pixelfed: add update script

(cherry picked from commit b8c2f83395)

pkgs/servers/web-apps/pixelfed/default.nix

@@ -38,7 +38,10 @@ in package.override rec {
     hash = "sha256-ZrvYKMSx5WymWR46/UKr5jCsclXXzBeY21ju22zeqN0=";
   };
 
-  passthru.tests = { inherit (nixosTests) pixelfed; };
+  passthru = {
+    tests = { inherit (nixosTests) pixelfed; };
+    updateScript = ./update.sh;
+  };
 
   meta = with lib; {
     description = "A federated image sharing platform";

pkgs/servers/web-apps/pixelfed/update.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env nix-shell
+#! nix-shell -I nixpkgs=../../../.. -i bash -p nix curl jq nix-update
+
+# check if composer2nix is installed
+if ! command -v composer2nix &> /dev/null; then
+  echo "Please install composer2nix (https://github.com/svanderburg/composer2nix) to run this script."
+  exit 1
+fi
+
+CURRENT_VERSION=$(nix eval -f ../../../.. --raw pixelfed.version)
+TARGET_VERSION_REMOTE=$(curl ${GITHUB_TOKEN:+" -u \":$GITHUB_TOKEN\""} https://api.github.com/repos/pixelfed/pixelfed/releases/latest | jq -r ".tag_name")
+TARGET_VERSION=${TARGET_VERSION_REMOTE:1}
+PIXELFED=https://github.com/pixelfed/pixelfed/raw/$TARGET_VERSION_REMOTE
+SHA256=$(nix-prefetch-url --unpack "https://github.com/pixelfed/pixelfed/archive/v$TARGET_VERSION/pixelfed.tar.gz")
+
+if [[ "$CURRENT_VERSION" == "$TARGET_VERSION" ]]; then
+  echo "pixelfed is up-to-date: ${CURRENT_VERSION}"
+  exit 0
+fi
+
+curl -LO "$PIXELFED/composer.json"
+curl -LO "$PIXELFED/composer.lock"
+
+composer2nix --name "pixelfed" \
+  --composition=composition.nix \
+  --no-dev
+rm composer.json composer.lock
+
+# change version number
+sed -e "s/version =.*;/version = \"$TARGET_VERSION\";/g" \
+    -e "s/sha256 =.*;/sha256 = \"$SHA256\";/g" \
+    -i ./default.nix
+
+cd ../../../..
+nix-build -A pixelfed