# gorun: run go code straight from web via go run

i don't have moral problems with "curl https://example.com/sometool-install | bash". my biggest problem with it is that one should not program shell scripts in the 21st century. these shell scripts are not standardized: each script installs random crap into different places. and after i stop using the tool, the out of date trash remains around.

fortunately go has a much nicer alternative: "go run example.com/sometool@latest". or if the example.com isn't a git repo then: "go run github.com/example/sometool@latest". this will download, compile, and run the latest version of the tool. subsequent runs will use the cached binary. go needs to be installed on the user's machine but it's not a huge package, i think that's acceptable.

because it will compile everything on the user's machine, the tool needs to be compact: avoid huge code and sprawling dependencies. it's surprisingly easy to get lot of things done in go with the standard packages only. embrace that, some small duplication here and there doesn't hurt.

one downside of using the @latest tag is that it would trigger lots of redownload and recompilation as the tool gets developed. avoid this issue via using a dev branch for development. merge the dev changes into the main branch only on a weekly basis. but if the tip is broken then the user can always specify a specific version: "go run github.com/example/sometool@v1.23.45".

a special "prev" branch could be maintained for the previous release too which lags behind the main branch with a week. then users can run a simple "go run github.com/example/sometool@prev" to run the previous stable version if the latest one is broken. it might take a few hours until go caches pick up any changes in branches though. therefore update the prev branch a day before updating the stable branch to ensure the user can go back as soon as the @latest tag gets updated. (there's a trick to invalidate @latest cache by force requesting a new version but i haven't found such a trick for @branch references.)

the user can also perma-install with "go install github.com...". this one puts the binary into the default $GOBIN directory. user can run the tool without "go run" if that path is in $PATH. startup will be a bit faster but the tool won't auto-update.

users can set up aliases too:

  alias sometool="go run example.com/sometool@latest"

i prefer shell wrappers to aliases because then i can use them from other tools such as vim:

  $ cat .bin/sometool
  #!/bin/sh
  go run github.com/example/sometool@latest

that's all i need to put into my dotfiles repo, i don't need to litter it with complex makefiles and install scripts. and works out of box on both archlinux and debian and is always up to date.

there are a couple tools i now use like this:

• https://pkg.go.dev/github.com/ypsu/pkgtrim: for intentional linux package management on my personal machines.
• https://pkg.go.dev/github.com/ypsu/textar/bin/textar: for creating human readable archive of files.

later i plan to use this method for setting up new personal machines with a single command. another usecase i have is to run a static set of pre/post commit checks in my git repos without needing to deal with writing complex shell scripts.

example:

  $ go run github.com/ypsu/textar/bin/textar@latest -help
  Manipulate .textar files.

  Create a textar file:  textar -c=archive.textar file1 file2 file3
  Extract a textar file: textar -x=archive.textar
  [...]

or in case you want to try it with a more official tool:

  $ go run golang.org/x/exp/cmd/txtar@latest --help
  Usage of /tmp/go-build1914875111/b001/exe/txtar:
    -extract
          if true, extract files from the archive instead of writing to it
    -list
          if true, list files from the archive instead of writing to it
    -unsafe
          allow extraction of files outside the current directory
    -x    short alias for --extract

very convenient. i wish companies would stop the curl|sh approach in favor of this. this has much better properties.

published on 2024-11-25

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