📦 Nexus Repository Manager on AlmaLinux: Central Hub for All Your Artifacts

Welcome to unified artifact management! 🎉 Ready to centralize all your dependencies and packages? Nexus Repository Manager OSS is the free, powerful repository manager that stores and manages your Maven, npm, Docker, and 20+ other formats! It’s the platform that becomes your single source of truth for all artifacts! Think of it as your universal package warehouse! 🚀✨

🤔 Why is Nexus Important?

Nexus revolutionizes artifact management! 🚀 Here’s why it’s amazing:

• 📦 Universal Storage - Maven, npm, Docker, PyPI, and more!
• 🔄 Proxy Repositories - Cache external dependencies!
• 🎯 Single Source - One place for all artifacts!
• 🔒 Access Control - Fine-grained permissions!
• 📊 Repository Health - Monitor artifact quality!
• 🆓 Completely Free - OSS edition forever!

It’s like having your own private package hub! 💰

🎯 What You Need

Before building your repository hub, ensure you have:

• ✅ AlmaLinux 9 server
• ✅ Root or sudo access
• ✅ At least 4GB RAM (8GB recommended)
• ✅ 4 CPU cores minimum
• ✅ 50GB free disk space
• ✅ Java 8 or 11
• ✅ Love for organized artifacts! 📦

📝 Step 1: System Preparation - Getting Ready!

Let’s prepare AlmaLinux 9 for Nexus! 🏗️

# Update system packages
sudo dnf update -y

# Install Java 8 (Nexus requirement)
sudo dnf install -y java-1.8.0-openjdk java-1.8.0-openjdk-devel

# Verify Java installation
java -version
# Should show: openjdk version "1.8.0_xxx"

# Create nexus user (no home directory needed)
sudo useradd -r -m -U -d /opt/nexus -s /bin/bash nexus

# Create necessary directories
sudo mkdir -p /opt/nexus
sudo mkdir -p /opt/sonatype-work

# Install required tools
sudo dnf install -y wget tar

Configure firewall for Nexus:

# Open Nexus port
sudo firewall-cmd --permanent --add-port=8081/tcp
# Open Docker registry port (if using)
sudo firewall-cmd --permanent --add-port=8082/tcp
sudo firewall-cmd --reload

# Verify ports
sudo firewall-cmd --list-ports
# Should show: 8081/tcp 8082/tcp

Configure system limits for Nexus:

# Increase file descriptors
sudo tee -a /etc/security/limits.conf << 'EOF'
nexus - nofile 65536
nexus - nproc 4096
EOF

# Create systemd override directory
sudo mkdir -p /etc/systemd/system/nexus.service.d/

# Set limits for systemd service
sudo tee /etc/systemd/system/nexus.service.d/override.conf << 'EOF'
[Service]
LimitNOFILE=65536
EOF

Perfect! System is ready! 🎯

🔧 Step 2: Installing Nexus - The Manual Way!

Let’s install Nexus Repository Manager! 🚀

Download and Extract Nexus:

# Download latest Nexus OSS (check for latest version)
cd /tmp
NEXUS_VERSION="3.61.0-02"
wget https://download.sonatype.com/nexus/3/nexus-${NEXUS_VERSION}-unix.tar.gz

# Extract to /opt
sudo tar -xzf nexus-${NEXUS_VERSION}-unix.tar.gz -C /opt/

# Rename for simplicity
sudo mv /opt/nexus-${NEXUS_VERSION} /opt/nexus/nexus
sudo mv /opt/sonatype-work /opt/nexus/

# Set ownership
sudo chown -R nexus:nexus /opt/nexus

# Verify installation
ls -la /opt/nexus/
# Should show: nexus and sonatype-work directories

Configure Nexus:

# Configure Nexus to run as nexus user
echo 'run_as_user="nexus"' | sudo tee /opt/nexus/nexus/bin/nexus.rc

# Configure JVM options
sudo vi /opt/nexus/nexus/bin/nexus.vmoptions

# Modify these settings:
# -Xms2048m
# -Xmx2048m
# -XX:MaxDirectMemorySize=3g
# -Djava.util.prefs.userRoot=/opt/nexus/sonatype-work/nexus3

Create Systemd Service:

# Create service file
sudo tee /etc/systemd/system/nexus.service << 'EOF'
[Unit]
Description=Nexus Repository Manager
After=network.target

[Service]
Type=forking
LimitNOFILE=65536
User=nexus
Group=nexus
ExecStart=/opt/nexus/nexus/bin/nexus start
ExecStop=/opt/nexus/nexus/bin/nexus stop
Restart=on-failure
RestartSec=20

[Install]
WantedBy=multi-user.target
EOF

# Reload systemd
sudo systemctl daemon-reload

# Enable and start Nexus
sudo systemctl enable nexus
sudo systemctl start nexus

# Check status
sudo systemctl status nexus
# Should show: active (running)

🌟 Step 3: Initial Setup - Your Repository Hub!

Time to configure Nexus! 🎮

Access Nexus:

# Wait for Nexus to fully start (2-3 minutes)
# Check logs
sudo tail -f /opt/nexus/sonatype-work/nexus3/log/nexus.log
# Look for: "Started Sonatype Nexus"

# Get initial admin password
sudo cat /opt/nexus/sonatype-work/nexus3/admin.password
# Save this password!

# Access Nexus
# URL: http://your-server-ip:8081
# Username: admin
# Password: (from admin.password file)

Setup Wizard:

1. Login with admin credentials
2. Change admin password immediately
3. Configure Anonymous Access:
   • Enable for public repositories
   • Disable for private setup
4. Complete setup

Dashboard shows:

• 📦 Browse - View repositories
• 🔧 Administration - System settings
• 🔍 Search - Find artifacts
• 📊 Support - Help resources

✅ Step 4: Creating Repositories - Let’s Store Artifacts!

Time to create repositories for different formats! 🎯

Create Maven Repository:

1. Go to Administration → Repositories
2. Click “Create repository”
3. Select “maven2 (hosted)”
4. Configure:
   • Name: maven-releases
   • Version policy: Release
   • Layout policy: Strict
   • Deployment policy: Disable redeploy
5. Create repository

Create snapshots repository:

1. Create another maven2 (hosted)
2. Configure:
   • Name: maven-snapshots
   • Version policy: Snapshot

Create npm Repository:

1. Create repository → npm (hosted)
2. Configure:
   • Name: npm-private
   • Deployment policy: Allow redeploy
3. Create repository

Create Docker Registry:

1. Create repository → docker (hosted)
2. Configure:
   • Name: docker-private
   • HTTP port: 8082
   • Enable Docker V1 API: ✓ (if needed)
3. Create repository

Create Proxy Repositories:

# Maven Central Proxy
# 1. Create repository → maven2 (proxy)
# 2. Configure:
#    - Name: maven-central
#    - Remote URL: https://repo1.maven.org/maven2/
#    - Use certificates: unchecked

# npm Registry Proxy
# 1. Create repository → npm (proxy)
# 2. Configure:
#    - Name: npm-registry
#    - Remote URL: https://registry.npmjs.org

# Docker Hub Proxy
# 1. Create repository → docker (proxy)
# 2. Configure:
#    - Name: docker-hub
#    - Remote URL: https://registry-1.docker.io
#    - Docker Index: Use Docker Hub

Create Group Repositories:

1. Create repository → maven2 (group)
2. Configure:
   • Name: maven-public
   • Member repositories:
     • maven-releases
     • maven-snapshots
     • maven-central
3. Create repository

🌟 Step 5: Using Nexus - Upload and Download!

Let’s use our repositories! 🎯

Configure Maven:

<!-- Add to ~/.m2/settings.xml -->
<settings>
  <servers>
    <server>
      <id>nexus-releases</id>
      <username>admin</username>
      <password>your-password</password>
    </server>
    <server>
      <id>nexus-snapshots</id>
      <username>admin</username>
      <password>your-password</password>
    </server>
  </servers>
  
  <mirrors>
    <mirror>
      <id>nexus</id>
      <mirrorOf>*</mirrorOf>
      <url>http://your-server-ip:8081/repository/maven-public/</url>
    </mirror>
  </mirrors>
</settings>

Deploy to Nexus:

<!-- Add to pom.xml -->
<distributionManagement>
  <repository>
    <id>nexus-releases</id>
    <url>http://your-server-ip:8081/repository/maven-releases/</url>
  </repository>
  <snapshotRepository>
    <id>nexus-snapshots</id>
    <url>http://your-server-ip:8081/repository/maven-snapshots/</url>
  </snapshotRepository>
</distributionManagement>

<!-- Deploy with: mvn deploy -->

Configure npm:

# Set registry for your scope
npm config set @mycompany:registry http://your-server-ip:8081/repository/npm-private/

# Login to Nexus
npm login --registry=http://your-server-ip:8081/repository/npm-private/
# Username: admin
# Password: your-password
# Email: [email protected]

# Publish package
npm publish --registry=http://your-server-ip:8081/repository/npm-private/

# Install from Nexus
npm install @mycompany/package --registry=http://your-server-ip:8081/repository/npm-public/

Configure Docker:

# Configure Docker for insecure registry
sudo vi /etc/docker/daemon.json
{
  "insecure-registries": ["your-server-ip:8082"]
}

# Restart Docker
sudo systemctl restart docker

# Login to Nexus Docker registry
docker login your-server-ip:8082
# Username: admin
# Password: your-password

# Tag and push image
docker tag myapp:latest your-server-ip:8082/myapp:latest
docker push your-server-ip:8082/myapp:latest

# Pull from Nexus
docker pull your-server-ip:8082/myapp:latest

🎮 Quick Examples

Example 1: CI/CD Integration

// Jenkins Pipeline example
pipeline {
    agent any
    
    stages {
        stage('Build') {
            steps {
                sh 'mvn clean package'
            }
        }
        
        stage('Deploy to Nexus') {
            steps {
                sh '''
                    mvn deploy:deploy-file \
                        -DgroupId=com.example \
                        -DartifactId=myapp \
                        -Dversion=${BUILD_NUMBER} \
                        -Dpackaging=jar \
                        -Dfile=target/myapp.jar \
                        -DrepositoryId=nexus-releases \
                        -Durl=http://nexus:8081/repository/maven-releases/
                '''
            }
        }
    }
}

Example 2: Cleanup Policies

# Create cleanup policy via API
curl -u admin:password -X POST \
  "http://your-server-ip:8081/service/rest/v1/cleanup-policies" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "cleanup-snapshots",
    "format": "maven2",
    "mode": "delete",
    "criteria": {
      "lastBlobUpdated": "30",
      "isPrerelease": "true"
    }
  }'

# Apply to repository
# Go to repository settings → Cleanup policies
# Select: cleanup-snapshots

Example 3: Repository Health Check

# Create scheduled task for health check
# Administration → System → Tasks → Create task
# Type: "Repository Health Check"
# Repository: maven-public
# Schedule: Daily at 2 AM

# Via REST API
curl -u admin:password \
  "http://your-server-ip:8081/service/rest/v1/repositories/maven-public/health-check"

🚨 Fix Common Problems

Problem 1: Nexus Won’t Start

Symptom: Service fails or stuck starting 😰

Fix:

# Check logs
sudo tail -n 100 /opt/nexus/sonatype-work/nexus3/log/nexus.log

# Common issue: Not enough memory
free -h
# Increase memory in nexus.vmoptions

# Check permissions
ls -la /opt/nexus/
# Should be owned by nexus user

# Manual start for debugging
sudo -u nexus /opt/nexus/nexus/bin/nexus run

# Check Java version
java -version
# Must be Java 8 or 11

Problem 2: Cannot Upload Artifacts

Symptom: 401 Unauthorized or 403 Forbidden 🔐

Fix:

# Check credentials in settings.xml
cat ~/.m2/settings.xml

# Verify repository permissions
# Administration → Security → Users
# Check user has nx-repository-admin privilege

# Check deployment policy
# Repository settings → Deployment policy
# Should be "Allow redeploy" for snapshots

# Test with curl
curl -u admin:password \
  --upload-file myapp.jar \
  "http://your-server-ip:8081/repository/maven-releases/com/example/myapp/1.0/myapp-1.0.jar"

Problem 3: Disk Space Issues

Symptom: Storage full, uploads failing 💾

Fix:

# Check disk usage
df -h /opt/nexus

# Run cleanup task
# Administration → System → Tasks
# Run: "Admin - Compact blob store"

# Delete old snapshots
# Create cleanup policy (see Example 2)

# Move blob store to larger disk
sudo systemctl stop nexus
sudo mv /opt/nexus/sonatype-work/nexus3/blobs /new/location/
sudo ln -s /new/location/blobs /opt/nexus/sonatype-work/nexus3/blobs
sudo systemctl start nexus

📋 Simple Commands Summary

💡 Tips for Success

🚀 Performance Optimization

Make Nexus super fast:

# Increase JVM heap
sudo vi /opt/nexus/nexus/bin/nexus.vmoptions
# -Xms4g
# -Xmx4g
# -XX:MaxDirectMemorySize=6g

# Enable G1 garbage collector
# -XX:+UseG1GC
# -XX:MaxGCPauseMillis=200

# Database optimization
# Administration → System → Capabilities
# Create: "Datastore JDBC" capability
# Configure PostgreSQL for better performance

# Restart Nexus
sudo systemctl restart nexus

🔒 Security Best Practices

Keep Nexus secure:

1. Enable HTTPS - Use SSL certificates! 🔐
2. LDAP Integration - Central authentication! 👥
3. Content Selectors - Fine-grained access! 🔑
4. Realms - Enable security features! 🛡️
5. Regular updates - Keep Nexus updated! 📦

# Setup HTTPS with reverse proxy
sudo dnf install -y nginx

cat << 'EOF' | sudo tee /etc/nginx/conf.d/nexus.conf
server {
    listen 443 ssl;
    server_name nexus.example.com;
    
    ssl_certificate /etc/ssl/certs/nexus.crt;
    ssl_certificate_key /etc/ssl/private/nexus.key;
    
    client_max_body_size 1G;
    
    location / {
        proxy_pass http://localhost:8081;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto "https";
    }
}
EOF

sudo systemctl restart nginx

📊 Monitoring and Backup

Keep Nexus healthy:

# Backup script
cat << 'EOF' > /usr/local/bin/backup-nexus.sh
#!/bin/bash
BACKUP_DIR="/backup/nexus"
DATE=$(date +%Y%m%d)

mkdir -p $BACKUP_DIR

# Stop Nexus
sudo systemctl stop nexus

# Backup data
tar -czf $BACKUP_DIR/nexus-data-$DATE.tar.gz /opt/nexus/sonatype-work/nexus3

# Start Nexus
sudo systemctl start nexus

# Keep only last 7 backups
find $BACKUP_DIR -name "*.tar.gz" -mtime +7 -delete

echo "Backup completed!"
EOF

chmod +x /usr/local/bin/backup-nexus.sh
# Add to cron: 0 2 * * * /usr/local/bin/backup-nexus.sh

🏆 What You Learned

You’re now a Nexus Repository expert! 🎓 You’ve successfully:

• ✅ Installed Nexus on AlmaLinux 9
• ✅ Created multiple repository types
• ✅ Configured Maven, npm, and Docker
• ✅ Set up proxy repositories
• ✅ Implemented cleanup policies
• ✅ Integrated with CI/CD
• ✅ Mastered artifact management

Your repository hub is production-ready! 📦

🎯 Why This Matters

Nexus transforms artifact management! With your repository manager, you can:

• 📦 Centralize everything - One source of truth!
• 🚀 Speed up builds - Local artifact caching!
• 🔒 Control access - Who gets what artifacts!
• 📊 Track usage - Know what’s being used!
• 💰 Save bandwidth - Cache external dependencies!

You’re not just storing artifacts - you’re creating a robust supply chain for your entire development process! Every dependency is managed, every artifact is tracked! 🎭

Keep building, keep managing, and remember - with Nexus, artifact chaos becomes organized bliss! ⭐

May your builds be fast and your artifacts always available! 🚀📦🙌