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diff --git a/docs/report/vpp_performance_tests/documentation/containers.rst b/docs/report/vpp_performance_tests/documentation/containers.rst new file mode 100644 index 0000000000..d3eeb71b0b --- /dev/null +++ b/docs/report/vpp_performance_tests/documentation/containers.rst @@ -0,0 +1,564 @@ + +.. _containter_orchestration_in_csit: + +Container Orchestration in CSIT +=============================== + +Overview +-------- + +Linux Containers +~~~~~~~~~~~~~~~~ + +Linux Containers is an OS-level virtualization method for running +multiple isolated Linux systems (containers) on a compute host using a +single Linux kernel. Containers rely on Linux kernel cgroups +functionality for controlling usage of shared system resources (i.e. +CPU, memory, block I/O, network) and for namespace isolation. The latter +enables complete isolation of applications' view of operating +environment, including process trees, networking, user IDs and mounted +file systems. + +:abbr:`LXC (Linux Containers)` combine kernel's cgroups and support for isolated +namespaces to provide an isolated environment for applications. Docker +does use LXC as one of its execution drivers, enabling image management +and providing deployment services. More information in [lxc]_, [lxc-namespace]_ +and [stgraber]_. + +Linux containers can be of two kinds: privileged containers and +unprivileged containers. + +Unprivileged Containers +~~~~~~~~~~~~~~~~~~~~~~~ + +Running unprivileged containers is the safest way to run containers in a +production environment. From LXC 1.0 one can start a full system +container entirely as a user, allowing to map a range of UIDs on the +host into a namespace inside of which a user with UID 0 can exist again. +In other words an unprivileged container does mask the userid from the +host, making it impossible to gain a root access on the host even if a +user gets root in a container. With unprivileged containers, non-root +users can create containers and will appear in the container as the +root, but will appear as userid <non-zero> on the host. Unprivileged +containers are also better suited to supporting multi-tenancy operating +environments. More information in [lxc-security]_ and [stgraber]_. + +Privileged Containers +~~~~~~~~~~~~~~~~~~~~~ + +Privileged containers do not mask UIDs, and container UID 0 is mapped to +the host UID 0. Security and isolation is controlled by a good +configuration of cgroup access, extensive AppArmor profile preventing +the known attacks as well as container capabilities and SELinux. Here a +list of applicable security control mechanisms: + +- Capabilities - keep (whitelist) or drop (blacklist) Linux capabilities, + [capabilities]_. +- Control groups - cgroups, resource bean counting, resource quotas, access + restrictions, [cgroup1]_, [cgroup2]_. +- AppArmor - apparmor profiles aim to prevent any of the known ways of + escaping a container or cause harm to the host, [apparmor]_. +- SELinux - Security Enhanced Linux is a Linux kernel security module + that provides similar function to AppArmor, supporting access control + security policies including United States Department of Defense–style + mandatory access controls. Mandatory access controls allow an + administrator of a system to define how applications and users can + access different resources such as files, devices, networks and inter- + process communication, [selinux]_. +- Seccomp - secure computing mode, enables filtering of system calls, + [seccomp]_. + +More information in [lxc-security]_ and [lxc-sec-features]_. + +**Linux Containers in CSIT** + +CSIT is using Privileged Containers as the ``sysfs`` is mounted with RW +access. Sysfs is required to be mounted as RW due to VPP accessing +:command:`/sys/bus/pci/drivers/uio_pci_generic/unbind`. This is not the case of +unprivileged containers where ``sysfs`` is mounted as read-only. + + +Orchestrating Container Lifecycle Events +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Following Linux container lifecycle events need to be addressed by an +orchestration system: + +1. Acquire - acquiring/downloading existing container images via + :command:`docker pull` or :command:`lxc-create -t download`. + +2. Build - building a container image from scratch or another + container image via :command:`docker build <dockerfile/composefile>` or + customizing LXC templates in + `https://github.com/lxc/lxc/tree/master/templates`_ + +3. (Re-)Create - creating a running instance of a container application + from anew, or re-creating one that failed. A.k.a. (re-)deploy via + :command:`docker run` or :command:`lxc-start` + +4. Execute - execute system operations within the container by attaching to + running container. THis is done by :command:`lxc-attach` or + :command:`docker exec` + +5. Distribute - distributing pre-built container images to the compute + nodes. Currently not implemented in CSIT. + + +Container Orchestration Systems Used in CSIT +-------------------------------------------- + +Current CSIT testing framework integrates following Linux container +orchestration mechanisms: + +- LXC/Docker for complete VPP container lifecycle control. +- Combination of Kubernetes (container orchestration), Docker (container + images) and Ligato (container networking). + +LXC +~~~ + +LXC is the well-known and heavily tested low-level Linux container +runtime [lxc-source]_, that provides a userspace interface for the Linux kernel +containment features. With a powerful API and simple tools, LXC enables +Linux users to easily create and manage system or application +containers. LXC uses following kernel features to contain processes: + +- Kernel namespaces: ipc, uts, mount, pid, network and user. +- AppArmor and SELinux security profiles. +- Seccomp policies. +- Chroot. +- Cgroups. + +CSIT uses LXC runtime and LXC usertools to test VPP data plane performance in +a range of virtual networking topologies. + +**Known Issues** + +- Current CSIT restriction: only single instance of lxc runtime due to + the cgroup policies used in CSIT. There is plan to add the capability into + code to create cgroups per container instance to address this issue. This sort + of functionality is better supported in LXC 2.1 but can be done is current + version as well. + +**Open Questions** + +- CSIT code is currently using cgroup to pin lxc data plane thread to + cpu cores after lxc container is created. In the future may find a + more universal way to do it. + +Docker +~~~~~~ + +Docker builds on top of Linux kernel containment features, and +offers a high-level tool for wrapping the processes, maintaining and +executing them in containers [docker]_. Currently it using *runc* a CLI tool for +spawning and running containers according to the `OCI specification +<https://www.opencontainers.org/>`_ + +A Docker container image is a lightweight, stand-alone, executable +package of a piece of software that includes everything needed to run +it: code, runtime, system tools, system libraries, settings. + +CSIT uses Docker to manage the maintenance and execution of +containerized applications used in CSIT performance tests. + +- Data plane thread pinning to CPU cores - Docker CLI and/or Docker + configuration file controls the range of CPU cores the Docker image + must run on. VPP thread pinning defined vpp startup.conf. + + +Kubernetes +~~~~~~~~~~ + +Kubernetes [k8s-doc]_, or K8s, is a production-grade container orchestration +platform for automating the deployment, scaling and operating +application containers. Kubernetes groups containers that make up an +application into logical units, pods, for easy management and discovery. +K8s pod definitions including compute resource allocation is provided in +.yaml files. + +CSIT uses K8s and its infrastructure components like etcd to control all +phases of container based virtualized network topologies. + +**Known Issues** + +- Unable to properly pin k8s pods and containers to cpu cores. This will be + addressed in Kubernetes 1.8+ in alpha testing. + +**Open Questions** + +- Clarify the functions provided by Contiv and Calico in Ligato system? + +Ligato +~~~~~~ + +Ligato [ligato]_ is an open-source project developing a set of cloud-native +tools for orchestrating container networking. Ligato integrates with FD.io VPP +using goVPP [govpp]_ and vpp-agent [vpp-agent]_. + +**Known Issues** + +**Open Questions** + +- Currently using a separate LF Jenkins job for building csit-centric + vpp_agent docker images vs. dockerhub/ligato ones. + +Implementation +-------------- + +CSIT container orchestration is implemented in CSIT Level-1 keyword +Python libraries following the Builder design pattern. Builder design +pattern separates the construction of a complex object from its +representation, so that the same construction process can create +different representations e.g. LXC, Docker, other. + +CSIT Robot Framework keywords are then responsible for higher level +lifecycle control of of the named container groups. One can have +multiple named groups, with 1..N containers in a group performing +different role/functionality e.g. NFs, Switch, Kafka bus, ETCD +datastore, etc. ContainerManager class acts as a Director and uses +ContainerEngine class that encapsulate container control. + +Current CSIT implementation is illustrated using UML Class diagram: + +1. Acquire +2. Build +3. (Re-)Create +4. Execute + +:: + + +-----------------------------------------------------------------------+ + | RF Keywords (high level lifecycle control) | + +-----------------------------------------------------------------------+ + | Construct VNF containers on all DUTs | + | Acquire all '${group}' containers | + | Create all '${group}' containers | + | Install all '${group}' containers | + | Configure all '${group}' containers | + | Stop all '${group}' containers | + | Destroy all '${group}' containers | + +-----------------+-----------------------------------------------------+ + | 1 + | + | 1..N + +-----------------v-----------------+ +--------------------------+ + | ContainerManager | | ContainerEngine | + +-----------------------------------+ +--------------------------+ + | __init()__ | | __init(node)__ | + | construct_container() | | acquire(force) | + | construct_containers() | | create() | + | acquire_all_containers() | | stop() | + | create_all_containers() | 1 1 | destroy() | + | execute_on_container() <>-------| info() | + | execute_on_all_containers() | | execute(command) | + | install_vpp_in_all_containers() | | system_info() | + | configure_vpp_in_all_containers() | | install_supervisor() | + | stop_all_containers() | | install_vpp() | + | destroy_all_containers() | | restart_vpp() | + +-----------------------------------+ | create_vpp_exec_config() | + | create_vpp_startup_config| + | is_container_running() | + | is_container_present() | + | _configure_cgroup() | + +-------------^------------+ + | + | + | + +----------+---------+ + | | + +------+-------+ +------+-------+ + | LXC | | Docker | + +--------------+ +--------------+ + | (inherinted) | | (inherinted) | + +------+-------+ +------+-------+ + | | + +---------+---------+ + | + | constructs + | + +---------v---------+ + | Container | + +-------------------+ + | __getattr__(a) | + | __setattr__(a, v) | + +-------------------+ + +Sequentional diagram that illustrates the creation of a single container. + +.. mk: what "RF KW" is meant below? +.. mk: the flow sequence should adhere to the lifecycle events listed earlier in this doc. + +:: + + Legend: + e = engine [Docker|LXC] + .. = kwargs (variable number of keyword argument) + + +-------+ +------------------+ +-----------------+ + | RF KW | | ContainerManager | | ContainerEngine | + +---+---+ +--------+---------+ +--------+--------+ + | | | + | 1: new ContainerManager(e) | | + +-+---------------------------->+-+ | + |-| |-| 2: new ContainerEngine | + |-| |-+----------------------->+-+ + |-| |-| |-| + |-| +-+ +-+ + |-| | | + |-| 3: construct_container(..) | | + |-+---------------------------->+-+ | + |-| |-| 4: init() | + |-| |-+----------------------->+-+ + |-| |-| |-| 5: new +-------------+ + |-| |-| |-+-------->| Container A | + |-| |-| |-| +-------------+ + |-| |-|<-----------------------+-| + |-| +-+ +-+ + |-| | | + |-| 6: acquire_all_containers() | | + |-+---------------------------->+-+ | + |-| |-| 7: acquire() | + |-| |-+----------------------->+-+ + |-| |-| |-| + |-| |-| |-+--+ + |-| |-| |-| | 8: is_container_present() + |-| |-| True/False |-|<-+ + |-| |-| |-| + |-| |-| |-| + +---------------------------------------------------------------------------------------------+ + | |-| ALT [isRunning & force] |-| |-|--+ | + | |-| |-| |-| | 8a: destroy() | + | |-| |-| |-<--+ | + +---------------------------------------------------------------------------------------------+ + |-| |-| |-| + |-| +-+ +-+ + |-| | | + |-| 9: create_all_containers() | | + |-+---------------------------->+-+ | + |-| |-| 10: create() | + |-| |-+----------------------->+-+ + |-| |-| |-+--+ + |-| |-| |-| | 11: wait('RUNNING') + |-| |-| |-<--+ + |-| +-+ +-+ + |-| | | + +---------------------------------------------------------------------------------------------+ + | |-| ALT | | | + | |-| (install_vpp, configure_vpp) | | | + | |-| | | | + +---------------------------------------------------------------------------------------------+ + |-| | | + |-| 12: destroy_all_containers() | | + |-+---------------------------->+-+ | + |-| |-| 13: destroy() | + |-| |-+----------------------->+-+ + |-| |-| |-| + |-| +-+ +-+ + |-| | | + +++ | | + | | | + + + + + +Container Data Structure +~~~~~~~~~~~~~~~~~~~~~~~~ + +Container is represented in Python L1 library as a separate Class with instance +variables and no methods except overriden ``__getattr__`` and ``__setattr__``. +Instance variables are assigned to container dynamically during the +``construct_container(**kwargs)`` call and are passed down from the RF keyword. + +Usage example: + +.. code-block:: robotframework + + | Construct VNF containers on all DUTs + | | [Arguments] | ${technology} | ${image} | ${cpu_count}=${1} | ${count}=${1} + | | ... + | | ${group}= | Set Variable | VNF + | | ${guest_dir}= | Set Variable | /mnt/host + | | ${host_dir}= | Set Variable | /tmp + | | ${skip_cpus}= | Evaluate | ${vpp_cpus}+${system_cpus} + | | Import Library | resources.libraries.python.ContainerUtils.ContainerManager + | | ... | engine=${technology} | WITH NAME | ${group} + | | ${duts}= | Get Matches | ${nodes} | DUT* + | | :FOR | ${dut} | IN | @{duts} + | | | {env}= | Create List | LC_ALL="en_US.UTF-8" + | | | ... | DEBIAN_FRONTEND=noninteractive | ETCDV3_ENDPOINTS=172.17.0.1:2379 + | | | ${cpu_node}= | Get interfaces numa node | ${nodes['${dut}']} + | | | ... | ${dut1_if1} | ${dut1_if2} + | | | Run Keyword | ${group}.Construct containers + | | | ... | name=${dut}_${group} + | | | ... | node=${nodes['${dut}']} + | | | ... | host_dir=${host_dir} + | | | ... | guest_dir=${guest_dir} + | | | ... | image=${image} + | | | ... | cpu_count=${cpu_count} + | | | ... | cpu_skip=${skip_cpus} + | | | ... | smt_used=${False} + | | | ... | cpuset_mems=${cpu_node} + | | | ... | cpu_shared=${False} + | | | ... | env=${env} + +Mandatory parameters to create standalone container are: ``node``, ``name``, +``image`` [image-var]_, ``cpu_count``, ``cpu_skip``, ``smt_used``, +``cpuset_mems``, ``cpu_shared``. + +There is no parameters check functionality. Passing required arguments is in +coder responsibility. All the above parameters are required to calculate the +correct cpu placement. See documentation for the full reference. + +Kubernetes +~~~~~~~~~~ + +Kubernetes is implemented as separate library ``KubernetesUtils.py``, +with a class with the same name. This utility provides an API for L2 +Robot Keywords to control ``kubectl`` installed on each of DUTs. One +time initialization script, ``resources/libraries/bash/k8s_setup.sh`` +does reset/init kubectl, applies Calico v2.4.1 and initializes the +``csit`` namespace. CSIT namespace is required to not to interfere with +existing setups and it further simplifies apply/get/delete +Pod/ConfigMap operations on SUTs. + +Kubernetes utility is based on YAML templates to avoid crafting the huge +YAML configuration files, what would lower the readability of code and +requires complicated algorithms. The templates can be found in +``resources/templates/kubernetes`` and can be leveraged in the future +for other separate tasks. + +Two types of YAML templates are defined: + +- Static - do not change between deployments, that is infrastructure + containers like Kafka, Calico, ETCD. + +- Dynamic - per test suite/case topology YAML files e.g. SFC_controller, + VNF, VSWITCH. + +Making own python wrapper library of ``kubectl`` instead of using the +official Python package allows to control and deploy environment over +the SSH library without the need of using isolated driver running on +each of DUTs. + +Ligato +~~~~~~ + +Ligato integration does require to compile the ``vpp-agent`` tool and build the +bundled Docker image. Compilation of ``vpp-agent`` depends on specific VPP. In +``ligato/vpp-agent`` repository there are well prepared scripts for building the +Docker image. Building docker image is possible via series of commands: + +:: + + git clone https://github.com/ligato/vpp-agent + cd vpp_agent/docker/dev_vpp_agent + sudo docker build -t dev_vpp_agent --build-arg AGENT_COMMIT=<agent commit id>\ + --build-arg VPP_COMMIT=<vpp commit id> --no-cache . + sudo ./shrink.sh + cd ../prod_vpp_agent + sudo ./build.sh + sudo ./shrink.sh + +CSIT requires Docker image to include the desired VPP version (per patch +testing, nightly testing, on demand testing). + +The entire build process of building ``dev_vpp_agent`` image heavily depends +on internet connectivity and also takes a significant amount of time (~1-1.5h +based on internet bandwidth and allocated resources). The optimal solution would +be to build the image on jenkins slave, transfer the Docker image to DUTs and +execute separate suite of tests. + +To adress the amount of time required to build ``dev_vpp_agent`` image, we can +pull existing specific version of ```dev_vpp_agent``` and exctract the +```vpp-agent``` from it. + +We created separate sets of Jenkins jobs, that will be executing following: + +1. Clone latest CSIT and Ligato repositaries. +2. Pull specific version of ``dev_vpp_agent`` image from Dockerhub. +3. Build ``prod_vpp_image`` Docker image from ``dev_vpp_agent`` image. +4. Shrink image using ``docker/dev_vpp_agent/shrink.sh`` script. +5. Transfer ``prod_vpp_agent_shrink`` image to DUTs. +6. Execute subset of performance tests designed for Ligato testing. + +:: + + +-----------------------------------------------+ + | ubuntu:16.04 <-----| Base image on Dockerhub + +------------------------^----------------------+ + | + | + +------------------------+----------------------+ + | ligato/dev_vpp_agent <------| Pull this image from + +------------------------^----------------------+ | Dockerhub ligato/dev_vpp_agent:<version> + | + | Extract agent.tar.gz from dev_vpp_agent + +------------------------+----------------------+ + | prod_vpp_agent <------| Build by passing own + +-----------------------------------------------+ | vpp.tar.gz (from nexus + | or built by JJB) and + | agent.tar.gz extracted + | from ligato/dev_vpp_agent + + +Approximate size of vnf-agent docker images: + +:: + + REPOSITORY TAG IMAGE ID CREATED SIZE + dev_vpp_agent latest 442771972e4a 8 hours ago 3.57 GB + dev_vpp_agent_shrink latest bd2e76980236 8 hours ago 1.68 GB + prod_vpp_agent latest e33a5551b504 2 days ago 404 MB + prod_vpp_agent_shrink latest 446b271cce26 2 days ago 257 MB + +In CSIT we need to create separate performance suite under +``tests/kubernetes/perf`` which contains modified Suite setup in comparison +to standard perf tests. This is due to reason that VPP will act as vswitch in +Docker image and not as standalone installed service. + +Tested Topologies +~~~~~~~~~~~~~~~~~ + +Listed CSIT container networking test topologies are defined with DUT +containerized VPP switch forwarding packets between NF containers. Each +NF container runs their own instance of VPP in L2XC configuration. + +Following container networking topologies are tested in CSIT |release|: + +- LXC topologies: + + - eth-l2xcbase-eth-2memif-1lxc. + - eth-l2bdbasemaclrn-eth-2memif-1lxc. + +- Docker topologies: + + - eth-l2xcbase-eth-2memif-1docker. + +- Kubernetes/Ligato topologies: + + - eth-1drcl2xcbase-eth-2memif-1drcl2xc. + - eth-1drcl2xcbase-eth-4memif-2drcl2xc. + - eth-1drcl2bdbasemaclrn-eth-2memif-1drcl2xc. + - eth-1drcl2bdbasemaclrn-eth-4memif-2drcl2xc. + + +References +---------- + +.. [lxc] `Linux Containers <https://linuxcontainers.org/>`_ +.. [lxc-namespace] `Resource management: Linux kernel Namespaces and cgroups <https://www.cs.ucsb.edu/~rich/class/cs293b-cloud/papers/lxc-namespace.pdf>`_. +.. [stgraber] `LXC 1.0: Blog post series <https://stgraber.org/2013/12/20/lxc-1-0-blog-post-series/>`_. +.. [lxc-security] `Linux Containers Security <https://linuxcontainers.org/lxc/security/>`_. +.. [capabilities] `Linux manual - capabilities - overview of Linux capabilities http://man7.org/linux/man-pages/man7/capabilities.7.html`_. +.. [cgroup1] `Linux kernel documentation: cgroups <https://www.kernel.org/doc/Documentation/cgroup-v1/cgroups.txt>`_. +.. [cgroup2] `Linux kernel documentation: Control Group v2 <https://www.kernel.org/doc/Documentation/cgroup-v2.txt>`_. +.. [selinux] `SELinux Project Wiki <http://selinuxproject.org/page/Main_Page>`_. +.. [lxc-sec-features] `LXC 1.0: Security features <https://stgraber.org/2014/01/01/lxc-1-0-security-features/>`_. +.. [lxc-source] `Linux Containers source <https://github.com/lxc/lxc>`_. +.. [apparmor] `Ubuntu AppArmor <https://wiki.ubuntu.com/AppArmor>`_. +.. [seccomp] `SECure COMPuting with filters <https://www.kernel.org/doc/Documentation/prctl/seccomp_filter.txt>`_. +.. [docker] `Docker <https://www.docker.com/what-docker>`_. +.. [k8s-doc] `Kubernetes documentation <https://kubernetes.io/docs/home/>`_. +.. [ligato] `Ligato <https://github.com/ligato>`_. +.. [govpp] `FD.io goVPP project <https://wiki.fd.io/view/GoVPP>`_. +.. [vpp-agent] `Ligato vpp-agent <https://github.com/ligato/vpp-agent>`_. +.. [image-var] Image parameter is required in initial commit version. There is plan to implement container build class to build Docker/LXC image. |