Implement generating thin-edge binariespost-merge/nix-thin-edge-builder

The flake now exports a working `lib.mkThinEdge` function with which
users can generate a working binary with only the components they wish
to include.

It works as follows:

- It pulls in all the dependencies required for the thin-edge CLI
- It then pulls in and patches the sources given. Any path references to
  tedge_api/lib are patched to their nix-store equivalencies.
- The Cargo.lock is generated by downloading the cargo index and
  overriding its location to be effectively offline
- A temporary Rust project is created, where all the different
  components are then referenced and pulled in.
- This Rust project is then compiled using `crane` (currently a private
  fork with some hacks due to a deficiency in Nix relating to importing
  store paths in the TOML reader)
- crane automatically copies the resulting binary to the output

Signed-off-by: Marcel Müller <m.mueller@ifm.com>

5 files changed, 228 insertions, 88 deletions

diff --git a/lib/nix-thin-edge-builder/flake.lock b/lib/nix-thin-edge-builder/flake.lock
index 31cda59b..d181e45d 100644
--- a/lib/nix-thin-edge-builder/flake.lock
+++ b/lib/nix-thin-edge-builder/flake.lock
@@ -9,15 +9,16 @@
         ]
       },
       "locked": {
-        "lastModified": 1660447363,
-        "narHash": "sha256-Y1OtGWEb0bgFlp9YULaiYcgfEoHVIz1NuXwzlFZ/0HE=",
-        "owner": "ipetkov",
+        "lastModified": 1661841194,
+        "narHash": "sha256-uTKGw9NVaJ/PlEoJzrnqYLU3ADOvGiXqeXr5pTX2WPE=",
+        "owner": "TheNeikos",
         "repo": "crane",
-        "rev": "5548a68f5d4d60a2315ab1232e6fba5528e71dc8",
+        "rev": "1bb502992605a5ffe5085987aa8924ae15c57349",
         "type": "github"
       },
       "original": {
-        "owner": "ipetkov",
+        "owner": "TheNeikos",
+        "ref": "fix/use_unsafe",
         "repo": "crane",
         "type": "github"
       }
@@ -70,11 +71,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1661300288,
-        "narHash": "sha256-R3FTmbhGhJ4bZZYFn/7KZjoFemhuSYCjPdPLzYSJKpI=",
+        "lastModified": 1661353537,
+        "narHash": "sha256-1E2IGPajOsrkR49mM5h55OtYnU0dGyre6gl60NXKITE=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "eb569cf5cc4ff90eb78896c04ee1fd377acc7e1b",
+        "rev": "0e304ff0d9db453a4b230e9386418fd974d5804a",
         "type": "github"
       },
       "original": {
diff --git a/lib/nix-thin-edge-builder/flake.nix b/lib/nix-thin-edge-builder/flake.nix
index 8ece62d3..904d0c93 100644
--- a/lib/nix-thin-edge-builder/flake.nix
+++ b/lib/nix-thin-edge-builder/flake.nix
@@ -1,7 +1,7 @@
 {
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
-    crane.url = "github:ipetkov/crane";
+    crane.url = "github:TheNeikos/crane/fix/use_unsafe";
     crane.inputs.nixpkgs.follows = "nixpkgs";
     flake-utils.url = "github:numtide/flake-utils";
   };
@@ -12,76 +12,112 @@
         craneLib = crane.lib.${system};
         pkgs = import nixpkgs { inherit system; };
       in
-    {
-      lib = rec {
-        officialComponents = [
-          (mkThinEdgeComponent { src = ../../plugins/plugin_avg; pluginBuilderPath = "foo"; })
-        ];
+      {
+        lib = rec {
+          officialComponents = [
+            (mkThinEdgeComponent { src = ../../plugins/plugin_avg; pluginBuilderPath = "plugin_avg::AvgPluginBuilder"; })
+          ];
 
-        mkThinEdgeComponent = attrs@{
-          name ? null,
-          version ? null,
-          src,
-          pluginBuilderPath,
-        }:
-        let
-          crateInfo = craneLib.crateNameFromCargoToml {
-            cargoToml = "${src}/Cargo.toml";
-          };
-        in {
-          name = if builtins.isNull name
-            then crateInfo.pname
-            else name;
+          mkThinEdgeComponent =
+            attrs@{ name ? null
+            , version ? null
+            , nativeBuildInputs ? [ ]
+            , buildInputs ? [ ]
+            , src
+            , pluginBuilderPath
+            ,
+            }:
+            let
+              crateInfo = craneLib.crateNameFromCargoToml {
+                cargoToml = "${src}/Cargo.toml";
+              };
+            in
+            {
+              name =
+                if builtins.isNull name
+                then crateInfo.pname
+                else name;
 
-          version = if builtins.isNull version
-            then crateInfo.version
-            else version;
+              version =
+                if builtins.isNull version
+                then crateInfo.version
+                else version;
 
-          inherit src pluginBuilderPath;
-        };
+              inherit src pluginBuilderPath nativeBuildInputs buildInputs;
+            };
+
+          mkThinEdgeCrateSource =
+            attrs@{ defaultComponents ? officialComponents
+            , extraComponents ? [ ]
+            ,
+            }:
+            let
+              allComponents = defaultComponents ++ extraComponents;
+
+              writeCargoToml = import ./writeCargoToml.nix;
+              writeSrcMainRs = import ./writeSrcMainRs.nix;
+              writeCargoRegistry = import ./writeCargoRegistry.nix;
 
-        mkThinEdgeCrateSource = attrs@{
-          defaultComponents ? officialComponents,
-          extraComponents ? [],
-        }:
-        let
-          allComponents = defaultComponents ++ extraComponents;
+              cargoToml = writeCargoToml {
+                inherit pkgs craneLib;
+                components = allComponents;
+              };
 
-          writeCargoToml = import ./writeCargoToml.nix;
-          writeSrcMainRs = import ./writeSrcMainRs.nix;
+              srcmainrs = writeSrcMainRs {
+                inherit pkgs craneLib;
+                components = allComponents;
+              };
 
-          cargoToml = writeCargoToml {
-            inherit craneLib;
-            components = allComponents;
-          };
+              cargoConfig = writeCargoRegistry {
+                inherit pkgs craneLib;
+              };
 
-          srcmainrs = writeSrcMainRs {
-            inherit pkgs craneLib;
-            components = allComponents;
-          };
+              thinEdgeLockFile = pkgs.runCommand "buildThinEdgeLockFile" { } ''
+                mkdir -p src
+                mkdir -p .cargo
+                mkdir -p home
+                HOME=$(pwd)/home
+                cp -v "${cargoToml}" Cargo.toml
+                cp -v "${cargoConfig}" .cargo/config.toml
+                cp -v "${srcmainrs}" src/main.rs
+                ${pkgs.cargo}/bin/cargo -v generate-lockfile --offline
+                cp Cargo.lock $out
+              '';
 
-          thinEdgeCrateSrc = pkgs.runCommand "buildThinEdgeCrateSrc" {} ''
-            mkdir -p $out/src
-            cp -v "${cargoToml}" $out/Cargo.toml
-            cp -v "${srcmainrs}" $out/src/main.rs
-          '';
-        in thinEdgeCrateSrc;
+              thinEdgeCrateSrc = pkgs.runCommand "buildThinEdgeCrateSrc" { } ''
+                mkdir -p $out/src
+                mkdir -p $out/.cargo
+                mkdir -p $out/home
+                cp -v "${cargoToml}" $out/Cargo.toml
+                cp -v "${thinEdgeLockFile}" $out/Cargo.lock
+                cp -v "${srcmainrs}" $out/src/main.rs
+              '';
+            in
+            thinEdgeCrateSrc;
 
-        mkThinEdge = attrs@{
-          defaultComponents ? officialComponents,
-          extraComponents ? [],
-        }:
-        let
-          thinEdgeCrateSrc = mkThinEdgeCrateSource {
-            inherit defaultComponents extraComponents;
-          };
+          mkThinEdge =
+            attrs@{ defaultComponents ? officialComponents
+            , extraComponents ? [ ]
+            }:
+            let
+              thinEdgeCrateSrc = mkThinEdgeCrateSource {
+                inherit defaultComponents extraComponents;
+              };
+              collectedInputs = {
+                buildInputs = pkgs.lib.lists.concatMap (comp: comp.buildInputs) extraComponents;
+                nativeBuildInputs = pkgs.lib.lists.concatMap (comp: comp.nativeBuildInputs) extraComponents;
+              };
 
-          builtPackage = craneLib.buildPackage {
-            pname = "thin-edge";
-            version = "0.1.0";
-            src = thinEdgeCrateSrc;
-          };
-        in builtPackage;
-      };
-    });
+
+              builtPackage = craneLib.buildPackage {
+                pname = "thin-edge";
+                version = "0.1.0";
+                src = thinEdgeCrateSrc;
+                buildInputs = collectedInputs.buildInputs;
+                nativeBuildInputs = collectedInputs.nativeBuildInputs;
+              };
+            in
+            builtPackage;
+        };
+      });
 }
diff --git a/lib/nix-thin-edge-builder/writeCargoRegistry.nix b/lib/nix-thin-edge-builder/writeCargoRegistry.nix
new file mode 100644
index 00000000..d536b2ab
--- /dev/null
+++ b/lib/nix-thin-edge-builder/writeCargoRegistry.nix
@@ -0,0 +1,20 @@
+{ craneLib, pkgs }:
+
+let
+  cratesIoRegistry = fetchGit {
+    url = "https://github.com/rust-lang/crates.io-index.git";
+    ref = "master";
+    rev = "e9936adc4a5f03f929c3d19a8d3bcc73479ccc9a";
+  };
+  localCrateRegistry = pkgs.linkFarm "local-crate-registry" [
+    { name = "index"; path = cratesIoRegistry; }
+  ];
+  config = {
+    source = {
+      crates-io = { 
+        local-registry = localCrateRegistry;
+      };
+    };
+  };
+in
+craneLib.writeTOML "Cargo.toml" config
diff --git a/lib/nix-thin-edge-builder/writeCargoToml.nix b/lib/nix-thin-edge-builder/writeCargoToml.nix
index 34a276af..91dc2288 100644
--- a/lib/nix-thin-edge-builder/writeCargoToml.nix
+++ b/lib/nix-thin-edge-builder/writeCargoToml.nix
@@ -1,43 +1,60 @@
-{ craneLib, components }:
+{ craneLib, components, pkgs }:
 
 let
   edition = "2021";
+  applyOverrides = replacements: pkg: pkgs.runCommand "apply-${pkg.name}" { } ''
+    cp -R ${pkg.src}/* .
+    rm Cargo.toml
+    cat ${pkg.src}/Cargo.toml ${pkgs.lib.concatMapStrings (r: '' | sed 's|${r.localPath}|"${r.src}"|' '') replacements} > Cargo.toml
+    cp -R ./ $out
+  '';
+  apiOnlyPatchCrates = [
+    { localPath = "\".*/tedge_api\""; src = ../../crates/core/tedge_api; }
+  ];
+  allPatchCrates = apiOnlyPatchCrates ++ [
+    { localPath = "\".*/tedge_lib\""; src = localCrates.tedge_lib.path; }
+    { localPath = "\".*/tedge_core\""; src = localCrates.tedge_core.path; }
+  ];
+  localCrates = {
+    tedge_api = { path = ../../crates/core/tedge_api; };
+    tedge_core = { path = applyOverrides apiOnlyPatchCrates { name = "tedge_core"; src = ../../crates/core/tedge_core; }; };
+    tedge_lib = { path = applyOverrides apiOnlyPatchCrates { name = "tedge_lib"; src = ../../crates/core/tedge_lib; }; };
+    tedge-cli = {
+      default-features = false;
+      path = applyOverrides allPatchCrates { name = "tedge-cli"; src = ../../tedge; };
+    };
+  };
 
   defaultDependencies = {
-    clap = { version = "3"; features = ["derive" "cargo" "suggestions"]; };
+    clap = { version = "3"; features = [ "derive" "cargo" "suggestions" ]; };
     toml = "0.5.8";
-    tokio = { version = "1"; features = ["fs" "macros" "rt-multi-thread" "signal"]; };
-    miette = { version = "4.7"; features = ["fancy"]; };
+    tokio = { version = "1"; features = [ "fs" "macros" "rt-multi-thread" "signal" ]; };
+    miette = { version = "4.7"; features = [ "fancy" ]; };
     cfg-if = "1";
     tracing = "0.1";
-    tracing-subscriber = { version = "0.3.11"; features = ["env-filter"]; };
+    tracing-subscriber = { version = "0.3.11"; features = [ "env-filter" ]; };
     tracing-chrome = "0.6";
     tracing-tracy = "0.9";
     cfg_table = "1.0.0";
     nu-ansi-term = "0.45.1";
-    pretty = { version = "0.11.3"; features = ["termcolor"]; };
+    pretty = { version = "0.11.3"; features = [ "termcolor" ]; };
     termcolor = "1.1.3";
     termimad = "0.20.1";
     term_size = "0.3.2";
     owo-colors = "3.4.0";
     textwrap = "0.15.0";
-
-    tedge_api = { path = "../crates/core/tedge_api"; };
-    tedge_core = { path = "../crates/core/tedge_core"; };
-    tedge_lib = { path = "../crates/core/tedge_lib"; };
-
-    env_logger = { version = "0.9"; optional = true; };
-  };
+  } // localCrates;
 
   componentDependencies =
     let
       mkDep = component: {
         name = component.name;
         value = {
-          path = component.src;
+          path = applyOverrides allPatchCrates component;
         };
       };
-    in builtins.listToAttrs (builtins.map mkDep components);
+    in
+    builtins.listToAttrs (builtins.map mkDep components);
 in
 
 craneLib.writeTOML "Cargo.toml" {
diff --git a/lib/nix-thin-edge-builder/writeSrcMainRs.nix b/lib/nix-thin-edge-builder/writeSrcMainRs.nix
index b95bca48..73493b38 100644
--- a/lib/nix-thin-edge-builder/writeSrcMainRs.nix
+++ b/lib/nix-thin-edge-builder/writeSrcMainRs.nix
@@ -5,8 +5,74 @@ let
 in
 pkgs.writeText "main.rs" ''
 /// This file was generated by nix
+use clap::Parser;
+use tracing::debug;
+use tracing::info;
 
-fn main() {
-  println!("HelloWorld");
+use tedge_cli::Registry;
+use tedge_lib::measurement::Measurement;
+use tedge_lib::notification::Notification;
+
+#[tokio::main]
+#[tracing::instrument]
+async fn main() -> miette::Result<()> {
+    let args = tedge_cli::cli::Cli::parse();
+    let _guard = tedge_cli::logging::setup_logging(
+        args.logging,
+        args.chrome_logging.as_ref(),
+        args.tracy_logging,
+    )?;
+    info!("Tedge booting...");
+    debug!(?args, "Tedge CLI");
+
+    let registry = tedge_cli::Registry::default();
+    info!("Building application");
+
+    ${ pkgs.lib.concatMapStrings (comp: ''
+      let registry = {
+                let kind_name: &'static str = <${comp.pluginBuilderPath} as tedge_api::PluginBuilder<tedge_core::PluginDirectory>>::kind_name();
+                info!(%kind_name, "Registering plugin builder");
+                let mut registry = registry;
+                if !registry.plugin_kinds.insert(kind_name.to_string()) {
+                    miette::bail!("Plugin kind '{}' was already registered, cannot register!", kind_name)
+                }
+
+                let kind_name_str = kind_name.to_string();
+                registry.doc_printers.insert(kind_name.to_string(), Box::new(move || {
+                    use std::io::Write;
+                    use miette::IntoDiagnostic;
+                    use pretty::Arena;
+
+                    let mut stdout = std::io::stdout();
+                    if let Some(config_desc) = <${comp.pluginBuilderPath} as tedge_api::PluginBuilder<tedge_core::PluginDirectory>>::kind_configuration() {
+                        let terminal_width = term_size::dimensions().map(|(w, _)| w).unwrap_or(80);
+                        let arena = Arena::new();
+
+                        let rendered_doc = tedge_cli::config::as_terminal_doc(&config_desc, &arena);
+
+                        let mut output = String::new();
+                        rendered_doc.render_fmt(terminal_width, &mut output).into_diagnostic()?;
+
+                        writeln!(stdout, " ----- Documentation for plugin '{}'", kind_name_str)
+                                .into_diagnostic()?;
+
+                        writeln!(stdout, "{}", output).into_diagnostic()?;
+                    } else {
+                        let msg = format!(" Documentation for plugin '{}' is unavailable", kind_name);
+                        writeln!(stdout, "{}", nu_ansi_term::Color::Red.bold().paint(msg))
+                            .into_diagnostic()?;
+                    }
+                    Ok(())
+                }));
+
+                tedge_cli::Registry {
+                    app_builder: registry.app_builder.with_plugin_builder(${comp.pluginBuilderPath}),
+                    plugin_kinds: registry.plugin_kinds,
+                    doc_printers: registry.doc_printers,
+                }
+      };
+    '') components }
+
+    tedge_cli::run_app(args, registry).await
 }
 ''