Results for category "OpenShift"

Migrating OpenShift 3 Container Runtime

While reaching its end of life, OpenShift 3 remains widely used, and in some cases still more reliable than its successor, OpenShift 4.

OpenShift was historically built on top of Docker, and introduced support for Cri-O, an alternative container runtime. Cri-o integration into OpenShift reached GA with its release 3.9, mid 2018 — based on Kubernetes 1.9 & Cri-o 1.9. Although it has not been without a few hiccups.

As of today, there are still a few bugs involving RPC overflows, when lots of containers are running on a Cri-O nodes, that could result in some operations, addressing all containers, to fail – eg: drains. Or some SDN corruptions, that I suspect to be directly related with Cri-O. Pending RFE to implement SELinux audit logging, similar to what already exists for Docker, … And the fact OpenShift 4 drops Docker support, while ideologically commendable, is quite a bold move right now, considering the youth of Cri-O.

Lately, a customer of mine contacted me regarding a cluster, as I did help them to deploy it. Mid 2019, an architect recommended the with OpenShift 3.11, Cri-O, and GlusterFS CNS storage – aka OCS, OpenShift Container Storage. We did set it up, cluster has been running for almost a year now, when customer opened a case with their support, complaining about an issue with GlusterFS containers behaving unexpectedly.

After a few weeks of troubleshooting, support got back to customer, arguing their setup was not supported, pointing us to a KB item none of us was aware of so far: while OpenShift 3.11 is fully supported with both Cri-O and GlusterFS CNS storage, their combination is not: only Docker, may be used with GlusterFS.

When realizing this, we had to come up with a plan, migrating container runtime from Cri-O to Docker, on any OpenShift node hosting GlusterFS, so support would keep investigating the original issue. Lacking any documentation covering such a migration, I’ve been deploying a lab, reproducing my customer’s cluster.

We will simplify it to an 11 nodes cluster: 3 masters, 3 gluster, 3 ingress, 2 computes. The GlusterFS nodes would also be hosting Prometheus and Hawkular. The Ingress nodes would host the Docker registry and OpenShift routers. We would also deploy a Git server and a few dummy Pods on the compute nodes, hosting some sources and generating activity on GlusterFS backed persistent volumes.

Having reproduced customer’s setup as close as I could, I would then repeat the following process, re-deploying all my GlusterFS nodes. First, let’s pick a node and drain it:

$ oc adm cordon gluster1.demo
$ oc adm drain gluster1.demo --ignore-daemonsets --delete-local-data

Next, we will connect that node, stop OpenShift services, container runtime, dnsmasq, purge some packages, … It will not clean up everything, though would be good enough for us:

# systemctl stop atomic-openshift-node
# systemctl stop crio
# systemctl stop docker
# systemctl disable atomic-openshift-node
# systemctl disable crio
# systemctl disable docker
# grep BOOTSTRAP_CONFIG /etc/sysconfig/atomic-openshift-node
BOOTSTRAP_CONFIG_NAME=node-cm-name
# cp -f /etc/origin/node/resolv.conf /etc/
# systemctl stop dnsmasq
# systemctl disable dnsmasq
# yum -y remove criu docker atomic-openshift-excluder atomic-openshift-docker-excluder cri-tools \
    atomic-openshift-hyperkube atomic-openshift-node docker-client cri-o atomic-openshift-clients \
    dnsmasq
# rm -fr /etc/origin /etc/dnsmasq.d/* /etc/sysconfig/atomic-openshift-node.rpmsave
# reboot

Once node would have rebooted, we may connect back, confirm DNS resolution still works, that container runtimes are gone, … Then we will delete the node from the API:

$ oc delete node gluster1.demo

Next, we would edit our Ansible inventory, reconfiguring that node to only use Docker. In the inventory file, we would add to that node variables some openshift_use_crio=False, overriding some default defined in our group_vars/OSEv3.yaml.

We would also change the openshift_node_group_name variable, to remove the Cri-o specifics from that node kubelet configuration. Note, in some cases, this could involved editing some custom openshift_node_groups definition. For most common deployments, we may only switch the node group name from a crio variant to its docker equivalent (eg: from node-config-infra-crio to node-config-infra).

Finally, still editing Ansible inventory, we would move our migrating node definition, out of the nodes group, and into the new_nodes one — doing so, if you never had to scale that cluster before, be careful that group should inherit your custom OSEv3 settings, maybe set it as children of the OSEv3 host group, though make sure it’s not a member of the node one. At that stage, it is also recommended to have fixed both OpenShift and GlusterFS versions, up to their patch number — in our case, we’re using OCP 3.11.161, OCS 3.11.4.

Make the the node groups configuration is up to date:

$ oc delete -n openshift-node custom-node-group-gfs1 #not necessary if using default node groups
$ ansible-playbook -i inventory /usr/share/ansible/openshift-ansible/playbooks/openshift-master/openshift_node_group.yml

Then, we may proceed as if adding a new node to our cluster:

$ ansible-playbook -i inventory /usr/share/ansible/openshift-ansible/playbooks/openshift-node/scaleup.yml

As soon as the node would have joined back our cluster, the GlusterFS container we were missing should start, using the exact same local volumes and configuration, only now it uses Docker.

Once that GlusterFS Pod is marked back healthy, rsh into any GlusterFS container and query for your volumes health:

$ oc rsh -n glusterfs-namespace ds/glusterfs-clustername
sh-4.2# gluster volume list | while read vol; do
gluster volume heal $vol info;
done


Internal healing mechanisms may not fix all issues, be sure your cluster is healthy before migrating another node. Meanwhile, we would edit back Ansible inventory and make sure to move our node, out of the new_nodes group and back into its original location.

Repeat with all node you need to migrate. Eventually, the openshift_use_crio definition could be moved into some host group settings, avoiding multiple definitions in nodes variables.

To further confirm we were not leaving the cluster in some inconsistent state, I’ve later upgraded that lab, to OCP 3.11.200 and OCS 3.11.5, with only one outstanding note: the atomic-openshift-excluder package was missing, on the nodes I did migrate. While it is installed during cluster deployment, it appears this is not the case during cluster scale outs. Could be a bug with openshift-ansible roles or playbooks: in doubt, make sure to install that package manually afterwards.

Overall, everything went great. While undocumented, this process is nothing extraordinary.

As of migrating to Docker-backed GlusterFS containers, I did reproduce that issue customer was complaining about. As well as another one, related to GlusterFS arbiter bricks space exhaustion.

Thank science, OCS4 is now based on Rook, and Ceph.

Packages Build Pipeline with OpenShift

As an other follow-up to my previous OpenShift posts, today we would look into Jenkins and Nexus integration with OpenShift, while building a dummy package shipping SSH Keys, both as a debien archive and RPM package.

If you’re not concerned with automating Nexus configuration, then you may use sonatype/nexus3 from the Docker hub setting up Nexus Repository Manager on OpenShift.
As I wanted to automate a few configuration tasks, I eventually started working on my own image, forking from a repository offered by Accenture. My copy isn’t yet released publicly, so I’ld just point out it creates a couple users uploading and downloading Artifacts.

Another subject to address would be to prepare a couple images building our Debian and RPM packages. Regarding RPMs, we could divert from Jenkins base slave image:

FROM openshift/jenkins-slave-base-centos7

RUN yum -y install epel-release \
    && yum -y install @development-tools centos-packager rpmdevtools \
    && yum -y install make wget git curl

USER 1001

While for Debian we would want to build some Stretch-based equivalent:

FROM debian:stretch

ENV HOME=/home/jenkins \
    DEBIAN_FRONTEND=noninteractive

USER root

ADD config/* /usr/local/bin/

RUN apt-get -y update \
    && apt-get -y install bc gettext git subversion openjdk-8-jre-headless gnupg curl wget \
                lsof rsync tar unzip debianutils zip bzip2 make gcc g++ devscripts debhelper \
    && apt-get clean \
    && rm -rf /var/lib/apt/lists/* \
    && mkdir -p /home/jenkins \
    && chown -R 1001:0 /home/jenkins \
    && chmod -R g+w /home/jenkins \
    && chmod 664 /etc/passwd \
    && chmod -R 775 /etc/alternatives /usr/lib/jvm \
    && chmod 775 /usr/bin /usr/share/man/man1

USER 1001

ENTRYPOINT [“/usr/local/bin/run-jnlp-client”]

From there, the last item we’ll need, building our packages, is their sources.

Building RPMs, we would write a Spec file such as the following:

Summary: My Package
Name: my-package
Version: 0.0.1
Release: 1%{?dist}
License: MIT
Source: https://repo/sources/el-%{name}-%{version}.tar.gz
URL: https://my.example.com

Autoreq: no
BuildRequires: git
BuildRequires: make

%description
Does something awesome

%global __os_install_post %{nil}
%define debug_package %{nil}
%prep
%autosetup
%build
%install
make install PREFIX=%{buildroot}

%pre
%prerun
%post
%files
%defattr(-,root,root)
%dir %{_datadir}/mydir
%{_datadir}/mydir/myfile

%changelog
 * Thu Aug 30 2018 It’s Me <mario@example.com> 0.0.1-1
 – Initial release – In an other castle?

Now regarding Debian packages, we would need to create a couple subdirectories, configuration files and scripts:

$ mkdir -p debian/source
$ echo “3.0 (quit)” >debian/source/format
$ echo 9 >debian/compat
$ for i in postinst preinst prerm pstrm; do
cat <<EOF >debian/$i
#!/bin/sh
# $i script for my-package

set -e

case “$1” in
  purge|remove|abort-install|disappear) ;;

  upgrade|failed-upgrade|abort-upgrade) ;;

  *)
    echo “postrm called with unknown argument \`$1′” >&2
    exit 1
    ;;
esac

#DEBHELPER#

exit 0
EOF
chmod +x debian/$i
done
$ for i in docs copyright missing-sources README.Debian; do
touch $i
done
$ cat <<EOF >debian/rules
#!/usr/bin/make -f
#DH_VERBOSE = 1

DPKG_EXPORT_BUILDFLAGS = 1
include /usr/share/dpkg/default.mk

# see FEATURE AREAS in dpkg-buildflags(1)
export DEB_BUILD_MAINT_OPTIONS = hardening=+all

# main packaging script based on dh7 syntax
%:
        dh $@

override_dh_auto_install:
        $(MAKE) install PREFIX=$(CURDIR)/debian/my-package

override_dh_auto_build:
        echo nothing to do

override_dh_auto_test:
        echo nothing to do
EOF
$ chmod +x debian/rules
$ cat <<EOF >debian/changelog
my-package (0.0.1-1) unstable; urgency=low

  * Initial release – In an other castle?

— It’s Me <mario@example.com> Thu, 30 Aug 2018 11:30:42 +0200
EOF

From there, we ensure our sources ships with a Makefile, providing with the following rules:

SHARE_DIR = $(PREFIX)/usr/share

createdebsource:
    LANG=C debuild -S -sa

createdebbin:
    LANG=C dpkg-buildpackage -us -uc

createrpm:
    versionNumber=`awk ‘/^Version:/{print $$2;exit;}’ el/my-package.spec`; \
    wdir=”`pwd`/..”; \
    buildroot=”$$wdir/rpmbuild”; \
    for d in SOURCES SPECS BUILD RPMS SRPMS; \
    do \
      mkdir -p “$$buildroot/$$d”; \
    done; \
    cp -p “$$wdir/el-my-package-$$versionNumber.tar.gz” “$$buildroot/SOURCES/”; \
    cp -p “$$wdir/my-package/el/my-package.spec” “$$buildroot/SPECS/”; \
    if ! whoami >/dev/null 2>&1; then \
      chown -R root:root “$$buildroot/SOURCES” “$$buildroot/SPECS”; \
    elif whoami 2>/dev/null | grep default >/dev/null; then \
      chown -R :root “$$buildroot/SOURCES” “$$buildroot/SPECS”; \
    fi; \
    ( \
      cd “$$buildroot”; \
      LANG=C rpmbuild –define “_topdir $$buildroot” -ba SPECS/my-package.spec && \
      find *RPMS -type f | while read output; \
        do \
          mv “$$output” $$wdir/; \
        done; \
    )

createinitialarchive:
    rm -fr .git .gitignore README.md
    versionNumber=`cat debian/changelog | awk ‘/my-package/{print $$2;exit}’ | sed -e ‘s|[()]||g’ -e ‘s|\\(.*\\)-[0-9]*\$$|\\1|’`; \
    ( \
      cd ..; \
      tar -czf my-package_$$versionNumber.orig.tar.gz my-package; \
      mv my-package my-package-$$versionNumber; \
      tar -czf el-my-package-$$versionNumber.tar.gz my-package-$$versionNumber; \
      mv my-package-$$versionNumber my-package; \
    )

install:
    mkdir -p $(SHARE_DIR)/mydir
    install -c -m 0644 myfile $(SHARE_DIR)/mydir/myfile

At which point, we may use the following OpenShift Template, creating a few secrets and a pair of Jenkins Pipelines, building Debian and RPM packages based on our previous images, then uploading their Artifacts to Nexus :

apiVersion: v1
kind: Template
metadata:
  name: my-package-template
objects:
– apiVersion: v1
  kind: Secret
  metadata:
    annotations:
      jenkins.io/credentials-description : ${APPLICATION_NAME} Git Token credential from Kubernetes
    labels:
      jenkins.io/credentials-type: secretText
    name: git-${APPLICATION_NAME}
  stringData:
    text: ${GIT_DEPLOYMENT_TOKEN}
– apiVersion: v1
  kind: Secret
  metadata:
    annotations:
      jenkins.io/credentials-description : ${APPLICATION_NAME} Nexus Credentials from Kubernetes
    labels:
      jenkins.io/credentials-type: usernamePassword
    name: nexus-${APPLICATION_NAME}
  stringData:
  password: ${NEXUS_ARTIFACTS_PASSWORD}
  username: ${NEXUS_ARTIFACTS_USERNAME}
– apiVersion: v1
  kind: BuildConfig
  metadata:
    annotations:
      description: Builds ${APPLICATION_NAME} rpm archive
    name: ${APPLICATION_NAME}-rpm
  spec:
    strategy:
      jenkinsPipelineStrategy:
        jenkinsfile: |-
          try {
            def pkgname = “${APPLICATION_NAME}”
            def label = “${pkgname}-${UUID.randomUUID().toString()}”
            podTemplate(label: label, name: label, cloud: ‘openshift’,
                containers: [ containerTemplate(name: ‘jnlp’, image: ‘${DOCKER_REGISTRY}/${CENTOS_IMAGE}’) ],
                inheritFrom: ‘nodejs’, serviceAccount: ‘jenkins’) {
              timeout(time: 40, unit: ‘MINUTES’) {
                node (label) {
                  stage(“Fetch”) {
                    sh “git config –global http.sslVerify false”
                    sh “mkdir ${pkgname}”
                    withCredentials([string(credentialsId: “git-${pkgname}”, variable: ‘GIT_TOKEN’)]) {
                      sh “echo ‘${SOURCE_REPOSITORY_URL}’ | sed ‘s|^\\(http[s]*://\\)\\(.*\\)|\\1${GIT_TOKEN}@\\2|’ >cloneFrom 2>/dev/null”
                    }
                    def cloneAddress = readFile(‘cloneFrom’).trim()
                    dir (“${pkgname}”) {
                      git([ branch: “master”, changelog: false, poll: false, url: cloneAddress ])
                    }
                  }
                  stage(“Build”) {
                    sh “””
                    ( cd ${pkgname} ; git rev-parse –short HEAD ) >gitHash
                    ( cd ${pkgname} ; make createinitialarchive ; make createrpm )
                    awk ‘/^Release:/{print \$2;exit;}’ ${pkgname}/el/${pkgname}.spec | cut -d% -f1 >patchNumber
                    awk ‘/^Version:/{print \$2;exit;}’ ${pkgname}/el/${pkgname}.spec >versionNumber
                    “””
                  }
                  stage(“Upload”) {
                    def gitHash = readFile(‘gitHash’).trim()
                    def patch = readFile(‘patchNumber’).trim()
                    def version = readFile(‘versionNumber’).trim()
                    sh “echo Uploading artifacts for ${version}-${patch}-${gitHash}”
                    nexusArtifactUploader(
                      nexusVersion: ‘${NEXUS_VERSION}’,
                      protocol: “${NEXUS_PROTO}”,
                      nexusUrl: “${NEXUS_REMOTE}”,
                      groupId: “${NEXUS_GROUP_ID}”,
                      version: “${version}-${patch}-${gitHash}”,
                      repository: “${NEXUS_RPM_REPOSITORY}”,
                      credentialsId: “nexus-${pkgname}”,
                      artifacts: [
                      [ artifactId: “${pkgname}-rpm”,
                      classifier: ”, type: ‘rpm’,
                      file: “${pkgname}-${version}-${patch}.el7.src.rpm” ],
                      [ artifactId: “${pkgname}-rpm”,
                      classifier: ”, type: ‘rpm’,
                      file: “${pkgname}-${version}-${patch}.el7.x86_64.rpm” ],
                      [ artifactId: “${pkgname}-rpm”,
                      classifier: ”, type: ‘tar.gz’,
                      file: “el-${pkgname}-${version}.tar.gz” ]
                      ]
                    )
                  }
                }
              }
            }
          } catch (err) {
            echo “in catch block”
            echo “Caught: ${err}”
            currentBuild.result = ‘FAILURE’
            throw err
          }
      type: JenkinsPipeline
– apiVersion: v1
  kind: BuildConfig
  metadata:
    annotations:
      description: Builds ${APPLICATION_NAME} deb archive
    name: ${APPLICATION_NAME}-deb
  spec:
    strategy:
      jenkinsPipelineStrategy:
        jenkinsfile: |-
          try {
            def pkgname = “${APPLICATION_NAME}”
            def label = “${pkgname}-${UUID.randomUUID().toString()}”
            podTemplate(label: label, name: label, cloud: ‘openshift’,
                containers: [ containerTemplate(name: ‘jnlp’, image: ‘${DOCKER_REGISTRY}/${DEBIAN_IMAGE}’) ],
                inheritFrom: ‘nodejs’, serviceAccount: ‘jenkins’) {
              timeout(time: 40, unit: ‘MINUTES’) {
                node (label) {
                  stage(“Fetch”) {
                    sh “git config –global http.sslVerify false”
                    sh “mkdir ${pkgname}”
                    withCredentials([string(credentialsId: “git-${pkgname}”, variable: ‘GIT_TOKEN’)]) {
                      sh “echo ‘${SOURCE_REPOSITORY_URL}’ | sed ‘s|^\\(http[s]*://\\)\\(.*\\)|\\1${GIT_TOKEN}@\\2|’ >cloneFrom 2>/dev/null”
                    }
                    def cloneAddress = readFile(‘cloneFrom’).trim()
                    dir (“${pkgname}”) {
                      git([ branch: “master”, changelog: false, poll: false, url: cloneAddress ])
                    }
                  }
                  stage(“Build”) {
                    sh “””
                    ( cd ${pkgname} ; git rev-parse –short HEAD ) >gitHash
                    ( cd ${pkgname} ; make createinitialarchive ; make createdebbin )
                    cat ${pkgname}/debian/changelog | awk ‘/${pkgname}/{print \$2;exit}’ | sed -e ‘s|[()]||g’ -e ‘s|.*-\\([0-9]*\\)\$|\\1|’ >patchNumber
                    cat ${pkgname}/debian/changelog | awk ‘/${pkgname}/{print \$2;exit}’ | sed -e ‘s|[()]||g’ -e ‘s|\\(.*\\)-[0-9]*\$|\\1|’ >versionNumber
                    “””
                  }
                  stage(“Upload”) {
                    def gitHash = readFile(‘gitHash’).trim()
                    def patch = readFile(‘patchNumber’).trim()
                    def version = readFile(‘versionNumber’).trim()
                    sh “echo Uploading artifacts for ${version}-${patch}-${gitHash}”
                    nexusArtifactUploader(
                      nexusVersion: ‘${NEXUS_VERSION}’,
                      protocol: “${NEXUS_PROTO}”,
                      nexusUrl: “${NEXUS_REMOTE}”,
                      groupId: “${NEXUS_GROUP_ID}”,
                      version: “${version}-${patch}-${gitHash}”,
                      repository: “${NEXUS_DEB_REPOSITORY}”,
                      credentialsId: “nexus-${pkgname}”,
                      artifacts: [
                      [ artifactId: “${pkgname}-deb”,
                      classifier: ”, type: ‘deb’,
                      file: “${pkgname}_${version}-${patch}_all.deb” ],
                      [ artifactId: “${pkgname}-deb”,
                      classifier: ”, type: ‘txt’,
                      file: “${pkgname}_${version}-${patch}_amd64.buildinfo” ],
                      [ artifactId: “${pkgname}-deb”,
                      classifier: ”, type: ‘txt’,
                      file: “${pkgname}_${version}-${patch}_amd64.changes” ],
                      [ artifactId: “${pkgname}-deb”,
                      classifier: ”, type: ‘tar.xz’,
                      file: “${pkgname}_${version}-${patch}.debian.tar.xz” ],
                      [ artifactId: “${pkgname}-dev”,
                      classifier: ”, type: ‘tar.gz’,
                      file: “${pkgname}_${version}.orig.tar.gz” ],
                      [ artifactId: “${pkgname}-deb”,
                      classifier: ”, type: ‘txt’,
                      file: “${pkgname}_${version}-${patch}.dsc” ]
                      ]
                    )
                  }
                }
              }
            }
          } catch (err) {
            echo “in catch block”
            echo “Caught: ${err}”
            currentBuild.result = ‘FAILURE’
            throw err
          }
      type: JenkinsPipeline
parameters:
– name: APPLICATION_NAME
  description: Package Name – should match that expected by package we’ll build
  displayName: Package Name
  value: my-package
– name: DEBIAN_IMAGE
  description: Jenkins Debian Agent Image – relative to DOCKER_REGISTRY
  displayName: Jenkins Debian Agent Image
  required: true
  value: “cicd/jenkins-agent-debian:latest”
– name: DOCKER_REGISTRY
  description: Docker Registry
  displayName: Docker Registry
  required: true
  value: docker-registry.default.svc:5000
– name: CENTOS_IMAGE
  description: Jenkins Centos Agent Image – relative to DOCKER_REGISTRY
  displayName: Jenkins Centos Agent Image
  required: true
  value: “cicd/jenkins-agent-centos:latest”
– name: GIT_DEPLOYMENT_TOKEN
  description: Git deployment token
  displayName: Git Deployment Token
  required: true
– name: NEXUS_ARTIFACTS_PASSWORD
  description: Nexus Artifacts Upload Password
  displayName: Nexus Artifacts Upload Password
  required: true
  value: admin123
– name: NEXUS_ARTIFACTS_USERNAME
  description: Nexus Artifacts Upload Username
  displayName: Nexus Artifacts Upload Username
  required: true
  value: admin
– name: NEXUS_GROUP_ID
  description: Nexus Group ID
  displayName: Nexus Group ID
  required: true
  value: com.example
– name: NEXUS_DEB_REPOSITORY
  description: Nexus Artifact Debian Repository – remote repository name
  displayName: Nexus Artifact Debian Repository
  required: true
  value: debian
– name: NEXUS_PROTO
  description: Nexus Proto – http or https
  displayName: Nexus Proto
  required: true
  value: http
– name: NEXUS_REMOTE
  description: Nexus Remote URL – proto-less URI connecting to Nexus
  displayName: Nexus Remote URL
  value: “nexus:8081”
  required: true
– name: NEXUS_RPM_REPOSITORY
  description: Nexus Artifact EL Repository – remote repository name
  displayName: Nexus Artifact EL Repository
  required: true
  value: centos
– name: NEXUS_VERSION
  description: Nexus Repository Version
  displayName: Nexus Repository Version
  required: true
  value: nexus3
– name: SOURCE_REPOSITORY_URL
  description: The URL of the repository with your application source code
  displayName: Git Repository URL
  required: true
  value: https://git.example.com/project/my-package