Introduction

This is the golang guest utilities for XenServer

XenStore golang client library

xe-guest-utilities.git/xenstoreclient

XenStore CLI

xe-guest-utilities.git/xenstore

Guest Utilities

xe-guest-utilities.git/xe-daemon

Build Instructions

Go development environment is required to build the guest utilities.

After commit 94942cd597e guest utilities not support version <= 1.11, with modern go versions (later than 1.11) we can build with below guides:

Build with GO111MODULE=off

In this case, project and source files are expected to put in GOPATH/src

1. Make sure go is installed in your environment, and set correctly in $PATH
2. Setup your go environment configurations

GOROOT In newer versions, we don't need to set up the $GOROOT variable unless you use different Go versions

GOPATH Go gets librarys from the directory GOPATH, so for the build to work, you need read/write permissions there. With GO111MODULE disabled, $GOPATH directory are expected to has below hierarchy.

└── src
    ├── github.com
    │   └── xenserver
    │       └── xe-guest-utilities
    |
    └── golang.org
        └── x
            └── sys

GO111MODULE Set GO111MODULE disabled e.g. let's say your project directory is /home/xe-guest-utilities-7.30.0

export GOPATH=/home/xe-guest-utilities-7.30.0
export GO111MODULE=off

3. Get the project

git clone https://github.com/xenserver/xe-guest-utilities.git $GOPATH/src/github.com/xenserver/xe-guest-utilities

4. Get external library

This project uses the golang.org/x/sys/unix library, you can use different methods to set the external library you use in your source code

go get -u golang.org/x/sys@latest

or

git clone git@github.com:golang/sys.git $GOPATH/src/golang.org/x/sys

5. Build Go into the right directory cd $GOPATH/src/github.com/xenserver/xe-guest-utilities now you can make build or make. Then you can get resulting files in build/, same layout as explained below

   • The binarys will be in build/obj
   • In build/stage are all required files and where they go when installed.

   • In build/dist is a tarball with all files,symlinks and permissions.

Build with GO111MODULE=on

In this case, we can place our project outside $GOPATH

1. Make sure go is installed in your environment, and set correctly in $PATH
2. Setup your go environment configurations

GOPATH Go gets librarys from the GOPATH, so for this to work, you need read/write permissions there.If in doubt, set GOPATH to a temporary location, ie: export GOPATH=$(pwd) sets GOPATH to the local folder

GO111MODULE With GO111MODULE enabled, go projects are no longer confined to $GOPATH, instead it use go.mod to keep track fo each package and it's version

e.g. let's say your project directory is /home/xe-guest-utilities-7.30.0

# export GOPATH=/home/xe-guest-utilities-7.30.0
# export GO111MODULE=on

3. Get the project

   git clone https://github.com/xenserver/xe-guest-utilities.git $GOPATH/xe-guest-utilities`

4. Set external library

This project uses the golang.org/x/sys/unix library, you can use different method to set the external library

• Download to $GOPATH manually

  git clone git@github.com:golang/sys.git $GOPATH/golang.org/x/sys

  And then add below content into go.mod before require golang.org/x/sys v0.0.0-20210414055047-fe65e336abe0 to manually point to the correct place to get module from the specific place.

  replace golang.org/x/sys v0.0.0-20210414055047-fe65e336abe0 => ../golang.org/x/sys

  Then sync the vendor directory by go mod vendor

• Use go module tool to get Sync the vendor directory by go mod vendor In this process go will download golang.org/x/sys of the version v0.0.0-20210414055047-fe65e336abe0 to the the vendor directory and refresh vendor/modules.txt

5. Build

Go into the right directory cd $GOPATH/xe-guest-utilities/, then you can use make build or make. resulting files are in build/, same layout as explained above

Collected information, by lifetime

static

• from /var/cache/xe-linux-distribution
  • data/os_*
• compiled in
  • attr/PVAddons/Installed = 1
  • attr/PVAddons/MajorVersion
  • attr/PVAddons/MinorVersion
  • attr/PVAddons/MicroVersion
  • attr/PVAddons/BuildVersion
• runtime-dependant
  • control/feature-balloon = [01]

changes on event (network config, hotplug, resume, migration...)

• from ifconfig/ip
  • attr/vif/$VIFID/ipv[46]/%d = $ADDR
  • xenserver/attr/net-sriov-vf/$VIFID/ipv[46]/%d = $ADDR
• from pvs, mount, /sys/block/, xenstore
  • data/volumes/%d/...
  • .../extents/0 = $BACKEND
  • .../name = /dev/xvd$X$N($PARTUUID) or /dev/xvd$X$N
  • .../size = $SIZE_IN_BYTES
  • .../mount_points/0 = $DIR or "[LVM]"
  • .../filesystem = $FSTYPE
• from /proc/meminfo
  • data/meminfo_total (or even static?)

ephemeral

• from /proc/meminfo
  • data/meminfo_free
• from pvs or free
  • data/volumes/%d/free
• data/updated: date of last update