diff --git a/README.md b/README.md
index e135257..7099e1c 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,6 @@
     `nix`):
        https://nixos.wiki/wiki/Flakes#Installing_flakes
 
-
 2. Get this nix flake template, it will be setup in a new directory
 `./tritonshell` (feel free to adjust this):
 ```
@@ -23,8 +22,13 @@ nix flake new --template "git+https://git.greenbaum.cloud/dev/tritonshell?ref=ma
 cd tritonshell
 ```
 
+3. Adjust `./flake.nix` to match domains and data centers of your Triton Data
+Center setup. Look for the `CUSTOMIZE` comment.
+```
+vim ./flake.nix
+```
 
-3. Ready to go:
+4. Ready to go:
 ```
 nix develop
 ```
@@ -36,5 +40,4 @@ can do so: just edit `flake.nix` and look for `extraDevshellPkgs`. Packages
 added here will be pulled from the `nixos-unstable` channel, you can [search
 for available packages here](https://search.nixos.org/packages?channel=unstable&from=0&size=50&sort=relevance&type=packages&query=hello).
 
-
 TODO: add `nix-direnv`
diff --git a/template/flake.lock b/template/flake.lock
index b4d11fe..e780d0f 100644
--- a/template/flake.lock
+++ b/template/flake.lock
@@ -6,11 +6,11 @@
         "nixpkgs": "nixpkgs"
       },
       "locked": {
-        "lastModified": 1644227066,
-        "narHash": "sha256-FHcFZtpZEWnUh62xlyY3jfXAXHzJNEDLDzLsJxn+ve0=",
+        "lastModified": 1646194241,
+        "narHash": "sha256-ahPiM14XXa2CQwzqHlGJNpplER2HGFx3DfLbBhIeubI=",
         "owner": "numtide",
         "repo": "devshell",
-        "rev": "7033f64dd9ef8d9d8644c5030c73913351d2b660",
+        "rev": "20d50fc6adf77fd8a652fc824c6e282d7737b85d",
         "type": "github"
       },
       "original": {
diff --git a/template/flake.nix b/template/flake.nix
index 8dd6f2b..68abf26 100644
--- a/template/flake.nix
+++ b/template/flake.nix
@@ -11,7 +11,24 @@
 
       # Internal utility package with shell function and env vars helper.
       # These get source'd in devshell.bash.extra when starting tritonshell
-      packages.triton-utils = import ./pkgs/triton-utils.nix { inherit nixpkgs; inherit system; };
+      packages = {
+        triton-utils = import ./pkgs/triton-utils.nix { inherit nixpkgs system; };
+        triton-docker-env =
+        let
+          # CUSTOMIZE:
+          # variables used to set triton env vars in tritonshell
+          # adjust to suit your Triton Data Center setup
+          # take a look at ./pkgs/triton-docker-env-shell.nix to see how these get used
+          cnsBaseDomain = "greenbaum.zone";
+          dataCenters = [ "cgn-1" "lev-1" ];
+          mantaDomain = "eu-central.manta.greenbaum.cloud";
+          tritonApiDomain = "api.greenbaum.cloud";
+        in
+        import ./pkgs/triton-docker-env.nix {
+          inherit nixpkgs system cnsBaseDomain dataCenters mantaDomain
+          tritonApiDomain;
+        };
+      };
 
       devShell =
       let
diff --git a/template/pkgs/triton-docker-env-shell.nix b/template/pkgs/triton-docker-env-shell.nix
new file mode 100644
index 0000000..a5bf1fb
--- /dev/null
+++ b/template/pkgs/triton-docker-env-shell.nix
@@ -0,0 +1,30 @@
+{ pkgs, cnsBaseDomain, dataCenters, mantaDomain, tritonApiDomain, ... }:
+with pkgs.nodePackages;
+''
+# script to set the docker, triton, manta and CNS env vars for the current
+# triton profile
+
+# set triton and docker host environment variables
+eval "$(triton env)"
+
+# get the user's UUID
+triton_account_uuid="$(triton account get --json | json id)"
+
+# set the CNS (container name service) base for auto-generated DNS records
+# in public and private networks
+# note, this makes assumptions that only work if you configured the nix
+# variables in flake.nix "CUSTOMIZE" section according to your Triton Data
+# Center setup
+for dc in ${pkgs.lib.concatStringsSep " " dataCenters}; do
+  if env | grep -q -E "SDC_URL=https://''${dc}.${tritonApiDomain}"; then
+    export \
+    TRITON_CNS_SEARCH_DOMAIN_PUBLIC="''${triton_account_uuid}.''${dc}.${cnsBaseDomain}" \
+    TRITON_CNS_SEARCH_DOMAIN_PRIVATE="''${triton_account_uuid}.''${dc}.int.${cnsBaseDomain}" \
+    TRITON_DC=''$dc
+  fi
+done
+
+export MANTA_URL=https://${mantaDomain}
+export MANTA_USER=$SDC_ACCOUNT
+export MANTA_KEY_ID=$SDC_KEY_ID
+''
diff --git a/template/pkgs/triton-docker-env.nix b/template/pkgs/triton-docker-env.nix
new file mode 100644
index 0000000..16659f4
--- /dev/null
+++ b/template/pkgs/triton-docker-env.nix
@@ -0,0 +1,11 @@
+{ nixpkgs, system, cnsBaseDomain, dataCenters, mantaDomain, tritonApiDomain, ... }:
+let
+  pkgs = import nixpkgs {
+    inherit system;
+  };
+in
+pkgs.writeShellApplication {
+  name = "triton-docker-env.sh";
+  runtimeInputs = with pkgs.nodePackages; [ triton json ];
+  text = import ./triton-docker-env-shell.nix { inherit pkgs cnsBaseDomain dataCenters mantaDomain tritonApiDomain; };
+}
diff --git a/template/pkgs/triton-utils.nix b/template/pkgs/triton-utils.nix
index 975dd85..4b9cfb0 100644
--- a/template/pkgs/triton-utils.nix
+++ b/template/pkgs/triton-utils.nix
@@ -6,14 +6,13 @@ let
 in
 pkgs.stdenv.mkDerivation {
   pname = "triton-utils";
-  version = "0.0.2";
+  version = "0.0.3";
   src = pkgs.lib.cleanSource ./.;
 
   installPhase = ''
       mkdir -p $out/bin $out/share/certs
       cd ./utils
       cp ./cacert-2022-02-01.pem $out/share/certs
-      cp ./triton-docker.env.sh $out/bin
       cp ./ttp.sh $out/bin
       cp ./unset-env.sh $out/bin
   '';
diff --git a/template/pkgs/utils/triton-docker.env.sh b/template/pkgs/utils/triton-docker.env.sh
deleted file mode 100644
index a90aa42..0000000
--- a/template/pkgs/utils/triton-docker.env.sh
+++ /dev/null
@@ -1,26 +0,0 @@
-#!/usr/bin/env bash
-# script to set the docker, triton, manta and CNS env vars for the current triton profile
-
-# set triton and docker host environment variables
-eval "$(triton env)"
-
-# get the user's UUID
-triton_account_uuid="$(triton account get --json | json id)"
-
-# set the CNS (container name service) base for auto-generated DNS records
-# in public and private networks
-# note, this makes assumptions that only work with Greenbaum's public cloud
-if env | grep -q -E "SDC_URL=https://api.greenbaum.cloud|SDC_URL=https://cgn-1.api.greenbaum.cloud"; then
-  export TRITON_CNS_SEARCH_DOMAIN_PUBLIC="${triton_account_uuid}.cgn-1.greenbaum.zone"
-  export TRITON_CNS_SEARCH_DOMAIN_PRIVATE="${triton_account_uuid}.cgn-1.int.greenbaum.zone"
-  export TRITON_DC=cgn-1
-fi
-if env | grep -q "SDC_URL=https://lev-1.api.greenbaum.cloud"; then
-  export TRITON_CNS_SEARCH_DOMAIN_PUBLIC="${triton_account_uuid}.lev-1.greenbaum.zone"
-  export TRITON_CNS_SEARCH_DOMAIN_PRIVATE="${triton_account_uuid}.lev-1.int.greenbaum.zone"
-  export TRITON_DC=lev-1
-fi
-
-export MANTA_URL=https://eu-central.manta.greenbaum.cloud
-export MANTA_USER=$SDC_ACCOUNT
-export MANTA_KEY_ID=$SDC_KEY_ID
diff --git a/template/tritonshell.nix b/template/tritonshell.nix
index c280980..126115b 100644
--- a/template/tritonshell.nix
+++ b/template/tritonshell.nix
@@ -55,10 +55,12 @@ pkgs.devshell.mkShell {
     pkgs.bash-completion
     # use docker-compose version 1.26.2 for best triton API compatibility
     pkgs20-09.docker-compose
-    # used in ./utils/triton-docker.env.sh
-    pkgs.nodePackages.json
-    pkgs.bunyan-rs
+    # shell scripts and utilities to set and unset triton environment variables
     self.packages.${system}.triton-utils
+    self.packages.${system}.triton-docker-env
+    # useful for working with JSON data
+    pkgs.jq
+    pkgs.bunyan-rs
   ] ++ extraDevshellPkgs;
 
   env = [
@@ -84,7 +86,7 @@ pkgs.devshell.mkShell {
 
   bash = {
     extra = ''
-      source ${self.packages.${system}.triton-utils}/bin/triton-docker.env.sh
+      source ${self.packages.${system}.triton-docker-env}/bin/triton-docker-env.sh
       source ${self.packages.${system}.triton-utils}/bin/ttp.sh
       if [ "$(uname)" == "Darwin" ]; then
         source $DEVSHELL_DIR/share/bash-completion/bash_completion