DevOps for Databases: vagrant+redis+sentinel+stunnel

Hello

Welcome to the second part of the series DevOps for Databases, in this post we will see how to install Redis database along with HA (two slaves) , sentinel a HA solution to monitor the redis nodes and stunnel for managing SSL connections to Redis using Ansible playbook. In addition there is also a vagrant file in the repository where you can build virtualboxes with centos 7 and a playbook will run. If you do not want to run with vagrant simple run the playbook.

Here are the things you will need to understand before you start.

1. Install vagrant and ansible in your machine, windows also do. Playbook will run on local mode if windows
2. You can download the git repository from here.
3. Look at variables in install/group_vars/redis_vars.yml for password, masternode, env etc
4. By default the nodes that built in vagrant having stgredis01/02/03 you can change if you want
5. If you want to use SSL and had readymade certificates copy them to install/roles/redis/files/ and mark ssl_mode: "Yes" in variable file install/group_vars/redis_vars.yml

Here is how it look like

If you want to build the machines on your laptop/machine for learning purpose. There's a file VagrantFile already in there. So run below, the following will build three boxes and provision playbook also.

cd <repositoryfolder>/

vagrant up

But if you want to run only playbook and you have machines built already

• Modify the variables in install/group_vars/redis_vars.yml
• Add the hostname in hosts file in <repositoryfolder>/hosts

Run the playbook

ansible-playbook install/redis.yml -i hosts

Log part of Vagrant

C:\Users\Sureshgandhi\Desktop\ansible-redis-sentinel-stunnel-master>vagrant up
Bringing machine 'stgredis01' up with 'virtualbox' provider...
Bringing machine 'stgredis02' up with 'virtualbox' provider...
Bringing machine 'stgredis03' up with 'virtualbox' provider...
==> stgredis01: Importing base box 'centos/7'...
Progress: 20%
==> stgredis01: Importing base box 'centos/7'...
==> stgredis01: Matching MAC address for NAT networking...
==> stgredis01: Checking if box 'centos/7' is up to date...
==> stgredis01: A newer version of the box 'centos/7' for provider 'virtualbox' is
==> stgredis01: available! You currently have version '1804.02'. The latest is version
==> stgredis01: '1812.01'. Run `vagrant box update` to update.
==> stgredis01: Setting the name of the VM: ansible-redis-sentinel-stunnel-master_stgredis01_1547554542974_39615
==> stgredis01: Clearing any previously set network interfaces...
==> stgredis01: Preparing network interfaces based on configuration...
stgredis01: Adapter 1: nat
stgredis01: Adapter 2: bridged
==> stgredis01: Forwarding ports...
stgredis01: 22 (guest) => 20122 (host) (adapter 1)
==> stgredis01: Running 'pre-boot' VM customizations...
==> stgredis01: Booting VM...
==> stgredis01: Waiting for machine to boot. This may take a few minutes...
stgredis01: SSH address: 127.0.0.1:20122
stgredis01: SSH username: vagrant
stgredis01: Inserting generated public key within guest...
stgredis01: Removing insecure key from the guest if it's present...
stgredis01: Key inserted! Disconnecting and reconnecting using new SSH key...
=> stgredis01: Machine booted and ready!

==> stgredis02: Importing base box 'centos/7'...
==> stgredis02: Matching MAC address for NAT networking...
==> stgredis02: Checking if box 'centos/7' is up to date...
==> stgredis02: A newer version of the box 'centos/7' for provider 'virtualbox' is
==> stgredis02: available! You currently have version '1804.02'. The latest is version
==> stgredis02: '1812.01'. Run `vagrant box update` to update.
==> stgredis02: Setting the name of the VM: ansible-redis-sentinel-stunnel-master_stgredis02_1547554542974_39615
==> stgredis02: Clearing any previously set network interfaces...
==> stgredis02: Preparing network interfaces based on configuration...
stgredis02: Adapter 1: nat
stgredis02: Adapter 2: bridged
==> stgredis02: Forwarding ports...
stgredis02: 22 (guest) => 20122 (host) (adapter 1)
==> stgredis02: Running 'pre-boot' VM customizations...
==> stgredis02: Booting VM...
==> stgredis02: Waiting for machine to boot. This may take a few minutes...
stgredis02: SSH address: 127.0.0.1:20122
stgredis02: SSH username: vagrant
stgredis02: Inserting generated public key within guest...
stgredis02: Removing insecure key from the guest if it's present...
stgredis02: Key inserted! Disconnecting and reconnecting using new SSH key...
=> stgredis02: Machine booted and ready!

==> stgredis03: Importing base box 'centos/7'...
==> stgredis03: Matching MAC address for NAT networking...
==> stgredis03: Checking if box 'centos/7' is up to date...
==> stgredis03: A newer version of the box 'centos/7' for provider 'virtualbox' is
==> stgredis03: available! You currently have version '1804.02'. The latest is version
==> stgredis03: '1812.01'. Run `vagrant box update` to update.
==> stgredis03: Setting the name of the VM: ansible-redis-sentinel-stunnel-master_stgredis03_1547554542974_39615
==> stgredis03: Clearing any previously set network interfaces...
==> stgredis03: Preparing network interfaces based on configuration...
stgredis03: Adapter 1: nat
stgredis03: Adapter 2: bridged
==> stgredis03: Forwarding ports...
stgredis03: 22 (guest) => 20122 (host) (adapter 1)
==> stgredis03: Running 'pre-boot' VM customizations...
==> stgredis03: Booting VM...
==> stgredis03: Waiting for machine to boot. This may take a few minutes...
stgredis03: SSH address: 127.0.0.1:20122
stgredis03: SSH username: vagrant
stgredis03: Inserting generated public key within guest...
stgredis03: Removing insecure key from the guest if it's present...
stgredis03: Key inserted! Disconnecting and reconnecting using new SSH key...
=> stgredis03: Machine booted and ready!

Log part of Playbook that is provisioned

PLAY [stgredis*] ***************************************************************

TASK [Gathering Facts] *********************************************************
ok: [stgredis01]

TASK [redis : Obtain hostname] *************************************************
changed: [stgredis01]

TASK [redis : Install dependencies] ********************************************
changed: [stgredis01]

TASK [redis : Install Yum Package] *********************************************
changed: [stgredis01]

TASK [redis : Download and install redis] **************************************
changed: [stgredis01]

TASK [redis : Create user] *****************************************************
changed: [stgredis01]

TASK [redis : Create Required Directories] *************************************
changed: [stgredis01]

TASK [redis : Disable THP support scripts added to rc.local] *******************
changed: [stgredis01]

TASK [redis : Change permissions of /etc/rc.local to make it run on boot] ******
changed: [stgredis01]

TASK [redis : Add or modify nofile soft limit for all] *************************
changed: [stgredis01]

TASK [redis : Add or modify fsize hard limit for the all. Keep or set the maximal value.] ***
changed: [stgredis01]

TASK [redis : Add or modify memlock, both soft and hard, limit for the user root with a comment.] ***
changed: [stgredis01]

TASK [redis : Add or modify hard nofile limits for wildcard *] *****************
changed: [stgredis01]

TASK [redis : Copy Redis Conf file] ********************************************
changed: [stgredis01]

TASK [redis : Copy Redis Conf file] ********************************************
changed: [stgredis01]

TASK [redis : Copy Sentinel Conf file] *****************************************
changed: [stgredis01]

TASK [redis : Copy Stunnel Conf file] ******************************************
changed: [stgredis01]

TASK [redis : Copy Redis Failover Script] **************************************
changed: [stgredis01]

TASK [redis : Change Failover Script Permissions] ******************************

TASK [redis : Create Permissions for Redis Conf Files] *************************
changed: [stgredis01]

TASK [redis : Copy Redis Init Script] ******************************************
changed: [stgredis01]

TASK [redis : Copy Sentinel Init Script] ***************************************
changed: [stgredis01]

TASK [redis : Copy Sentinel Init Script] ***************************************
changed: [stgredis01]

TASK [redis : Update redis clustername in sentinel conf] ***********************
changed: [stgredis01]

TASK [redis : Update redis masternode name in sentinel conf] *******************
changed: [stgredis01]

TASK [redis : Update redis masternode name in sentinel conf] *******************
changed: [stgredis01]

TASK [redis : Update redis VIPADDRESS in stunnel conf] *************************
ok: [stgredis01]

TASK [redis : Update redis VIPADDRES in failover script] ***********************
changed: [stgredis01]

TASK [redis : Update redis masterauth in Redis conf] ***************************
changed: [stgredis01]

TASK [redis : Update redis masterauth in Redis conf] ***************************
changed: [stgredis01]

TASK [redis : Update redis masterauth in sentinel conf] ************************
changed: [stgredis01]

TASK [redis : Update redis requirepass in Redis conf] **************************
changed: [stgredis01]

TASK [redis : Update redis datadirect in Redis conf] ***************************
changed: [stgredis01]

TASK [redis : Fix ASCII Characters issues in shell scripts] ********************
changed: [stgredis01]

TASK [redis : Update stunnel file with right keys] *****************************
changed: [stgredis01]

TASK [redis : Copy SSL Certificate to Stunnel] *********************************
skipping: [stgredis01]

TASK [redis : Copy SSL Key to Stunnel] *****************************************
skipping: [stgredis01]

TASK [redis : Update Stunnel stuff] ********************************************
skipping: [stgredis01]

TASK [redis : Copy Hosts file] ************************************************
changed: [stgredis01]

TASK [redis : Update hosts file with right environment Dev/QA/STG/PRD] *********
changed: [stgredis01]

TASK [redis : Update hosts file with right environment Dev/QA/STG/PRD] *********
changed: [stgredis01]

TASK [redis : Update hosts file with right subnet] *****************************
ok: [stgredis01]

TASK [redis : Add Line for slaveof configuration] ******************************
ok : [stgredis01]

TASK [redis : Start redis Service] *********************************************
changed: [stgredis01]

TASK [redis : Start sentinel service] ******************************************
changed: [stgredis01]

TASK [redis : Start Stunnel service] *******************************************
skipping: [stgredis01]

PLAY RECAP *********************************************************************
stgredis01 : ok=41 changed=38 unreachable=0 failed=0

Redis Status once Boxes built and Provisioned

Note: There's lot of warnings and optimizations need for Playbook, feel free to modify the repository code and commit. When I find some time will do accordingly.

Happy Learning

-Suresh