slack-cli: init at 0.18.0

slack-cli must be configured using the SLACK_CLI_TOKEN environment
variable. Using `slack init` will not work because it tries to write to
the Nix store.

pkgs/tools/networking/slack-cli/default.nix

@@ -0,0 +1,25 @@
+# slack-cli must be configured using the SLACK_CLI_TOKEN environment
+# variable. Using `slack init` will not work because it tries to write
+# to the Nix store.
+
+{ stdenv, lib, fetchurl, makeWrapper, curl, jq }:
+
+stdenv.mkDerivation rec {
+  name = "slack-cli";
+  version = "0.18.0";
+
+  src = fetchurl {
+    url = "https://github.com/rockymadden/slack-cli/archive/v${version}.tar.gz";
+    sha256 = "0q19l88c1mvnzya58q21pc3v6mff56z43288kzk50000ri286wq2";
+  };
+
+  buildInputs = [ makeWrapper ];
+
+  dontBuild = true;
+
+  installPhase = ''
+    mkdir -p $out/bin
+    cp src/slack $out/bin
+    wrapProgram $out/bin/slack --prefix PATH : ${lib.makeBinPath [ curl jq ]}
+  '';
+}

pkgs/top-level/all-packages.nix

@@ -16695,6 +16695,8 @@ with pkgs;
 
   slack = callPackage ../applications/networking/instant-messengers/slack { };
 
+  slack-cli = callPackage ../tools/networking/slack-cli { };
+
   singularity = callPackage ../applications/virtualization/singularity { };
 
   spectrwm = callPackage ../applications/window-managers/spectrwm { };