More scaffolding

Signed-off-by: Ana Hobden <operator@hoverbear.org>

src/actions/base/configure_nix_daemon_service.rs

@@ -1,6 +1,6 @@
 use crate::HarmonicError;
 
-use super::{ActionDescription, ActionReceipt, Actionable, Revertable};
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, Revertable};
 
 #[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
 pub struct ConfigureNixDaemonService {}
@@ -13,6 +13,7 @@ impl ConfigureNixDaemonService {
 
 #[async_trait::async_trait]
 impl<'a> Actionable<'a> for ConfigureNixDaemonService {
+    type Receipt = ConfigureNixDaemonServiceReceipt;
     fn description(&self) -> Vec<ActionDescription> {
         vec![
             ActionDescription::new(
@@ -24,7 +25,7 @@ impl<'a> Actionable<'a> for ConfigureNixDaemonService {
         ]
     }
 
-    async fn execute(self) -> Result<ActionReceipt, HarmonicError> {
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
         todo!()
     }
 }

src/actions/base/configure_shell_profile.rs

@@ -1,6 +1,6 @@
 use crate::HarmonicError;
 
-use super::{ActionDescription, ActionReceipt, Actionable, Revertable};
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, Revertable};
 
 #[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
 pub struct ConfigureShellProfile {}
@@ -13,6 +13,7 @@ impl ConfigureShellProfile {
 
 #[async_trait::async_trait]
 impl<'a> Actionable<'a> for ConfigureShellProfile {
+    type Receipt = ConfigureShellProfileReceipt;
     fn description(&self) -> Vec<ActionDescription> {
         vec![
             ActionDescription::new(
@@ -24,7 +25,7 @@ impl<'a> Actionable<'a> for ConfigureShellProfile {
         ]
     }
 
-    async fn execute(self) -> Result<ActionReceipt, HarmonicError> {
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
         todo!()
     }
 }

src/actions/base/create_directory.rs

@@ -5,7 +5,7 @@ use std::{
 
 use crate::HarmonicError;
 
-use super::{ActionDescription, ActionReceipt, Actionable, Revertable};
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, Revertable};
 
 #[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
 pub struct CreateDirectory {
@@ -29,6 +29,7 @@ impl CreateDirectory {
 
 #[async_trait::async_trait]
 impl<'a> Actionable<'a> for CreateDirectory {
+    type Receipt = CreateDirectoryReceipt;
     fn description(&self) -> Vec<ActionDescription> {
         vec![ActionDescription::new(
             format!("Create the directory `/nix`"),
@@ -38,7 +39,7 @@ impl<'a> Actionable<'a> for CreateDirectory {
         )]
     }
 
-    async fn execute(self) -> Result<ActionReceipt, HarmonicError> {
+    async fn execute(self) -> Result<CreateDirectoryReceipt, HarmonicError> {
         let Self {
             path,
             user,
@@ -46,12 +47,12 @@ impl<'a> Actionable<'a> for CreateDirectory {
             mode,
         } = self;
         todo!();
-        Ok(ActionReceipt::CreateDirectory(CreateDirectoryReceipt {
+        Ok(CreateDirectoryReceipt {
             path,
             user,
             group,
             mode,
-        }))
+        })
     }
 }
 

src/actions/base/create_group.rs

@@ -1,6 +1,6 @@
 use crate::HarmonicError;
 
-use super::{ActionDescription, ActionReceipt, Actionable, Revertable};
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, Revertable};
 
 #[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
 pub struct CreateGroup {
@@ -16,6 +16,7 @@ impl CreateGroup {
 
 #[async_trait::async_trait]
 impl<'a> Actionable<'a> for CreateGroup {
+    type Receipt = CreateGroupReceipt;
     fn description(&self) -> Vec<ActionDescription> {
         let name = &self.name;
         let uid = &self.uid;
@@ -27,9 +28,9 @@ impl<'a> Actionable<'a> for CreateGroup {
         )]
     }
 
-    async fn execute(self) -> Result<ActionReceipt, HarmonicError> {
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
         let Self { name, uid } = self;
-        Ok(ActionReceipt::CreateGroup(CreateGroupReceipt { name, uid }))
+        Ok(CreateGroupReceipt { name, uid })
     }
 }
 

src/actions/base/create_user.rs

@@ -1,6 +1,6 @@
 use crate::HarmonicError;
 
-use super::{ActionDescription, ActionReceipt, Actionable, Revertable};
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, Revertable};
 
 #[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
 pub struct CreateUser {
@@ -16,6 +16,7 @@ impl CreateUser {
 
 #[async_trait::async_trait]
 impl<'a> Actionable<'a> for CreateUser {
+    type Receipt = CreateUserReceipt;
     fn description(&self) -> Vec<ActionDescription> {
         let name = &self.name;
         let uid = &self.uid;
@@ -27,9 +28,9 @@ impl<'a> Actionable<'a> for CreateUser {
         )]
     }
 
-    async fn execute(self) -> Result<ActionReceipt, HarmonicError> {
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
         let Self { name, uid } = self;
-        Ok(ActionReceipt::CreateUser(CreateUserReceipt { name, uid }))
+        Ok(CreateUserReceipt { name, uid })
     }
 }
 

src/actions/base/fetch_nix.rs

@@ -0,0 +1,59 @@
+use std::path::{Path, PathBuf};
+
+use reqwest::Url;
+
+use crate::HarmonicError;
+
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, Revertable};
+
+#[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
+pub struct FetchNix {
+    url: Url,
+    destination: PathBuf,
+}
+
+impl FetchNix {
+    pub fn plan(url: Url, destination: PathBuf) -> Self {
+        Self { url, destination }
+    }
+}
+
+#[async_trait::async_trait]
+impl<'a> Actionable<'a> for FetchNix {
+    type Receipt = FetchNixReceipt;
+    fn description(&self) -> Vec<ActionDescription> {
+        let Self {
+            url, destination
+        } = &self;
+        vec![ActionDescription::new(
+            format!("Fetch Nix from `{url}`"),
+            vec![format!(
+                "Fetch a Nix archive and unpack it to `{}`", destination.display()
+            )],
+        )]
+    }
+
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
+        let Self { url, destination } = self;
+        Ok(FetchNixReceipt { url, destination })
+    }
+}
+
+#[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
+pub struct FetchNixReceipt {
+    url: Url,
+    destination: PathBuf,
+}
+
+#[async_trait::async_trait]
+impl<'a> Revertable<'a> for FetchNixReceipt {
+    fn description(&self) -> Vec<ActionDescription> {
+        todo!()
+    }
+
+    async fn revert(self) -> Result<(), HarmonicError> {
+        todo!();
+
+        Ok(())
+    }
+}

src/actions/base/mod.rs

@@ -0,0 +1,29 @@
+/*! Actions which do not only call other base plugins. */
+
+mod configure_nix_daemon_service;
+mod configure_shell_profile;
+mod create_directory;
+mod create_group;
+mod create_user;
+mod fetch_nix;
+mod move_unpacked_nix;
+mod place_channel_configuration;
+mod place_nix_configuration;
+mod setup_default_profile;
+mod start_systemd_service;
+
+pub use configure_nix_daemon_service::{
+    ConfigureNixDaemonService, ConfigureNixDaemonServiceReceipt,
+};
+pub use configure_shell_profile::{ConfigureShellProfile, ConfigureShellProfileReceipt};
+pub use create_directory::{CreateDirectory, CreateDirectoryReceipt};
+pub use create_group::{CreateGroup, CreateGroupReceipt};
+pub use create_user::{CreateUser, CreateUserReceipt};
+pub use fetch_nix::{FetchNix, FetchNixReceipt};
+pub use move_unpacked_nix::{MoveUnpackedNix, MoveUnpackedNixReceipt};
+pub use place_channel_configuration::{
+    PlaceChannelConfiguration, PlaceChannelConfigurationReceipt,
+};
+pub use place_nix_configuration::{PlaceNixConfiguration, PlaceNixConfigurationReceipt};
+pub use setup_default_profile::{SetupDefaultProfile, SetupDefaultProfileReceipt};
+pub use start_systemd_service::{StartSystemdService, StartSystemdServiceReceipt};

src/actions/base/move_unpacked_nix.rs

@@ -0,0 +1,53 @@
+use std::path::PathBuf;
+
+use crate::HarmonicError;
+
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, Revertable};
+
+#[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
+pub struct MoveUnpackedNix {
+    source: PathBuf,
+}
+
+impl MoveUnpackedNix {
+    pub fn plan(source: PathBuf) -> Self {
+        Self { source, }
+    }
+}
+
+#[async_trait::async_trait]
+impl<'a> Actionable<'a> for MoveUnpackedNix {
+    type Receipt = MoveUnpackedNixReceipt;
+    fn description(&self) -> Vec<ActionDescription> {
+        let Self { source } = &self;
+        vec![ActionDescription::new(
+            format!("Move the downloaded Nix into `/nix`"),
+            vec![format!(
+                "Nix is downloaded to `{}` and should be in `nix`", source.display(),
+            )],
+        )]
+    }
+
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
+        let Self { source } = self;
+        Ok(MoveUnpackedNixReceipt { })
+    }
+}
+
+#[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
+pub struct MoveUnpackedNixReceipt {
+    
+}
+
+#[async_trait::async_trait]
+impl<'a> Revertable<'a> for MoveUnpackedNixReceipt {
+    fn description(&self) -> Vec<ActionDescription> {
+        todo!()
+    }
+
+    async fn revert(self) -> Result<(), HarmonicError> {
+        todo!();
+
+        Ok(())
+    }
+}

src/actions/base/place_channel_configuration.rs

@@ -1,6 +1,6 @@
 use crate::HarmonicError;
 
-use super::{ActionDescription, ActionReceipt, Actionable, Revertable};
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, Revertable};
 
 #[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
 pub struct PlaceChannelConfiguration {}
@@ -13,6 +13,7 @@ impl PlaceChannelConfiguration {
 
 #[async_trait::async_trait]
 impl<'a> Actionable<'a> for PlaceChannelConfiguration {
+    type Receipt = PlaceChannelConfigurationReceipt;
     fn description(&self) -> Vec<ActionDescription> {
         vec![
             ActionDescription::new(
@@ -24,7 +25,7 @@ impl<'a> Actionable<'a> for PlaceChannelConfiguration {
         ]
     }
 
-    async fn execute(self) -> Result<ActionReceipt, HarmonicError> {
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
         todo!()
     }
 }

src/actions/base/place_nix_configuration.rs

@@ -1,6 +1,6 @@
 use crate::HarmonicError;
 
-use super::{ActionDescription, ActionReceipt, Actionable, Revertable};
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, Revertable};
 
 #[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
 pub struct PlaceNixConfiguration {}
@@ -13,6 +13,7 @@ impl PlaceNixConfiguration {
 
 #[async_trait::async_trait]
 impl<'a> Actionable<'a> for PlaceNixConfiguration {
+    type Receipt = PlaceNixConfigurationReceipt;
     fn description(&self) -> Vec<ActionDescription> {
         vec![
             ActionDescription::new(
@@ -24,7 +25,7 @@ impl<'a> Actionable<'a> for PlaceNixConfiguration {
         ]
     }
 
-    async fn execute(self) -> Result<ActionReceipt, HarmonicError> {
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
         todo!()
     }
 }

src/actions/base/setup_default_profile.rs

@@ -1,6 +1,6 @@
 use crate::HarmonicError;
 
-use super::{ActionDescription, ActionReceipt, Actionable, Revertable};
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, Revertable};
 
 #[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
 pub struct SetupDefaultProfile {}
@@ -13,6 +13,7 @@ impl SetupDefaultProfile {
 
 #[async_trait::async_trait]
 impl<'a> Actionable<'a> for SetupDefaultProfile {
+    type Receipt = SetupDefaultProfileReceipt;
     fn description(&self) -> Vec<ActionDescription> {
         vec![
             ActionDescription::new(
@@ -24,7 +25,7 @@ impl<'a> Actionable<'a> for SetupDefaultProfile {
         ]
     }
 
-    async fn execute(self) -> Result<ActionReceipt, HarmonicError> {
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
         todo!()
     }
 }

src/actions/base/start_systemd_service.rs

@@ -1,6 +1,6 @@
 use crate::HarmonicError;
 
-use super::{ActionDescription, ActionReceipt, Actionable, Revertable};
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, Revertable};
 
 #[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
 pub struct StartSystemdService {}
@@ -13,6 +13,7 @@ impl StartSystemdService {
 
 #[async_trait::async_trait]
 impl<'a> Actionable<'a> for StartSystemdService {
+    type Receipt = StartSystemdServiceReceipt;
     fn description(&self) -> Vec<ActionDescription> {
         vec![
             ActionDescription::new(
@@ -24,7 +25,7 @@ impl<'a> Actionable<'a> for StartSystemdService {
         ]
     }
 
-    async fn execute(self) -> Result<ActionReceipt, HarmonicError> {
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
         todo!()
     }
 }

src/actions/create_users.rs

@@ -1,117 +0,0 @@
-use tokio::task::JoinSet;
-
-use crate::HarmonicError;
-
-use super::{ActionDescription, ActionReceipt, Actionable, CreateUser, Revertable};
-
-#[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
-pub struct CreateUsers {
-    nix_build_user_prefix: String,
-    nix_build_user_id_base: usize,
-    daemon_user_count: usize,
-    children: Vec<CreateUser>,
-}
-
-impl CreateUsers {
-    pub fn plan(
-        nix_build_user_prefix: String,
-        nix_build_user_id_base: usize,
-        daemon_user_count: usize,
-    ) -> Self {
-        let children = (0..daemon_user_count)
-            .map(|count| {
-                CreateUser::plan(
-                    format!("{nix_build_user_prefix}{count}"),
-                    nix_build_user_id_base + count,
-                )
-            })
-            .collect();
-        Self {
-            nix_build_user_prefix,
-            nix_build_user_id_base,
-            daemon_user_count,
-            children,
-        }
-    }
-}
-
-#[async_trait::async_trait]
-impl<'a> Actionable<'a> for CreateUsers {
-    fn description(&self) -> Vec<ActionDescription> {
-        let nix_build_user_prefix = &self.nix_build_user_prefix;
-        let nix_build_user_id_base = &self.nix_build_user_id_base;
-        let daemon_user_count = &self.daemon_user_count;
-        vec![
-            ActionDescription::new(
-                format!("Create build users"),
-                vec![
-                    format!("The nix daemon requires system users it can act as in order to build"),
-                    format!("This action will create {daemon_user_count} users with prefix `{nix_build_user_prefix}` starting at uid `{nix_build_user_id_base}`"),
-                ],
-            )
-        ]
-    }
-
-    async fn execute(self) -> Result<ActionReceipt, HarmonicError> {
-        // TODO(@hoverbear): Abstract this, it will be common
-        let Self { children, .. } = self;
-        let mut set = JoinSet::new();
-        let mut successes = Vec::with_capacity(children.len());
-        let mut errors = Vec::default();
-
-        for child in children {
-            let _abort_handle = set.spawn(async move { child.execute().await });
-        }
-
-        while let Some(result) = set.join_next().await {
-            match result {
-                Ok(Ok(success)) => successes.push(success),
-                Ok(Err(e)) => errors.push(e),
-                Err(e) => errors.push(e.into()),
-            };
-        }
-
-        if !errors.is_empty() {
-            // If we got an error in a child, we need to revert the successful ones:
-            let mut failed_reverts = Vec::default();
-            for success in successes {
-                match success.revert().await {
-                    Ok(()) => (),
-                    Err(e) => failed_reverts.push(e),
-                }
-            }
-
-            if !failed_reverts.is_empty() {
-                return Err(HarmonicError::FailedReverts(errors, failed_reverts));
-            }
-
-            if errors.len() == 1 {
-                return Err(errors.into_iter().next().unwrap());
-            } else {
-                return Err(HarmonicError::Multiple(errors));
-            }
-        }
-
-        Ok(ActionReceipt::CreateUsers(CreateUsersReceipt {
-            children: successes,
-        }))
-    }
-}
-
-#[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
-pub struct CreateUsersReceipt {
-    children: Vec<ActionReceipt>,
-}
-
-#[async_trait::async_trait]
-impl<'a> Revertable<'a> for CreateUsersReceipt {
-    fn description(&self) -> Vec<ActionDescription> {
-        todo!()
-    }
-
-    async fn revert(self) -> Result<(), HarmonicError> {
-        todo!();
-
-        Ok(())
-    }
-}

src/actions/meta/configure_nix.rs

@@ -1,6 +1,6 @@
 use crate::{HarmonicError, InstallSettings};
 
-use super::{ActionDescription, ActionReceipt, Actionable, Revertable};
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, Revertable};
 
 #[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
 pub struct ConfigureNix {}
@@ -13,18 +13,19 @@ impl ConfigureNix {
 
 #[async_trait::async_trait]
 impl<'a> Actionable<'a> for ConfigureNix {
+    type Receipt = ConfigureNixReceipt;
     fn description(&self) -> Vec<ActionDescription> {
         vec![
             ActionDescription::new(
-                "Start the systemd Nix daemon".to_string(),
+                "Configure the Nix daemon".to_string(),
                 vec![
-                    "The `nix` command line tool communicates with a running Nix daemon managed by your init system".to_string()
+                    "Blah".to_string()
                 ]
             ),
         ]
     }
 
-    async fn execute(self) -> Result<ActionReceipt, HarmonicError> {
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
         todo!()
     }
 }

src/actions/meta/create_nix_tree.rs

@@ -1,6 +1,6 @@
 use crate::{HarmonicError, InstallSettings};
 
-use super::{ActionDescription, ActionReceipt, Actionable, Revertable};
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, Revertable};
 
 #[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
 pub struct CreateNixTree {
@@ -15,6 +15,7 @@ impl CreateNixTree {
 
 #[async_trait::async_trait]
 impl<'a> Actionable<'a> for CreateNixTree {
+    type Receipt = CreateNixTreeReceipt;
     fn description(&self) -> Vec<ActionDescription> {
         vec![ActionDescription::new(
             format!("Create a directory tree in `/nix`"),
@@ -24,9 +25,9 @@ impl<'a> Actionable<'a> for CreateNixTree {
         )]
     }
 
-    async fn execute(self) -> Result<ActionReceipt, HarmonicError> {
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
         let Self { settings: _ } = self;
-        Ok(ActionReceipt::CreateNixTree(CreateNixTreeReceipt {}))
+        Ok(CreateNixTreeReceipt {})
     }
 }
 

src/actions/meta/create_nix_tree_dirs.rs

@@ -1,6 +1,6 @@
 use crate::HarmonicError;
 
-use super::{ActionDescription, ActionReceipt, Actionable, Revertable};
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, Revertable};
 
 #[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
 pub struct CreateNixTreeDirs {}
@@ -13,6 +13,7 @@ impl CreateNixTreeDirs {
 
 #[async_trait::async_trait]
 impl<'a> Actionable<'a> for CreateNixTreeDirs {
+    type Receipt = CreateNixTreeDirsReceipt;
     fn description(&self) -> Vec<ActionDescription> {
         vec![ActionDescription::new(
             format!("Create a directory tree in `/nix`"),
@@ -22,11 +23,9 @@ impl<'a> Actionable<'a> for CreateNixTreeDirs {
         )]
     }
 
-    async fn execute(self) -> Result<ActionReceipt, HarmonicError> {
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
         let Self {} = self;
-        Ok(ActionReceipt::CreateNixTreeDirs(
-            CreateNixTreeDirsReceipt {},
-        ))
+        Ok(CreateNixTreeDirsReceipt {})
     }
 }
 

src/actions/meta/create_users_and_group.rs

@@ -0,0 +1,137 @@
+use tokio::task::JoinSet;
+
+use crate::{HarmonicError, InstallSettings};
+
+use crate::actions::base::{CreateGroup, CreateUserReceipt, CreateGroupReceipt};
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, CreateUser, Revertable};
+
+#[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
+pub struct CreateUsersAndGroup {
+    settings: InstallSettings,
+    create_group: CreateGroup,
+    create_users: Vec<CreateUser>,
+}
+
+impl CreateUsersAndGroup {
+    pub fn plan(
+        settings: InstallSettings
+    ) -> Self {
+        let create_group = CreateGroup::plan(settings.nix_build_group_name.clone(), settings.nix_build_group_id);
+        let create_users = (0..settings.daemon_user_count)
+            .map(|count| {
+                CreateUser::plan(
+                    format!("{}{count}", settings.nix_build_user_prefix),
+                    settings.nix_build_user_id_base + count,
+                )
+            })
+            .collect();
+        Self {
+            settings,
+            create_group,
+            create_users,
+        }
+    }
+}
+
+#[async_trait::async_trait]
+impl<'a> Actionable<'a> for CreateUsersAndGroup {
+    type Receipt = CreateUsersAndGroupReceipt;
+    fn description(&self) -> Vec<ActionDescription> {
+        let Self {
+            create_users: _,
+            create_group: _,
+            settings: InstallSettings {
+                explain: _,
+                daemon_user_count,
+                channels: _,
+                modify_profile: _,
+                nix_build_group_name,
+                nix_build_group_id,
+                nix_build_user_prefix,
+                nix_build_user_id_base,
+                nix_package_url,
+            }
+        } = &self;
+
+        vec![
+            ActionDescription::new(
+                format!("Create build users and group"),
+                vec![
+                    format!("The nix daemon requires system users it can act as in order to build"),
+                    format!("This action will create group `{nix_build_group_name}` with uid `{nix_build_group_id}`"),
+                    format!("This action will create {daemon_user_count} users with prefix `{nix_build_user_prefix}` starting at uid `{nix_build_user_id_base}`"),
+                ],
+            )
+        ]
+    }
+
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
+        let Self { create_users, create_group, settings: _ } = self;
+
+        // Create group
+        let create_group = create_group.execute().await?;
+
+        // Create users
+        // TODO(@hoverbear): Abstract this, it will be common
+        let mut set = JoinSet::new();
+        let mut successes = Vec::with_capacity(create_users.len());
+        let mut errors = Vec::default();
+
+        for create_user in create_users {
+            let _abort_handle = set.spawn(async move { create_user.execute().await });
+        }
+
+        while let Some(result) = set.join_next().await {
+            match result {
+                Ok(Ok(success)) => successes.push(success),
+                Ok(Err(e)) => errors.push(e),
+                Err(e) => errors.push(e.into()),
+            };
+        }
+
+        if !errors.is_empty() {
+            // If we got an error in a child, we need to revert the successful ones:
+            let mut failed_reverts = Vec::default();
+            for success in successes {
+                match success.revert().await {
+                    Ok(()) => (),
+                    Err(e) => failed_reverts.push(e),
+                }
+            }
+
+            if !failed_reverts.is_empty() {
+                return Err(HarmonicError::FailedReverts(errors, failed_reverts));
+            }
+
+            if errors.len() == 1 {
+                return Err(errors.into_iter().next().unwrap());
+            } else {
+                return Err(HarmonicError::Multiple(errors));
+            }
+        }
+
+        Ok(CreateUsersAndGroupReceipt {
+            create_group,
+            create_users: successes,
+        })
+    }
+}
+
+#[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
+pub struct CreateUsersAndGroupReceipt {
+    create_group: CreateGroupReceipt,
+    create_users: Vec<CreateUserReceipt>,
+}
+
+#[async_trait::async_trait]
+impl<'a> Revertable<'a> for CreateUsersAndGroupReceipt {
+    fn description(&self) -> Vec<ActionDescription> {
+        todo!()
+    }
+
+    async fn revert(self) -> Result<(), HarmonicError> {
+        todo!();
+
+        Ok(())
+    }
+}

src/actions/meta/mod.rs

@@ -0,0 +1,15 @@
+/*! Actions which only call other base plugins. */
+
+mod create_nix_tree;
+mod create_nix_tree_dirs;
+mod create_users_and_group;
+mod configure_nix;
+mod start_nix_daemon;
+mod provision_nix;
+
+pub use create_nix_tree::{CreateNixTree, CreateNixTreeReceipt};
+pub use create_nix_tree_dirs::{CreateNixTreeDirs, CreateNixTreeDirsReceipt};
+pub use create_users_and_group::{CreateUsersAndGroup, CreateUsersAndGroupReceipt};
+pub use configure_nix::{ConfigureNix, ConfigureNixReceipt};
+pub use start_nix_daemon::{StartNixDaemon, StartNixDaemonReceipt};
+pub use provision_nix::{ProvisionNix, ProvisionNixReceipt};

src/actions/meta/provision_nix.rs

@@ -0,0 +1,79 @@
+use tempdir::TempDir;
+
+use crate::actions::base::{FetchNix, MoveUnpackedNix, FetchNixReceipt, MoveUnpackedNixReceipt};
+use crate::{HarmonicError, InstallSettings};
+
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, Revertable};
+
+use super::{CreateUsersAndGroup, CreateNixTree, create_users_and_group, create_nix_tree, CreateUsersAndGroupReceipt, CreateNixTreeReceipt};
+
+#[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
+pub struct ProvisionNix {
+    fetch_nix: FetchNix,
+    create_users_and_group: CreateUsersAndGroup,
+    create_nix_tree: CreateNixTree,
+    move_unpacked_nix: MoveUnpackedNix,
+}
+
+impl ProvisionNix {
+    pub fn plan(settings: InstallSettings) -> Result<Self, HarmonicError> {
+        let tempdir = TempDir::new("nix").map_err(HarmonicError::TempDir)?;
+
+        let fetch_nix = FetchNix::plan(settings.nix_package_url.clone(), tempdir.path().to_path_buf());
+        let create_users_and_group = CreateUsersAndGroup::plan(settings.clone());
+        let create_nix_tree = CreateNixTree::plan(settings.clone());
+        let move_unpacked_nix = MoveUnpackedNix::plan(tempdir.path().to_path_buf());
+        Ok(Self { fetch_nix, create_users_and_group, create_nix_tree, move_unpacked_nix })
+    }
+}
+
+#[async_trait::async_trait]
+impl<'a> Actionable<'a> for ProvisionNix {
+    type Receipt = ProvisionNixReceipt;
+    fn description(&self) -> Vec<ActionDescription> {
+        let Self { fetch_nix, create_users_and_group, create_nix_tree, move_unpacked_nix } = &self;
+
+        let mut buf = fetch_nix.description();
+        buf.append(&mut create_users_and_group.description());
+        buf.append(&mut create_nix_tree.description());
+        buf.append(&mut move_unpacked_nix.description());
+        
+        buf
+    }
+
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
+        let Self { fetch_nix, create_nix_tree, create_users_and_group, move_unpacked_nix } = self;
+
+        // We fetch nix while doing the rest, then move it over. 
+        let fetch_nix_handle = tokio::spawn(async move { fetch_nix.execute().await });
+        
+        let create_users_and_group = create_users_and_group.execute().await?;
+        let create_nix_tree = create_nix_tree.execute().await?;
+
+        let fetch_nix = fetch_nix_handle.await??;
+        let move_unpacked_nix = move_unpacked_nix.execute().await?;
+
+        Ok(ProvisionNixReceipt { fetch_nix, create_users_and_group, create_nix_tree, move_unpacked_nix })
+    }
+}
+
+#[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
+pub struct ProvisionNixReceipt {
+    fetch_nix: FetchNixReceipt,
+    create_users_and_group: CreateUsersAndGroupReceipt,
+    create_nix_tree: CreateNixTreeReceipt,
+    move_unpacked_nix: MoveUnpackedNixReceipt,
+}
+
+#[async_trait::async_trait]
+impl<'a> Revertable<'a> for ProvisionNixReceipt {
+    fn description(&self) -> Vec<ActionDescription> {
+        todo!()
+    }
+
+    async fn revert(self) -> Result<(), HarmonicError> {
+        todo!();
+
+        Ok(())
+    }
+}

src/actions/meta/start_nix_daemon.rs

@@ -1,6 +1,6 @@
-use crate::{settings, HarmonicError, InstallSettings};
+use crate::{HarmonicError, InstallSettings};
 
-use super::{ActionDescription, ActionReceipt, Actionable, Revertable};
+use crate::actions::{ActionDescription, ActionReceipt, Actionable, Revertable};
 
 #[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
 pub struct StartNixDaemon {}
@@ -13,6 +13,7 @@ impl StartNixDaemon {
 
 #[async_trait::async_trait]
 impl<'a> Actionable<'a> for StartNixDaemon {
+    type Receipt = StartNixDaemonReceipt;
     fn description(&self) -> Vec<ActionDescription> {
         vec![
             ActionDescription::new(
@@ -24,7 +25,7 @@ impl<'a> Actionable<'a> for StartNixDaemon {
         ]
     }
 
-    async fn execute(self) -> Result<ActionReceipt, HarmonicError> {
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
         todo!()
     }
 }

src/actions/mod.rs

@@ -1,43 +1,37 @@
-mod configure_nix;
-mod configure_nix_daemon_service;
-mod configure_shell_profile;
-mod create_directory;
-mod create_group;
-mod create_nix_tree;
-mod create_nix_tree_dirs;
-mod create_user;
-mod create_users;
-mod place_channel_configuration;
-mod place_nix_configuration;
-mod setup_default_profile;
-mod start_nix_daemon;
-mod start_systemd_service;
+pub mod base;
+pub mod meta;
 
-pub use configure_nix::{ConfigureNix, ConfigureNixReceipt};
-pub use configure_nix_daemon_service::{
+use base::{
     ConfigureNixDaemonService, ConfigureNixDaemonServiceReceipt,
-};
-pub use configure_shell_profile::{ConfigureShellProfile, ConfigureShellProfileReceipt};
-pub use create_directory::{CreateDirectory, CreateDirectoryReceipt};
-pub use create_group::{CreateGroup, CreateGroupReceipt};
-pub use create_nix_tree::{CreateNixTree, CreateNixTreeReceipt};
-pub use create_nix_tree_dirs::{CreateNixTreeDirs, CreateNixTreeDirsReceipt};
-pub use create_user::{CreateUser, CreateUserReceipt};
-pub use create_users::{CreateUsers, CreateUsersReceipt};
-pub use place_channel_configuration::{
+    ConfigureShellProfile, ConfigureShellProfileReceipt,
+    CreateDirectory, CreateDirectoryReceipt,
+    CreateGroup, CreateGroupReceipt,
+    CreateUser, CreateUserReceipt,
+    FetchNix, FetchNixReceipt,
+    MoveUnpackedNix, MoveUnpackedNixReceipt,
     PlaceChannelConfiguration, PlaceChannelConfigurationReceipt,
+    PlaceNixConfiguration, PlaceNixConfigurationReceipt,
+    SetupDefaultProfile, SetupDefaultProfileReceipt,
+    StartSystemdService, StartSystemdServiceReceipt,
 };
-pub use place_nix_configuration::{PlaceNixConfiguration, PlaceNixConfigurationReceipt};
-pub use setup_default_profile::{SetupDefaultProfile, SetupDefaultProfileReceipt};
-pub use start_nix_daemon::{StartNixDaemon, StartNixDaemonReceipt};
-pub use start_systemd_service::{StartSystemdService, StartSystemdServiceReceipt};
+use meta::{
+    ConfigureNix, ConfigureNixReceipt,
+    CreateNixTree, CreateNixTreeReceipt,
+    CreateNixTreeDirs, CreateNixTreeDirsReceipt,
+    CreateUsersAndGroup, CreateUsersAndGroupReceipt,
+    StartNixDaemon, StartNixDaemonReceipt,
+};
+
 
 use crate::HarmonicError;
 
+use self::meta::{ProvisionNix, ProvisionNixReceipt};
+
 #[async_trait::async_trait]
 pub trait Actionable<'a>: serde::de::Deserialize<'a> + serde::Serialize {
+    type Receipt;
     fn description(&self) -> Vec<ActionDescription>;
-    async fn execute(self) -> Result<ActionReceipt, HarmonicError>;
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError>;
 }
 
 #[async_trait::async_trait]
@@ -67,17 +61,20 @@ pub enum Action {
     ConfigureNixDaemonService(ConfigureNixDaemonService),
     ConfigureNix(ConfigureNix),
     ConfigureShellProfile(ConfigureShellProfile),
-    CreateDirectory(CreateUser),
+    CreateDirectory(CreateDirectory),
     CreateGroup(CreateGroup),
     CreateNixTreeDirs(CreateNixTreeDirs),
     CreateNixTree(CreateNixTree),
     CreateUser(CreateUser),
-    CreateUsers(CreateUsers),
+    CreateUsersAndGroup(CreateUsersAndGroup),
+    FetchNix(FetchNix),
+    MoveUnpackedNix(MoveUnpackedNix),
     PlaceChannelConfiguration(PlaceChannelConfiguration),
     PlaceNixConfiguration(PlaceNixConfiguration),
     SetupDefaultProfile(SetupDefaultProfile),
     StartNixDaemon(StartNixDaemon),
-    StartSystemdService(StartNixDaemon),
+    StartSystemdService(StartSystemdService),
+    ProvisionNix(ProvisionNix),
 }
 
 #[derive(Debug, serde::Deserialize, serde::Serialize, Clone)]
@@ -90,16 +87,20 @@ pub enum ActionReceipt {
     CreateNixTreeDirs(CreateNixTreeDirsReceipt),
     CreateNixTree(CreateNixTreeReceipt),
     CreateUser(CreateUserReceipt),
-    CreateUsers(CreateUsersReceipt),
+    CreateUsersAndGroup(CreateUsersAndGroupReceipt),
+    FetchNix(FetchNixReceipt),
+    MoveUnpackedNix(MoveUnpackedNixReceipt),
     PlaceChannelConfiguration(PlaceChannelConfigurationReceipt),
     PlaceNixConfiguration(PlaceNixConfigurationReceipt),
     SetupDefaultProfile(SetupDefaultProfileReceipt),
     StartNixDaemon(StartNixDaemonReceipt),
-    StartSystemdService(StartNixDaemonReceipt),
+    StartSystemdService(StartSystemdServiceReceipt),
+    ProvisionNix(ProvisionNixReceipt),
 }
 
 #[async_trait::async_trait]
 impl<'a> Actionable<'a> for Action {
+    type Receipt = ActionReceipt;
     fn description(&self) -> Vec<ActionDescription> {
         match self {
             Action::ConfigureNixDaemonService(i) => i.description(),
@@ -110,31 +111,37 @@ impl<'a> Actionable<'a> for Action {
             Action::CreateNixTreeDirs(i) => i.description(),
             Action::CreateNixTree(i) => i.description(),
             Action::CreateUser(i) => i.description(),
-            Action::CreateUsers(i) => i.description(),
+            Action::CreateUsersAndGroup(i) => i.description(),
+            Action::FetchNix(i) => i.description(),
+            Action::MoveUnpackedNix(i) => i.description(),
             Action::PlaceChannelConfiguration(i) => i.description(),
             Action::PlaceNixConfiguration(i) => i.description(),
             Action::SetupDefaultProfile(i) => i.description(),
             Action::StartNixDaemon(i) => i.description(),
             Action::StartSystemdService(i) => i.description(),
+            Action::ProvisionNix(i) => i.description(),
         }
     }
 
-    async fn execute(self) -> Result<ActionReceipt, HarmonicError> {
+    async fn execute(self) -> Result<Self::Receipt, HarmonicError> {
         match self {
-            Action::ConfigureNixDaemonService(i) => i.execute().await,
-            Action::ConfigureNix(i) => i.execute().await,
-            Action::ConfigureShellProfile(i) => i.execute().await,
-            Action::CreateDirectory(i) => i.execute().await,
-            Action::CreateGroup(i) => i.execute().await,
-            Action::CreateNixTreeDirs(i) => i.execute().await,
-            Action::CreateNixTree(i) => i.execute().await,
-            Action::CreateUser(i) => i.execute().await,
-            Action::CreateUsers(i) => i.execute().await,
-            Action::PlaceChannelConfiguration(i) => i.execute().await,
-            Action::PlaceNixConfiguration(i) => i.execute().await,
-            Action::SetupDefaultProfile(i) => i.execute().await,
-            Action::StartNixDaemon(i) => i.execute().await,
-            Action::StartSystemdService(i) => i.execute().await,
+            Action::ConfigureNixDaemonService(i) => i.execute().await.map(ActionReceipt::ConfigureNixDaemonService),
+            Action::ConfigureNix(i) => i.execute().await.map(ActionReceipt::ConfigureNix),
+            Action::ConfigureShellProfile(i) => i.execute().await.map(ActionReceipt::ConfigureShellProfile),
+            Action::CreateDirectory(i) => i.execute().await.map(ActionReceipt::CreateDirectory),
+            Action::CreateGroup(i) => i.execute().await.map(ActionReceipt::CreateGroup),
+            Action::CreateNixTreeDirs(i) => i.execute().await.map(ActionReceipt::CreateNixTreeDirs),
+            Action::CreateNixTree(i) => i.execute().await.map(ActionReceipt::CreateNixTree),
+            Action::CreateUser(i) => i.execute().await.map(ActionReceipt::CreateUser),
+            Action::CreateUsersAndGroup(i) => i.execute().await.map(ActionReceipt::CreateUsersAndGroup),
+            Action::FetchNix(i) => i.execute().await.map(ActionReceipt::FetchNix),
+            Action::MoveUnpackedNix(i) => i.execute().await.map(ActionReceipt::MoveUnpackedNix),
+            Action::PlaceChannelConfiguration(i) => i.execute().await.map(ActionReceipt::PlaceChannelConfiguration),
+            Action::PlaceNixConfiguration(i) => i.execute().await.map(ActionReceipt::PlaceNixConfiguration),
+            Action::SetupDefaultProfile(i) => i.execute().await.map(ActionReceipt::SetupDefaultProfile),
+            Action::StartNixDaemon(i) => i.execute().await.map(ActionReceipt::StartNixDaemon),
+            Action::StartSystemdService(i) => i.execute().await.map(ActionReceipt::StartSystemdService),
+            Action::ProvisionNix(i) => i.execute().await.map(ActionReceipt::ProvisionNix),
         }
     }
 }
@@ -151,12 +158,15 @@ impl<'a> Revertable<'a> for ActionReceipt {
             ActionReceipt::CreateNixTreeDirs(i) => i.description(),
             ActionReceipt::CreateNixTree(i) => i.description(),
             ActionReceipt::CreateUser(i) => i.description(),
-            ActionReceipt::CreateUsers(i) => i.description(),
+            ActionReceipt::CreateUsersAndGroup(i) => i.description(),
+            ActionReceipt::FetchNix(i) => i.description(),
+            ActionReceipt::MoveUnpackedNix(i) => i.description(),
             ActionReceipt::PlaceChannelConfiguration(i) => i.description(),
             ActionReceipt::PlaceNixConfiguration(i) => i.description(),
             ActionReceipt::SetupDefaultProfile(i) => i.description(),
             ActionReceipt::StartNixDaemon(i) => i.description(),
             ActionReceipt::StartSystemdService(i) => i.description(),
+            ActionReceipt::ProvisionNix(i) => i.description(),
         }
     }
 
@@ -170,12 +180,15 @@ impl<'a> Revertable<'a> for ActionReceipt {
             ActionReceipt::CreateNixTreeDirs(i) => i.revert().await,
             ActionReceipt::CreateNixTree(i) => i.revert().await,
             ActionReceipt::CreateUser(i) => i.revert().await,
-            ActionReceipt::CreateUsers(i) => i.revert().await,
+            ActionReceipt::CreateUsersAndGroup(i) => i.revert().await,
+            ActionReceipt::FetchNix(i) => i.revert().await,
+            ActionReceipt::MoveUnpackedNix(i) => i.revert().await,
             ActionReceipt::PlaceChannelConfiguration(i) => i.revert().await,
             ActionReceipt::PlaceNixConfiguration(i) => i.revert().await,
             ActionReceipt::SetupDefaultProfile(i) => i.revert().await,
             ActionReceipt::StartNixDaemon(i) => i.revert().await,
             ActionReceipt::StartSystemdService(i) => i.revert().await,
+            ActionReceipt::ProvisionNix(i) => i.revert().await,
         }
     }
 }

src/plan.rs

@@ -2,8 +2,12 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     actions::{
-        Action, ActionDescription, ActionReceipt, Actionable, ConfigureNix, CreateNixTree,
-        Revertable, StartNixDaemon,
+        Action, ActionDescription, ActionReceipt, Actionable, Revertable,
+        meta::{
+            ConfigureNix,
+            ProvisionNix,
+            StartNixDaemon,
+        },
     },
     settings::InstallSettings,
     HarmonicError,
@@ -79,7 +83,7 @@ impl InstallPlan {
     }
     pub async fn new(settings: InstallSettings) -> Result<Self, HarmonicError> {
         let actions = vec![
-            Action::CreateNixTree(CreateNixTree::plan(settings.clone())),
+            Action::ProvisionNix(ProvisionNix::plan(settings.clone())?),
             Action::ConfigureNix(ConfigureNix::plan(settings.clone())),
             Action::StartNixDaemon(StartNixDaemon::plan(settings.clone())),
         ];

src/settings.rs

@@ -10,6 +10,7 @@ pub struct InstallSettings {
     pub(crate) nix_build_group_id: usize,
     pub(crate) nix_build_user_prefix: String,
     pub(crate) nix_build_user_id_base: usize,
+    pub(crate) nix_package_url: Url,
 }
 
 impl Default for InstallSettings {
@@ -23,6 +24,7 @@ impl Default for InstallSettings {
             nix_build_group_id: 3000,
             nix_build_user_prefix: String::from("nixbld"),
             nix_build_user_id_base: 3001,
+            nix_package_url: "https://releases.nixos.org/nix/nix-2.11.0/nix-2.11.0-x86_64-linux.tar.xz".parse().expect("Could not parse default Nix archive url, please report this issue")
         }
     }
 }
@@ -67,4 +69,8 @@ impl InstallSettings {
         self.nix_build_user_id_base = count;
         self
     }
+    pub fn nix_package_url(&mut self, url: Url) -> &mut Self {
+        self.nix_package_url = url;
+        self
+    }
 }