From c2438526018277af027ffc42993c72e0a057f2ce Mon Sep 17 00:00:00 2001
From: pazpi <pasettodavide@gmail.com>
Date: Sun, 25 Aug 2024 15:44:51 +0200
Subject: [PATCH] WIP: New module for handling podman pod

Handles basic container, needs to be expanded to all options
---
 modules/virtualisation/podman-pod.nix | 170 ++++++++++++++++++++++++++
 1 file changed, 170 insertions(+)
 create mode 100644 modules/virtualisation/podman-pod.nix

diff --git a/modules/virtualisation/podman-pod.nix b/modules/virtualisation/podman-pod.nix
new file mode 100644
index 0000000..814a7d7
--- /dev/null
+++ b/modules/virtualisation/podman-pod.nix
@@ -0,0 +1,170 @@
+# Save this as podman-pod.nix
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.podmanPods;
+
+  podOptions = { name, config, ... }: {
+    options = {
+      name = mkOption {
+        type = types.str;
+        description = "Name of the pod";
+      };
+      ports = mkOption {
+        type = types.listOf types.str;
+        default = [ ];
+        description = "List of port mappings (e.g. ['8080:80'])";
+      };
+      containers = mkOption {
+        type = types.attrsOf (types.submodule {
+          options = {
+            image = mkOption {
+              type = types.str;
+              description = "Docker image for the container";
+            };
+            extraOptions = mkOption {
+              type = types.listOf types.str;
+              default = [ ];
+              description = "Additional options for the container";
+            };
+          };
+        });
+        default = { };
+        description = "Containers to run in the pod";
+      };
+    };
+  };
+
+  createPodScript = name: podDef:
+    let
+      podDefinitionString = builtins.toJSON { inherit (podDef) ports; };
+    in
+    pkgs.writeScript "manage-pod-${name}.sh" ''
+      #!/usr/bin/env nix-shell
+      #!nix-shell -i bash -p htop curl
+
+      set -e
+
+      POD_NAME="${name}"
+      POD_DEFINITION='${podDefinitionString}'
+
+      create_pod() {
+        podman pod create --name "$POD_NAME" \
+          ${concatStringsSep " " (map (port: "--publish ${port}") podDef.ports)}
+      }
+
+      if podman pod exists "$POD_NAME"; then
+        CURRENT_CONFIG=$(podman pod inspect "$POD_NAME" | jq -c '.[0] | {ports: [.PortMappings[].HostPort | tostring + ":" + (.ContainerPort | tostring)]}')
+        if [ "$CURRENT_CONFIG" != "$POD_DEFINITION" ]; then
+          echo "Pod configuration has changed. Recreating pod..."
+          podman pod rm -f "$POD_NAME"
+          create_pod
+        else
+          echo "Pod configuration unchanged."
+        fi
+      else
+        echo "Pod does not exist. Creating..."
+        create_pod
+      fi
+    '';
+in
+{
+  options.services.podmanPods = mkOption {
+    type = types.attrsOf (types.submodule podOptions);
+    default = { };
+    description = "Podman pods to create";
+  };
+
+  config = mkIf (cfg != { }) {
+    virtualisation.podman.enable = true;
+    virtualisation.oci-containers.backend = "podman";
+
+    environment.systemPackages = [ pkgs.jq ];
+
+    systemd.services = mapAttrs'
+      (name: podDef:
+        nameValuePair "podman-pod-${name}" {
+          description = "Manage Podman pod: ${name}";
+          serviceConfig = {
+            Type = "oneshot";
+            ExecStart = "${createPodScript name podDef}";
+          };
+          path = [ pkgs.podman ];
+          wantedBy = [ "multi-user.target" ];
+        }
+      )
+      cfg //
+    mapAttrs'
+      (podName: podDef:
+        nameValuePair "podman-pod-${podName}" {
+          after = [ "network.target" ];
+          wantedBy = [ "multi-user.target" ];
+        }
+      )
+      cfg //
+    mapAttrs'
+      (podName: podDef:
+        nameValuePair "podman-${podName}" {
+          after = [ "podman-pod-${podName}.service" ];
+          requires = [ "podman-pod-${podName}.service" ];
+          partOf = [ "podman-pod-${podName}.service" ];
+        }
+      )
+      (flattenAttrs (mapAttrsToList
+        (podName: podDef:
+          mapAttrs'
+            (containerName: containerDef:
+              nameValuePair "${podName}-${containerName}" containerDef
+            )
+            podDef.containers
+        )
+        cfg));
+
+    virtualisation.oci-containers.containers = flatten (mapAttrsToList
+      (podName: podDef:
+        mapAttrsToList
+          (containerName: containerDef:
+            nameValuePair "${podName}-${containerName}" ({
+              inherit (containerDef) image;
+              extraOptions = [ "--pod=${podName}" ] ++ containerDef.extraOptions;
+            })
+          )
+          podDef.containers
+      )
+      cfg);
+
+    networking.firewall.allowedTCPPorts = flatten (mapAttrsToList
+      (name: podDef:
+        map (portMapping: lib.toInt (lib.head (lib.splitString ":" portMapping))) podDef.ports
+      )
+      cfg);
+
+    # systemd.services = mapAttrs'
+    #   (podName: podDef:
+    #     nameValuePair "podman-pod-${podName}" {
+    #       after = [ "network.target" ];
+    #       wantedBy = [ "multi-user.target" ];
+    #     }
+    #   )
+    #   cfg //
+    # mapAttrs'
+    #   (podName: podDef:
+    #     nameValuePair "podman-${podName}" {
+    #       after = [ "podman-pod-${podName}.service" ];
+    #       requires = [ "podman-pod-${podName}.service" ];
+    #       partOf = [ "podman-pod-${podName}.service" ];
+    #     }
+    #   )
+    #   (flattenAttrs (mapAttrsToList
+    #     (podName: podDef:
+    #       mapAttrs'
+    #         (containerName: containerDef:
+    #           nameValuePair "${podName}-${containerName}" containerDef
+    #         )
+    #         podDef.containers
+    #     )
+    #     cfg));
+  };
+}