DevOps

I recently found an interesting tool run-gemini-cli, a GitHub Action that integrates Gemini directly into your repositories. I was intrigued by its promise to perform pull request reviews, triage issues, and even modify code using conversational commands right inside GitHub action workflow. Let’s try it out. My goal was to see if I could use this action to get instant, automated feedback on pull requests. Instead of waiting for a human to spot simple issues, I wanted an AI to do the first pass, check for common problems, and even explain code changes on demand. ...

In the last post, I used Claude Code with Kimi K2 to complete the Django web app layout optimization. One thing I wasn’t satisfied with was the pagination system on this Django blog. It used a numbered pagination interface at the bottom of the home page—functional, but a bit dated. I wanted to modernize it with automatic loading of more posts via infinite scroll. However, I couldn’t get this done using Kimi K2. Despite spending a significant number of tokens (and money), the model couldn’t provide a working solution. ...

I originally used Jekyll, a straightforward static site generator, to build my blog. It was easy to set up and ideal for managing content in Markdown. However, it had its limitations: serving only static content meant a lack of dynamic features and essential tools like a built-in database and user management. That’s when I decided to migrate to Django. With its ability to handle dynamic content and a fully integrated database, it was the perfect solution and the clear choice for the future of my blog. ...

Effortless Coding with Claude Code and Kimi K2: Features, Pricing, and Setup Guide Recently Kimi K2 became one of the most popular model in HuggingFace, claimed its compatible with Claude Code API. With my new sign up and got a $15 free credit, Let’s see how it can intergrate with Claud Code and validate its coding performance! 🧠 Claude Code + Kimi K2? Claude Code is command-line tool from Anthropic Claude, powered by its latest models (Opus, Sonnet, Haiku). It is highly effective but can be expensive. ...

“Design a Jenkins pipeline can handle multiple destination: EC2, EKS across different environments” Jenkins CD Pipeline Design In last post, I was able to create a Jenkins Universal CI Pipeline to create blog docker image and push to DockerHub: Jenkins - Universal CI Pipeline with Ansible & Terraform Now it is time to design the continuous deployment pipeline with Ansible and Terraform for infrastructure provision and application configuration and deployment. ...

“Such a long time I nearly forgot how to use Jenkins..” Jenkins recap It has been some time since I adapted CI/CD pipelines from Jenkins to AWS CodePipeline and GitHub Actions workflows. Now, it’s time to recap and improve some of my previous Jenkins practices. Universal Jenkins Docker image design This time, instead of installing Jenkins on a server, I prefer to containerize a universal Jenkins Docker image with the necessary packages installed, so it provides consistency and reproducibility, portability, and easy updates and rollbacks. ...

In the company, we use AWS SSO for user authentication; when a new user is created from Azure AD, it will automatically synced by AWS IAM Identity Center and Azure AD integration, and then our team will need to handle the SSO user assignment to put them in the required AWS accounts with requested permission sets, it became a pain when such requests coming more frequently and every time an individual user or a whole team with different accounts and permission requirements need to be fulfilled, so how to handle this efficiently become my recent topic. ...

Despite all the challenges, in the last 2 years, clever people still managed ways to deploy production-grade database within a Kubernetes cluster by using Kubernetes as a platform to develop custom resource definition (CRDs) like helm charts like bitnami/postgresql-ha, and PostgreSQL Operator like CrunchyData/postgres-operator or zalando/postgres-operator. Last post I was able to deploy a single PostgreSQL in local k8s, but I had to manually create Kubernetes namespaces, define database creds, configuration and environment variables into k8s secret and configmap, also to define the statefulset yaml with volume claim template. ...

PostgreSQL by default does not build for Kubernetes, and a database with StatefulSet workload in K8S can be brutal to manage. In my lab K8S cluster, here we create namespace, secret, configmap, PVC, and StatefulSet to run a single PostgreSQL. # create namespace "postgresql" [root@freeipa-server ~]# kubectl create ns postgresql namespace/postgresql created # create secret to store database creds [root@freeipa-server ~]# kubectl -n postgresql create secret generic postgresql --from-literal POSTGRES_USER="postgresadmin" --from-literal POSTGRES_PASSWORD='admin123' --from-literal POSTGRES_DB="postgresdb" --from-literal REPLICATION_USER="replicationuser" --from-literal REPLICATION_PASSWORD='replicationPassword' secret/postgresql created # create configmap, pvc, statefulset with init container to run postgresql [root@freeipa-server ~]# vim stateful.yaml apiVersion: v1 kind: ConfigMap metadata: name: postgres data: pg_hba.conf: |+ # TYPE DATABASE USER ADDRESS METHOD host replication replicationuser 0.0.0.0/0 md5 # "local" is for Unix domain socket connections only local all all trust # IPv4 local connections: host all all 127.0.0.1/32 trust # IPv6 local connections: host all all ::1/128 trust # Allow replication connections from localhost, by a user with the # replication privilege. local replication all trust host replication all 127.0.0.1/32 trust host replication all ::1/128 trust host all all all scram-sha-256 postgresql.conf: |+ data_directory = '/data/pgdata' hba_file = '/config/pg_hba.conf' ident_file = '/config/pg_ident.conf' port = 5432 listen_addresses = '*' max_connections = 100 shared_buffers = 128MB dynamic_shared_memory_type = posix max_wal_size = 1GB min_wal_size = 80MB log_timezone = 'Etc/UTC' datestyle = 'iso, mdy' timezone = 'Etc/UTC' #locale settings lc_messages = 'en_US.utf8' # locale for system error message lc_monetary = 'en_US.utf8' # locale for monetary formatting lc_numeric = 'en_US.utf8' # locale for number formatting lc_time = 'en_US.utf8' # locale for time formatting default_text_search_config = 'pg_catalog.english' #replication wal_level = replica archive_mode = on archive_command = 'test ! -f /data/archive/%f && cp %p /data/archive/%f' max_wal_senders = 3 --- apiVersion: apps/v1 kind: StatefulSet metadata: name: postgres spec: selector: matchLabels: app: postgres serviceName: "postgres" replicas: 1 template: metadata: labels: app: postgres spec: terminationGracePeriodSeconds: 30 initContainers: - name: init image: postgres:15.0 command: [ "bash", "-c" ] args: - | #create archive directory mkdir -p /data/archive && chown -R 999:999 /data/archive volumeMounts: - name: data mountPath: /data readOnly: false containers: - name: postgres image: postgres:15.0 args: ["-c", "config_file=/config/postgresql.conf"] ports: - containerPort: 5432 name: database env: - name: PGDATA value: "/data/pgdata" - name: POSTGRES_USER valueFrom: secretKeyRef: name: postgresql key: POSTGRES_USER optional: false - name: POSTGRES_PASSWORD valueFrom: secretKeyRef: name: postgresql key: POSTGRES_PASSWORD optional: false - name: POSTGRES_DB valueFrom: secretKeyRef: name: postgresql key: POSTGRES_DB optional: false volumeMounts: - name: config mountPath: /config readOnly: false - name: data mountPath: /data readOnly: false volumes: - name: config configMap: name: postgres defaultMode: 0755 volumeClaimTemplates: - metadata: name: data spec: accessModes: [ "ReadWriteOnce" ] storageClassName: "standard" resources: requests: storage: 100Mi --- apiVersion: v1 kind: Service metadata: name: postgres labels: app: postgres spec: ports: - port: 5432 targetPort: 5432 name: postgres clusterIP: None selector: app: postgres [root@freeipa-server ~]# kubectl create -f stateful.yaml -n postgresql configmap/postgres created statefulset.apps/postgres created service/postgres created # validate for pvc, pods [root@freeipa-server ~]# kubectl get pvc -n postgresql NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE data-postgres-0 Bound pvc-dd89fc0a-915f-40eb-b61f-917234074a61 100Mi RWO longhorn 19m [root@freeipa-server ~]# kubectl get all -n postgresql NAME READY STATUS RESTARTS AGE pod/postgres-0 1/1 Running 0 6m29s NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/postgres ClusterIP None <none> 5432/TCP 6m29s NAME READY AGE statefulset.apps/postgres 1/1 6m29s # check container logs for database connection status [root@freeipa-server ~]# kubectl logs -n postgresql postgres-0 Defaulted container "postgres" out of: postgres, init (init) The files belonging to this database system will be owned by user "postgres". This user must also own the server process. The database cluster will be initialized with locale "en_US.utf8". The default database encoding has accordingly been set to "UTF8". The default text search configuration will be set to "english". Data page checksums are disabled. fixing permissions on existing directory /data/pgdata ... ok creating subdirectories ... ok selecting dynamic shared memory implementation ... posix selecting default max_connections ... 100 selecting default shared_buffers ... 128MB selecting default time zone ... Etc/UTC creating configuration files ... ok running bootstrap script ... ok performing post-bootstrap initialization ... ok initdb: warning: enabling "trust" authentication for local connections initdb: hint: You can change this by editing pg_hba.conf or using the option -A, or --auth-local and --auth-host, the next time you run initdb. syncing data to disk ... ok Success. You can now start the database server using: pg_ctl -D /data/pgdata -l logfile start waiting for server to start....2024-01-12 00:52:56.718 UTC [49] LOG: starting PostgreSQL 15.0 (Debian 15.0-1.pgdg110+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 10.2.1-6) 10.2.1 20210110, 64-bit 2024-01-12 00:52:56.719 UTC [49] LOG: listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432" 2024-01-12 00:52:56.730 UTC [49] LOG: could not open usermap file "/config/pg_ident.conf": No such file or directory 2024-01-12 00:52:56.733 UTC [52] LOG: database system was shut down at 2024-01-12 00:52:55 UTC 2024-01-12 00:52:56.744 UTC [49] LOG: database system is ready to accept connections done server started CREATE DATABASE /usr/local/bin/docker-entrypoint.sh: ignoring /docker-entrypoint-initdb.d/* 2024-01-12 00:52:56.957 UTC [49] LOG: received fast shutdown request waiting for server to shut down....2024-01-12 00:52:56.961 UTC [49] LOG: aborting any active transactions 2024-01-12 00:52:56.962 UTC [49] LOG: background worker "logical replication launcher" (PID 56) exited with exit code 1 2024-01-12 00:52:56.963 UTC [49] LOG: shutting down 2024-01-12 00:52:57.042 UTC [49] LOG: checkpoint starting: shutdown immediate ..2024-01-12 00:52:59.314 UTC [49] LOG: checkpoint complete: wrote 918 buffers (5.6%); 0 WAL file(s) added, 0 removed, 1 recycled; write=0.434 s, sync=0.014 s, total=2.279 s; sync files=250, longest=0.007 s, average=0.001 s; distance=11271 kB, estimate=11271 kB 2024-01-12 00:52:59.318 UTC [49] LOG: database system is shut down done server stopped PostgreSQL init process complete; ready for start up. 2024-01-12 00:52:59.385 UTC [1] LOG: starting PostgreSQL 15.0 (Debian 15.0-1.pgdg110+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 10.2.1-6) 10.2.1 20210110, 64-bit 2024-01-12 00:52:59.385 UTC [1] LOG: listening on IPv4 address "0.0.0.0", port 5432 2024-01-12 00:52:59.385 UTC [1] LOG: listening on IPv6 address "::", port 5432 2024-01-12 00:52:59.389 UTC [1] LOG: listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432" 2024-01-12 00:52:59.398 UTC [1] LOG: could not open usermap file "/config/pg_ident.conf": No such file or directory 2024-01-12 00:52:59.404 UTC [67] LOG: database system was shut down at 2024-01-12 00:52:59 UTC 2024-01-12 00:52:59.415 UTC [1] LOG: database system is ready to accept connections Conclusion ...

Last post I started a hands-on session with PostgreSQL installation on both Docker and Docker Compose, explored important PostgreSQL configuration, and was able to mount persistent volumes and config files to customize PostgreSQL. In this post, I will set up a second PostgreSQL instance to establish primary and standby replication for PostgreSQL HA, using some pg tools. Lastly, we will test failover by shutting down the primary and promoting the standby instance. ...