Container

When implementing distributed systems, client-server architectures and simple applications with network related functionalities, everything is fine when we’re in the development or in the testing stage because the network is reliable and the communicating systems are not as stressed as they are in production. But to sleep well we want to validate how resilient we have implemented our systems, how they behave when the network fails, the latency rises, the bandwidth is limited, connections time out and so on. ...

Inspect Docker Image with dive Install dive brew install dive Now we can run dive against any Docker image we wish to inspect…​ Run dive dive confluentinc/cp-kafka:5.4.3 Figure 1. Screenshot of dive analyzing the Kafka Docker image Resources: dive on GitHub Introspect Private Docker Registry List images: curl -s https://the-registry-url/v2/_catalog Get tags for an image curl -s https://the-registry-url/v2/the-image-name/tags/list An example: curl -s https://registry.local/v2/alpine/rabbitmq/tags/list {"name":"alpine/rabbitmq","tags":["3.9.17"]} Run Trivy Scan for Docker Image docker run aquasec/trivy image IMAGE:TAG ...

Common operations Add Helm Repository helm repo add NAME URL e.g. for the Bitnami repository: helm repo add bitnami https://charts.bitnami.com/bitnami 1 ↵ "bitnami" has been added to your repositories List Repositories helm repo list 130 ↵ NAME URL bitnami https://charts.bitnami.com/bitnami Searching in a Helm Repository helm search repo wordpress NAME CHART VERSION APP VERSION DESCRIPTION bitnami/wordpress 15.2.30 6.1.1 WordPress is the world's most popular blogging ... bitnami/wordpress-intel 2.1.31 6.1.1 DEPRECATED WordPress for Intel is the most popu... ...

Start an Image with kcat / kafka-cat for Debugging kubectl -n NAMESPACE run "$(whoami)-debug" -it --rm \ --image=confluentinc/cp-kafkacat:6.1.9 \ --restart=Never \ -- bash Dockerfile for Kafka Analysis Container with different Tools With jq, kafka console tools, schema registry tools and kafkacat installed …​. Dockerfile FROM confluentinc/cp-kafka:6.2.1 as cp-kafka FROM confluentinc/cp-schema-registry:6.2.1 as cp-schema-registry FROM debian:10-slim ARG DEBIAN_FRONTEND=noninteractive # Install necessary tools RUN apt-get update && apt-get install -y \ curl \ jq \ yq \ && rm -rf /var/lib/apt/lists/* # Install kafkacat binary RUN apt-get update && apt-get install -y kafkacat && rm -rf /var/lib/apt/lists/* # Copy Kafka binaries COPY --from=cp-kafka /usr/bin/kafka-* /usr/bin/ COPY --from=cp-schema-registry /usr/bin/schema-registry* /usr/bin/ # Copy entrypoint script COPY entrypoint.sh /usr/bin/entrypoint.sh RUN chmod +x /usr/bin/entrypoint.sh ENTRYPOINT ["/usr/bin/entrypoint.sh"] ...

Get size of a table SELECT pg_size_pretty(pg_total_relation_size('schemaname.tablename')); Select unique combination of fields / tuples SELECT DISTINCT ON(field1, field2) field1, field2 FROM thetable Select rows where a combination of fields is not unique SELECT columnA, columnB, count(*) AS count FROM thetable GROUP BY columnA, columnB HAVING count(*) > 1 Search for rows with array containing value Assuming, the field appointments has the type date[] SELECT * FROM mtable WHERE appointments @> ARRAY['2023-09-19'::date] ...