Sync bash aliases and ssh keys across devices

I suggest you don't sync SSH keys. That's just increasing the blast radius of any one of those machines being compromised.

Exactly this. Don't move private keys between machines. Generate them where you need them, it's not like they cost anything
I mean, you want to copy the public keys that represents your machines, right?
- Fair point, but I would equate that with syncing the authorized_keys file rather than thinking about how to sync the keys.
Right. Use some kind of centralized authentication like freeipa.

For bash aliases, I just pull down a .bashrc from github gists.
- Is the url is easy to rember?

Dotfiles go in git, SSH keys are state.

I'm looking to migrate to home-manager though because I use Nix on all my devices anyways.

Home manager is great
I also have multiple versions of by bash_profile with syntax specific to the OS. It checks if we're on MacOS or Linux with a kernel check and then reads the appropriate ancillary bash_profile for that platform. Anything that can live in the main bash_profile with the same command on both platforms lives there and anything that needs to be system-specific is in the other one.

I have all my important functions as individual files that get loaded with the following:

function loadfuncs() { local funcdir="$HOME/.dotfiles/functions/" [ -e "${funcdir}".DS_Store ] && rm "$HOME/.dotfiles/functions/.DS_Store" local n=0 for i in "${funcdir}"*; do source "$(realpath $i)" n=$(( n + 1 )) done } loadfuncs
- Interesting way to go about it. Though when I'm at the point where I need differences between linux and darwin, I'm probably going to do that at the home-manager level.

I'm surprised no one mentioned ansible yet. It's meant for this (and more).

By ssh keys I assume you're talking about authorized_keys, not private keys. I agree with other posters that private keys should not be synced, just generate new ones and add them to the relevant servers authorized_keys with ansible.

I use Ansible for this as well. It's great. I encrypt secrets with Ansible vault and then use it to set keys, permissions, config files, etc. across my various workstations. Makes setup and troubleshooting a breeze.
If the keys are password protected.... eh why not sync them.

Also ssh certificates are a thing, they make doing that kind of stuff way easier instead of updating known hosts and authorized keys all the time
- Passwords will be brute forced if it can be done offline.
  
  Private SSH keys should never leave a machine. If a key gets compromised without you knowing, in worst case you will revoke the access it has once the machine's lifespan is over. If you copy around one key, it may get compromised on any of the systems, and you will never revoke the access it has.
  
  And you may not want to give all systems the same access everywhere. With one key per machine, you can have more granularity for access.

This looks popular: www.chezmoi.io

+1 this, it is amazing. The scripting features are the cherry on top.

Git and GNU stow.

I love this solution, I've been using it for years. I had previously just been using the home directory is a git repo approach, and it never quite felt natural to me and came with quite a few annoyances. Adding stow to the mix was exactly what I needed.
Ditto -- I've been keeping a central to me git repo for my settings for years. Any new machine I'm on 'git clone ; ./settings/setup.sh', then my pull'd .profile does a git pull on login.
This is the only answer for me. Bonus points if your .login file does a background git pull.

On my devices like PCs, laptops or phones, syncthing syncs all my .rc files, configs, keys, etc.

For things like servers, routers, etc. I rely on OpenSSH's ability to send over environmental variables to send my aliases and functions.
On the remote I have
[ -n "$SSH_CONNECTION" ] && eval "$(echo "$LC_RC" | { { base64 -d || openssl base64 -d; } | gzip -d; } 2>/dev/null)"
in whatever is loaded when I connect (.bashrc, usually)
On the local machine
alias ssh="$([ -z "$SSH_CONNECTION" ] && echo 'LC_RC=$(gzip < ~/.rc | base64 -w 0)') ssh'

That's not the best way to do that by any means (it doesn't work with dropbear, for example), but for cases like that I have other non-generic, one-off solutions.

Syncthing. If you want flatpak, syncthingy.

Its simply best, does all the annoying background things like webUI, machines, versioning, verifying etc. If you disable global discovery you can use it tough LAN only

yadm

Yet Another Stow-Based Dotfile Sync Manager

yas-bdsm
I use it with GitHub, works amazing on multiple boxes, OSX and Linux. For SSH keys, just use KeePassXC and SyncThing.

Have you considered a shared folder with Syncthing?

That my solution. I have a 'Sync' folder on every device's Home folder, and then I use some aliases to determine whether to grab the bash_aliases file or replace it:

alias dba='diff -s ~/.bash_aliases ~/Sync/.bash_aliases' # compare files

alias s2ba='cp ~/Sync/.bash_aliases ~/' # Push from Sync folder to current bash aliases

alias ba2s='cp ~/.bash_aliases ~/Sync/' # Push from current bash aliases to Sync folder

By far, the diff alias is the most used. It allows for a quick check on what is different between files w/o having to open them up

I use a git repo combined with the basic install utility. Clone the repo, run the app installer, then run the install script. For symlinks I just use a zsh script.

Thanks that's a good idea.

Just use backpack or sshrc or kyrat.

I like this approach. Had never heard of those solutions. Thanks!

I keep my dotfiles in a got repo and just do a git pull your update them. That could definitely be a cron job if you needed.

SSH keys are a little trickier. I’d like to tell you I have a unique key for each of my desktop machines since that would be best practice, but that’s not the case. Instead I have a Syncthing shared folder. When I get around to cleaning that up, I’ll probably do just that and keep an authorize_keys and known_hosts file in git so I can pull them to needed hosts and a cron job to keep them updated.

ssh keys go into my keepass db, keepassxc imports them into gpg agent or ssh agent. Bash aliases and so on are in my dotfiles

Use a git repo and stow tool. For updating, you only need run git pull (and stow if you create config for a new software). If you modify some config, just git add && git commit && git push.
With this way, you can also record change history of your config.

Several good suggestions on here already. Home manager might be another approach.

My solution is not ideal:

I created a directory, called ~/config_sync. I create sym links for config files, like ~/.bashtc to ~/config_sync/bashrc

However, I need to record the sym links I've created, and repeat this process on new machines

Look into using GNU stow! It's exactly what you're doing but it creates the symlinks for you.

1password does this for me, when it comes to ssh keys, and it's great. All I have to do on a new machine is setup the ssh-agent, which is also practically preconfigured. The actual key never leaves the password manager

I use a git repo combined with the basic install utility. Clone the repo, run the app installer, then run the install script. For symlinks I just use a zsh script.

At work, for new hires, I wrote an Ansible script that runs locally to install stuff from homebrew, set up directories and files, etc.