RHEV: recovery VM in Unknown state

If an operation that implies a state change on a VM fails, sometimes RHEV sets the VM status to ‘Unknown’.
This morning, after a fail of a ‘Power off’ operation on a VM in panic – due to a bug ([vdsm] AttributeError: GuestAgent instance has no attribute ‘_sock’) – the VM state was set to ‘Unknown’.
In this case basically you don’t can do anything…
If you know the real state of your VM, you can manually change it and restart the VM. So I set the state of my VM to 0 (stopped) and I restarted it.

[root@rhevm ~]# psql -U engine
psql (8.4.20)
Digita "help" per avere un aiuto.

engine=> select vm_guid from vm_static where vm_name='server.example.com';
vm_guid
--------------------------------------
2d1e72a1-16c4-4f38-a21e-78113669dd98
(1 riga)

engine=> select status from vm_dynamic where vm_guid='2d1e72a1-16c4-4f38-a21e-78113669dd98';
status
--------
7
(1 riga)

engine=> update vm_dynamic set status=0 where vm_guid='2d1e72a1-16c4-4f38-a21e-78113669dd98';
UPDATE 1
[oVirt shell (connected)]# action vm server.example.com start

job-id : 7f1ac179-047c-4d50-932f-3ae7970c96e2
status-state: complete
vm-id : 2d1e72a1-16c4-4f38-a21e-78113669dd98

Provisioning openstack on vmware infrastructure.

As I didn’t found extensive docs about provisioning Red Hat Openstack on a vmware infrastructure, I browsed the python code.

Python is a very expressive and clear language and you can get to the point in a moment!

I then was able to create the following instack.json to power-management a set of vmware machines.

Despite the many ways to pass ssh_* variables via ironic, the right way of running it via the instack.json is to:

– use the `pm_virt_type` instead of `ssh_virt_type`;
– express the ssh_key_content in the pm_password parameter like shown in the docs;
– set capabilities like profile and boot_option directly.

The key should be json-serialized on one line, replacing CR with ‘\n’.


{
    "nodes":[
        {
            "mac":[
                "00:0c:29:00:00:01"
            ],
            "capabilities": "profile:control,boot_option:local"
            "cpu":"8",
            "memory":"16384",
            "disk":"60",
            "arch":"x86_64",
            "pm_type":"pxe_ssh",
            "pm_virt_type": "vmware",
            "pm_addr":"172.18.0.1",
            "pm_user":"vmadmin",
            "pm_password":"-----BEGIN RSA PRIVATE KEY-----\nMY\nRSA\nKEY\n-----END RSA PRIVATE KEY-----"
        },
{..other nodes..} 

green_paint_roller

$ mv vaunaspada labs

Avete cercato vaunaspada.babel.it e vi siete ritrovati su labs.par-tec.it? Non siete vittime di un DNS spoofing, abbiamo solo dato una rinfrescata al blog, allineandolo al nuovo brand e look&feel.

Ciò che non cambia è la natura tecnica dei contenuti e l’entusiasmo del nostro team nel condividere le proprie esperienze con i propri simili.


Were you searching for vaunaspada.babel.it and you ended up on labs.par-tec.it? You are not the victim of a DNS spoofing, we just gave our blog a makeover, matching it with our (new) brand and look&feel.

What stays the same is the technical nature of the contents and the enthusiasm of our team in sharing their experience with others of their own kind.

Enjoy 😉

FullText Indexing IPv6 addresses with MySQL 5.7

MySQL 5.7 supports generated fields. This is particularly useful for searching the string representation of numeric stored ip addresses:

CREATE TABLE catalog(
ip varbinary(16) not null,
hostname varchar(64) not null,
label varchar(64),
ip_ntoa varchar(64) generated always as (inet6_ntoa(ip)) STORED, -- generate and store fields with the address representation
fulltext key (hostname, ip_ntoa, label)
);

When inserting values

INSERT INTO catalog(ip,hostname,label) VALUES
(inet6_aton('127.0.0.1'), 'localhost', 'lo'),
(inet6_aton('192.168.0.1'), 'gimli', 'stage,ipv4'),
(inet6_aton('fdfe::5a55:caff:fefa:9089'), 'legolas', 'router,ipv6'),
(inet6_aton('fdfe::5a55:caff:fefa:9090'), 'boromir', 'router,ipv6')

you can search in OR mode with

SELECT hostname FROM catalog WHERE
  MATCH(ip_ntoa, hostname, label)
  AGAINST('9089 router');
-- returns every entry matching ANY needle
***1***
hostname: legolas
***2***
hostname: boromir

Or exact matches

SELECT hostname FROM catalog WHERE
  MATCH(ip_ntoa, hostname, label)
  AGAINST('+9089 +router' in boolean mode);
-- returns ONE entry matching ALL needles
***1***
hostname: legolas

Adding docker images to openshift 3.1

Openshift 3.1 is based on Kubernetes and Docker, and provides a small set of images including jboss EAP 6.4.

You can add new images in two steps:

1- create an ImageStream, that’s a docker image + a set of labels
2- create a Template using that ImageStream

To create the ImageStream read carefully the following description.

# Create the ImageStream
oc create -f - <<EOF
apiVersion: v1
kind: ImageStream
metadata:
  name: wildfly9-openshift
  namespace: openshift        # Set this to "openshift" if you want to make this image globally visible
spec:
  dockerImageRepository: docker.io/openshift/wildfly-90-centos7:latest  # The original docker hub repo
  tags:
  - annotations:
      description: Wildfly 9.0 S2I images.
      iconClass: icon-jboss
      sampleRef: 9.0.x 
      supports: wildfly:9,javaee:7,java:8,
      tags: builder,javaee,java,jboss
      version: "1.0"
    name: "1.0"
status:
  dockerImageRepository: ""


Roundcube: risolvere l’errore Net_LDAP2_RootDSE::construct() must be public

Per rosolvere il seguente errore in roundcube

PHP Fatal error: Access level to Net_LDAP2_RootDSE::__construct() must be public (as in class PEAR) in roundcubemail/vendor/pear-pear.php.net/Net_LDAP2/Net/LDAP2/RootDSE.php on line 238

Seguire i passi:

  • cd <roundcube-root-folder>
  • Installare composer.phar: curl -s https://getcomposer.org/installer | php
  • copiare il template composer.json-dist in composer.json
  • modificare il file composer.json, nella sezione “require” aggiungere la riga"pear-pear.php.net/net_ldap2": "~2.2.0",
  • lanciare il comando: php composer.phar update

Back from MongoDB Essentials Training

This week I joined MongoDB Essentials training in Roma.

Mongo is a fast document oriented database supporting consistency, replication for HA and sharding for scaling read OR writes.

Transactions are at document level, so no joins and isolation levels.

A nice training – covering many database design technologies and giving even a theoretical overview of performance and scalability issues.

Concepts like Working Set, Replication types and issues, Indexes side-effects, Sharding and Hashing were introduced both theoretically and pratically.

Being a class of 10+ people with mixed background (MS, Linux, Oracle) it was hard to squeeze all this theory and practice in 3 days. The instructor asked us the parts we’d like to cover more: we pick Schema Design, Replication and Sharding.
Besides, such a large class give us a lot discussion and networking opportunity: we even created a freenode chatroom!

People interested in the subject can drop me a line and have a look at this github repo

Enjoy! R.

docker multihost network: an epiphany of namespaces.

Playing with docker multihost network this week-end.

With multihost networking you can run communicating containers on different docker nodes.
The magic relies on:
– a shared kv store (Eg. consul) for ipaddresses;
– a netns for vxlan for communication with a bridge and no processes attached.

Every network created using the Overlay driver has its own network namespace.
And for every network (& its subnet combination), we create a linux bridge inside that dedicated namespace.
The host end of the veth pair is moved into this namespace and attached to the bridge (inside of that namespace).
Hence, if you look for the veth pair in the host namespace, you wont find any :-).

If you look for vxlan setup on the boot2docker distro you have to dig deep ;).
1- docker netns is stored in /var/run/docker/netns. To access it you need to

#ln -s /var/run/docker/netns /var/run;

2- Now you can look for the vxlan netns, which has the same id on every machine:

#ip netns ls | while read a; do
    ip netns exec $a ip l | grep vxlan -q && echo $a;done

The vxlan references the UDP port for communication (eg. dstport 46354).

87: vxlan1:  mtu 1500 qdisc noqueue master br0 state UNKNOWN mode DEFAULT group default
    link/ether da:69:8d:4d:b9:39 brd ff:ff:ff:ff:ff:ff promiscuity 1
    vxlan id 256 srcport 0 0 dstport 46354 proxy l2miss l3miss ageing 300
    bridge_slave

3- Every container with EXPOSEd ports has a veth paired with a veth in the vxlan netns;

4- the veth in vxlan netns are slaves of br0;

5- br0 has an ip, and is the default gw for containers.