stillhq.com : Mikal, a geek from Canberra living in Silicon Valley

Configuring docker to use rexray and Ceph for persistent storage

Sun, 28 May 2017 18:45:00 -800

For various reasons I wanted to play with docker containers backed by persistent Ceph storage. rexray seemed like the way to do that, so here are my notes on getting that working... First off, I needed to install rexray: root@labosa:~/rexray# curl -sSL https://dl.bintray.com/emccode/rexray/install | sh Selecting previously unselected package rexray. (Reading database ... 177547 files and directories currently installed.) Preparing to unpack rexray_0.9.0-1_amd64.deb ... Unpacking rexray (0.9.0-1) ... Setting up rexray (0.9.0-1) ... rexray has been installed to /usr/bin/rexray REX-Ray ------- Binary: /usr/bin/rexray Flavor: client+agent+controller SemVer: 0.9.0 OsArch: Linux-x86_64 Branch: v0.9.0 Commit: 2a7458dd90a79c673463e14094377baf9fc8695e Formed: Thu, 04 May 2017 07:38:11 AEST libStorage ---------- SemVer: 0.6.0 OsArch: Linux-x86_64 Branch: v0.9.0 Commit: fa055d6da595602715bdfd5541b4aa6d4dcbcbd9 Formed: Thu, 04 May 2017 07:36:11 AEST Which is of course horrid. What that script seems to have done is install a deb'd version of rexray based on an alien'd package: root@labosa:~/rexray# dpkg -s rexray Package: rexray Status: install ok installed Priority: extra Section: alien Installed-Size: 36140 Maintainer: Travis CI User Architecture: amd64 Version: 0.9.0-1 Depends: libc6 (>= 2.3.2) Description: Tool for managing remote & local storage. A guest based storage introspection tool that allows local visibility and management from cloud and storage platforms. . (Converted from a rpm package by alien version 8.86.) If I was building anything more than a test environment I think I'd want to do a better job of installing rexray than this, so you've been warned. Next to configure rexray to use Ceph. The configuration details are cunningly hidden in the libstorage docs, and aren't mentioned at all in the rexray docs, so you probably want to take a look at the libstorage docs on ceph. First off, we need to install the ceph tools, and copy the ceph authentication information from the the ceph we installed using openstack-ansible earlier. root@labosa:/etc# apt-get install ceph-common root@labosa:/etc# scp -rp 172.29.239.114:/etc/ceph . The authenticity of host '172.29.239.114 (172.29.239.114)' can't be established. ECDSA key fingerprint is SHA256:SA6U2fuXyVbsVJIoCEHL+qlQ3xEIda/MDOnHOZbgtnE. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '172.29.239.114' (ECDSA) to the list of known hosts. rbdmap 100% 92 0.1KB/s 00:00 ceph.conf 100% 681 0.7KB/s 00:00 ceph.client.admin.keyring 100% 63 0.1KB/s 00:00 ceph.client.glance.keyring 100% 64 0.1KB/s 00:00 ceph.client.cinder.keyring 100% 64 0.1KB/s 00:00 ceph.client.cinder-backup.keyring 71 0.1KB/s 00:00 root@labosa:/etc# modprobe rbd You also need to configure rexray. My first attempt looked like this: root@labosa:/var/log# cat /etc/rexray/config.yml libstorage: service: ceph And the rexray output sure made it look like it worked... root@labosa:/etc# rexray service start ● rexray.service - rexray Loaded: loaded (/etc/systemd/system/rexray.service; enabled; vendor preset: enabled) Active: active (running) since Mon 2017-05-29 10:14:07 AEST; 33ms ago Main PID: 477423 (rexray) Tasks: 5 Memory: 1.5M CPU: 9ms CGroup: /system.slice/rexray.service └─477423 /usr/bin/rexray start -f May 29 10:14:07 labosa systemd[1]: Started rexray. Which looked good, but /var/log/syslog said: May 29 10:14:08 labosa rexray[477423]: REX-Ray May 29 10:14:08 labosa rexray[477423]: ------- May 29 10:14:08 labosa rexray[477423]: Binary: /usr/bin/rexray May 29 10:14:08 labosa rexray[477423]: Flavor: client+agent+controller May 29 10:14:08 labosa rexray[477423]: SemVer: 0.9.0 May 29 10:14:08 labosa rexray[477423]: OsArch: Linux-x86_64 May 29 10:14:08 labosa rexray[477423]: Branch: v0.9.0 May 29 10:14:08 labo[...]

So you want to setup a Ceph dev environment using OSA

Sat, 27 May 2017 18:30:00 -800

Support for installing and configuring Ceph was added to openstack-ansible in Ocata, so now that I have a need for a Ceph development environment it seems logical that I would build it by building an openstack-ansible Ocata AIO. There were a few gotchas there, so I want to explain the process I used.

First off, Ceph is enabled in an openstack-ansible AIO using a thing I've never seen before called a "Scenario". Basically this means that you need to export an environment variable called "SCENARIO" before running the AIO install. Something like this will do the trick?L:

export SCENARIO=ceph

Next you need to set the global pg_num in the ceph role or the install will fail. I did that with this patch:

--- /etc/ansible/roles/ceph.ceph-common/defaults/main.yml       2017-05-26 08:55:07.803635173 +1000
+++ /etc/ansible/roles/ceph.ceph-common/defaults/main.yml       2017-05-26 08:58:30.417019878 +1000
@@ -338,7 +338,9 @@
 #     foo: 1234
 #     bar: 5678
 #
-ceph_conf_overrides: {}
+ceph_conf_overrides:
+  global:
+    osd_pool_default_pg_num: 8
 
 
 #############
@@ -373,4 +375,4 @@
 # Set this to true to enable File access via NFS.  Requires an MDS role.
 nfs_file_gw: true
 # Set this to true to enable Object access via NFS. Requires an RGW role.
-nfs_obj_gw: false
\ No newline at end of file
+nfs_obj_gw: false

That of course needs to be done after the Ceph role has been fetched, but before it is executed, so in other words after the AIO bootstrap, but before the install.

And that was about it (although of course that took a fair while to work out). I have this automated in my little install helper thing, so I'll never need to think about it again which is nice.

Once Ceph is installed, you interact with it via the monitor container, not the utility container, which is a bit odd. That said, all you really need is the Ceph config file and the Ceph utilities, so you could move those elsewhere.

root@labosa:/etc/openstack_deploy# lxc-attach -n aio1_ceph-mon_container-a3d8b8b1
root@aio1-ceph-mon-container-a3d8b8b1:/# ceph -s
    cluster 24424319-b5e9-49d2-a57a-6087ab7f45bd
     health HEALTH_OK
     monmap e1: 1 mons at {aio1-ceph-mon-container-a3d8b8b1=172.29.239.114:6789/0}
            election epoch 3, quorum 0 aio1-ceph-mon-container-a3d8b8b1
     osdmap e20: 3 osds: 3 up, 3 in
            flags sortbitwise,require_jewel_osds
      pgmap v36: 40 pgs, 5 pools, 0 bytes data, 0 objects
            102156 kB used, 3070 GB / 3070 GB avail
                  40 active+clean
root@aio1-ceph-mon-container-a3d8b8b1:/# ceph osd tree
ID WEIGHT  TYPE NAME       UP/DOWN REWEIGHT PRIMARY-AFFINITY 
-1 2.99817 root default                                      
-2 2.99817     host labosa                                   
 0 0.99939         osd.0        up  1.00000          1.00000 
 1 0.99939         osd.1        up  1.00000          1.00000 
 2 0.99939         osd.2        up  1.00000          1.00000 

Tags for this post: openstack osa ceph openstack-ansible
Related posts: Configuring docker to use rexray and Ceph for persistent storage

Comment

The Collapsing Empire

Wed, 20 Apr 2016 16:53:00 +1000

(image) ISBN: 076538888X LibraryThing

Another excellent book by Ben Goldacre. In this book he argues that modern medicine is terribly corrupted by the commercial forces that act largely unchecked in the marketplace -- studies which don't make a new drug look good go missing; new drugs are compared only against placebo and not against the current best treatment; doctors are routinely bribed with travel, training and small perks. Overall I'm left feeling like things haven't improved much since this book was published, given that these behaviors still seem common. The book does offer concrete actions that we could take to fix things, but I don't see many of these happening any time soon, which is a worrying place to be. Overall, a disturbing but important read. Tags for this post: book ben_goldacre medicine science corruption non_fiction Related posts: Bad Science; Sixty five roses (Cystic Fibrosis); On Cars; Being Geek; Audio from linux.conf.au 2005 continued; High Output Management

Comment Recommend a book

Comments (0) - Read and Add your own Comments