Add flake to build custom thin-edge binary

This patch adds a flake which is capable of building a custom
composition of thin-edge.io with a (possibly user-)defined set of
components.

Co-authored-by: Marcel Müller <m.mueller@ifm.com>
Signed-off-by: Marcel Müller <m.mueller@ifm.com>
Signed-off-by: Matthias Beyer <matthias.beyer@ifm.com>

4 files changed, 247 insertions, 0 deletions

diff --git a/lib/nix-thin-edge-builder/flake.lock b/lib/nix-thin-edge-builder/flake.lock
new file mode 100644
index 00000000..31cda59b
--- /dev/null
+++ b/lib/nix-thin-edge-builder/flake.lock
@@ -0,0 +1,97 @@
+{
+  "nodes": {
+    "crane": {
+      "inputs": {
+        "flake-compat": "flake-compat",
+        "flake-utils": "flake-utils",
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1660447363,
+        "narHash": "sha256-Y1OtGWEb0bgFlp9YULaiYcgfEoHVIz1NuXwzlFZ/0HE=",
+        "owner": "ipetkov",
+        "repo": "crane",
+        "rev": "5548a68f5d4d60a2315ab1232e6fba5528e71dc8",
+        "type": "github"
+      },
+      "original": {
+        "owner": "ipetkov",
+        "repo": "crane",
+        "type": "github"
+      }
+    },
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1650374568,
+        "narHash": "sha256-Z+s0J8/r907g149rllvwhb4pKi8Wam5ij0st8PwAh+E=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "b4a34015c698c7793d592d66adbab377907a2be8",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
+    "flake-utils": {
+      "locked": {
+        "lastModified": 1656928814,
+        "narHash": "sha256-RIFfgBuKz6Hp89yRr7+NR5tzIAbn52h8vT6vXkYjZoM=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "7e2a3b3dfd9af950a856d66b0a7d01e3c18aa249",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_2": {
+      "locked": {
+        "lastModified": 1659877975,
+        "narHash": "sha256-zllb8aq3YO3h8B/U0/J1WBgAL8EX5yWf5pMj3G0NAmc=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "c0e246b9b83f637f4681389ecabcb2681b4f3af0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1661300288,
+        "narHash": "sha256-R3FTmbhGhJ4bZZYFn/7KZjoFemhuSYCjPdPLzYSJKpI=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "eb569cf5cc4ff90eb78896c04ee1fd377acc7e1b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "crane": "crane",
+        "flake-utils": "flake-utils_2",
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/lib/nix-thin-edge-builder/flake.nix b/lib/nix-thin-edge-builder/flake.nix
new file mode 100644
index 00000000..8ece62d3
--- /dev/null
+++ b/lib/nix-thin-edge-builder/flake.nix
@@ -0,0 +1,87 @@
+{
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    crane.url = "github:ipetkov/crane";
+    crane.inputs.nixpkgs.follows = "nixpkgs";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = inputs@{ self, nixpkgs, flake-utils, crane, ... }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        craneLib = crane.lib.${system};
+        pkgs = import nixpkgs { inherit system; };
+      in
+    {
+      lib = rec {
+        officialComponents = [
+          (mkThinEdgeComponent { src = ../../plugins/plugin_avg; pluginBuilderPath = "foo"; })
+        ];
+
+        mkThinEdgeComponent = attrs@{
+          name ? null,
+          version ? null,
+          src,
+          pluginBuilderPath,
+        }:
+        let
+          crateInfo = craneLib.crateNameFromCargoToml {
+            cargoToml = "${src}/Cargo.toml";
+          };
+        in {
+          name = if builtins.isNull name
+            then crateInfo.pname
+            else name;
+
+          version = if builtins.isNull version
+            then crateInfo.version
+            else version;
+
+          inherit src pluginBuilderPath;
+        };
+
+        mkThinEdgeCrateSource = attrs@{
+          defaultComponents ? officialComponents,
+          extraComponents ? [],
+        }:
+        let
+          allComponents = defaultComponents ++ extraComponents;
+
+          writeCargoToml = import ./writeCargoToml.nix;
+          writeSrcMainRs = import ./writeSrcMainRs.nix;
+
+          cargoToml = writeCargoToml {
+            inherit craneLib;
+            components = allComponents;
+          };
+
+          srcmainrs = writeSrcMainRs {
+            inherit pkgs craneLib;
+            components = allComponents;
+          };
+
+          thinEdgeCrateSrc = pkgs.runCommand "buildThinEdgeCrateSrc" {} ''
+            mkdir -p $out/src
+            cp -v "${cargoToml}" $out/Cargo.toml
+            cp -v "${srcmainrs}" $out/src/main.rs
+          '';
+        in thinEdgeCrateSrc;
+
+        mkThinEdge = attrs@{
+          defaultComponents ? officialComponents,
+          extraComponents ? [],
+        }:
+        let
+          thinEdgeCrateSrc = mkThinEdgeCrateSource {
+            inherit defaultComponents extraComponents;
+          };
+
+          builtPackage = craneLib.buildPackage {
+            pname = "thin-edge";
+            version = "0.1.0";
+            src = thinEdgeCrateSrc;
+          };
+        in builtPackage;
+      };
+    });
+}
diff --git a/lib/nix-thin-edge-builder/writeCargoToml.nix b/lib/nix-thin-edge-builder/writeCargoToml.nix
new file mode 100644
index 00000000..34a276af
--- /dev/null
+++ b/lib/nix-thin-edge-builder/writeCargoToml.nix
@@ -0,0 +1,51 @@
+{ craneLib, components }:
+
+let
+  edition = "2021";
+
+  defaultDependencies = {
+    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"]; };
+    cfg-if = "1";
+    tracing = "0.1";
+    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"]; };
+    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; };
+  };
+
+  componentDependencies =
+    let
+      mkDep = component: {
+        name = component.name;
+        value = {
+          path = component.src;
+        };
+      };
+    in builtins.listToAttrs (builtins.map mkDep components);
+in
+
+craneLib.writeTOML "Cargo.toml" {
+  package = {
+    name = "thin-edge";
+    version = "0.1.0";
+    edition = "2021";
+  };
+
+  dependencies = defaultDependencies // componentDependencies;
+}
diff --git a/lib/nix-thin-edge-builder/writeSrcMainRs.nix b/lib/nix-thin-edge-builder/writeSrcMainRs.nix
new file mode 100644
index 00000000..b95bca48
--- /dev/null
+++ b/lib/nix-thin-edge-builder/writeSrcMainRs.nix
@@ -0,0 +1,12 @@
+{ pkgs, craneLib, components }:
+
+let
+  foo = 1;
+in
+pkgs.writeText "main.rs" ''
+/// This file was generated by nix
+
+fn main() {
+  println!("HelloWorld");
+}
+''