Docker Environment Setup for Apache Ambari

This guide helps you set up a Docker environment for Apache Ambari development and testing. Using Docker containers provides a lightweight alternative to full virtual machines while still allowing you to create a multi-node environment for Ambari.

Prerequisites

Before proceeding, ensure you have the following installed on your system:

• Docker Engine (version 20.10.0 or later)
• Docker Compose (version 2.0.0 or later)
• At least 8GB of free RAM (for a 4-node cluster)
• At least 20GB of free disk space

Useful Docker Shortcuts

Quick Container Access

To make it easier to access your Docker containers, you can add a helpful shell function to your system. This function allows you to quickly enter any container with a simple command.

Add the following function to your /etc/profile (requires root access):

# Login as root or use sudo
sudo su -

# Edit the profile file
vi /etc/profile

# Add this function at the end of the file
dke() {
    docker exec -it "$1" /bin/bash
}

# Save the file and exit
# Source the profile to apply changes immediately
source /etc/profile

After adding this function, you can quickly enter any container using:

# Enter the Ambari server container
dke bigtop_hostname0

# Enter an agent container
dke bigtop_hostname1

This shortcut saves you from typing the full docker exec -it container_name /bin/bash command each time you need to access a container.

Overview

This setup creates a multi-container environment with:

• One container (bigtop_hostname0) for the Ambari Server
• Three containers (bigtop_hostname1, bigtop_hostname2, bigtop_hostname3) for Ambari Agents
• A shared volume for the Ambari repository
• The BigTop image which includes many pre-configured dependencies

The setup uses the bigtop/puppet:trunk-rockylinux-8 image, which is pre-configured with many of the dependencies needed for Ambari and Hadoop services.

1. Create a Docker Compose File

Create a file named docker-compose.yml with the following content:

version: '3'

services:
  bigtop_hostname0:
    command: /sbin/init
    domainname: bigtop.apache.org
    image: bigtop/puppet:trunk-rockylinux-8
    mem_limit: 8g
    mem_swappiness: 0
    ports:
      - "8080:8080"
    privileged: true
    volumes:
      - ./ambari-repo:/var/repo/ambari

  bigtop_hostname1:
    command: /sbin/init
    domainname: bigtop.apache.org
    image: bigtop/puppet:trunk-rockylinux-8
    mem_limit: 8g
    mem_swappiness: 0
    privileged: true
    volumes:
      - ./ambari-repo:/var/repo/ambari

  bigtop_hostname2:
    command: /sbin/init
    domainname: bigtop.apache.org
    image: bigtop/puppet:trunk-rockylinux-8
    mem_limit: 8g
    mem_swappiness: 0
    privileged: true
    volumes:
      - ./ambari-repo:/var/repo/ambari

  bigtop_hostname3:
    command: /sbin/init
    domainname: bigtop.apache.org
    image: bigtop/puppet:trunk-rockylinux-8
    mem_limit: 8g
    mem_swappiness: 0
    privileged: true
    volumes:
      - ./ambari-repo:/var/repo/ambari

This configuration creates four containers:

• bigtop_hostname0: Ambari Server node with port 8080 exposed
• bigtop_hostname1, bigtop_hostname2, bigtop_hostname3: Ambari Agent nodes

Each container uses the bigtop/puppet:trunk-rockylinux-8 image, which is pre-configured with many of the dependencies needed for Ambari and Hadoop services.

2. Create a Directory for Ambari Repository

Create a directory to store Ambari RPMs that will be shared with all containers:

mkdir -p ambari-repo

If you have Ambari RPMs, place them in this directory. Otherwise, you'll configure the containers to use online repositories later.

3. Create a Hosts File

The containers need to be able to communicate with each other using hostnames. Create a hosts file that will be mounted in each container:

mkdir -p conf
cat > conf/hosts << EOF
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

# Container hostnames
172.20.0.2  bigtop_hostname0
172.20.0.3  bigtop_hostname1
172.20.0.4  bigtop_hostname2
172.20.0.5  bigtop_hostname3
EOF

Now update your docker-compose.yml to mount this hosts file:

version: '3'

services:
  bigtop_hostname0:
    command: /sbin/init
    domainname: bigtop.apache.org
    image: bigtop/puppet:trunk-rockylinux-8
    mem_limit: 8g
    mem_swappiness: 0
    ports:
      - "8080:8080"
    privileged: true
    volumes:
      - ./ambari-repo:/var/repo/ambari
      - ./conf/hosts:/etc/hosts

  bigtop_hostname1:
    command: /sbin/init
    domainname: bigtop.apache.org
    image: bigtop/puppet:trunk-rockylinux-8
    mem_limit: 8g
    mem_swappiness: 0
    privileged: true
    volumes:
      - ./ambari-repo:/var/repo/ambari
      - ./conf/hosts:/etc/hosts

  bigtop_hostname2:
    command: /sbin/init
    domainname: bigtop.apache.org
    image: bigtop/puppet:trunk-rockylinux-8
    mem_limit: 8g
    mem_swappiness: 0
    privileged: true
    volumes:
      - ./ambari-repo:/var/repo/ambari
      - ./conf/hosts:/etc/hosts

  bigtop_hostname3:
    command: /sbin/init
    domainname: bigtop.apache.org
    image: bigtop/puppet:trunk-rockylinux-8
    mem_limit: 8g
    mem_swappiness: 0
    privileged: true
    volumes:
      - ./ambari-repo:/var/repo/ambari
      - ./conf/hosts:/etc/hosts

4. Understanding the BigTop Image

The bigtop/puppet:trunk-rockylinux-8 image is part of the Apache BigTop project, which provides a framework for building and testing Hadoop-related projects. This image includes:

• Rocky Linux 8 as the base OS
• Pre-installed Java and development tools
• Puppet for configuration management
• System configurations optimized for Hadoop ecosystem services

Using this image simplifies the setup process as many of the dependencies required for Ambari are already installed or configured.

5. Start the Docker Environment

Launch the Docker containers:

docker-compose up -d

This command starts the containers in detached mode. You should see output indicating that the containers are being created.

6. Verify the Environment

Ensure all containers are running and properly configured:

# Check container status
docker ps

# Test network connectivity between containers
docker exec -it bigtop_hostname0 ping -c 2 bigtop_hostname1
docker exec -it bigtop_hostname0 ping -c 2 bigtop_hostname2
docker exec -it bigtop_hostname0 ping -c 2 bigtop_hostname3

7. Configure SSH Access Between Containers

SSH setup is required for Ambari to function properly. Execute these commands:

First, on the bigtop_hostname0 container:

docker exec -it bigtop_hostname0 bash

# Generate SSH key
ssh-keygen -t rsa -N "" -f ~/.ssh/id_rsa

# Start SSH service
systemctl enable sshd
systemctl start sshd

# Exit the container
exit

Now set up SSH on the agent containers and copy the server's key:

# For bigtop_hostname1
docker exec -it bigtop_hostname1 bash
ssh-keygen -t rsa -N "" -f ~/.ssh/id_rsa
systemctl enable sshd
systemctl start sshd
exit

# For bigtop_hostname2
docker exec -it bigtop_hostname2 bash
ssh-keygen -t rsa -N "" -f ~/.ssh/id_rsa
systemctl enable sshd
systemctl start sshd
exit

# For bigtop_hostname3
docker exec -it bigtop_hostname3 bash
ssh-keygen -t rsa -N "" -f ~/.ssh/id_rsa
systemctl enable sshd
systemctl start sshd
exit

# Copy SSH key from server to agents
docker exec -it bigtop_hostname0 bash
cat ~/.ssh/id_rsa.pub | docker exec -i bigtop_hostname1 bash -c 'cat >> ~/.ssh/authorized_keys'
cat ~/.ssh/id_rsa.pub | docker exec -i bigtop_hostname2 bash -c 'cat >> ~/.ssh/authorized_keys'
cat ~/.ssh/id_rsa.pub | docker exec -i bigtop_hostname3 bash -c 'cat >> ~/.ssh/authorized_keys'

# Test SSH connections
ssh -o StrictHostKeyChecking=no bigtop_hostname1 echo "Connection successful"
ssh -o StrictHostKeyChecking=no bigtop_hostname2 echo "Connection successful"
ssh -o StrictHostKeyChecking=no bigtop_hostname3 echo "Connection successful"
exit

8. Disable Security Features

For development environments, disable SELinux and firewall on all containers:

# For each container (bigtop_hostname0, bigtop_hostname1, bigtop_hostname2, bigtop_hostname3)
docker exec -it bigtop_hostname0 bash
setenforce 0
sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config
exit

9. Install Required Packages on All Containers

Execute these commands on each container (bigtop_hostname0, bigtop_hostname1, bigtop_hostname2, bigtop_hostname3):

# Example for bigtop_hostname0 container
docker exec -it bigtop_hostname0 bash

# Install basic utilities
dnf install -y sudo openssh-server openssh-clients which iproute net-tools less vim-enhanced

# Install development tools
dnf install -y initscripts wget curl tar unzip git

# Enable PowerTools repository (needed for some dependencies)
dnf install -y dnf-plugins-core
dnf config-manager --set-enabled powertools

# Update the system
dnf update -y

# Exit the container
exit

Repeat for bigtop_hostname1, bigtop_hostname2, and bigtop_hostname3 containers.

10. Enable Development Repository

The Rocky Linux development repository needs to be enabled on each container to install dependencies required for Ambari:

# For each container (bigtop_hostname0, bigtop_hostname1, bigtop_hostname2, bigtop_hostname3)
docker exec -it bigtop_hostname0 bash

# Edit the Rocky-Devel repository configuration
vi /etc/yum.repos.d/Rocky-Devel.repo

# There are two possible scenarios:
# 1. If all lines are commented (start with #), uncomment all lines
# 2. If you see "enabled=0", change it to "enabled=1"

# After editing, verify the repository is enabled
dnf repolist | grep devel
exit

Troubleshooting

If you encounter issues with the Docker environment:

Container Connectivity Issues

# Check if all containers are running
docker ps -a

# Check network configuration
docker network inspect bridge

# Restart a specific container
docker restart bigtop_hostname0

SSH Issues

# Check SSH service status
docker exec -it bigtop_hostname0 systemctl status sshd

# Verify SSH key permissions
docker exec -it bigtop_hostname0 ls -la ~/.ssh/

# Check SSH configuration
docker exec -it bigtop_hostname0 cat /etc/ssh/sshd_config | grep PasswordAuthentication
docker exec -it bigtop_hostname0 cat /etc/ssh/sshd_config | grep PermitRootLogin

Resource Issues

If containers are terminating unexpectedly, you might need to allocate more resources to Docker:

# Check container logs
docker logs bigtop_hostname0

# Check resource usage
docker stats

BigTop Image Specific Issues

If you encounter issues with the BigTop image:

# Check if Java is installed correctly
docker exec -it bigtop_hostname0 java -version

# Verify puppet is available
docker exec -it bigtop_hostname0 puppet --version

# Check for any BigTop-specific logs
docker exec -it bigtop_hostname0 ls -la /var/log/

Next Steps

Now that your Docker environment is set up, proceed to the Installation Guide to install and configure Ambari Server and Agents. The installation guide provides standardized instructions that work across all environments (Vagrant, Docker, and bare metal/KVM).

When following the installation guide, remember:

1. All commands should be run as root (which is the default user in the BigTop containers)
2. Run Ambari Server setup and installation on the bigtop_hostname0 container
3. Run Ambari Agent installation on all containers
4. Access the Ambari Web UI via http://localhost:8080 after installation

The Docker environment provides a lightweight and reproducible way to test and develop with Apache Ambari, while following the same installation and configuration steps as other deployment methods.