1 files changed, 63 insertions, 0 deletions
diff --git a/modules/apps/docker/default.nix b/modules/apps/docker/default.nix
new file mode 100644
index 0000000..7698959
--- /dev/null
+++ b/modules/apps/docker/default.nix
@@ -0,0 +1,63 @@
+{ config, pkgs, lib, ... }:
+
+let
+
+  inherit (builtins) toJSON;
+
+  inherit (lib)
+    filterAttrs foldl mapAttrsToList mkOption optional
+    ;
+
+  inherit (lib.types) attrsOf submodule;
+
+  explicit = filterAttrs (n: v: n != "_module" && v != null);
+
+  instances = explicit config.nixsap.apps.docker;
+
+  groups = mapAttrsToList (_: i: i.daemon.group) instances;
+  clis = mapAttrsToList (_: i: i.docker-cli) instances;
+
+  mkService = name: opts:
+    let
+      config-file = pkgs.runCommand "dockerd-${name}.json" {} ''
+        cat <<'EOF' | ${pkgs.jq}/bin/jq . > $out
+        ${toJSON (explicit (opts.daemon))}
+        EOF
+      '';
+    in {
+      "docker-${name}" = {
+        description = "Docker daemon (${name})";
+        wantedBy = [ "multi-user.target" ];
+        after = [ "local-fs.target" ];
+        path = [ pkgs.kmod ] ++ (optional (opts.daemon.storage-driver == "zfs") pkgs.zfs);
+        preStart = ''
+          mkdir -p -- '${opts.daemon.data-root}'
+          rm -rf --  '${opts.daemon.exec-root}'
+          mkdir -p --  '${opts.daemon.exec-root}'
+
+          chown -c -- 'root:root' '${opts.daemon.data-root}'
+          chmod -c -- u=rwX,g=rX,o= '${opts.daemon.data-root}'
+        '';
+        serviceConfig = {
+          ExecStart = "${opts.package}/bin/dockerd --config-file ${config-file}";
+          ExecReload = "${pkgs.procps}/bin/kill -s HUP $MAINPID";
+        };
+      };
+    };
+
+in {
+
+  options.nixsap.apps.docker = mkOption {
+    description = "Instances of Docker";
+    type = attrsOf (submodule (import ./instance.nix pkgs));
+    default = {};
+  };
+
+  config = {
+    systemd.services = foldl (a: b: a//b) {} (mapAttrsToList mkService instances);
+    nixsap.system.groups = groups;
+    environment.systemPackages = clis;
+  };
+
+}
+