Merge pull request 'feat(ci): shell-customization' (#32) from lbailly/liminix:shell-customization into main

Reviewed-on: DGNum/liminix#32

.forgejo/workflows/build.yaml

@@ -38,3 +38,13 @@ jobs:
         run: |
           # Enter the shell
           nix-build ci.nix -A wlan
+
+  test_shell_customization:
+    runs-on: nix
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Build VM QEMU MIPS
+        run: |
+          # Enter the shell
+          nix-build ci.nix -A custom-shell

modules/base.nix

@@ -4,11 +4,13 @@
 
 { lib, pkgs, config, ...}:
 let
-  inherit (lib) mkEnableOption mkOption types isDerivation hasAttr ;
+  inherit (lib) mkEnableOption mkOption types isDerivation hasAttr concatStringsSep mapAttrsToList;
   inherit (pkgs.pseudofile) dir symlink;
   inherit (pkgs.liminix.networking) address interface;
   inherit (pkgs.liminix.services) bundle;
 
+  # TODO: escape shell argument.
+  exportVar = name: value: "export ${name}=\"${value}\"";
   type_service = pkgs.liminix.lib.types.service;
 
 in {
@@ -22,6 +24,24 @@ in {
           /run/current-system, we just add the paths in /etc/profile
         '';
       };
+
+      environmentVariables = mkOption {
+        type = types.attrsOf types.str;
+        description = ''
+          Attribute set of environment variables to make available
+          in a login shell.
+
+          The value is assumed to be escaped and the name to be valid.
+        '';
+      };
+
+      prompt = mkOption {
+        type = types.str;
+        default = "$(whoami)@$(hostname) # ";
+        description = ''
+          Prompt string (PS1) for the shell.
+        '';
+      };
     };
     services = mkOption {
       type = types.attrsOf type_service;
@@ -111,6 +131,8 @@ in {
 
     defaultProfile.packages = with pkgs;
       [ s6 s6-init-bin execline s6-linux-init s6-rc ];
+    # Set the useful PS1 prompt by default.
+    defaultProfile.environmentVariables.PS1 = lib.mkDefault config.defaultProfile.prompt;
 
     boot.commandLine = [
       "panic=10 oops=panic init=/bin/init loglevel=8"
@@ -183,6 +205,7 @@ in {
           (pkgs.writeScript ".profile" ''
             PATH=${lib.makeBinPath config.defaultProfile.packages}:/bin
             export PATH
+            ${concatStringsSep "\n" (mapAttrsToList exportVar config.defaultProfile.environmentVariables)}
           '');
       in dir {
         inherit profile;

modules/hostname.nix

@@ -1,7 +1,6 @@
 { lib, pkgs, config, ...}:
 let
   inherit (lib) mkOption types;
-  inherit (pkgs.liminix.services) oneshot;
 in {
   options = {
     hostname = mkOption {
@@ -12,12 +11,21 @@ in {
       default = "liminix";
       type = types.nonEmptyStr;
     };
-  };
-  config = {
-    services.hostname = oneshot {
-      name = "hostname-${builtins.substring 0 12 (builtins.hashString "sha256" config.hostname)}";
-      up = "echo ${config.hostname} > /proc/sys/kernel/hostname";
-      down = "true";
+    hostname-script = mkOption {
+      description = ''
+        Script that outputs the system hostname on stdin.
+      '';
+      default = pkgs.writeScript "hostname-gen" ''
+        #!/bin/sh
+        echo ${config.hostname}
+      '';
+      defaultText = ''
+        pkgs.writeScript "hostname-gen" '''
+        #!/bin/sh
+        echo ''${config.hostname}
+      '''
+      '';
+      type = types.package;
     };
   };
 }

modules/s6/default.nix

@@ -30,6 +30,8 @@ let
     installPhase = ''
       mkdir $out
       cp -r $src $out/scripts
+      substituteInPlace $out/scripts/rc.init \
+        --replace-fail 'config.hostname' "${config.hostname-script}"
       chmod -R +w $out
     '';
   };

modules/s6/scripts/rc.init

@@ -36,6 +36,7 @@ fi
 ### (replace /run/service with your scandir)
 s6-rc-init -d -c /etc/s6-rc/compiled /run/service
 
+config.hostname > /proc/sys/kernel/hostname
 
 ### 2. Starting the wanted set of services
 ### This is also called every time you change runlevels with telinit.

tests/ci.nix

@@ -10,4 +10,5 @@
   tftpboot = import ./tftpboot/test.nix;
   updown = import ./updown/test.nix;
   inout = import ./inout/test.nix;
+  custom-shell = import ./custom-shell/test.nix;
 }

tests/custom-shell/check-prompt.expect

@@ -0,0 +1,7 @@
+set timeout 60
+
+spawn socat unix-connect:vm/console -
+expect {
+  "root@liminix blah blah > " { exit 0 }
+  timeout { exit 1 }
+}

tests/custom-shell/configuration.nix

@@ -0,0 +1,13 @@
+{ config, pkgs, lib, ... } :
+let
+  inherit (pkgs.liminix.networking) interface address hostapd route dnsmasq;
+  inherit (pkgs.liminix.services) oneshot longrun bundle target;
+in rec {
+  imports = [
+    ../../modules/network
+  ];
+
+  defaultProfile.prompt = "$(whoami)@$(hostname) blah blah > ";
+
+  defaultProfile.packages = with pkgs; [ ];
+}

tests/custom-shell/test.nix

@@ -0,0 +1,21 @@
+{
+  liminix
+, nixpkgs
+}:
+let img = (import liminix {
+      inherit nixpkgs;
+      device = import "${liminix}/devices/qemu/";
+      liminix-config = ./configuration.nix;
+    }).outputs.default;
+    pkgs = import nixpkgs { overlays = [(import ../../overlay.nix)]; };
+in pkgs.runCommand "check" {
+  nativeBuildInputs = with pkgs; [
+    expect socat
+  ] ;
+} ''
+. ${../test-helpers.sh}
+
+mkdir vm
+${img}/run.sh --background ./vm
+expect ${./check-prompt.expect} |tee output && mv output $out
+''