podman: add module

Adds a new Podman module for creating user containers and networks as
systemd services. These are installed to the user's
`$XDG_CONFIG/systemd/user` directory.

modules/lib/maintainers.nix

@@ -43,6 +43,12 @@
     github = "Avimitin";
     githubId = 30021675;
   };
+  bamhm182 = {
+    name = "bamhm182";
+    email = "bamhm182@gmail.com";
+    github = "bamhm182";
+    githubId = 920269;
+  };
   blmhemu = {
     name = "blmhemu";
     email = "19410501+blmhemu@users.noreply.github.com";
@@ -288,6 +294,16 @@
     github = "NitroSniper";
     githubId = 44097331;
   };
+  n-hass = {
+    name = "Nicholas Hassan";
+    email = "nick@hassan.host";
+    github = "n-hass";
+    githubId = 72363381;
+    keys = [{
+      longkeyid = "rsa4096/0xFC95AB946A781EE7";
+      fingerprint = "FDEE 6116 DBA7 8840 7323  4466 A371 5973 2728 A6A6";
+    }];
+  };
   seylerius = {
     email = "sable@seyleri.us";
     name = "Sable Seyler";

modules/misc/news.nix

@@ -1813,6 +1813,20 @@ in {
           systems" section in the Home Manager mantual for more.
         '';
       }
+
+      {
+        time = "2024-11-01T19:44:59+00:00";
+        condition = hostPlatform.isLinux;
+        message = ''
+          A new module is available: 'services.podman'.
+
+          Podman is a daemonless container engine that lets you manage
+          containers, pods, and images.
+
+          This Home Manager module allows you to define containers that will run
+          as systemd services.
+        '';
+      }
     ];
   };
 }

modules/modules.nix

@@ -352,6 +352,7 @@ let
     ./services/plan9port.nix
     ./services/playerctld.nix
     ./services/plex-mpv-shim.nix
+    ./services/podman-linux
     ./services/polybar.nix
     ./services/poweralertd.nix
     ./services/psd.nix

modules/services/podman-linux/activation.nix

@@ -0,0 +1,99 @@
+{ config, podman-lib, ... }:
+
+{
+  cleanup = ''
+    PATH=$PATH:${podman-lib.newuidmapPaths}
+    export VERBOSE=true
+
+    DRYRUN_ENABLED() {
+      return $([ -n "''${DRY_RUN:-}" ] && echo 0 || echo 1)
+    }
+
+    VERBOSE_ENABLED() {
+      return $([ -n "''${VERBOSE:-}" ] && echo 0 || echo 1)
+    }
+
+    cleanup() {
+      local resourceType=$1
+      local manifestFile="${config.xdg.configHome}/podman/$2"
+      local extraListCommands="''${3:-}"
+      [[ $resourceType = "container" ]] && extraListCommands+=" -a"
+
+      [ ! -f "$manifestFile" ] && VERBOSE_ENABLED && echo "Manifest does not exist: $manifestFile" && return 0
+
+      VERBOSE_ENABLED && echo "Cleaning up ''${resourceType}s not in manifest..." || true
+
+      loadManifest "$manifestFile"
+
+      formatString="{{.Name}}"
+      [[ $resourceType = "container" ]] && formatString="{{.Names}}"
+
+      local listOutput=$(${config.services.podman.package}/bin/podman $resourceType ls $extraListCommands --filter 'label=nix.home-manager.managed=true' --format "$formatString")
+
+      IFS=$'\n' read -r -d "" -a podmanResources <<< "$listOutput" || true
+
+      if [ ''${#podmanResources[@]} -eq 0 ]; then
+        VERBOSE_ENABLED && echo "No ''${resourceType}s available to process." || true
+      else
+        for resource in "''${podmanResources[@]}"; do
+            if ! isResourceInManifest "$resource"; then
+              removeResource "$resourceType" "$resource"
+            else
+              VERBOSE_ENABLED && echo "Keeping managed $resourceType: $resource" || true
+            fi
+          done
+      fi
+    }
+
+    isResourceInManifest() {
+      local resource="$1"
+      for manifestEntry in "''${resourceManifest[@]}"; do
+        if [ "$resource" = "$manifestEntry" ]; then
+          return 0  # Resource found in manifest
+        fi
+      done
+      return 1  # Resource not found in manifest
+    }
+
+    # Function to fill resourceManifest from the manifest file
+    loadManifest() {
+      local manifestFile="$1"
+      VERBOSE_ENABLED && echo "Loading manifest from $manifestFile..." || true
+      IFS=$'\n' read -r -d "" -a resourceManifest <<< "$(cat "$manifestFile")" || true
+    }
+
+    removeResource() {
+      local resourceType="$1"
+      local resource="$2"
+      echo "Removing orphaned $resourceType: $resource"
+      commands=()
+      case "$resourceType" in
+        "container")
+          commands+="${config.services.podman.package}/bin/podman $resourceType stop $resource"
+          commands+="${config.services.podman.package}/bin/podman $resourceType rm -f $resource"
+          ;;
+        "network")
+          commands+="${config.services.podman.package}/bin/podman $resourceType rm $resource"
+          ;;
+      esac
+      for command in "''${commands[@]}"; do
+        command=$(echo $command | tr -d ';&|`')
+        DRYRUN_ENABLED && echo "Would run: $command" && continue || true
+        VERBOSE_ENABLED && echo "Running: $command" || true
+        if [[ "$(eval "$command")" != "$resource" ]]; then
+          echo -e "\tCommand failed: ''${command}"
+          usedByContainers=$(${config.services.podman.package}/bin/podman container ls -a --filter "$resourceType=$resource" --format "{{.Names}}")
+          echo -e "\t$resource in use by containers: $usedByContainers"
+        fi
+      done
+    }
+
+    resourceManifest=()
+    [[ "$@" == *"--verbose"* ]] && VERBOSE="true"
+    [[ "$@" == *"--dry-run"* ]] && DRY_RUN="true"
+
+    for type in "container" "network"; do
+      cleanup "$type" "''${type}s.manifest"
+    done
+  '';
+}