Add option to build a custom, slimmer, JRE for datomic

CHANGELOG.md

@@ -23,11 +23,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - nix pkg: Exposed more packages: `datomic-shell`, `datomic-run`, `datomic-repl`, `datomic-peer-server`
 - nixos module: You can now configure: logging, extra classpath entries, and extra java options.
 - nix pkg: Added datomic-pro-peer package which is the datomic peer library with all of its dependencies
+- nix pkg: Added option to build slimmed down JRE for datomic-pro
 
 ### Changed
 
 - nix pkg: Updated datomic-pro to version 1.0.7260
-- nix pkg: Switched to Nix's JDK 21 headless package (now that it is sufficiently headless
+- nix pkg: Switched to Nix's JDK 21 headless package (which is supported by Datomic)
+- oci image: Use the slimmed down JRE and a custom babashka build to reduce size of the image
 
 ### Fixed
 

flake.nix

@@ -2,24 +2,26 @@
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
     flake-utils.url = "github:numtide/flake-utils";
-    #clj-nix.url = "github:jlesquembre/clj-nix";
+    clj-nix.url = "github:jlesquembre/clj-nix";
   };
 
   outputs =
     {
       self,
       nixpkgs,
       flake-utils,
+      clj-nix,
     }:
     flake-utils.lib.eachDefaultSystem (
       system:
       let
         pkgs = import nixpkgs {
           inherit system;
-          overlays = [ self.overlays."${system}" ];
+          overlays = [
+            clj-nix.overlays.default
+            self.overlays."${system}"
+          ];
         };
-
-        jdk-minimal = pkgs.jdk21_headless;
       in
       {
         overlays = final: prev: {
@@ -70,6 +72,7 @@
           buildInputs = [
             pkgs.skopeo
             pkgs.babashka
+            pkgs.dive
             pkgs.gnumake
           ];
         };

nixos-modules/datomic-console.nix

@@ -18,7 +18,6 @@ in
     services.datomic-console = {
       enable = lib.mkEnableOption "Datomic Console";
       package = lib.mkPackageOption pkgs "datomic-pro" { };
-      javaPackage = lib.mkPackageOption pkgs "jdk21_headless" { };
       port = lib.mkOption {
         type = lib.types.port;
         description = "The port the console will bind to";
@@ -151,7 +150,6 @@ in
         db_uri="$(<"$CREDENTIALS_DIRECTORY/datomic-console-db-uri")"
         ${cfg.package}/bin/datomic-console -p ${toString cfg.port} "${cfg.alias}" "$db_uri"
       '';
-      path = [ cfg.javaPackage ];
       environment =
         {
           DATOMIC_JAVA_OPTS = toString extraJavaOptions;

pkgs/datomic-generate-properties.nix

@@ -1,39 +1,49 @@
 {
+  hostname,
   lib,
+  mkBabashka,
   stdenv,
-  fetchzip,
-  babashka,
-  dockerTools,
-  datomic-pro,
-  hostname,
+  substituteAll,
   ...
 }:
 
-stdenv.mkDerivation (finalAttrs: {
-  pname = "datomic-generate-properties";
-  version = "0.1";
+stdenv.mkDerivation (
+  finalAttrs:
+  let
+    bb = mkBabashka {
+      bbLean = true;
+      wrap = false;
+      withFeatures = [ "transit" ];
+    };
+  in
+  {
+    pname = "datomic-generate-properties";
+    version = "0.1";
 
-  src = ./generate-properties.clj;
+    src = substituteAll {
+      babashkaBin = "${bb}/bin/bb";
+      src = ./generate-properties.clj;
+    };
 
-  dontUnpack = true;
-  propagatedBuildInputs = [
-    babashka
-    hostname
-  ];
-  installPhase = ''
-    runHook preInstall
-    ls -al $src
-    mkdir -p $out/bin
-    cp -r $src $out/bin/datomic-generate-properties
-    chmod +x $out/bin/datomic-generate-properties
-    find $out
-    runHook postInstall
-  '';
-  meta = {
-    description = "Generates a java properties file for Datomic Pro based off of environment variables and sane defaults.";
-    homepage = "";
-    changelog = "";
-    license = lib.licenses.asl20;
-    mainProgram = "datomic-generate-properties";
-  };
-})
+    dontUnpack = true;
+    propagatedBuildInputs = [
+      hostname
+    ];
+    installPhase = ''
+      runHook preInstall
+      ls -al $src
+      mkdir -p $out/bin
+      cp -r $src $out/bin/datomic-generate-properties
+      chmod +x $out/bin/datomic-generate-properties
+      find $out
+      runHook postInstall
+    '';
+    meta = {
+      description = "Generates a java properties file for Datomic Pro based off of environment variables and sane defaults.";
+      homepage = "";
+      changelog = "";
+      license = lib.licenses.asl20;
+      mainProgram = "datomic-generate-properties";
+    };
+  }
+)

pkgs/datomic-pro-container-image.nix

@@ -1,14 +1,11 @@
 {
-  babashka,
   cacert,
   coreutils,
   datomic-generate-properties,
   datomic-pro,
   dockerTools,
-  fetchzip,
   hostname,
   imageTag,
-  jre_minimal,
   lib,
   mysql_jdbc,
   runCommand,
@@ -20,17 +17,21 @@
 }:
 
 let
-  jre = jre_minimal;
   datomicBuild = datomic-pro.override {
+    withCustomJre = true;
     extraJavaPkgs = [
       sqlite-jdbc
       mysql_jdbc
     ];
   };
+  entrypointSmall = writeShellScriptBin "datomic-entrypoint" ''
+    #! ${runtimeShell}
+      ${datomicBuild}/bin/datomic-transactor "$DATOMIC_TRANSACTOR_PROPERTIES_PATH"
+  '';
   entrypoint = writeShellScriptBin "datomic-entrypoint" ''
     #! ${runtimeShell}
     set -e
-    export PATH=${hostname}/bin:${jre}/bin:${coreutils}/bin:${babashka}:$PATH
+    export PATH=${hostname}/bin:${coreutils}/bin:$PATH
     if [ "$(id -u)" = "0" ]; then
       echo "WARNING: Running Datomic as root is not recommended. Please run as a non-root user."
       echo "         This can be ignored if you are using rootless mode."
@@ -71,24 +72,21 @@ dockerTools.buildLayeredImage {
   contents = [
     dockerTools.usrBinEnv
     dockerTools.binSh
-    babashka
-    cacert
-    coreutils
-    datomic-generate-properties
-    datomicBuild
-    entrypoint
-    env-shim
-    jre
-    mysql_jdbc
-    sqlite-jdbc
+    #cacert
+    #datomic-generate-properties
+    #datomicBuild
+    #entrypoint
+    #env-shim
+    #mysql_jdbc
+    #sqlite-jdbc
   ];
   extraCommands = ''
     mkdir -p tmp
     chmod 1777 tmp
   '';
 
   config = {
-    Entrypoint = [ "${entrypoint}/bin/datomic-entrypoint" ];
+    Entrypoint = [ "${entrypointSmall}/bin/datomic-entrypoint" ];
     Env = [
       "DATOMIC_TRANSACTOR_PROPERTIES_PATH=/config/transactor.properties"
       "LC_ALL=C.UTF-8"

pkgs/datomic-pro-peer.nix

@@ -3,8 +3,6 @@
   maven,
   fetchzip,
   stdenv,
-  jre,
-  jdk,
   ...
 }:
 
@@ -29,8 +27,6 @@ stdenv.mkDerivation (
         maven
       ];
 
-      JAVA_HOME = jdk;
-
       buildPhase = ''
         runHook preBuild
         mvn de.qaware.maven:go-offline-maven-plugin:1.2.8:resolve-dependencies -Dmaven.repo.local=$out/.m2