9 ms·

GNU Shepherd 0.6.0

94 points by lelf 8y ago

preek 8y ago
For those interested in shepherd, I highly recommend GNU Guix[1] which is a great functional package manager and can also bundle it's own Linux distro (called Guix SD). 1. https://www.gnu.org/software/guix/ https://www.gnu.org/software/guix/
bovermyer 8y ago
Is Shepherd meant to be a replacement for systemd (et al), then? If so, what makes it different? If not, what's it for?
- bjoli 8y ago
  It is the unit system of GNU guix, and it has a better integration with the guix. You write guix packages and manage the Daemon using the same language. I'd suspect that you with ease can programmatically interface with both of them using guile as well. As a scheme fanboy I like the idea of being able to use a proper programming language (opinions may differ) for my startup scripts Edit: read about how guix uses services here: https://www.gnu.org/software/guix/manual/en/html_node/Defining-Services.html#Defining-Services https://www.gnu.org/software/guix/manual/en/html_node/Defini...
  - majewsky 8y ago
    > I like the idea of being able to use a proper programming language (opinions may differ) for my startup scripts I don't know. I rather like the NixOS way, where a proper programming language generates the startup scripts (or, in that case, systemd units), but then those scripts are dumb and obvious. Many things are better when they're dumb and obvious.
    - armitron 8y ago
      The problem with Nix is that it's not a proper programming language. I'll take Scheme over yet another obscure language that manages to irritate me in many ways.
      - res0nat0r 8y ago
        I setup and used a headless nixos box for about a year or so, it was fun to play around with but I did get tired after a while of the nix programming language. It was just too weird to figure out and google around to try and find what I needed to do sometimes. Trying to get virtualenvs of python packages, or using rbenv / bundler type installs for ruby was also just too much of a pain in the butt. https://nixos.org/nixpkgs/manual/#sec-language-ruby https://nixos.org/nixpkgs/manual/#sec-language-ruby Trying to figure my way around installing ruby/python libraries just was too hard most of the time without a good amount of work that it wasn't worth it in the long run. Guix has been on my radar to try and install and play with in-depth soon. If their installer will work with a VM without a days worth of research to work around any quirks I'm all in for checking it out.
        lfam 8y ago
        Installing Guix in a VM has its own section of the manual: https://www.gnu.org/software/guix/manual/en/html_node/Installing-GuixSD-in-a-VM.html https://www.gnu.org/software/guix/manual/en/html_node/Instal...
        res0nat0r 8y ago
        I think I remember trying that a while back and couldn't quite get it working, I'll need to try again soon.
      - pknopf 8y ago
        If you want immutability with a traditional package manager, try Darch: https://godarch.com https://godarch.com
    - bjoli 8y ago
      I agree, but having an option instead of having to do ExecStop=path-to-shell-script-that-does-some-stupid-housekeeping is pretty neat. Most shepherd service definitions are simple and stupid, but as always it is a matter of taste.
      - nerdponx 8y ago
        But the shell scripts are more or less portable across systems, whereas this way you were asking developers to re-implement the same cleanup logic in another language.
      - stephenr 8y ago
        > but having an option instead of having to do ExecStop=path-to-shell-script-that-does-some-stupid-housekeeping is pretty neat. IMO this is usually the result of eg a Debian package that also ships sysvinit startup scripts, and thus they share some logic. If it’s not that case I wonder why the cleanup can’t just be handled in the unit directly.
        Skunkleton 8y ago
        Perhaps the service being managed doesn't clean up after itself properly? It is a fairly common pattern for a program to ship without startup scripts, and then have startup scripts added by package maintainers.
        stephenr 8y ago
        Right that’s certainly a thing but what I meant is, why not just put the cleanup instructions in the unit file.
        Skunkleton 8y ago
        Because "cleanup" can be non-trivial. Maintaining scripts inside unit files is a pain in the ass.
  - stephenr 8y ago
    As someone typically working with others startup units but sometimes writing my own, I appreciate a declarative format that allows user-overrides and has pretty standardised ways of doing things. Sysvinit scripts showed us what happens when you give startup authors more power. Even if you hate systemd’s politics/etc the actual units themselves are objectively better IMO because they’re declarative.
    - bjoli 8y ago
      Well, the service difinition part of shepherd is pretty declarative: (make <service> #:provides '(blahblah) #:start (...) #:stop (...))) The difference is that start/stop must be guile procedures that starts or stops a command. I suspect there is a nice macro for just running a regular shell command, but I'm not sure.
      - stephenr 8y ago
        It’s guile. They’re instances of the <service> class (apparently). That is specifically not declarative and the fact that the only example in the official documentation is essentially the same as your example, says this project is not ready for use by humans. If you (the project) cant show a full example service definition to start something why would anyone bother going forward.
    - _emacsomancer_ 8y ago
      > Even if you hate systemd’s politics/etc the actual units themselves are objectively better IMO because they’re declarative. It's a pity the overall system is so inflexible and brittle. Well, that and the 'death by a thousand (theoretically independent but tightly coupled) systemd components'.
      - stephenr 8y ago
        It has it's issues, definitely, and I'm not thrilled about "make everything part of the systemd project" - but in terms of providing a way to run your services, I think it's got a lot of functionality that e.g. sysvinit could never really support.
- nerdponx 8y ago
  https://www.gnu.org/software/shepherd/ https://www.gnu.org/software/shepherd/ It replaces the init & service management features of systemd.
- nextos 8y ago
  Yes, it is an alternative init system. So it can replace systemd. It is in fact used as such in GuixSD, the NixOS alternative by GNU which is written in Guile Scheme.
  - privateSFacct 8y ago
    Yowks - I know systemd gets lots of hate and this is “real” programming - but it does feel a bit niche from a language etc perspective?
    - nextos 8y ago
      I don't think Guile is too niche. In fact, Guix has a quite active community. Nowhere as Nix in terms of activity, but it's pretty nice and very friendly too.
      - dwohnitmok 8y ago
        I don't know about Guile's popularity, but I use NixOS as my daily driver distro and in my experience Nix is already very niche in the programming circles I run in. That's not to say Guix shouldn't be developed or that Shepherd is bad, it's just that I would definitely call Guix niche.
- laumars 8y ago
  > what makes it different? It's GNU, others aren't. There will be other well reasoned arguments in favour of Shepherd but it essentially boils down to the same reason Hurd (the kernel) is a thing when GNU/Linux is already widespread. That all said, I don't see the harm in competing solutions. Better to have a choice rather than lock ins.
  - aries1980 8y ago
    Systemd is licenced under LGPL, why would it lock you in?
    - laumars 8y ago
      Sorry, that was a poor choice of words on my part. What I really meant was "better to have more options rather than fewer".
    - yarrel 8y ago
      It's locking people in by eating the OS and making it difficult to move away from its tightly coupled and increasingly tightly integrated components (that, we must never forget, are not a single binary).
    - yjftsjthsd-h 8y ago
      It only supports Linux, for one. Shepherd supports HURD and probably other systems.
- deleted 8y ago
  [deleted]
- bitwize 8y ago
  Shepherd (as dmd) predates the systemd project considerably. It is intended to fill the same niche (init system, process monitor) as systemd, though.
afranchuk 8y ago
Does anyone have experience with both Shepherd and runit[1]? And if so, can you provide a comparison of the two? [1]: http://smarden.org/runit/ http://smarden.org/runit/
- _emacsomancer_ 8y ago
  I use both. However, I'm mainly interacting as a 'regular user', but as such a user, both are pleasant to interact with, and don't try to be too clever or overly complex, and thus I don't encounter the same sorts of issues with them that I do with other init/daemon-managers.
nerdponx 8y ago
I'd like to know how this compares to Systemd's actual service management features (systemctl, journalctl, etc). I love how declarative Systemd is. There's an example in the docs which gives a good idea (https://www.gnu.org/software/shepherd/manual/shepherd.html#Service-Examples https://www.gnu.org/software/shepherd/manual/shepherd.html#S...), but it helps to hear the experiences of people who use it in practice.
gigatexal 8y ago
As a side note the GNU SD distro looks cool. I like the declarative way of doing things and it really seems to be following the infrastructure as code idea.
sevensor 8y ago
It makes me happy to see the GNU OS still being assembled, bit by bit. I've written previously about how much I appreciate the Guile info manual. For a document in a relatively obscure help system (other than Emacs users, who even knows about Texinfo?), it's carefully written with an eye to empowering its users. It's perhaps a bit quixotic, but you get the feeling that the GNU project really wants to deliver an OS written in Scheme all the way down, totally under the control of an enlightened end user. The Shepherd project certainly fits with that vision.
- enriquto 8y ago
  I love dearly the GNU project and the beautiful, nicely worded documentation which is always a pleasure to read (when rendered as pdf documents). However, the info format is unfathomable; if it is possible to really hate one file format, it must be this one.
  - sevensor 8y ago
    I hesitate to speak for emacs users, because I'm not one really, but I suspect the info format feels really comfortable when viewed with emacs.
    - jefft255 8y ago
      It’s nice indeed. Not special, but certainly smooth to use. Never used it outside of emacs though.
    - opan 8y ago
      I started using info more after installing the Guix system. One thing that made me use emacs over info was that with evil-mode you could use vim bindings to read info pages through emacs. It was a bit more like 'less' then.
  - badsectoracula 8y ago
    Note that Texinfo != info, the former is a document source format similar to DocBook (but much simpler), the latter is a very simple hypertext format with preformatted text and support for indices (think of it as a text-based CHM). You can use the former to generate the latter, but Texinfo can be used to generate several other types of documents, including plain text, PDF and HTML (and yes, also CHM). Also note that the info file format is independent from the GNU info viewer, that most people associate with, and there are other viewers for it, including pinfo and tkinfo (Tcl/Tk viewer) and some other help systems have support for it, like GNOME's and KDE's help viewers. And yes, there is also support for it on Emacs (which AFAIK is the only viewer with image support). FWIW personally i like using tkinfo.

94 points by lelf 8y ago

For those interested in shepherd, I highly recommend GNU Guix[1] which is a great functional package manager and can also bundle it's own Linux distro (called Guix SD). 1. https://www.gnu.org/software/guix/ https://www.gnu.org/software/guix/

bovermyer 8y ago

Is Shepherd meant to be a replacement for systemd (et al), then? If so, what makes it different? If not, what's it for?

bjoli 8y ago
It is the unit system of GNU guix, and it has a better integration with the guix. You write guix packages and manage the Daemon using the same language. I'd suspect that you with ease can programmatically interface with both of them using guile as well. As a scheme fanboy I like the idea of being able to use a proper programming language (opinions may differ) for my startup scripts Edit: read about how guix uses services here: https://www.gnu.org/software/guix/manual/en/html_node/Defining-Services.html#Defining-Services https://www.gnu.org/software/guix/manual/en/html_node/Defini...
- majewsky 8y ago
  > I like the idea of being able to use a proper programming language (opinions may differ) for my startup scripts I don't know. I rather like the NixOS way, where a proper programming language generates the startup scripts (or, in that case, systemd units), but then those scripts are dumb and obvious. Many things are better when they're dumb and obvious.
  - armitron 8y ago
    The problem with Nix is that it's not a proper programming language. I'll take Scheme over yet another obscure language that manages to irritate me in many ways.
    - res0nat0r 8y ago
      I setup and used a headless nixos box for about a year or so, it was fun to play around with but I did get tired after a while of the nix programming language. It was just too weird to figure out and google around to try and find what I needed to do sometimes. Trying to get virtualenvs of python packages, or using rbenv / bundler type installs for ruby was also just too much of a pain in the butt. https://nixos.org/nixpkgs/manual/#sec-language-ruby https://nixos.org/nixpkgs/manual/#sec-language-ruby Trying to figure my way around installing ruby/python libraries just was too hard most of the time without a good amount of work that it wasn't worth it in the long run. Guix has been on my radar to try and install and play with in-depth soon. If their installer will work with a VM without a days worth of research to work around any quirks I'm all in for checking it out.
      - lfam 8y ago
        Installing Guix in a VM has its own section of the manual: https://www.gnu.org/software/guix/manual/en/html_node/Installing-GuixSD-in-a-VM.html https://www.gnu.org/software/guix/manual/en/html_node/Instal...
        res0nat0r 8y ago
        I think I remember trying that a while back and couldn't quite get it working, I'll need to try again soon.
    - pknopf 8y ago
      If you want immutability with a traditional package manager, try Darch: https://godarch.com https://godarch.com
  - bjoli 8y ago
    I agree, but having an option instead of having to do ExecStop=path-to-shell-script-that-does-some-stupid-housekeeping is pretty neat. Most shepherd service definitions are simple and stupid, but as always it is a matter of taste.
    - nerdponx 8y ago
      But the shell scripts are more or less portable across systems, whereas this way you were asking developers to re-implement the same cleanup logic in another language.
    - stephenr 8y ago
      > but having an option instead of having to do ExecStop=path-to-shell-script-that-does-some-stupid-housekeeping is pretty neat. IMO this is usually the result of eg a Debian package that also ships sysvinit startup scripts, and thus they share some logic. If it’s not that case I wonder why the cleanup can’t just be handled in the unit directly.
      - Skunkleton 8y ago
        Perhaps the service being managed doesn't clean up after itself properly? It is a fairly common pattern for a program to ship without startup scripts, and then have startup scripts added by package maintainers.
        stephenr 8y ago
        Right that’s certainly a thing but what I meant is, why not just put the cleanup instructions in the unit file.
        Skunkleton 8y ago
        Because "cleanup" can be non-trivial. Maintaining scripts inside unit files is a pain in the ass.
- stephenr 8y ago
  As someone typically working with others startup units but sometimes writing my own, I appreciate a declarative format that allows user-overrides and has pretty standardised ways of doing things. Sysvinit scripts showed us what happens when you give startup authors more power. Even if you hate systemd’s politics/etc the actual units themselves are objectively better IMO because they’re declarative.
  - bjoli 8y ago
    Well, the service difinition part of shepherd is pretty declarative: (make <service> #:provides '(blahblah) #:start (...) #:stop (...))) The difference is that start/stop must be guile procedures that starts or stops a command. I suspect there is a nice macro for just running a regular shell command, but I'm not sure.
    - stephenr 8y ago
      It’s guile. They’re instances of the <service> class (apparently). That is specifically not declarative and the fact that the only example in the official documentation is essentially the same as your example, says this project is not ready for use by humans. If you (the project) cant show a full example service definition to start something why would anyone bother going forward.
  - _emacsomancer_ 8y ago
    > Even if you hate systemd’s politics/etc the actual units themselves are objectively better IMO because they’re declarative. It's a pity the overall system is so inflexible and brittle. Well, that and the 'death by a thousand (theoretically independent but tightly coupled) systemd components'.
    - stephenr 8y ago
      It has it's issues, definitely, and I'm not thrilled about "make everything part of the systemd project" - but in terms of providing a way to run your services, I think it's got a lot of functionality that e.g. sysvinit could never really support.
nerdponx 8y ago
https://www.gnu.org/software/shepherd/ https://www.gnu.org/software/shepherd/ It replaces the init & service management features of systemd.
nextos 8y ago
Yes, it is an alternative init system. So it can replace systemd. It is in fact used as such in GuixSD, the NixOS alternative by GNU which is written in Guile Scheme.
- privateSFacct 8y ago
  Yowks - I know systemd gets lots of hate and this is “real” programming - but it does feel a bit niche from a language etc perspective?
  - nextos 8y ago
    I don't think Guile is too niche. In fact, Guix has a quite active community. Nowhere as Nix in terms of activity, but it's pretty nice and very friendly too.
    - dwohnitmok 8y ago
      I don't know about Guile's popularity, but I use NixOS as my daily driver distro and in my experience Nix is already very niche in the programming circles I run in. That's not to say Guix shouldn't be developed or that Shepherd is bad, it's just that I would definitely call Guix niche.
laumars 8y ago
> what makes it different? It's GNU, others aren't. There will be other well reasoned arguments in favour of Shepherd but it essentially boils down to the same reason Hurd (the kernel) is a thing when GNU/Linux is already widespread. That all said, I don't see the harm in competing solutions. Better to have a choice rather than lock ins.
- aries1980 8y ago
  Systemd is licenced under LGPL, why would it lock you in?
  - laumars 8y ago
    Sorry, that was a poor choice of words on my part. What I really meant was "better to have more options rather than fewer".
  - yarrel 8y ago
    It's locking people in by eating the OS and making it difficult to move away from its tightly coupled and increasingly tightly integrated components (that, we must never forget, are not a single binary).
  - yjftsjthsd-h 8y ago
    It only supports Linux, for one. Shepherd supports HURD and probably other systems.
deleted 8y ago
[deleted]
bitwize 8y ago
Shepherd (as dmd) predates the systemd project considerably. It is intended to fill the same niche (init system, process monitor) as systemd, though.

afranchuk 8y ago

Does anyone have experience with both Shepherd and runit[1]? And if so, can you provide a comparison of the two? [1]: http://smarden.org/runit/ http://smarden.org/runit/

_emacsomancer_ 8y ago
I use both. However, I'm mainly interacting as a 'regular user', but as such a user, both are pleasant to interact with, and don't try to be too clever or overly complex, and thus I don't encounter the same sorts of issues with them that I do with other init/daemon-managers.

nerdponx 8y ago

I'd like to know how this compares to Systemd's actual service management features (systemctl, journalctl, etc). I love how declarative Systemd is. There's an example in the docs which gives a good idea (https://www.gnu.org/software/shepherd/manual/shepherd.html#Service-Examples https://www.gnu.org/software/shepherd/manual/shepherd.html#S...), but it helps to hear the experiences of people who use it in practice.

gigatexal 8y ago

As a side note the GNU SD distro looks cool. I like the declarative way of doing things and it really seems to be following the infrastructure as code idea.

sevensor 8y ago

It makes me happy to see the GNU OS still being assembled, bit by bit. I've written previously about how much I appreciate the Guile info manual. For a document in a relatively obscure help system (other than Emacs users, who even knows about Texinfo?), it's carefully written with an eye to empowering its users. It's perhaps a bit quixotic, but you get the feeling that the GNU project really wants to deliver an OS written in Scheme all the way down, totally under the control of an enlightened end user. The Shepherd project certainly fits with that vision.

enriquto 8y ago
I love dearly the GNU project and the beautiful, nicely worded documentation which is always a pleasure to read (when rendered as pdf documents). However, the info format is unfathomable; if it is possible to really hate one file format, it must be this one.
- sevensor 8y ago
  I hesitate to speak for emacs users, because I'm not one really, but I suspect the info format feels really comfortable when viewed with emacs.
  - jefft255 8y ago
    It’s nice indeed. Not special, but certainly smooth to use. Never used it outside of emacs though.
  - opan 8y ago
    I started using info more after installing the Guix system. One thing that made me use emacs over info was that with evil-mode you could use vim bindings to read info pages through emacs. It was a bit more like 'less' then.
- badsectoracula 8y ago
  Note that Texinfo != info, the former is a document source format similar to DocBook (but much simpler), the latter is a very simple hypertext format with preformatted text and support for indices (think of it as a text-based CHM). You can use the former to generate the latter, but Texinfo can be used to generate several other types of documents, including plain text, PDF and HTML (and yes, also CHM). Also note that the info file format is independent from the GNU info viewer, that most people associate with, and there are other viewers for it, including pinfo and tkinfo (Tcl/Tk viewer) and some other help systems have support for it, like GNOME's and KDE's help viewers. And yes, there is also support for it on Emacs (which AFAIK is the only viewer with image support). FWIW personally i like using tkinfo.