I mentioned yesterday that VMware made vSphere Integrated Containers (VIC) v0.4.0 available. Included in this version is support for container volumes. Now, as mentioned yesterday, VIC is still a work in progress, and not everything has yet been implemented. In this post I want to step you through some of the enhancements that we have made around docker volume support in VIC. This will hopefully provide you with enough information so that you can try this out for yourself.
To begin with, you need to ensure that a “volume store” is created when the VCH (Virtual Container Host) is deployed. This is a datastore and folder where the volumes are stored, and for ease of use, you can apply a label to it. One useful tit-bit here is that if you use the label “default” for your volume store, you do not have to specify it in the docker volume command line. For example, if I deploy a VCH as follows, note the –volume-store parameter. The format is “label:datastore/folder-on-datastore”. Here I have requested that the volume store be placed on the isilion-nfs-01 datastore in the folder called docker-vols. I have also labeled it as “default”. For information on the other parameters, refer to my previous post – Getting started with VIC v0.4.0.
root@photon [ /workspace/vic ]# ./vic-machine-linux create \
--bridge-network Bridge-DPG --image-datastore isilion-nfs-01 \
-t 'administrator@vsphere.local:zzzzz@10.27.51.103' \
--compute-resource Mgmt --external-network VMNW51 --name VCH01 \
--volume-store "default:isilion-nfs-01/docker-vols"
INFO[2016-07-14T11:25:13Z] ### Installing VCH ####
INFO[2016-07-14T11:25:13Z] Generating certificate/key pair - private key in ./VCH01-key.pem
INFO[2016-07-14T11:25:13Z] Validating supplied configuration
INFO[2016-07-14T11:25:13Z] Firewall status: DISABLED on /CNA-DC/host/Mgmt/10.27.51.8
INFO[2016-07-14T11:25:13Z] Firewall configuration OK on hosts:
INFO[2016-07-14T11:25:13Z] /CNA-DC/host/Mgmt/10.27.51.8
INFO[2016-07-14T11:25:13Z] License check OK on hosts:
INFO[2016-07-14T11:25:13Z] /CNA-DC/host/Mgmt/10.27.51.8
INFO[2016-07-14T11:25:13Z] DRS check OK on:
INFO[2016-07-14T11:25:13Z] /CNA-DC/host/Mgmt/Resources
INFO[2016-07-14T11:25:14Z] Creating Resource Pool VCH01
INFO[2016-07-14T11:25:14Z] Creating directory [isilion-nfs-01] docker-vols
INFO[2016-07-14T11:25:14Z] Datastore path is [isilion-nfs-01] docker-vols
INFO[2016-07-14T11:25:14Z] Creating appliance on target
INFO[2016-07-14T11:25:14Z] Network role client is sharing NIC with external
INFO[2016-07-14T11:25:14Z] Network role management is sharing NIC with external
INFO[2016-07-14T11:25:15Z] Uploading images for container
INFO[2016-07-14T11:25:15Z] bootstrap.iso
INFO[2016-07-14T11:25:15Z] appliance.iso
INFO[2016-07-14T11:25:20Z] Registering VCH as a vSphere extension
INFO[2016-07-14T11:25:26Z] Waiting for IP information
INFO[2016-07-14T11:25:52Z] Waiting for major appliance components to launch
INFO[2016-07-14T11:25:52Z] Initialization of appliance successful
INFO[2016-07-14T11:25:52Z]
INFO[2016-07-14T11:25:52Z] Log server:
INFO[2016-07-14T11:25:52Z] https://10.27.51.42:2378
INFO[2016-07-14T11:25:52Z]
INFO[2016-07-14T11:25:52Z] DOCKER_HOST=10.27.51.42:2376
INFO[2016-07-14T11:25:52Z]
INFO[2016-07-14T11:25:52Z] Connect to docker:
INFO[2016-07-14T11:25:52Z] docker -H 10.27.51.42:2376 --tls info
INFO[2016-07-14T11:25:52Z] Installer completed successfully
root@photon [ /workspace/vic ]#
Now that my VCH is deployed and my docker endpoint is available, we can use the docker command to create volumes and attach them to containers.
First thing to note – the “docker volume ls” and the “docker volume inspect” commands are not yet implemented. So we do not yet have a good way of examining the storage consumption and layout through the docker API. This is work in progress however. That aside, we can still create and consume volumes. Here is how to do that.
root@photon [ /workspace/vic ]# docker -H 10.27.51.42:2376 --tls volume create \
--name=demo --opt Capacity=1024
demo
root@photon [ /workspace/vic ]#
So one thing to point out here – the Capacity=1024 option in the docker volume create command is a representation of 1MB blocks. So what was created is a 1GB VMDK. My understanding is that we will add additional granularity to this capacity option going forward.root@photon [ /workspace/vic ]# docker -H 10.27.51.42:2376 --tls run \ -v demo:/demo -it ubuntu /bin/bash root@3ef0b682bc8d:/# root@3ef0b682bc8d:/# mount | grep demo /dev/sdb on /demo type ext4 (rw,noatime,data=ordered) root@3ef0b682bc8d:/# df -h Filesystem Size Used Avail Use% Mounted on devtmpfs 965M 0 965M 0% /dev tmpfs 1003M 0 1003M 0% /dev/shm tmpfs 1003M 136K 1003M 1% /run tmpfs 1003M 0 1003M 0% /sys/fs/cgroup /dev/sda 7.8G 154M 7.2G 3% / tmpfs 128M 43M 86M 34% /.tether tmpfs 1.0M 0 1.0M 0% /.tether-init rootfs 965M 0 965M 0% /lib/modules /dev/disk/by-label/fe01ce2a7fbac8fa 976M 1.3M 908M 1% /demo root@751ecc91c355:/#
root@3ef0b682bc8d:/# cd /demo root@3ef0b682bc8d:/demo# echo "important" >> need-to-persist.txt root@3ef0b682bc8d:/demo# cat need-to-persist.txt important root@3ef0b682bc8d:/demo# cd .. root@3ef0b682bc8d:/# exit exit
root@photon [ /workspace/vic ]# docker -H 10.27.51.42:2376 --tls run \ -v demo:/demo -it busybox Unable to find image 'busybox:latest' locally latest: Pulling from library/busybox a3ed95caeb02: Pull complete 8ddc19f16526: Pull complete Digest: sha256:65ce39ce3eb0997074a460adfb568d0b9f0f6a4392d97b6035630c9d7bf92402 Status: Downloaded newer image for library/busybox:latest / # df Filesystem 1K-blocks Used Available Use% Mounted on devtmpfs 987544 0 987544 0% /dev tmpfs 1026584 0 1026584 0% /dev/shm tmpfs 1026584 132 1026452 0% /run tmpfs 1026584 0 1026584 0% /sys/fs/cgroup /dev/sda 8125880 19612 7670456 0% / tmpfs 131072 43940 87132 34% /.tether tmpfs 1024 0 1024 0% /.tether-init /dev/disk/by-label/fe01ce2a7fbac8fa 999320 1288 929220 0% /demo / # cd /demo /demo # ls lost+found need-to-persist.txt /demo # cat need-to-persist.txt important /demo #
There you have it – docker volumes in VIC. One final note is what happens when the VCH is deleted. If the VCH is deleted, then the docker volumes associated with that VCH are also deleted (although I also believe that we will change this behavior in future versions):
root@photon [ /workspace/vic ]# ./vic-machine-linux delete -t 'administrator@vsphere.local:zzzzz@10.27.51.103' \ --compute-resource Mgmt --name VCH01 INFO[2016-07-14T14:36:26Z] ### Removing VCH #### INFO[2016-07-14T14:36:26Z] Removing VMs INFO[2016-07-14T14:36:29Z] Removing images INFO[2016-07-14T14:36:29Z] Removing volumes INFO[2016-07-14T14:36:29Z] Removing appliance VM network devices INFO[2016-07-14T14:36:30Z] Removing VCH vSphere extension INFO[2016-07-14T14:36:35Z] Removing Resource Pool VCH01 INFO[2016-07-14T14:36:35Z] Completed successfully root@photon-NaTv5i8IA [ /workspace/vic ]#
So for now, be careful if you place data in a volume, and then remove the VCH as this will also remove the volumes.
OK – one final test. Let’s assume that you did not use the “default” label, or that you had multiple volume store specified in the command line (which is perfectly acceptable). How then would you select the correct datastore for the volume? Let’s deploy a new VCH, and this time we will set the label to NFS:
root@photon [ /workspace/vic ]# ./vic-machine-linux create \ --bridge-network Bridge-DPG --image-datastore isilion-nfs-01 \ -t 'administrator@vsphere.local:VMware123!@10.27.51.103' \ --compute-resource Mgmt --external-network VMNW51 --name VCH01 \ --volume-store "NFS:isilion-nfs-01/docker-vols" INFO[2016-07-14T14:43:04Z] ### Installing VCH #### INFO[2016-07-14T14:43:04Z] Generating certificate/key pair - private key in ./VCH01-key.pem INFO[2016-07-14T14:43:05Z] Validating supplied configuration INFO[2016-07-14T14:43:05Z] Firewall status: DISABLED on /CNA-DC/host/Mgmt/10.27.51.8 INFO[2016-07-14T14:43:05Z] Firewall configuration OK on hosts: INFO[2016-07-14T14:43:05Z] /CNA-DC/host/Mgmt/10.27.51.8 INFO[2016-07-14T14:43:05Z] License check OK on hosts: INFO[2016-07-14T14:43:05Z] /CNA-DC/host/Mgmt/10.27.51.8 INFO[2016-07-14T14:43:05Z] DRS check OK on: INFO[2016-07-14T14:43:05Z] /CNA-DC/host/Mgmt/Resources INFO[2016-07-14T14:43:06Z] Creating Resource Pool VCH01 INFO[2016-07-14T14:43:06Z] Datastore path is [isilion-nfs-01] docker-vols INFO[2016-07-14T14:43:06Z] Creating appliance on target INFO[2016-07-14T14:43:06Z] Network role management is sharing NIC with client INFO[2016-07-14T14:43:06Z] Network role external is sharing NIC with client INFO[2016-07-14T14:43:08Z] Uploading images for container INFO[2016-07-14T14:43:08Z] bootstrap.iso INFO[2016-07-14T14:43:08Z] appliance.iso INFO[2016-07-14T14:43:13Z] Registering VCH as a vSphere extension INFO[2016-07-14T14:43:18Z] Waiting for IP information INFO[2016-07-14T14:43:44Z] Waiting for major appliance components to launch INFO[2016-07-14T14:43:44Z] Initialization of appliance successful INFO[2016-07-14T14:43:44Z] INFO[2016-07-14T14:43:44Z] Log server: INFO[2016-07-14T14:43:44Z] https://10.27.51.47:2378 INFO[2016-07-14T14:43:44Z] INFO[2016-07-14T14:43:44Z] DOCKER_HOST=10.27.51.47:2376 INFO[2016-07-14T14:43:44Z] INFO[2016-07-14T14:43:44Z] Connect to docker: INFO[2016-07-14T14:43:44Z] docker -H 10.27.51.47:2376 --tls info INFO[2016-07-14T14:43:44Z] Installer completed successfully
Now we want to create a volume, but place it in the folder/datastore identified by the label NFS. First, let’s try to create a volume as before:
root@photon [ /workspace/vic ]# docker -H 10.27.51.47:2376 --tls --tls \ volume create --name=demo --opt Capacity=1024 Error response from daemon: Server error from Portlayer: [POST /storage/volumes/][500]\ createVolumeInternalServerError
Yes – we know it is a horrible error message, and we will fix that. But to make it work, you now need another option to docker volume called VolumeStore. Here it is.
root@photon [ /workspace/vic ]# docker -H 10.27.51.47:2376 --tls \ volume create --name=demo --opt Capacity=1024 --opt VolumeStore=NFS demo root@photon [ /workspace/vic ]#
Now you can consume the volume in the same way as it was shown in the previous example.
Caution: A number of commands shown here will definitely change in future releases of VIC. However, what I have shown you is how to get started with docker volumes in VIC v0.4.0. If you do run into some anomalies that are not described in the post, and you feel it is a mismatch in behavior with standard docker, please let me know. I will feed this back to our engineering team, who are always open to suggestions on how to make VIC as seamless as possible to standard docker behavior.
The post Container Volumes in VIC v0.4.0 appeared first on CormacHogan.com.