Add libs

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

lib/default.nix

@@ -0,0 +1,5 @@
+{ pkgs, ... }:
+{
+  fetchers = import ./fetchers { inherit pkgs; };
+  runtime = import ./runtime { inherit pkgs; };
+}

lib/fetchers/default.nix

@@ -0,0 +1,4 @@
+{ pkgs, ... }:
+{
+  sshKnownHosts = import ./sshKnownHosts { inherit pkgs; };
+}

lib/fetchers/sshKnownHosts/default.nix

@@ -0,0 +1,33 @@
+{ pkgs, ... }:
+pkgs.lib.fetchers.withNormalizedHash { } (
+  {
+    host,
+    name ? "ssh-known-hosts-${host}",
+    outputHash,
+    outputHashAlgo,
+    port ? 22,
+    keyTypes ? [
+      "rsa"
+      "ecdsa"
+      "ed25519"
+    ],
+  }:
+  let
+    keyTypeArgs = pkgs.lib.concatStringsSep "," keyTypes;
+  in
+  pkgs.runCommandLocal name
+    {
+      inherit outputHash outputHashAlgo;
+      outputHashMode = "flat";
+      preferLocalBuild = true;
+
+      nativeBuildInputs = with pkgs; [
+        openssh
+        gnugrep
+        coreutils
+      ];
+    }
+    ''
+      ssh-keyscan -p ${toString port} -t ${keyTypeArgs} ${host} | grep -v '^#' | sort > $out
+    ''
+)

lib/runtime/default.nix

@@ -0,0 +1,4 @@
+{ pkgs, ... }:
+{
+  merge = import ./merge { inherit pkgs; };
+}

lib/runtime/merge/default.nix

@@ -0,0 +1,4 @@
+{ pkgs, ... }:
+{
+  keyValue = import ./keyValue { inherit pkgs; };
+}

lib/runtime/merge/keyValue/default.nix

@@ -0,0 +1,11 @@
+{ pkgs, ... }:
+"${
+  pkgs.writeShellApplication {
+    name = "merge-key-value";
+    runtimeInputs = with pkgs; [
+      coreutils
+      gawk
+    ];
+    text = builtins.readFile ./key-value.sh;
+  }
+}/bin/merge-key-value"

lib/runtime/merge/keyValue/key-value.sh

@@ -0,0 +1,15 @@
+# shellcheck shell=bash
+
+source=$(realpath -m "$1")
+target=$(realpath -m "$2")
+
+if [[ -f "$target" ]]; then
+  temp=$(mktemp)
+  awk -F '=' 'NR==FNR{a[$1]=$0;next}($1 in a){$0=a[$1]}1' "$source" "$target" > "$temp"
+  mv "$temp" "$target"
+else
+  mkdir -p "$(dirname "$target")"
+  cp "$source" "$target"
+fi
+
+echo "Configuration file $target has been updated."