The document provides an introduction to containerization, emphasizing the advantages of using containers over traditional virtualization. Key topics include the use of containers in CI/CD pipelines, testing, deployment, and scalability, as well as an overview of Docker and Kubernetes. It also highlights additional resources such as Docker registries and a GitHub repository for further information.

1. A Hands-on Intro to
Containers
Gene Gotimer
Principal DevOps Engineer at Praeses, LLC
@OtherDevOpsGene

2. What are containers?
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3. Virtualization
• One physical system simulating multiple virtual systems
• Shared:
• CPU
• Memory
• Networking
• Hard drive
• Peripherals
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4. Containerization
Containers are not miniature VMs They are apps that run on the host
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5. Where should we use
containers?
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6. Pipeline infrastructure
• Jenkins
• Slaves are fresh Docker images created as needed
• Always a clean build environment
• Easy to parallelize
• Jenkins X
• “opinionated way to do continuous delivery with Kubernetes”
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7. Testing
• Selenium Grid nodes
• Easy to spin up nodes with different versions of different browsers
• Makes parallel testing easy
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8. Deployments
• Always a fresh system
• No garbage built up from prior deploys
• Everyone can have their own
• Create and recreate on demand
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9. Immutable
• Installed and configured
• Just use as is
• Deploy only once
• No installation or configuration to do
• Can be passed through the SDLC as a single piece
• Never changes, so what was tested is exactly what was deployed
• No more “works on my machine”
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10. Scalability
• Immutable, so they can easily be cloned
• Elasticity- spin up and shut down instances as needed
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11. Experimentation
• Experiment with
• New tools
• New versions
• New techniques
• New configurations
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12. Docker basics
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13. Docker
• Containerization software
• Free, open-source
• Runs on Windows, Mac, Linux
• Easy to install
• Works well in AWS, Azure, Google
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14. Layers
Containers are layers of filesystems
Files overlap, but do not replace
14
RUN set -xe && echo '#&/bin/sh' > … 811B
ADD file:435d9776fdd3a183… 72.9MB
RUN [ -z "$(apt-get indextargets)" ]… 0B
RUN mkdir -p /run/systemd && echo ‘d… 7B
CMD ["/bin/bash"] 0B
instance data container layer
(read-write)
immutable
image
layers
(read-only)
ubuntu:20.04 container
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15. Image and container
• Image – software bundle that will run on Docker
• Container – running (or stopped) instance of an image
• read-write layer overlaid
images
containers
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16. Registry
• Registry – cloud repository of Docker images
• public or hosted
• Docker Hub – public hosted registry - https:&&hub.docker.com/
• Some Cloud alternatives:
• Google GCR - https:&&cloud.google.com/container-registry/
• Amazon ECR - https:&&aws.amazon.com/ecr/
• Quay - https:&&quay.io/
• Some on-premises alternatives:
• Sonatype Nexus - https:&&w&&.sonatype.com/
• JFrog Artifactory - https:&&jfrog.com/
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17. Kubernetes (k8s)
• Open-source container orchestration framework
• service discovery
• load balancing
• storage orchestration
• automated rollouts and rollbacks
• self-healing
• secret management
• horizontal scaling
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18. GitHub repo
https:&&github.com/OtherDevOpsGene/intro-to-docker
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19. Questions?
Gene Gotimer
Principal DevOps Engineer at Praeses, LLC
@OtherDevOpsGene