Review at amazon: SAP Cloud Platform

Last week i read this book:

Before starting with the Oracle Cloud i wanted to read something other than AWS or Microsoft Azure. I was surprised at the completely different target of this cloud in respect to AWS and Azure. It is much more focused on business and business value - which is clearly one core domains of SAP.

This book contains a very well written introduction into cloud services - many other books could take this as an example. Very impressing are the over 120 mainly conceptional pictures - they make it much easier to understand the SAP Cloud Platform.

If you are interested, take a look at my review at amazon.de (like all my reviews: written in german ;-).

Oracle Database 19c (19.3) released!

And after nearly 3 months of waiting - Oracle released 19c:

First special feature: The rpm is still there and the release is only done for Linux and Oracle Solaris.

To get to the Linux download page just click here.

But the Grid Infrastructure is still not delivered as RPM package. :-(

Wireguard: An easy way to build VPNs

Last week i came across the following tool:

https://www.wireguard.com/

If you want to build up a VPN you can choose one of the following strategies:

• based on IPSec
• using TLS

(These two are the options to choose - of course there are some others...)

The nice thing with wireguard (from the linux point of view) is, that the wireguard interfaces are handled like all other  network interfaces on your device.

If you are really interested in this way, you should read the whitepaper. Here some excerpts:

... IPSec ... updating these data structures based on the results of a key exchange, generally done with IKEv2 [13], itself a complicated protocol with much choice and malleability. The complexity, as well as the sheer amount of code, of this solution is considerable. Administrators have a completely separate set of firewalling semantics and secure labeling for IPsec packets.

... based solution that uses TLS. By virtue of it being in user space, it has very poor performance—since packets must be copied multiple times between kernel space and user space—and a long-lived daemon is required; OpenVPN appears far from stateless to an administrator.

A WireGuard interface,wg0, can be added and configured to have a tunnelIP address of10.192.122.3in a/24subnet with the standard ip(8)utilities...

One design goal of WireGuard is to avoid storing any state prior to authentication and to not send any responses to unauthenticated packets. With no state stored for unauthenticated packets, and with no response generated,WireGuard is invisible to illegitimate peers and network scanners. Several classes of attacks are avoided bynot allowing unauthenticated packets to influence any state. And more generally, it is possible to implement WireGuard in a way that requires no dynamic memory allocation at all, even for authenticated packets, as explained in section 7.

So next step is to install this VPN solution and see, if the administration is really so easy as promised...

Oracle VM Server: Working with ovm cli

After getting the ovmcli run, here some commands which are quite helpful, when you are working with Oracle VM server.
But first:
Starting the ovmcli is done via

ssh admin@localhost -p 10000

at the OVM Manager.

After that you can get some overviews:

OVM> list server
Command: list server
Status: Success
Time: 2019-01-25 06:56:55,065 EST
Data: 
  id:18:e2:a6:9d:5c:b6:48:3a:9b:d2:b0:0f:56:7e:ab:e9  name:oraclevm
OVM> list vm
Command: list vm
Status: Success
Time: 2019-01-25 06:56:57,357 EST
Data: 
  id:0004fb0000060000fa3b1b883e717582  name:myAlpineLinux
OVM> list ServerPool
Command: list ServerPool
Status: Success
Time: 2019-01-25 06:57:12,165 EST
Data: 
  id:0004fb0000020000fca85278d951ce27  name:MyServerPool

A complete list of all list commands can be obtained like this:

OVM> list ?
          AccessGroup
          AntiAffinityGroup
          Assembly
          AssemblyVirtualDisk
          AssemblyVm
          BondPort
          ControlDomain
          Cpu
          CpuCompatibilityGroup
          FileServer
          FileServerPlugin
          FileSystem
          Job
          Manager
          Network
          PeriodicTask
          PhysicalDisk
          Port
          Repository
          RepositoryExport
          Server
          ServerController
          ServerPool
          ServerPoolNetworkPolicy
          ServerUpdateGroup
          ServerUpdateRepository
          StorageArray
          StorageArrayPlugin
          StorageInitiator
          Tag
          VirtualAppliance
          VirtualApplianceVirtualDisk
          VirtualApplianceVm
          VirtualCdrom
          VirtualDisk
          VlanInterface
          Vm
          VmCloneCustomizer
          VmCloneNetworkMapping
          VmCloneStorageMapping
          VmDiskMapping
          Vnic
          VolumeGroup

An overview which kind of command can be used like list:

OVM> help
For Most Object Types:
    create  [(attribute1)="value1"] ... [on  ]
    delete  
    edit    (attribute1)="value1" ...
    list 
    show  
For Most Object Types with Children:
    add   to  
    remove   from  
Client Session Commands:
    set alphabetizeAttributes=[Yes|No]
    set commandMode=[Asynchronous|Synchronous]
    set commandTimeout=[1-43200]
    set endLineChars=[CRLF,CR,LF]
    set outputMode=[Verbose,XML,Sparse]
    showclisession
Other Commands:
    exit
    showallcustomcmds
    showcustomcmds 
    showobjtypes
    showversion

If you want to get you vm.cfg file, you can use the id from "list vm" and type:

OVM> getVmCfgFileContent Vm id=0004fb0000060000fa3b1b883e717582
Command: getVmCfgFileContent Vm id=0004fb0000060000fa3b1b883e717582
Status: Success
Time: 2019-01-25 06:59:46,875 EST
Data: 
  OVM_domain_type = xen_pvm
  bootargs = 
  disk = [file:/OVS/Repositories/0004fb0000030000dad74d9c43176d2e/ISOs/0004fb0000150000226a713414eaa501.iso,xvda:cdrom,r,file:/OVS/Repositories/0004fb0000030000dad74d9c43176d2e/VirtualDisks/0004fb0000120000f62a7bba83063840.img,xvdb,w]
  bootloader = /usr/bin/pygrub
  vcpus = 1
  memory = 512
  on_poweroff = destroy
  OVM_os_type = Other Linux
  on_crash = restart
  cpu_weight = 27500
  OVM_description = 
  cpu_cap = 0
  on_reboot = restart
  OVM_simple_name = myAlpineLinux
  name = 0004fb0000060000fa3b1b883e717582
  maxvcpus = 1
  vfb = [type=vnc,vncunused=1,vnclisten=127.0.0.1,keymap=en-us]
  uuid = 0004fb00-0006-0000-fa3b-1b883e717582
  guest_os_type = linux
  OVM_cpu_compat_group = 
  OVM_high_availability = false
  vif = []

Very helpful is the Oracle documentation (here).