Awesome
bosh-linux-stemcell-builder
Tools for creating stemcells.
Building a stemcell locally
First make sure you have a local copy of this repository. Additionally, you must
download an external asset - VMware-ovftool-*.bundle
. See External Assets
for instructions on where to download it from. Please place that asset in
ci/docker
directory.
If you already have a stemcell-building environment set up and ready, skip to the Build Steps section. Otherwise, follow one of these two methods before trying to run the commands in Build Steps.
If you have docker installed,
host$ cd ci/docker
host$ ./run os-image-stemcell-builder
If you are not running on Linux or you do not have Docker installed, use
vagrant
to start a new VM which has Docker, and then change back into the
./docker
directory...
host$ vagrant up
host$ vagrant ssh
Once you have Docker running, run ./run
...
vagrant$ cd /opt/bosh/ci/docker
vagrant$ ./run os-image-stemcell-builder
container$ whoami
ubuntu
You're now ready to continue from the Build Steps section.
Troubleshooting: if you run into issues, try destroying any existing VM, update your box, and try again...
host$ vagrant destroy
host$ vagrant box update
Build Steps
At this point, you should be ssh'd and running within a docker container in the
bosh-linux-stemcell-builder
directory. Start by installing the latest
dependencies before continuing to a specific build task...
$ echo $PWD
/opt/bosh
$ bundle install --local
If you receive an Bundle error you need to install the bundler version specified in the error message
$ gem install bundler -v 1.17.3
$ bundle install --local
Build an OS image
An OS image is a tarball that contains a snapshot of an entire OS filesystem that contains all the libraries and system utilities that the BOSH agent depends on. It does not contain the BOSH agent or the virtualization tools: there is a separate Rake task that adds the BOSH agent and a chosen set of virtualization tools to any base OS image, thereby producing a stemcell. The OS Image should be rebuilt when you are making changes to packages we install in the operating system, or when making changes to how we configure those packages, or if you need to pull in and test an updated package from upstream.
$ mkdir -p $PWD/tmp
$ bundle exec rake stemcell:build_os_image[ubuntu,xenial,$PWD/tmp/ubuntu_base_image.tgz]
The arguments to stemcell:build_os_image
are:
operating_system_name
(ubuntu
): identifies which type of OS to fetch. Determines which package repository and packaging tool will be used to download and assemble the files. Currently, onlyubuntu
is recognized.operating_system_version
(xenial
): an identifier that the system may use to decide which release of the OS to download. Acceptable values depend on the operating system. Forubuntu
, usexenial
.os_image_path
($PWD/tmp/ubuntu_base_image.tgz
): the path to write the finished OS image tarball to. If a file exists at this path already, it will be overwritten without warning.
Building a Stemcell
The stemcell should be rebuilt when you are making and testing BOSH-specific changes on top of the base OS image such as new bosh-agent versions, or updating security configuration, or changing user settings.
$ mkdir -p $PWD/tmp
$ bundle exec rake stemcell:build_with_local_os_image[aws,xen,ubuntu,xenial,$PWD/tmp/ubuntu_base_image.tgz,"1.23"]
The arguments to stemcell:build_with_local_os_image
are:
infrastructure_name
(aws
): Which IAAS you are producing the stemcell for. Determines which virtualization tools to package on top of the stemcell.hypervisor_name
(xen
): Depending on what the IAAS supports, which hypervisor to target.operating_system_name
(ubuntu
): Type of OS. Same asstemcell:build_os_image
operating_system_version
(xenial
): OS release. Same asstemcell:build_os_image
os_image_path
($PWD/tmp/ubuntu_base_image.tgz
): Path to base OS image produced instemcell:build_os_image
build_number
(1.23
): Stemcell version.
The final argument, which specifies the build number, is optional and will default to '0000'
Testing
How to run tests for OS Images
The OS tests are meant to be run against the OS environment to which they
belong. When you run the stemcell:build_os_image
rake task, it will create a
.raw OS image that it runs the OS specific tests against. You will need to run
the rake task the first time you create your docker container, but everytime
after, as long as you do not destroy the container, you should be able to just
run the specific tests.
To run the ubuntu_xenial_spec.rb
tests for example you will need to:
bundle exec rake stemcell:build_os_image[ubuntu,xenial,$PWD/tmp/ubuntu_base_image.tgz]
- -update tests-
Then run the following:
cd /opt/bosh/bosh-stemcell
OS_IMAGE=/opt/bosh/tmp/ubuntu_base_image.tgz bundle exec rspec -fd spec/os_image/ubuntu_xenial_spec.rb
How to run tests for Stemcell
When you run the stemcell:build_with_local_os_image
or stemcell:build
rake
task, it will create a stemcell that it runs the stemcell specific tests
against. You will need to run the rake task the first time you create your
docker container, but everytime after, as long as you do not destroy the
container, you should be able to just run the specific tests.
To run the stemcell tests when building against local OS image you will need to:
bundle exec rake stemcell:build_with_local_os_image[aws,xen,ubuntu,xenial,$PWD/tmp/ubuntu_base_image.tgz]
- -make test changes-
Then run the following:
$ cd /opt/bosh/bosh-stemcell; \
STEMCELL_IMAGE=/mnt/stemcells/aws/xen/ubuntu/work/work/aws-xen-ubuntu.raw \
STEMCELL_WORKDIR=/mnt/stemcells/aws/xen/ubuntu/work/work/chroot \
OS_NAME=ubuntu \
bundle exec rspec -fd --tag ~exclude_on_aws \
spec/os_image/ubuntu_xenial_spec.rb \
spec/stemcells/ubuntu_xenial_spec.rb \
spec/stemcells/go_agent_spec.rb \
spec/stemcells/aws_spec.rb \
spec/stemcells/stig_spec.rb \
spec/stemcells/cis_spec.rb
ShelloutTypes
In pursuit of more robustly testing, we wrote our testing library for stemcell contents, called ShelloutTypes.
The ShelloutTypes code has its own unit tests, but require root privileges and
an ubuntu chroot environment to run. For this reason, we use the
bosh/main-ubuntu-chroot
docker imagefor unit tests. To run these unit tests
locally, run:
$ docker run bosh/main-ubuntu-chroot # now in /opt/bosh
$ source /etc/profile.d/chruby.sh
$ chruby 2.3.1
$ #create user for ShelloutTypes::File tests
$ chroot /tmp/ubuntu-chroot /bin/bash -c 'useradd -G nogroup shellout'
$ bundle install --local
$ cd bosh-stemcell
$ bundle exec rspec spec/ --tag shellout_types
The above strategy is derived from our CI unit testing job's script.
Troubleshooting
If you find yourself debugging any of the above processes, here is what you need to know:
-
Most of the action happens in Bash scripts, which are referred to as stages, and can be found in
stemcell_builder/stages/<stage_name>/apply.sh
. -
While debugging a particular stage that is failing, you can resume the process from that stage by adding
resume_from=<stage_name>
to the end of yourbundle exec rake
command. When a stage'sapply.sh
fails, you should see a message of the formCan't find stage '<stage>' to resume from. Aborting.
so you know which stage failed and where you can resume from after fixing the problem. Please use caution as stages are not guaranteed to be idempotent.Example usage:
$ bundle exec rake stemcell:build_os_image[ubuntu,xenial,$PWD/tmp/ubuntu_base_image.tgz] resume_from=rsyslog_config
-
Directory renamed before its status could be extracted
If you run into the following error whilst builing an image with Docker:
ubuntu@98b2a2aed0e6:/opt/bosh$ bundle exec rake stemcell:build_with_local_os_image[vsphere,esxi,ubuntu,xenial,$PWD/tmp/ubuntu_base_image.tgz,705] cd /opt/bosh/bosh-stemcell; OS_IMAGE=/opt/bosh/tmp/ubuntu_base_image.tgz bundle exec rspec -fd spec/os_image/ubuntu_xenial_spec.rb All stemcell_tarball tests are being skipped. STEMCELL_WORKDIR needs to be set All stemcell_image tests are being skipped. STEMCELL_IMAGE needs to be set Run options: exclude {:stemcell_image=>true, :stemcell_tarball=>true, :shellout_types=>true} Ubuntu 16.04 OS image tar: ./var/log: Directory renamed before its status could be extracted
You can convert Docker's storage driver to
aufs
as described here.
Pro Tips
- If the OS image has been built and so long as you only make test case
modifications you can just rerun the tests (without rebuilding OS image).
Details in section
How to run tests for OS Images
- If the Stemcell has been built and you are only updating tests, you do not
need to re-build the stemcell. You can simply rerun the tests (without
rebuilding Stemcell. Details in section
How to run tests for Stemcell
- It's possible to verify OS/Stemcell changes without making a deployment using
the stemcell. For an AWS specific ubuntu stemcell, the filesytem is available
at
/mnt/stemcells/aws/xen/ubuntu/work/work/chroot
External Assets
The ovftool installer from VMWare can be found at my.vmware.com.
The ovftool installer must be copied into the ci/docker/os-image-stemcell-builder next to the Dockerfile or you will receive the error
Step 24/30 : ADD ${OVF_TOOL_INSTALLER} /tmp/ovftool_installer.bundle
ADD failed: stat /var/lib/docker/tmp/docker-builder389354746/VMware-ovftool-4.1.0-2459827-lin.x86_64.bundle: no such file or directory
Rebuilding the docker image
The Docker image is published to
bosh/os-image-stemcell-builder
.
You will need the ovftool installer present on your filesystem.
Rebuild the container with the build
script...
vagrant$ ./build os-image-stemcell-builder
When ready, push
to DockerHub and use the credentials from LastPass...
vagrant$ cd os-image-stemcell-builder
vagrant$ ./push