Migrate CircleCI to Buildkite

- Use Nixkite to define a Buildkite pipeline in Nix.
- Modify the "test-ets.sh" script to reflect the new Buildkite
  environment.
- Remove old CircleCI config.
- Update the solidity compiler to version 0.5.1 because that's the
  version currently available in the Nix environment.

Author: sevanspowell

.buildkite/default.nix

@@ -0,0 +1 @@
+import (import ../nix/sources.nix).nixkite

.buildkite/pipeline.nix

@@ -0,0 +1,88 @@
+{ cfg, pkgs, ... }:
+
+with cfg.steps.commands;
+
+let
+  commonAttrs = {
+    retry.automatic = true;
+    agents.queue = "project42";
+  };
+in
+
+{
+  steps.commands = {
+    compile = commonAttrs // {
+      label = "compile everything";
+      command = ''
+        nix-shell --run '$SBT compile-all'
+      '';
+    };
+
+    style = commonAttrs // {
+      dependsOn = [ compile ];
+      label = "scalastyle";
+      command = ''
+        nix-shell --run '$SBT scalastyle test:scalastyle'
+      '';
+    };
+
+    test-unit = commonAttrs // {
+      dependsOn = [ compile ];
+      label = "unit tests";
+      command = ''
+        nix-shell --run '$SBT coverage test'
+      '';
+      artifactPaths = [
+        "target/test-reports/**/*"
+        "target/scala/2.12/scoverage-report/**/*"
+        "target/scala/2.12/coverage-report/**/*"
+      ];
+    };
+
+    test-evm = commonAttrs // {
+      dependsOn = [ compile ];
+      label = "EVM tests";
+      command = ''
+        nix-shell --run '$SBT coverage evm:test'
+      '';
+      artifactPaths = [
+        "target/test-reports/**/*"
+        "target/scala/2.12/scoverage-report/**/*"
+        "target/scala/2.12/coverage-report/**/*"
+      ];
+    };
+
+    test-integration = commonAttrs // {
+      dependsOn = [ compile ];
+      label = "integration tests";
+      command = ''
+        nix-shell --run '$SBT coverageOff it:test'
+      '';
+      artifactPaths = [ "target/test-reports/**/*" ];
+    };
+
+    test-ets = commonAttrs // {
+      dependsOn = [ compile ];
+      label = "ETS";
+      command = ''
+        nix-shell --run './test-ets.sh'
+      '';
+    };
+
+    coverageReport = commonAttrs // {
+      dependsOn = [ test-unit test-evm ];
+      label = "coverage report";
+      command = ''
+        nix-shell --run '$SBT coverageReport coverageAggregate'
+      '';
+    };
+
+    additional = commonAttrs // {
+      dependsOn = [ compile ];
+      label = "additional compilation & dist";
+      command = ''
+        nix-shell --run '$SBT benchmark:compile snappy:compile dist'
+      '';
+    };
+  };
+}

.buildkite/pipeline.yml

@@ -0,0 +1,8 @@
+steps:
+  - label: ":nix::point_right::pipeline:"
+    command: |
+      export NIX_PATH="nixpkgs=$(nix eval --raw '(import nix/sources.nix).nixpkgs')"
+      nix eval --json '(import ./.buildkite { pipeline = ./.buildkite/pipeline.nix; })' \
+      | buildkite-agent pipeline upload --no-interpolation
+    agents:
+      queue: project42

.buildkite/shell.nix

@@ -0,0 +1,30 @@
+{ pkgs }:
+
+let
+
+  # TODO, share this code with mantis build in this project
+  # sbt-protoc puts the scala plugin in /tmp/protobridge<some-random-number>.
+  # it is in fact a shell script with a standard `#!/usr/bin/env sh` shebang
+  # that makes the Nix sandbox ANGRY and breaks all the things in a cryptic,
+  # hairpull-inducing way. So we gotta sed it out. Not the prettiest thing
+  # but it works.
+  protoc-wrapper = pkgs.writeShellScriptBin "protoc" ''
+    set -e
+
+    for f in "$@"; do
+      echo ''${f##*=}
+    done | grep protocbridge | xargs sed -i "1s|.*|#!${pkgs.bash}/bin/bash|"
+
+    exec ${pkgs.protobuf}/bin/protoc "$@"
+  '';
+
+in
+
+  with pkgs;
+  
+  mkShell {
+  
+    buildInputs = [ sbt solc jdk8 protoc-wrapper ];
+    # SBT = "sbt -v -mem 2048 -J-Xmx4g -Dsbt.ivy.home=/cache/ivy2 -Dsbt.boot.directory=/cache/sbt -Dmaven.repo.local=/cache/maven -Dnix=true";
+    SBT = "sbt -v -mem 2048 -J-Xmx4g -Dnix=true";
+  }

.circleci/Dockerfile

@@ -35,6 +35,18 @@
         "url": "https://github.com/nmattia/niv/archive/f73bf8d584148677b01859677a63191c31911eae.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
+    "nixkite": {
+        "branch": "master",
+        "description": "Nixkite is a Buildkite pipeline generation tool using the NixOS module system",
+        "homepage": null,
+        "owner": "input-output-hk",
+        "repo": "nixkite",
+        "rev": "11c40d1591e294a2da275aaeb9e21a45319a4673",
+        "sha256": "1cfiqv4n54g9xkm5zvypxfrr8ajpbggvpjn6dp1l9kfc2aknpgiz",
+        "type": "tarball",
+        "url": "https://github.com/input-output-hk/nixkite/archive/11c40d1591e294a2da275aaeb9e21a45319a4673.tar.gz",
+        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
+    },
     "nixpkgs": {
         "branch": "nixos-20.03",
         "description": "Nixpkgs/NixOS branches that track the Nixpkgs/NixOS channels",

.circleci/config.yml

@@ -97,7 +97,7 @@ object Dependencies {
     "org.scala-sbt.ipcsocket" % "ipcsocket" % "1.1.0",
     "com.google.guava" % "guava" % "29.0-jre",
     "org.xerial.snappy" % "snappy-java" % "1.1.7.7",
-    "org.web3j" % "core" % "5.0.0" % Test
+    "org.web3j" % "core" % "3.4.0" % Test
   )
 
   val prometheus: Seq[ModuleID] = {