-auth' config file like so:
mosquitto -c /mosquitto-no-auth.conf
I had the same problem while running it inside docker container (generated with docker-compose).
In docker-compose.yml file this is done with:
command: mosquitto -c /mosquitto-no-auth.conf

Docker dynamic load balancing with Nginx

I'm doing an internship focused on Docker and I have to load-balance an application which have a client, a server and a database. I use Nginx as a load-balancer and my goal is to dynamically scale the number of server containers according their CPU usage. For instance if the CPU usage is over 60% I want to add a new container on the fly without restarting Nginx to divide the CPU usage.
I have to modify the nginx.conf file to add a new container but I have to restart the Nginx container to apply the changes, which is very slow.
So my question is : is there a (free) way to do it dynamically ?
Tell me if you want further information and forgive my poor english.
Thanks.
EDIT : I did as #Konstantin Azizov told me :
docker cp ./new.conf $(docker ps -f "name=dockerizedrubis_nginx" -q ):/etc/nginx/nginx.conf
docker exec $(docker ps -f "name=dockerizedrubis_nginx" -q) bash -c 'kill -HUP $(cat /run/nginx.pid)'
docker exec $(docker ps -f "name=dockerizedrubis_nginx" -q) bash -c '/etc/init.d/nginx reload'
The configuration file is well pasted in the container supporting Nginx, I send the HUP signal to reconfigure the Nginx process et then I reload to apply my changes. There are no errors and the reload on-the-fly works fine but my new nodes are not taken into account by Nginx, the requests are still only directed to the first node created ...
EDIT 2 : I found the origin of the problem. It seems like in order to update the /etc/hosts of a container after a 'docker-compose scale', this container needs to be stopped, removed and restarted. In my case, I really don't want to stop the container supporting Nginx.
Question : Anyone has an idea of how to update /etc/hosts of a container after a re-scale without having to restart the container (beside a dirty script) ?
Thanks.
I used the nginx-proxy image from Json Wilder for a while to load balance between containers, and it works for more than one scalable service. It monitors the docker daemon and if an event happens it rebuilds the nginx config file adding the new container instances when you are scaling out or removing it if you are scaling in.
Since Docker 1.10 (not sure if this is the correct version) there is a internal DNS embedded into Docker daemon, so since then I am using the round robin feature from it. Now I am using the oficial nginx image to proxy pass the requests to the a domain that I define as alias into network options. I do not know if I was clear due to my poor english but I believe my Github example may help.
Unfortunately there is no easy(free) way to change configuration without restarting, the only way to achieve zero-downtime scaling it's graceful restart, when you restarting Nginx gracefully it will spawn new instance with new configuration wait until it boots up and then kill old instance with the previous configuration.
See official guide.

Permission Issue with Docker Volume Driver for Azure File Storage

I am following the readme for this project (https://github.com/Azure/azurefile-dockervolumedriver/blob/master/contrib/init/upstart/README.md), but when I try and mount a volume on a container like this
docker volume create -d azurefile -o share=myshare --name=myvol
docker run -i -t -v myvol:/data busybox
(inside the container)
# cd /data
# touch file.txt
I get this error:
Error response from daemon: VolumeDriver.Mount: mount failed: exit status 32
output="mount.cifs kernel mount options: ip=168.61.57.82,unc=\\\\cmstoragecd.file.core.windows.net\\myshare,vers=3.0,dir_mode=0777,file_mode=0777,user=cmstoragecd,pass=********\nmount
error(13): Permission denied\nRefer to the mount.cifs(8) manual page (e.g. man mount.cifs)\n"
This is running on an Ubuntu 14.04 server on Azure. I have successfully used the extension with similiar servers, but it is now not working. What can I do to debug this?
your answer is correct. CIFS in many Linux distros currently do not have encryption support ––which Azure File Storage requires in cross-region SMB traffic.
Quoting the note at https://azure.microsoft.com/en-us/documentation/articles/storage-how-to-use-files-linux/
Note: The Linux SMB client doesn’t yet support encryption, so mounting a file share from Linux still requires that the client be in the same Azure region as the file share. However, encryption support for Linux is on the roadmap of Linux developers responsible for SMB functionality. Linux distributions that support encryption in the future will be able to mount an Azure File share from anywhere as well.
In the future, please consider directly contacting to us by opening a new issue on our GitHub repository at: https://github.com/Azure/azurefile-dockervolumedriver/issues.
I managed to get around this error by using a storage account in the same region as the Azure VM. Originally I had a VM running in West Europe, using a file share in East US.

SELinux Policy to Allow NGINX Access to Parallels Shared Folders on Mac

I'm trying to keep SELinux enforcing but to allow NGINX to directly access shared OSX folders that are connected via Parallels Desktop.
Host system: Mac OSX 10.10
Parallels Desktop: 10
Running Virtual OS: CentOS 7 (minimal / command line)
I have the the Parallels tools installed and in CentOS I see the shared folder: /media/psf/Shared-Folder
When I set the Nginx server root to that folder I get a 403 Forbidden. I know it is a configuration parameter that needs editing because if I change SELinux to Permissive, the files are served correctly in NGINX.
When checking how the files are mounted I see this:
root root system_u:object_r:removable_t:s0 /media/psf/Shared-Folder/
I can see the 'removable_t' context - however - my issue is that I cannot seem to find a way to allow the httpd service to serve files that are mounted as removable storage.
I have tried:
chcon -R -t public_content_t /media/psf/Shared_Folder/
chcon -R -t httpd_sys_content_t /media/psf/Development-Projects/
and in all cases I get a "chcon: failed to change context of: '...': Operational not supported" error.
Checking /usr/sbin/getsebool -a | grep http I do not see any option to allow httpd to access removable storage mounts.
Last item: I do not believe I can change the way Parallels mounts the shared folders.
Question: Is there a way to keep SELinux enforcing but to allow NGINX to directly access shared OSX folders that are connected via Parallels Desktop?
What you need to do is use semanage.To get it you have to install policycoreutils-python.
The same type of question has already been asked Here. Cheers!

mount: nfs access denied by server

Am trying to mount a NFS device in my linux machine.
My /etc/fstab is like this,
192.168.0.5:/volume2/Asterisk_Recordings /var/spool/newnfs nfs rsize=32768,wsize=32768,intr,noatime 1 0
My /etc/mtab is like this,
192.168.0.5:/volume2/Asterisk_Recordings /var/spool/newnfs nfs rw,addr=192.168.0.5 0 0
I have enabled NFS in my NAS device.
When i type mount " mount -t nfs -v 192.168.0.5:/volume2/Asterisk_Recordings /var/spool/newnfs/" I get like this,
mount.nfs: timeout set for Thu Aug 1 07:01:04 2013
mount.nfs: trying text-based options 'vers=4,addr=192.168.0.5,clientaddr=192.168.1.1'
mount.nfs: mount(2): Permission denied
mount.nfs: access denied by server while mounting 192.168.0.5:/volume2/Asterisk_Recordings
Any possible reasons?
Thanks in advance.
This error can also occur if the /etc/hosts file on the nfs server maps the hostname of the client to an incorrect IP address, or the IP address of the client to an incorrect hostname. It is quick and easy to check, so worth doing before looking for other problems. Note that, if you do have to change any entries then the nfs-server has to be stopped and re-started, as it reads the hosts file only when it is started.
Is there a config file on the NAS where to put allowances for clients? E.g. in debian based OS the config file is "/etc/exports" and you would put there "/volume2/Asterisk_Recordings 192.168.1.1(rw,sync)" and activate this with "exportfs -a" (your NAS may do this automatically if you update the config via a web interface, I guess.) Check also https://stackoverflow.com/questions/22246477/mounting-nfs-results-in-access-denied-by-server.
Remember to add IP addresses/hostnames of your NFS' clients to /etc/hosts.allow of NFS' server
nfs: clienthost2, clienthost2, clienthost3
You might restart nfs config and nfs service on the NFS server as well as run export again.
systemctl restart nfs-config.service
systemctl status nfs.service
exportfs -arv
I have a Debian 10 system with a Debian 10 VM running inside it. I wanted to access a physical partition from the hard drive on the VM. I mounted the physical drive on the host and exported it. I was not able to mount it on the guest continually getting a access denied error
The solution after many hours was to add the no_all_squash option in the exports file. This is supposed to be the default but I needed to add it explicitly. As soon as I did that the problem went away and I could mount the file system. Unfortunately I could not see the files on the fs.
/media/dev 192.168.100.0/24(rw,sync,no_subtree_check,no_root_squash,no_all_squash)
On the server I could see the files and on the host I could not.
I had to change the line to
/media/dev 192.168.100.0/255.255.255.0(rw,sync,no_subtree_check,no_root_squash,no_all_squash)
to see the actual files that were on the file sets
I saw this error presumably due to an older NFS client and adding -o nfsvers=3 fixed the issue for me e.g. mount -t nfs -o nfsvers=3 x.x.x.x:/nfs_mount /mnt/nfs_mount
Or in /etc/fstab
x.x.x.x://nfs_mount /mnt/nfs_mount nfs proto=tcp,port=2049,nfsvers=3 0 0
Ref: https://www.thegeekdiary.com/mount-nfs-access-denied-by-server-while-mounting-how-to-resolve/

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