RancherOs Installation

To install RancherOS on your ESXi server, first of all, download rancheros ISO image from its website here

1. Create new Virtual Machine for RancherOS

On ESXi, create a new Virtual Machine with at least 1GB memory. After you created appliance, upload rancheros.iso to your ESXi datastore and set CD/DVD rom to use it.

2. Start rancheros

Once you clicked start button, the OS will boot up rapidly and prompt for login. Now rancheros is running in your RAM, you can login with credential rancher/rancher. Anything you change now will not be saved after you reboot. What we need is a docker ready OS so we need to install Rancher OS to our disk.

3. Prepare your cloud-config.yml

Before we install rancheros to our hard disk, you need to setup cloud-config first.

You also need to generate a new SSH key for cloud-config.yml file by following this article

Add your public key to cloud-config.yml file like following:

This is for rancher os first boot configuration after installation, you can use your private key to connect this host.

Next, we are going to configure network before installation. Following is an example, you need to configure DNS, IP address of interface and default gateway.

 - ssh-rsa AAAAB3NzaCURHZlGvtcq4bZXxkl wid@voxteneo.asia
hostname: rancheros-cd01
        dhcp: false
        mtu: 1500

Make sure you only have one ethernet interface, current rancher os installer has problem when configuring multiple NICs.

At last, you need to put your cloud-config.yml to rancher os. After you login, configure a accessible temporary IP address and default gateway on eth0, then scp your cloud-config.yml to it.

Following is an example

On RancherOS, configure IP and default gateway

$ sudo ip addr add dev eth0
$ sudo route add default gw

On your local machine, copy your cloud-config.yml to RancherOS via SCP or other method.

4. Install

You should be all set if you done everything right in previous steps. Now we can call installer to initiate installation.

$ ros install -c cloud-config.yml -d /dev/sda --append "rancher.password=rancher"

Installer will download rancher/os to your system and format /dev/sda.

At last, installer will prompt for reboot, after manual reboot you can configure own rancher os now.


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How to add DKIM record on zimbra 8.7

Step 1. Modify DKIM generator

a. Edit (as root) script file /opt/zimbra/libexec/zmdkimkeyutil and replace all ‘2048’ occurrences with ‘1024’.
This will allow creation of DKIM key with length 1024 and set it as default value.

nano /opt/zimbra/libexec/zmdkimkeyutil

replace all 3 ‘2048’ occurrences with ‘1024’ and then save and exit

Step 2. generate a new DKIM, replace example.com with your domain. Please note you’ll need to generate a DKIM for each domain

switch to zimbra user : su – zimbra

/opt/zimbra/libexec/zmdkimkeyutil -a -d example.com

Step 3. Retrieving the stored DKIM data for your domain – replace example.com with your domain
as zimbra user run command below;

/opt/zimbra/libexec/zmdkimkeyutil -q -d example.com

zimbra@example.com:~$ /opt/zimbra/libexec/zmdkimkeyutil -a -d example.com
DKIM Data added to LDAP for domain example.com with selector 0E9F184A-9577-11E1-AD0E-2A2FBBAC6BCB
Public key to enter into DNS:
0E9F184A-9577-11E1-AD0E-2A2FBBAC6BCB._domainkey IN TXT “v=DKIM1;=rsa;
/6LYWYU1whOQ9oKZVAwWHSovAWZpByqNMZmFg7QIDAQAB” ; —– DKIM 0E9F184A-9577-11E1-AD0E-2A2FBBAC6BCB for example.com

Step 4.
highlight and copy: 0E9F184A-9577-11E1-AD0E-2A2FBBAC6BCB._domainkey

highlight and copy: v=DKIM1; k=rsa;

highlight and copy: p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDY5CBg15nZ2vYnRmrNub6Jn6ghQ2DXQbQgOJ/E5IGziUYEuE2OnxkBm1h3jived21uHjpNy0naOZjLj0xLyyjclVy1chrhSbsGAhe8HLXUsdXyfRvNTq8NWLsUnMEsoomtJCJ

Step 5. verify DKIM key using this link http://dkimcore.org/tools/keycheck.html

Step 6.

– login to your DNS web portal
– create new TXT entry

– add the 0E9F184A-9577-11E1-AD0E-2A2FBBAC6BCB._domainkey in the hostname field

– add the public DKIM key into destination / target field
v=DKIM1; k=rsa; P=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDY5CBg15nZ2vYnRmrNub6Jn6ghQ2DXQbQgOJ/E5IGziUYEuE2OnxkBm1h3jived21uHjpNy0naOZjLj0xLyyjclVy1chrhSbsGAhe8HLXUsdXyfRvNTq8NWLsUnMEsoomtJCJ

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