Merge pull request #141 from lhuard1A/virt

Add libvirt as a provider for openshift-ansible

1 files changed, 92 insertions, 0 deletions

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+
+LIBVIRT Setup instructions
+==========================
+
+`libvirt` is an `openshift-ansible` provider that uses `libvirt` to create local Fedora VMs that are provisioned exactly the same way that cloud VMs would be provisioned.
+
+This makes `libvirt` useful to develop, test and debug Openshift and openshift-ansible locally on the developer’s workstation before going to the cloud.
+
+Install dependencies
+--------------------
+
+1. Install [dnsmasq](http://www.thekelleys.org.uk/dnsmasq/doc.html)
+2. Install [ebtables](http://ebtables.netfilter.org/)
+3. Install [qemu](http://wiki.qemu.org/Main_Page)
+4. Install [libvirt](http://libvirt.org/)
+5. Enable and start the libvirt daemon, e.g:
+   * ``systemctl enable libvirtd``
+   * ``systemctl start libvirtd``
+6. [Grant libvirt access to your user¹](https://libvirt.org/aclpolkit.html)
+7. Check that your `$HOME` is accessible to the qemu user²
+
+#### ¹ Depending on your distribution, libvirt access may be denied by default or may require a password at each access.
+
+You can test it with the following command:
+```
+virsh -c qemu:///system pool-list
+```
+
+If you have access error messages, please read https://libvirt.org/acl.html and https://libvirt.org/aclpolkit.html .
+
+In short, if your libvirt has been compiled with Polkit support (ex: Arch, Fedora 21), you can create `/etc/polkit-1/rules.d/50-org.libvirt.unix.manage.rules` as follows to grant full access to libvirt to `$USER`
+
+```
+sudo /bin/sh -c "cat - > /etc/polkit-1/rules.d/50-org.libvirt.unix.manage.rules" << EOF
+polkit.addRule(function(action, subject) {
+        if (action.id == "org.libvirt.unix.manage" &&
+            subject.user == "$USER") {
+                return polkit.Result.YES;
+                polkit.log("action=" + action);
+                polkit.log("subject=" + subject);
+        }
+});
+EOF
+```
+
+If your libvirt has not been compiled with Polkit (ex: Ubuntu 14.04.1 LTS), check the permissions on the libvirt unix socket:
+
+```
+ls -l /var/run/libvirt/libvirt-sock
+srwxrwx--- 1 root libvirtd 0 févr. 12 16:03 /var/run/libvirt/libvirt-sock
+
+usermod -a -G libvirtd $USER
+# $USER needs to logout/login to have the new group be taken into account
+```
+
+(Replace `$USER` with your login name)
+
+#### ² Qemu will run with a specific user. It must have access to the VMs drives
+
+All the disk drive resources needed by the VMs (Fedora disk image, cloud-init files) are put inside `~/libvirt-storage-pool-openshift/`.
+
+As we’re using the `qemu:///system` instance of libvirt, qemu will run with a specific `user:group` distinct from your user. It is configured in `/etc/libvirt/qemu.conf`. That qemu user must have access to that libvirt storage pool.
+
+If your `$HOME` is world readable, everything is fine. If your `$HOME` is private, `ansible` will fail with an error message like:
+
+```
+error: Cannot access storage file '$HOME/libvirt-storage-pool-openshift/lenaic-master-216d8.qcow2' (as uid:99, gid:78): Permission denied
+```
+
+In order to fix that issue, you have several possibilities:
+* set `libvirt_storage_pool_path` inside `playbooks/libvirt/openshift-cluster/launch.yml` and `playbooks/libvirt/openshift-cluster/terminate.yml` to a directory:
+  * backed by a filesystem with a lot of free disk space
+  * writable by your user;
+  * accessible by the qemu user.
+* Grant the qemu user access to the storage pool.
+
+On Arch:
+
+```
+setfacl -m g:kvm:--x ~
+```
+
+Test the setup
+--------------
+
+```
+cd openshift-ansible
+
+bin/cluster create -m 1 -n 3 libvirt lenaic
+
+bin/cluster terminate libvirt lenaic
+```