My Openshift Cheatsheet

openshift-cheatsheet.md

• Binary Builds

oc new-build --binary=true --name=ola2 --image-stream=redhat-openjdk18-openshift
oc start-build ola2 --from-file=./target/ola.jar --follow
oc new-app 

• Turn off/on DC triggers to do a batch of changes without spam many deployments

oc rollout pause dc <dc name>
oc rollout resume dc <dc name> 

• get a route URL using OC

http://$(oc get route nexus3 --template='{{ .spec.host }}')

• Using Nexus repo manager to store deployment artifacts Maven uses settings.xml in $HOME/.m2 for configuration outside of pom.xml:

<?xml version="1.0"?>
<settings>
  <mirrors>
    <mirror>
      <id>Nexus</id>
      <name>Nexus Public Mirror</name>
      <url>http://nexus-opentlc-shared.cloudapps.na.openshift.opentlc.com/content/groups/public/</url>
      <mirrorOf>*</mirrorOf>
    </mirror>
  </mirrors>
  <servers>
  <server>
    <id>nexus</id>
    <username>admin</username>
    <password>admin123</password>
  </server>
</servers>
</settings>

Maven can automatically store artifacts using -DaltDeploymentRepository parameter for deploy task:

mvn deploy -DskipTests=true \
-DaltDeploymentRepository= nexus::default::http://nexus3.nexus.svc.cluster.local:8081/repository/releases

• to update a DeploymentConfig in order to change the Docker Image used bythe POD's container

oc project <project>
oc get is

oc import-image <image name> --from=docker.io/<imagerepo>/<imagename> --all --confirm

oc get istag

OC_EDITOR="vim" oc edit dc/<your_dc>

    spec:
      containers:
      - image: docker.io/openshiftdemos/gogs@sha256:<the new image digest from Image Stream>
        imagePullPolicy: Always

• BuildConfig with Source pull secrets

oc secrets new-basicauth gogs-basicauth --username=<your gogs login> --password=<gogs pwd>
oc set build-secret --source bc/tasks gogs-basicauth

• Create a configmap file and mount as a volume on DC

oc create configmap myconfigfile --from-file=./configfile.txt
oc set volumes dc/printenv --add --overwrite=true --name=config-volume --mount-path=/data -t configmap --configmap-name=myconfigfile

• create a secret via CLI

oc create secret generic mysec --from-literal=app_user=superuser --from-literal=app_password=topsecret
oc env dc/printenv --from=secret/mysec
oc set volume dc/printenv --add --name=db-config-volume --mount-path=/dbconfig --secret-name=printenv-db-secret

• Configure Liveness/Readiness probes on DCs

oc set probe dc cotd1 --liveness -- echo ok
oc set probe dc/cotd1 --readiness --get-url=http://:8080/index.php --initial-delay-seconds=2 

• Create a new JOB

oc run pi --image=perl --replicas=1  --restart=OnFailure \
    --command -- perl -Mbignum=bpi -wle 'print bpi(2000)'

• CRON JOB

oc run pi --image=perl --schedule='*/1 * * * *' \
    --restart=OnFailure --labels parent="cronjobpi" \
    --command -- perl -Mbignum=bpi -wle 'print bpi(2000)'

• A/B Deployments - Split route trafic between services

oc expose service cotd1 --name='abcotd' -l name='cotd'
oc set route-backends abcotd --adjust cotd2=+20%
oc set route-backends abcotd cotd1=50 cotd2=50

• to pull an image directly from red hat offcial docker registry

docker pull registry.access.redhat.com/jboss-eap-6/eap64-openshift

• to validate a openshift/kubernates resource definition (json/yaml file) in order to find malformed/sintax problems

oc create --dry-run --validate -f openshift/template/tomcat6-docker-buildconfig.yaml

• to prune old objects

• https://docs.openshift.com/container-platform/3.3/admin_guide/pruning_resources.html

• to enable cluster GC

• https://docs.openshift.com/container-platform/3.3/admin_guide/garbage_collection.html

• to get ther current user Barear Auth Token

oc whoami -t

• to test the OSE Master API

curl -k -H "Authorization: Bearer <api_token>" https://<master_host>:8443/api/v1/namespaces/<projcet_name>/pods/https:<pod_name>:8778/proxy/jolokia/

# get pod memory via jmx
curl -k -H "Authorization: Bearer <api_token>" https://<master_host>:8443/api/v1/namespaces/<projcet_name>/pods/https:<pod_name>:8778/proxy/jolokia//read/java.lang:type\=Memory/HeapMemoryUsage | jq .

• to login via CLI oc

oc login --username=tuelho --insecure-skip-tls-verify --server=https://master00-${guid}.oslab.opentlc.com:8443

# to login as Cluster Admin through master host
oc login -u system:admin -n openshift

• to view the cluster roles and their associated rule sets in the cluster policy

oc describe clusterPolicy default

• add a role to user

#local binding
oadm policy add-role-to-user <role> <username>

#cluster biding
oadm policy add-cluster-role-to-user <role> <username>

• add privileged role to ruan a docker image with root user inside openshift

oadm policy add-scc-to-user anyuid -z default

for more details consult: https://docs.openshift.com/enterprise/3.1/admin_guide/manage_authorization_policy.html

• to test a POD service locally

ip=`oc describe pod hello-openshift|grep IP:|awk '{print $2}'`
curl http://${ip}:8080

• to access a POD container shell

oc exec -ti  `oc get pods |  awk '/registry/ { print $1; }'` /bin/bash

#new way to do the same:
oc rsh <container-name>

• to edit an object/resource

oc edit <object_type>/<object_name>

#eg

oc edit dc/myDeploymentConfig

• Ataching a new PersistentVolumeClaim to a DeploymentConfig

oc volume dc/docker-registry \
   --add --overwrite \
   -t persistentVolumeClaim \
   --claim-name=registry-claim \
   --name=registry-storage

• Docker builder app creation

oc new-app --docker-image=openshift/hello-openshift:v1.0.6 -l "todelete=yes"

• To create an app using a template (eap64-basic-s2i): Ticketmonster demo

oc new-app javaee6-demo
oc new-app --template=eap64-basic-s2i -p=APPLICATION_NAME=ticketmonster,SOURCE_REPOSITORY_URL=https://github.com/jboss-developer/ticket-monster,SOURCE_REPOSITORY_REF=2.7.0.Final,CONTEXT_DIR=demo

• STI app creation

oc new-app https://github.com/openshift/sinatra-example -l "todelete=yes"
oc new-app openshift/php~https://github.com/openshift/sti-php -l "todelete=yes"

• To watch a build process log

oc get builds
oc logs -f builds/sti-php-1

• To create application using Git repository at current directory:

$ oc new-app

• To create application using remote Git repository and context subdirectory:

$ oc new-app https://github.com/openshift/sti-ruby.git \
    --context-dir=2.0/test/puma-test-app

• To create application using remote Git repository with specific branch reference:

$ oc new-app https://github.com/openshift/ruby-hello-world.git#beta4

New App From Source Code

Build Strategy Detection

If new-app finds a Dockerfile in the repository, it uses docker build strategy Otherwise, new-app uses source strategy

To specify strategy, set --strategy flag to source or docker Example: To force new-app to use docker strategy for local source repository:

$ oc new-app /home/user/code/myapp --strategy=docker

• to create a definition generated by oc new-app command based on S2I support

$ oc new-app https://github.com/openshift/simple-openshift-sinatra-sti.git -o json | \
   tee ~/simple-sinatra.json

• To create application from MySQL image in Docker Hub:

$ oc new-app mysql

• To create application from local registry:

$ oc new-app myregistry:5000/example/myimage

If the registry that the image comes from is not secured with SSL, cluster administrators must ensure that the Docker daemon on the OpenShift Enterprise nodes is run with the --insecure-registry flag pointing to that registry. You must also use the --insecure-registry=true flag to tell new-app that the image comes from an insecure registry.

• To create application from stored template:

$ oc create -f examples/sample-app/application-template-stibuild.json
$ oc new-app ruby-helloworld-sample

• To set environment variables when creating application for database image:

$ oc new-app openshift/postgresql-92-centos7 \
    -e POSTGRESQL_USER=user \
    -e POSTGRESQL_DATABASE=db \
    -e POSTGRESQL_PASSWORD=password

• To output new-app artifacts to file, edit them, then create them using oc create:

$ oc new-app https://github.com/openshift/ruby-hello-world -o json > myapp.json
$ vi myapp.json
$ oc create -f myapp.json

• To deploy two images in single pod:

$ oc new-app nginx+mysql

• To deploy together image built from source and external image:

$ oc new-app \
    ruby~https://github.com/openshift/ruby-hello-world \
    mysql \
    --group=ruby+mysql

• to export all the project's objects/resources as a single template:

$ oc export all --as-template=<template_name>

You can also substitute a particular resource type or multiple resources instead of all. Run $ oc export -h for more examples

• to create a new project using oadm and defining an admin user

$ oadm new-project instant-app --display-name="instant app example project" \
    --description='A demonstration of an instant-app/template' \
    --node-selector='region=primary' --admin=andrew

• to create an app using oc CLI based on a template

$ oc new-app --template=mysql-ephemeral --param=MYSQL_USER=mysqluser,MYSQL_PASSWORD=redhat,MYSQL_DATABASE=mydb,DATABASE_SERVICE_NAME=database

• to see a list of env vars defined in a DeploymentConfig object

$ oc env dc database --list
# deploymentconfigs database, container mysql
MYSQL_USER=***
MYSQL_PASSWORD=***
MYSQL_DATABASE=***

• to manage enviorenmet variables in different ose objects types.

The first adds, with value /data. The second updates, with value /opt.

$ oc env dc/registry STORAGE=/data
$ oc env dc/registry --overwrite STORAGE=/opt

To unset environment variables in the pod templates:

$ oc env <object-selection> KEY_1- ... KEY_N- [<common-options>]

The trailing hyphen (-, U+2D) is required.

This example removes environment variables ENV1 and ENV2 from deployment config d1:

$ oc env dc/d1 ENV1- ENV2-

This removes environment variable ENV from all replication controllers:

$ oc env rc --all ENV-

This removes environment variable ENV from container c1 for replication controller r1:

To list environment variables in pods or pod templates:

$ oc env rc r1 --containers='c1' ENV-

This example lists all environment variables for pod p1:

$ oc env <object-selection> --list [<common-options>]

$ oc env pod/p1 --list

• to apply some change (patch)

oc patch dc/<dc_name> \
   -p '{"spec":{"template":{"spec":{"nodeSelector":{"nodeLabel":"logging-es-node-1"}}}}}'

• to apply a vlome storage

oc volume dc/<dc_name> \
          --add --overwrite --name=<volume_name> \
          --type=persistentVolumeClaim --claim-name=<claim_name>

• to make a node unschedulable in a cluster

oadm manage node <nome do node > --schedulable=false

• to create a registry with storage-volume mounted on host

oadm registry --service-account=registry \
    --config=/etc/origin/master/admin.kubeconfig \
    --credentials=/etc/origin/master/openshift-registry.kubeconfig \
    --images='registry.access.redhat.com/openshift3/ose-${component}:${version}' \
    --mount-host=<path> --selector=meuselector

• to export all resources from a project/namespace as a template

oc export all --as-template=<template_name>

• to create a build from a Dockerfile

# create the build
cat ./path/to/your/Dockerfile | oc new-build --name=build-from-docker --binary --strategy=docker -l app=app-from-custom-docker-build  -D -

#if you need to give some input to your Docker Build process
oc start-build build-from-docker --from-dir=. --follow

# create an OSE app from the docker build image
oc new-app app-from-custom-docker-build -l app=app-from-custom-docker-build

oc expose service app-from-custom-docker-build

• to copy files to/from a POD

#Ref: https://docs.openshift.org/latest/dev_guide/copy_files_to_container.html

oc rsync /home/user/source devpod1234:/src

oc rsync devpod1234:/src /home/user/source

Cluster nodes CleanUp

1. Desliga todos os containers que vc não tá usando no seu ambiente do openshift
2. Executa em todos os nodes e master o comando: docker rm $(docker ps -a -q)
3. Remove todas as imagens de todos os nodes e master. Para isso loga em cada uma delas via ssh e remove as imagens usando docker rmi . Pega as imagens que começa com o ip do registry 172.30...
4. configurar GC: https://docs.openshift.com/enterprise/3.1/admin_guide/garbage_collection.html

##Tips

• internal DNS name of ose/kubernetes services
• follows the pattern <service-name>.<project>.svc.cluster.local

Object Type	Example
Default	<pod_namespace>.cluster.local
Services	.<pod_namespace>.svc.cluster.local
Endpoints	..endpoints.cluster.local

"he only caveat to this, is that if we are using the multi-tenant OVS networking plugin, our cluster administrators will have to make visible our ci project to all other projects:" Ref: https://blog.openshift.com/improving-build-time-java-builds-openshift/

$ oadm pod-network make-projects-global ci

• Adjust Master Log Level To adjust openshift-master log level, edit following line of /etc/sysconfig/atomic-openshift-master from master VM:

OPTIONS=--loglevel=4

To make changes valid, restart atomic-openshift-master service:

$ sudo -i systemctl restart atomic-openshift-master.service

In node machine, to provide filtered information:

# journalctl -f -u atomic-openshift-node

• Enable EAP clustering/replication

Make sure that your default service account has sufficient privileges to communicate with the Kubernetes REST API. Add the view role to serviceaccount for the project:

$ oc policy add-role-to-user view system:serviceaccount:$(oc project -q):default

Examine the first entry in the log file:

Service account has sufficient permissions to view pods in kubernetes (HTTP 200). Clustering will be available.

Creating a new Template

• Common strategy for building template definitions:
• Use oc new-app and oc expose to manually create resources application needs
• Test to make sure resources work as expected
• Use oc export with -o json option to export existing resource definitions
• Merge resource definitions into template definition file
• Add parameters
• Test resource definition in another project

JSON syntax errors are not easy to identify, and OpenShift is sensitive to them, refusing JSON files that most browsers would accept as valid. Use jsonlint -s from the python-demjson package, available from EPEL, to identify syntax issues in a JSON resource definition file.

• Use oc new-app with -o json option to bootstrap your new template definition file

oc new-app -o json openshift/hello-openshift > hello.json 

• Converting the Resource Definition to a Template
• Change kind attribute from List to Template
• Make two changes to metadata object:
• Add name attribute and value so template has name users can refer to
• Add annotations containing description attribute for template, so users know what template is supposed to do.
• Rename items array attribute as objects

Working with Templates

• to list all parameters from mysql-persistent template:

$ oc process --parameters=true -n openshift mysql-persistent

• Customizing resources from a preexisting Template

Example:

$ oc export -o json
	-n openshift mysql-ephemeral > mysql-ephemeral.json
... change the mysql-ephemeral.json file ...
$ oc process -f mysql-ephemeral.json \
	-v MYSQL_DATABASE=testdb,MYSQL_USE=testuser,MYSQL_PASSWORD=
	> testdb.json
$ oc create -f testdb.json

oc process uses the -v option to provide parameter values, while oc new-app command uses the -p option.