Data Preserved during Redeploy

The platform automatically preserves sensitive system files and container configurations to ensure that all your customizations are present on containers after redeployment. The default list includes the following data:

• all the previously specified custom container configurations (like run commands, links, variables, etc.) won’t be affected
  • including the content of volumes (default and custom ones)
• AutoFS and NFS related configurations (/etc/autofs.jelastic, /etc/auto.master, /etc/exports)
• firewall configurations (/etc/nftables/container-defined.nft, /etc/nftables/user-defined.nft, /etc/sysconfig/iptables-custom, /etc/sysconfig/iptables4-jelastic, /etc/sysconfig/iptables6-jelastic, /etc/iptables/rules.v4)
• SSH access data (/root/.ssh/authorized_keys, /root/.ssh/authorized_keys2, /root/.ssh/id_rsa)

Additionally, each platform-managed container is provided with a special /etc/jelastic/redeploy.conf file. It lists the software stack-specific configs required to ensure container operability. These settings are also automatically preserved by the platform during the container redeployment. You can easily access the file (e.g., via the dedicated Favorites shortcut in the embedded file manager) and modify it if needed.

The redeploy.conf file is divided into system and custom sections.

System Files and Folders

Each platform-managed container is provided with a predefined list of system configuration files that should be preserved during the redeployment. You don’t need to manually change this list unless you know exactly what you are doing.

The exact list varies for different software stacks but also has several common configuration files that are included in all containers:

• /etc/jelastic/redeploy.conf - saves the current redeployment config itself (to store the list of required files and directories during each further container redeploy)
• ${home}/.bash_profile - contains the default SSH shell settings (shell introduction message, the required configuration files to be fetched, etc.)
• /etc/nftables/container-defined.nft - contains default image specific firewall rules
• /etc/nftables/user-defined.nft - sets user-defined custom firewall rules

  Note: For legacy Centos 7 based containers, the following firewall configs are used instead:

  • /etc/sysconfig/iptables - keeps the default firewall rules
  • /etc/sysconfig/iptables-custom - contains custom firewall rules
• /var/lib/jelastic/keys - stores uploaded SSH private keys, which are necessary to access the container via SSH and for interaction with other containers

Custom Files and Folders

You can supplement the default list of system configurations with your custom files and folders (if needed). Open the redeploy.conf file and add an entry to the “custom files and folders” section with a full path to the required item (each entry should be in a separate line).

It is recommended to only add system configuration files that are required to ensure container operability during redeployment. Use container volumes for other cases (e.g., to keep your application data).

If needed, you can keep the configuration file existing and new versions (i.e., before and after redeployment). Namely, a backup copy of the existing configuration file will be created before replacing the original file with a version from the new tag.

To create a backup, you need to specify a path to the necessary file in redeploy.conf and add the “backup:” prefix to the record:

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backup:{path_to_file} 

After the redeploy, config from the old container can be easily recognized by the appropriate “backup” or “timestamp” extensions. They can be used for an instant rollback upon incompatibility with the new configs or for analysis of the changes:

• {file_name} - file from the redeployment target image (from the new tag)
• {file_name}.{timestamp} - backup version of the file created just before the redeploy operation (a separate file for each redeployment to a different tag)
• {file_name}.backup - the latest backup of the file (automatically replaces the previous same-named backup)

This way, you can easily switch to the previously used settings by substituting the file with its backup (through file renaming or content copying).

What’s next?

• Redeploy Containers
• Redeploy Containers API
• Container Configuration