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If something can make ansible easier for me to try out like this tool while being pragmatic, I will give this a try someday thank you!
How accurate does this tool end up becoming though? Like can I just run some bunch of commands to setup a server and then use this with ansible?
Would this end up being a good use for it or would I just re-invent something similar to cloud-init on wrong abstraction. (On all fairness, one thing troubling me about cloud-init is that I would need to probably have a list of all commands that I want to run and all changes which sometimes if history command might have some issues or you do end up writing files etc. ends up being a little messy)
I haven't played that much with both cloud-init and ansible either but I am super interested to know more about enroll and others as well as I found it really cool!
> How accurate does this tool end up becoming though? Like can I just run some bunch of commands to setup a server and then use this with ansible?
Yes, exactly: let's say you provision a VPS and then install some stuff on it, configure some configs, create a crontab, create a user account. Running 'enroll harvest' on it will detect all of that, and 'enroll manifest' will then convert that 'harvest' into Ansible roles/playbooks.
> Would this end up being a good use for it or would I just re-invent something similar to cloud-init on wrong abstraction. (On all fairness, one thing troubling me about cloud-init is that I would need to probably have a list of all commands that I want to run and all changes which sometimes if history command might have some issues or you do end up writing files etc. ends up being a little messy)
Yeah, your instinct is right on the latter point. Ansible and Cloud-init are similar in that they are both 'declarative' systems to say what should exist on the machine. Ansible has some advantages in that it compares with the current setup to see if it needs to change anything. Cloud-init (in my experience) is a bit more crude: 'just run this stuff the first time the machine is booted'.
I'm sure there are different ways of using it, but in my experience, cloud-init is really designed to 'run once' (first time setup). For example, if you provision a machine with Terraform or OpenTofu, and you pass in cloud-init, then later if you change the cloud-init data, it wants to destroy the machine and rebuild it (unless you configure it explicitly not to do that, by which you have to tell it to 'ignore' changes to the cloud-init).
Whereas with Ansible, you're at least equipped with a solid foundation that you can extend over time - you'll no doubt eventually need to make changes to your server post the initial setup.
If you're new to Ansible, Enroll will be a quick way to get up and running with working Ansible configuration and you can adapt it from there as you learn it.
Admittedly, to satisfy a lot of corner cases (or support different Linux distros), the Ansible code that Enroll generates is a bit complex to read compared to a 'bespoke' home-grown playbook, on the other hand, it's perfectly correct code and you'd be immediately exposed to good practice syntax.
Let me know if you get to try it!
Awesome stuff!
If you are using a Debian-like or Fedora-like workstation, it's also really useful to 'ansibilize' your desktop OS in case you need to reinstall :)
I'm pondering adding some sort of `--enforce` argument to make it re-apply a 'golden' harvest state if you really want to be strictly against drift. For now, it's notifications only though.
A system that has neither a store nor the config (container image) not easily reconstructable as you miss too much metadata.
I just saved the state of my WSL2 instance, pushed it to github. Amazingly simple.
FWIW, I was required to add the --harvest, which your quick start seems to be missing?
ie I used:
uvx enroll single-shot --harvest ./harvest --out ./ansible
Indeed when using single-shot, indeed you need to supply the path to the harvest so that the 'manifest' part under the hood, knows what to use.
(By contrast, if you are using just the 'enroll harvest' command by itself, and omit the --out option, it will by default store the harvest in a random directory in ~/.cache/enroll/harvest/xxxxxxx)
Thanks for trying it out!
Even with a tool, people will still have to understand the output, enough that they can spot situations like "this part doesn't make sense at all", "that bit isn't static", "holy crud, there's an unsecured secret", "this part suggests a dependency on this other server we didn't know was involved, and which the tool doesn't investigate".
It does an okay job at this sort of thing, but definitely human eyes are needed :)
- Sent from my NixOS daily-driver, which only cost me a small number of grey hairs
Does it check extended filesystem labels with e.g. getfacl for SELinux support?
I've also done this more than a few times and not written a tool.
At least once I've scripted better then regex to convert a configuration file to a Jinja2 templated configuration file (from the current package's default commented config file with the latest options). And then the need is to diff: non-executable and executable guidelines, the package default config (on each platform), and our config.
Sometimes it's better not to re-specify a default config param and value, but only if the defaults are sane on every platform. Cipher lists for example.
P2V (physical to virtual) workflows don't result in auditable system policy like this.
Most of the OS and Userspace packages backed up in full system images (as with typical P2V workflows) are exploitably out of date in weeks or months.
To do immutable upgrades with rollback, Rpm-ostree distros install the RPM packages atop the latest signed immutable rootfs image, and then layer /etc on top (and mounts in /var which hosts flatpaks and /var/home). It keeps a list of packages to reinstall and it does a smart merge of /etc. Unfortunately etckeeper (which auto-git-commits /etc before and after package upgrades) doesn't yet work with rpm-ostree distros.
Ansible does not yet work with rpm-ostree distros. IIRC the primary challenge is that ansible wants to run each `dnf install` individually and that takes forever with rpm-ostree. It is or is not the same to install one long list of packages individually or to install multiple groups of packages in the same sequence. It should be equivalent if the package install and post-install scripts are idempotent, but is not equivalent if e.g. `useradd` is called without an explicit UID in package scripts which run as roo, too.
I wrote a PR to get structured output (JSON) from `dnf history`, but it was for dnf4.
From https://news.ycombinator.com/item?id=43617363 :
> upgrading the layered firefox RPM without a reboot requires -A/--apply-live (which runs twice) and upgrading the firefox flatpak doesn't require a reboot, but SELinux policies don't apply to flatpaks which run unconfined FWIU.
Does it log a list of running processes and their contexts; with `ps -Z`?
There are also VM-level diff'ing utilities for forensic-level differencing.
> Could it also detect changed package files; if there are per-package-file checksums like with debsums and `rpm -V`?
Yes, that's exactly what it does. See https://git.mig5.net/mig5/enroll/src/branch/main/enroll/debi... and https://git.mig5.net/mig5/enroll/src/branch/main/enroll/rpm....
It also tries to ignore packages that came with the distro automatically, e.g focusing on stuff that was explicitly installed (based on 'apt-mark showmanual' for Debian, and 'dnf -q repoquery --userinstalled' (and related commands, like dnf -q history userinstalled) for RH-like)
> Does it check extended filesystem labels with e.g. getfacl for SELinux support?
Not yet, but that's interesting, I'll look into it.
> At least once I've scripted better then regex to convert a configuration file to a Jinja2 templated configuration file (from the current package's default commented config file with the latest options).
Yep, that was the inspiration for my companion tool https://git.mig5.net/mig5/jinjaturtle (which enroll will automatically try and use if it finds it on the $PATH - if it can't find it, it will just use 'copy' mode for Ansible tasks, and the original files).
Note that running the `enroll manifest` command against multiple separate 'harvests' (e.g harvested from separate machines) but storing it in the same common manifest location, will 'merge' the Ansible manifests. Thereby 'growing' the Ansible manifest as needed. But each host 'feature flips' on/off which files/templates should be deployed on it, based on what was 'harvested' from that host.
> Does it log a list of running processes and their contexts; with `ps -Z`?
It doesn't use ps, but it examines systemctl to get a list of running services and also timers. Have a look at https://git.mig5.net/mig5/enroll/src/branch/main/enroll/syst...
Thanks for the other ideas! I'll look into them.
Does it already indirectly diff the output of `systemd-analyze security`?
How to transform the generated playbooks to - instead of ansible builtins - use a role from ansible-galaxy for example?
How to generate tests or stub tests (or a HEALTHCHECK command/script, or k8s Liveness/Readiness/Startup probes, and/or a Nagios or a Prometheus monitoring config,) given ansible inventory and/or just enroll?
Ansible Molecule used to default to pytest-testinfra for the verify step but the docs now mention an ansible-native way that works with normal inventory that can presumably still run testinfra tests as a verify step. https://docs.ansible.com/projects/molecule/configuration/?h=...
MacOS: honebrew_tap_module, homebrew_module, homebrew_cask_module, osx_defaults_module
Conda (Win/Mac/Lin, AMD64, ARM64, PPC64, RISC-V 64 (*), WASM)
CycloneDX/cyclonedx-python generates SBOMs from venv, conda, pip requirements.txt, pipenv, poetry, pdm, uv: https://github.com/CycloneDX/cyclonedx-python
Container config: /var, $DOCKER_HOST, Podman, Docker, $KUBECONFIG defaults to ~/.kube/config (kube config view), Podman rootless containers
Re: vm live migration, memory forensics, and diff'ing whole servers:
Live migration and replication solutions already have tested bit-level ~diffing that would also be useful to compare total machine state between 2 or more instances. At >2 nodes, what's anomalous? And how and why do the costs of convergence-based configuration management differ from golden image -based configuration management?
E.g. vmdiff diffs VMs. The README says it only diffs RAM on Windows. E.g. AVML and linpmem and volatility3 work with Linux.
/? volatility avml inurl:awesome https://www.google.com/search?q=volatiloty+avml+inurl%3Aawes...
1) stuff in /etc that doesn't belong to any obvious package, ends up in an 'etc_custom' role
2) stuff in /usr/local ends up in a 'usr_local_custom' role
3) Anything you include with --include will end up in a special 'extra_paths' role.
Here's a demo (which is good, helped me spot a small bug, the role is included twice in the playbook :) I'll get that fixed!) https://asciinema.org/a/765385
Thanks for your interest!
uv tool run enroll single-shot --harvest ./harvest --out ./ansible
There is the --exclude option which might help (also keep in mind you can define an enroll.ini file to manage the flags so it's less cumbersome). Otherwise, you can always prune the roles from the ansible dir/playbook.
I'm going to continue to work on easy options to skip stuff. In particular I do think many of the 'lib' packages could be omitted if they are just dependencies of other packages already detected as part of the harvest. (Need to basically build a dependency graph)
Thanks for trying it out!
What I mean is in some large companies you are given a host that already has lots of config changes, possibly by ansible. Then your team has to configure on top of those changes, maybe ansible again. I'd like to run on the baseline system given to create a baseline, then on a production host to see how it drifted.
Sorry if this is in the docs, cool tool!
Treat that as your 'golden' harvest state. You could then run a 'harvest' on the production system. You'd then be able to run 'enroll diff --old baseline --new production' to compare the difference.
You could also first run the manifest of the baseline harvest against your production, to ensure it has (at least) all the same things as the baseline.
A 'harvest' of production after that, would probably then show just stuff that existed on production already that wasn't in the baseline.
I hope that makes sense!
I had documented everything up to a point on this beatie and then things have got out of hand. I now have all the changes from after I went off piste.
What a great tool.
Thank you.
The reason I'm asking is because I'm interested in how much confidence could be lent to this tool with regards to more old and obscure machines that have been running for years.
I run QubesOS as my workstation, so it's been really beneficial here, because Qubes is all VMs and templates. I've been 'harvesting' one Qube VM and then building another and running the manifest on the second machine. It's been working very well to align it with the first machine. Most of my testing has been visually watching the Ansible play install/configure things that I expect to see occur.
Where it falls down:
1) Systems that are so old, the packages that it detected as being installed, are no longer 'installable' on a new system (e.g the apt repositories no longer have those packages, they just did at the time of the original install)
2) Packages that were installed not via an apt repo but, say, dpkg -i (of a .deb file). Slack Desktop is a good example. Obviously the deb is not in the harvest, so it fails there.
So, there'll always be corner cases, but assuming everything that you have installed on the old/obscure machine is still something that can be installed via the usual methods, it should be okay. (If you are running a system that is so old, its packages are no longer available upstream, it's probably time to let it go! :) )
You'll want to use --exclude-path to ignore some server-specific stuff, perhaps, such as static network configuration etc. And of course, you can also comment out whatever roles are superfluous, in the playbook, before running it.
Always use --check with Ansible first just in case.
Is it expected that it does not allocate a TTY for sudo password prompts when connecting to a remote machine via SSH? How would I use it otherwise?
I'm about to make a new release and I'll set `get_pty=True` for the paramiko calls that use sudo. I'm not 100% sure if it will fix it for all use cases, but hopefully it will.
Yeah, I haven't been confident enough with Forgejo's federation capabilities yet to open up PRs/login etc. Maybe soon. Trying to avoid using Github and the other big providers if I can help it :) but I recognise it's a hindrance..
I'll happily take a patch and credit you, if you can be bothered, but I understand if not. Feel free to email mig@mig5.net
Appreciate it!
I don't know if this touches networking or not but I've always deliberately avoided configuring (most) networking on Ansible after having shot myself in the foot too many times.
I like this in theory and will give it a shot but I'm wary of getting bled out by all the sharp corner cases...
Let me break it down as to what harvest does:
1) Detects the OS and its package backend (e.g dpkg vs rpm etc)
2) Detects what packages are installed
3) For each package, it tries to detect files in /etc/ that have been modified from the default that get shipped with the package . It does't walk the whole filesystem, it looks straight in /etc for stuff here.
4) It detects running/enabled services and timers via systemd. For each of these, it looks for the unit files, any 'drop-in' files, environment variable files, etc, as well as what executable it executes, and tries to map those systemd services to the packages it's already learned about earlier (that way, those 'packages' or future Ansible roles, can also be associated with 'handlers' in Ansible, to handle restart of the services if/when the configs change)
5) Aside from known packages already learned, it optimistically tries to capture extra system configuration in /etc that is common for config management. This is stuff like crons, logrotate configs, networking settings (as you noted!), hosts files, etc.
6) It also looks for other snowflake stuff in /etc not associated with packages/services or other typical system config, and will put these into an etc_custom role
7) Likewise, it looks in /usr/local for stuff, on the assumption that this is an area that custom apps/configs might've been placed in. These go into a usr_local_custom role.
8) It captures non-system user accounts, their group memberships and their .ssh/authorized_keys
9) takes into account anything the user set with --exclude-path or --include-path . For anything extra that is included, it will put these into an 'extra_paths' role. The location could be anywhere e.g something in /opt, /srv/ whatever you want.
10) writes the state.json and captures the artifacts
So yes, you're right - it does capture stuff that many people might want to exclude if they are going to use the manifests to build other machines from that harvest (as opposed to just rebuild the same machine itself).
But you can use --exclude-path /etc/network and so on to skip the bits you don't want. You also can always comment out from the playbook.yml or delete certain roles it generates once you've run the 'enroll manifest'.
It doesn't have any knowledge of Ansible Galaxy roles/modules etc. It generates all the roles itself. I admit, many of the existing roles out there are a lot more pleasant/easier to read (especially Jeff Geerling's). I still use those myself day to day. A lot of configs out there are also good candidates for being Jinja templates with abstracted vars for separate hosts. Enroll does use my companion tool JinjaTurtle if it's installed, but JinjaTurtle only recognises certain types of files (.ini style, .json, .xml, .yaml, .toml, but not special ones like Nginx or Apache conf files which have their own special syntax).
I consider Enroll to be a good 'quick, grab it all, so I can sleep at night' method, perhaps best for DR purposes.
In terms of safety measures: it doesn't traverse symlinks, and it has an 'IgnorePolicy' that makes it ignore most binary files (except GPG binary keys used with apt) - though if you specify certain paths with --include-path and use --dangerous, it will skip its own policy. See https://git.mig5.net/mig5/enroll/src/branch/main/enroll/igno... .
It will skip files that are too large, and it also currently has a hardcoded cap of the number of files that it will harvest (4000 for /etc/ and /usr/local/etc and /usr/local/bin, and 500 per 'role'), to avoid 'bomb' situations.
I think your caution is very warranted and wise, and I highly recommend to always use --check with Ansible when/if you get to applying the playbook!
Thanks again.
https://enroll.sh/docs.html#harvest
I've also published a JSONSchema of the state.json file here to help people understand its structure: https://enroll.sh/schema.html
https://asciinema.org/a/765293
Enroll will automatically make use of jinjaturtle if it's on the $PATH, to generate templates.
JinjaTurtle is just chef's kiss. Definitely taking both for a spin.
I had a lot of good feedback directly from the comments here, and have made a new release that contains some bug fixes, as well as an improvement to support remote harvesting when the user requires a password for sudo. Thanks to 'slhck' here for the help, advice and patch for that.
There have also been some questions about 'what does enroll harvest actually capture in its state'. I've updated the docs here to clarify the process:
https://enroll.sh/docs.html#harvest
And for the data/API nerds, I've also published a JSON Schema of the state.json file here:
Thanks again!
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