Review for EX180 Flashcards
Podman Section
Run and Manage Containers
Task 1.
Edit the registries:
sudo vi /etc/containers/registries.conf
Enter your cloud_user password.
Find the the registries.search parameter line and add ‘registry-1:5000’ to end of registry (remember to press i to enter insert mode).
Find the registries.insecure parameter line and add ‘registry-1:5000’ as an insecure registry.
Save and quit the file by pressing Escape followed by :wq.
Task 2.
Pull the latest Nginx image docker.io/library/nginx:
podman pull docker.io/library/nginx
Verify the pull was complete:
podman images
Clear your screen:
clear
Run a container using the Nginx image with the specified parameters:
podman run -d –name=web-vol -v /home/cloud_user/web:/usr/share/nginx/html/:Z –pod task-2 docker.io/library/nginx
Verify you can access the web page:
curl localhost:8081
Save a copy of the container logs to a file named web-vol.log:
podman logs web-vol > web-vol.log
Verify the copy of the container logs was saved:
ls web-vol.log
Review the contents of web-vol.log copy:
less web-vol.log
Task 3.
Pull the latest MySQL image from docker.io/library/mysql (this may take a few minutes):
podman pull docker.io/library/mysql
clear your screen.
Verify the image was pulled:
podman images
Start a container with the specified variables:
podman run -d –name=mysql-llama -e MYSQL_PASSWORD=badpass -e MYSQL_USER=guru -e MYSQL_ROOT_PASSWORD=supersecret -e MYSQL_DATABASE=llama -p 3306:3306 docker.io/library/mysql
clear your screen.
Verfiy the MySQL instance is running and confirm that the llama database is present:
echo “show databases;” | mysql -uguru -pbadpass –protocol tcp -h localhost
Make a directory named mysql_logs:
mkdir mysql_logs
Copy the log file /var/lib/mysql/mysql/general_log_213.sdi to the directory:
podman cp mysql-llama:/var/lib/mysql/mysql/general_log_213.sdi mysql_logs/
Verify the log file was copied successfully:
ls -l mysql_logs/
Task 4.
Log in to the registry:
podman login -u cloud_user registry-1:5000
Enter your cloud_user password.
View the images:
podman search registry-1:5000/
Inspect the image for alternate tags:
skopeo inspect docker://registry-1:5000/nginx | less
clear your screen.
Start the container using the image with the alternate tag (not latest):
podman run -d –name=web-default -p 8080:80 registry-1:5000/nginx:useme
Verify the default message:
curl localhost:8080
clear your screen.
Connect to the container:
podman exec -it web-default bash
Edit the file:
vi /usr/share/nginx/html/index.html
Clear Replace Me and type A guru was here!.
Save and quit the file by pressing Escape followed by :wq.
Exit the file:
exit
Verify the change using curl:
curl localhost:8080
Commit the new container to new image:
podman commit web-default registry-1:5000/nginx:web-guru
clear your screen.
Review the images to confirm registry-1:5000/nginx with the tag web-guru was created successfully:
podman images
Build and Run Custom Images
Task 5.
View the images:
podman images
Push your new image to registry-1:5000:
podman push registry-1:5000/nginx:web-guru registry-1:5000/nginx:web-guru
clear your screen.
Stop the existing container:
podman stop web-default
Start a new one container:
podman run -d –name=web-guru -p 8080:80 registry-1:5000/nginx:web-guru
Verify the change was saved in the new image and is present in the new container (You should see the A guru was here! message):
curl localhost:8080
Save the image to a tar file:
podman save -o guru-web.tar registry-1:5000/nginx:web-guru
List guru-web.tar:
ls guru-web.tar
Task 6.
List the docker directory:
ls docker
List the files:
ls files
Move into the docker directory:
cd docker
Copy the ZIP and tar files to the docker directory:
cp ../files/* .
List the files:
ls
clear your screen.
Edit the Dockerfile (you can review the file in this Git repo):
vim Dockerfile
Change the color of the comments to grey for better readability:
:hi Comment ctermfg=grey
Under #Please use image registry.access.redhat.com/ubi8/ubi:8.4, enter:
FROM registry.access.redhat.com/ubi8/ubi:8.4
Under Set yourself as the Maintainer of this image, enter:
MAINTAINER <YOUR_NAME></YOUR_NAME>
Under #Provide a brief description of the image next to LABEL description=, enter (make sure you are using straight quotation marks):
“New web server”
Under #Install nginx and unzip, enter:
RUN yum install -y nginx unzip
Under #Use ENV to set the variable PORT to 90, enter:
ENV PORT=90
Under #Use the variable $PORT to expose the set port, enter:
EXPOSE $PORT
Under #Copy nginx_conf.zip to /tmp/, enter:
COPY nginx_conf.zip /tmp/
Under #Extract /tmp/nginx_conf.zip to /etc/nginx and overwrite any existing files, enter:
RUN unzip -o /tmp/nginx_conf.zip -d /etc/nginx/
Under #Extract llama_cart.tar to /usr/share/nginx/html/, enter:
ADD llama_cart.tar /usr/share/nginx/html/
Under #Set the workdir to /tar_file/ and copy llama_cart.tar to this directory without uncompressing it, enter:
WORKDIR /tar_file/
COPY llama_cart.tar .
Under #Set the container to start “nginx” with options “-g” and “daemon off” as overwritable options (hint: use ENTRYPOINT and CMD), enter:
ENTRYPOINT [“nginx”]
CMD [“-g”, “daemon off;”]
Save and quit the file by pressing Escape followed by :wq.
Task 7.
Build the image (this may take a few minutes):
podman build -t llama-cart:v1 .
clear your screen:
Review the images:
podman images
Start a new container:
podman run -d –name=llama-web -p 8090:90 localhost/llama-cart:v1
clear your screen.
Confirm the container is running:
curl localhost:8090
clear your screen.
Navigate to the cloud_user home directory:
cd
Navigate to server_info.txt:
cat server_info.txt
Copy the public DNS name, paste it into a new browser, and add :8090 to the end to confirm the custom image is running.
OC Section
Creating Applications with OpenShift
Task 8:
Create new project named guru-php with display name of Test hello guru project:
oc new-project guru-php –display-name=”Test hello guru project”
clear your screen.
Create the new PHP app with the specified configuration and this GitHub repo:
oc new-app –name=hello-guru –as-deployment-config php~https://github.com/linuxacademy/Red-Hat-Certified-Specialist-in-Containers-and-Kubernetes –context-dir=php-hello-world -l app=hello-guru
clear your screen.
Retrieve the resources and wait until the pod build is ready (this may take a few minutes):
oc get all | less
Retrieve the service:
oc get service
Expose the service:
oc expose service hello-guru
Retrieve the routes:
oc get routes
Test the route:
curl <ROUTE_HOSTNAME></ROUTE_HOSTNAME>
Task 9: CodeReady Containers
Create new project named inventory:
oc new-project inventory
clear your screen.
Download the template file:
curl https://raw.githubusercontent.com/linuxacademy/Red-Hat-Certified-Specialist-in-Containers-and-Kubernetes/main/multi-container/multi_test.yaml -o multi_test.yaml
Verify the file was created:
ls multi_test.yaml
clear your screen.
Publish the template to the current project:
oc create -f multi_test.yaml
Verify the template was created:
oc get templates
clear your screen.
Process the template, save it to a file named
processed_template.yaml, and set the following parameters:
oc process -f multi_test.yaml -p NAME=fruit-stand -p DATABASE_NAME=fruit_stand -p DATABASE_USER=guru -p DATABASE_PASSWORD=badpass -p DATABASE_ADMIN_PASSWORD=badidea -l app=guru-fruit > processed_template.yaml
Verify the file was created:
ls processed_template.yaml
clear your screen.
Create the application:
oc create -f processed_template.yaml
clear your screen.
Retrieve the resources (it may take a few minutes until the build is complete):
oc get all | less
Retrieve the resources with the above command to confirm pod/fruit-stand and pod/postgresql are running.
oc get pods
Scroll down to the route section, copy the route hostname, and paste it into a new browser.
curl or HTTP
Task 10: Confirm you’re logged in to the inventory project:
oc project
Build the required directories:
mkdir -p logs/pod-fruit-stand logs/pod-postgres
List the logs:
ls -ls logs
clear your screen.
Retrieve the pods:
oc get pods
Sync /var/log from the running fruit-stand pod to the respective directory. Note: It will show an rsync error in CRC if rsync is not installed. The command will still work by falling back to tar:
oc rsync <FRUIT_STAND_POD>:/var/log/ logs/pod-fruit-stand/</FRUIT_STAND_POD>
clear your screen.
Retrieve the pods:
oc get pods
Sync /var/log from the running postgresql pod to the
respective directory. Note: It will show an rsync error in CRC if rsync is not installed. The command will still work by falling back to tar:
oc rsync <POSTGRESQL_POD>:/var/log/ logs/pod-postgres/
clear the screen.
Check the directories:
ls logs/*
Task 10: OpenShift Sandbox
Confirm you're in the <username>-stage project:
oc project
Build the required directories:
mkdir -p logs/pod-fruit-stand logs/pod-postgres
List the logs:
ls logs
Retrieve the pods:
oc get pods</username></POSTGRESQL_POD>
Sync /var/log from the running fruit-stand pod to the respective directory. Note: It will show an rsync error in OpenShift sandbox if rsync is not installed. The command will still work by falling back to tar:
oc rsync <FRUIT_STAND_POD>:/var/log/ logs/pod-fruit-stand/</FRUIT_STAND_POD>
Retrieve the logs:
ls logs/pod-fruit-stand/
clear your screen.
Retrieve the pods:
oc get pods
Sync /var/log from the running postgresql pod to the respective directory:
oc rsync <POSTGRESQL_POD>:/var/log/ logs/pod-postgres/</POSTGRESQL_POD>
Retrieve the logs:
ls logs/pod-postgres/
