hello-world

Hello world example

This simple example shows how to use wrangler with a flake.

It assumes:

• that flakes are enabled in your system - see here for more info on this.
• that you have direnv installed and set up.

To date, this has only been tested on x86_64-linux NixOS systems; we would be happy to have input from users on other systems.

To run it, simply open a shell in this directory; if direnv is active, it should ask you to enable direnv for this directory. You should see something like the following (depending on what shell you use etc):

🕙 13:03:30 ❯ cd examples/hello-world/
direnv: error /home/sean/Work/wrangler/examples/hello-world/.envrc is blocked. Run `direnv allow` to approve its content

Run direnv allow:

🕙 13:04:02 ❯ direnv allow
direnv: loading ~/Work/wrangler/examples/hello-world/.envrc
direnv: using flake
direnv: nix-direnv: Using cached dev shell
direnv: export +AR +AS +CC +CONFIG_SHELL +CXX +HOST_PATH +IN_NIX_SHELL +LD +NIX_BINTOOLS +NIX_BINTOOLS_WRAPPER_TARGET_HOST_x86_64_unknown_linux_gnu +NIX_BUILD_CORES +NIX_CC +NIX_CC_WRAPPER_TARGET_HOST_x86_64_unknown_linux_gnu +NIX_CFLAGS_COMPILE +NIX_ENFORCE_NO_NATIVE +NIX_HARDENING_ENABLE +NIX_LDFLAGS +NIX_STORE +NM +OBJCOPY +OBJDUMP +RANLIB +READELF +SIZE +SOURCE_DATE_EPOCH +STRINGS +STRIP +__structuredAttrs +buildInputs +buildPhase +builder +cmakeFlags +configureFlags +depsBuildBuild +depsBuildBuildPropagated +depsBuildTarget +depsBuildTargetPropagated +depsHostHost +depsHostHostPropagated +depsTargetTarget +depsTargetTargetPropagated +doCheck +doInstallCheck +dontAddDisableDepTrack +mesonFlags +name +nativeBuildInputs +out +outputs +patches +phases +preferLocalBuild +propagatedBuildInputs +propagatedNativeBuildInputs +shell +shellHook +stdenv +strictDeps +system ~PATH ~XDG_DATA_DIRS

This should run flake.nix to create a development shell which contains the latest version of wrangler; this will create a flake.lock file in the current directory which you can commit if you like - if you commit this, then you are pinning the wrangler version until you perform nix flake update. You can use wrangler directly from the command line as follows:

🕙 13:05:19 ✖  wrangler --version

 ⛅️ wrangler 3.67.1
-------------------

To run the hello-world application locally:

🕙 13:05:22 ❯ wrangler dev

 ⛅️ wrangler 3.67.1
-------------------

[wrangler:inf] Ready on http://localhost:8989
⎔ Starting local server...
╭─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ [b] open a browser, [d] open Devtools, [l] turn off local mode, [c] clear console, [x] to exit                                                              │
╰─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯

Point your browser at http://localhost:8989 to see the simple web page served by the worker running locally.

Updating to a newer version of wrangler

If you use the github url for wrangler, you should simply be able to run nix flake update: this will check if there have been any updates to this github repo and update flake.lock and wrangler accordingly.

If you're using the flakehub link for wrangler, you will need to update the link in the flake.nix file to use the latest version.

Adding this to an existing project

To add this functionality to an existing project which uses wrangler, simply copy the .envrc and flake.nix files and amend as necessary. You will probably have to add some extra files and directories to your .gitignore if you enable this for the first time within the project.