Posts on DAWN's Blog

Harbor Active-Standby Deployment: From Installation to HTTPS and Replication

Tue, 04 Aug 2026 00:00:00 +0000

Complete guide to deploying Harbor enterprise Docker registry with active-standby architecture, HTTP/HTTPS modes, self-signed certificates, and cross-host replication.

OpenStack Cloud OS: Core Architecture and Automated Deployment

Tue, 06 Oct 2026 20:35:00 +0800

From core components (Nova/Glance/Neutron/Cinder, etc.) to one-click Packstack-based automated deployment of the Victoria release, plus Rsyslog log troubleshooting.

OpenStack Cinder Block Storage Explained: Local LVM + iSCSI Volumes and NFS Backend Integration

Mon, 05 Oct 2026 23:30:00 +0800

A walkthrough of OpenStack Cinder block storage: how volume creation and attachment split between Cinder and Nova, the full local LVM + iSCSI path (VG/LV, turning the controller into an iSCSI target with targetcli, attaching via libvirt), plus NFS backend configuration and dashboard operations.

OpenStack Core Services Explained: Keystone Authentication, Nova Compute, and Glance/Swift Image Storage

Mon, 05 Oct 2026 00:21:00 +0800

A walkthrough of OpenStack’s three core services: Keystone multi-domain support, service/endpoint registration and policy-file authorization; Nova’s modules (api/scheduler/conductor/compute/novncproxy), the message queue and the differential disk; and the Glance image service switched to a Swift object-storage backend.

OpenStack Cloud Server Provisioning

Sun, 04 Oct 2026 21:50:00 +0800

From the web dashboard to the CLI, a complete walkthrough of provisioning OpenStack cloud servers: creating and deleting tenants/users/images/flavors/networks/routers/security groups/key pairs/floating IPs, plus iptables SNAT/DNAT and Nova cell_v2 discover_hosts troubleshooting.

systemd Service Management & Multi-version MySQL Deployment

Sat, 03 Oct 2026 17:11:00 +0800

A hands-on guide to systemd Unit management and multi-version (5.6/5.7), multi-instance MySQL deployment: two production daemon configs, archive download, initialization, per-instance config files, and start/stop plus three-service status verification.

MySQL in Practice: Binary Installation, Start/Stop, and Password Management

Sat, 03 Oct 2026 14:53:00 +0800

A complete MySQL 8.0 operations guide: installing from the official binary package, OS prep, initialization, config file, multiple start/stop methods, plus password set/change and forgot-password reset.

SonarQube in Practice: Self-hosted Deployment, Token Setup, and Code Quality Scanning

Fri, 02 Oct 2026 14:12:00 +0800

A complete hands-on SonarQube self-hosting guide: JDK 8 and MySQL 5.6 setup, extracting SonarQube with plugins, running as a non-root user, web token configuration, and scanning code with the sonar-scanner client.

Jenkins in Practice: Self-hosted Deployment, Plugin Setup, and GitLab-Driven CI

Thu, 01 Oct 2026 21:28:00 +0800

A complete hands-on Jenkins self-hosting guide: RPM install of JDK and Jenkins, running as root, offline plugin install, and wiring GitLab SSH keyless access with webhook-triggered CI builds.

GitLab in Practice: Self-hosted Deployment, SSH Keyless Access, and Repository Management

Thu, 01 Oct 2026 17:50:00 +0800

A complete hands-on guide to self-hosting GitLab: RPM install, components, common commands, web UI setup, SSH keyless access, and multi-user collaboration.

Git in Practice: Installation, Essential Commands, and Branch Management

Thu, 01 Oct 2026 01:20:00 +0800

A hands-on Git walkthrough covering installation, everyday commands, branch workflows, and conflict resolution.

Custom Monitoring in Zabbix

Wed, 23 Sep 2026 18:30:00 +0800

A hands-on Zabbix custom monitoring guide — collect custom metrics such as login user count and free-memory percentage with UserParameter, verify them via zabbix_get, then add items, value mappings, and triggers (including a multi-condition trigger) on the web UI for custom alerting.

Splitting the Zabbix Database

Wed, 23 Sep 2026 16:00:00 +0800

For high-concurrency enterprise Zabbix scenarios — move the database off the Zabbix server onto a dedicated MariaDB server (11.0.1.52): create the database and grant privileges, export and import the data, update the Web UI and Server database connection settings, then restart the services.

Monitoring Server Information with Zabbix

Wed, 23 Sep 2026 13:21:00 +0800

How to deploy the Zabbix agent on a target server (web02, 11.0.1.8), point it at the Zabbix server, and start monitoring it from the Zabbix web UI.

Installing and Deploying Zabbix

Wed, 23 Sep 2026 01:52:00 +0800

Step-by-step guide to installing Zabbix 5.0 on CentOS 7 — configuring repositories, installing the server/agent/frontend, setting up MariaDB, importing the schema, and switching the web UI to Chinese with a custom font.

Manually Deploying a Kubernetes v1.30 Cluster (via kubeadm)

Fri, 07 Aug 2026 13:52:00 +0800

A step-by-step guide to manually deploying a Kubernetes v1.30 cluster with kubeadm — covering firewall/SELinux, swap, kernel modules, Containerd, kubeadm init, worker join, Calico, and an IPVS add-on.

KVM Virtualization from Beginner to Practice: Deployment, Management, and Network Configuration

Sun, 02 Aug 2026 00:00:00 +0000

A systematic introduction to KVM virtualization technology, covering development history, deployment methods, virtual machine management, network mode configuration, and automated VM installation using the command line.

Docker Image Too Large? 10 Tips to Shrink It by 90%

Thu, 30 Jul 2026 12:00:00 +0800

10 proven techniques to reduce Docker image size by over 90%.

How to Make Dockerfile Builds Faster: 10 Practical Optimization Tips

Thu, 30 Jul 2026 11:00:00 +0800

10 proven tips — from cache strategy to multi-stage builds — to dramatically cut Docker build time.

COPY vs ADD in Dockerfile: A Detailed Comparison

Thu, 30 Jul 2026 10:00:00 +0800

COPY and ADD can both copy files, but their behaviors differ greatly. This article explains the difference through side-by-side comparisons and examples.

CentOS Deployment Guide for Claude Code: Full Walkthrough

Sat, 04 Jul 2026 05:00:00 +0800

Deploy Claude Code on CentOS from scratch — covers Node.js installation, API key configuration, and common troubleshooting.

flannel in Action: Building Docker Cross-Host Container Networks from Scratch

Wed, 21 May 2025 00:00:00 +0000

flannel in Action: Building Docker Cross-Host Container Networks from Scratch

I. Network Environment Planning

etcd host IP: 192.168.8.88 hostname: docker-network
Host1 IP: 192.168.8.188 hostname: web01
Host2 IP: 192.168.8.99 hostname: web02

II. etcd Host Configuration

Step 1: Download and Extract etcd

Download etcd-v3.6.0-linux-amd64.tar.gz package from github.com
Copy the package to the etcd host /root directory and extract:

`1`	`[root@docker-network ~]# tar -zxvf etcd-v3.6.0-linux-amd64.tar.gz`

Step 2: Install etcd Executable Files

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[root@docker-network ~]# cd etcd-v3.6.0-linux-amd64
[root@docker-network etcd-v3.6.0-linux-amd64]# cp etcd* /usr/local/bin/

Step 3: Create Data Directory

`1`	`[root@docker-network ~]# mkdir /var/lib/etcd`

Step 4: Configure and Start etcd Service

Create etcd.service file:

`1`	`[root@docker-network ~]# vim /usr/lib/systemd/system/etcd.service`

[Unit]
Description=etcd_service
[Service]
ExecStart=/usr/local/bin/etcd --name etcd1 --data-dir /var/lib/etcd --listen-client-urls http://192.168.8.88:2379,http://127.0.0.1:2379 --advertise-client-urls http://192.168.8.88:2379,http://127.0.0.1:2379
[Install]
WantedBy=multi-user.target

Reload system service configuration and start etcd:

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[root@docker-network ~]# systemctl daemon-reload
[root@docker-network ~]# systemctl enable etcd.service
[root@docker-network ~]# systemctl restart etcd.service

Verify etcd listening status:

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[root@docker-network ~]# netstat -tulnp |grep :2379
tcp        0      0 192.168.8.88:2379       0.0.0.0:*               LISTEN      1912/etcd
tcp        0      0 127.0.0.1:2379          0.0.0.0:*               LISTEN      1912/etcd

Step 5: Add flannel Network Configuration to etcd

etcdctl --endpoints http://127.0.0.1:2379 put /coreos.com/network/config '{"Network": "172.16.0.0/16", "SubnetLen": 24, "SubnetMin": "172.16.1.0","SubnetMax": "172.16.10.0", "Backend": {"Type": "vxlan"}}'

The above content is all on one line. Verify that the configuration was written successfully