fix(bootstrap): define CODER_ADMIN_* on coder-init-admin, not coder.service

Move the admin bootstrap credentials (CODER_ADMIN_EMAIL/USERNAME/PASSWORD)
out of the long-running coder.service environment and onto the
coder-init-admin.service (and its dependent coder-reset.service), so they
are only present where the bootstrap actually needs them.

coder-init-admin and coder-reset still inherit coder.service's environment
for CODER_PG_CONNECTION_URL; the admin creds are merged in via
systemd.services.coder-init-admin.environment in local.nix. GitHub OAuth
vars remain on coder.service since the server reads them.

Refs #29

Author: phorcys420

configuration.nix

@@ -405,8 +405,11 @@ in
     programs.git.config.safe.directory = [ "/etc/nixos-repo" ];
 
     # ── Coder server ──────────────────────────────────────────────────────────
-    # Base env vars live here. Secrets (admin creds, OAuth, etc.) are merged in
-    # via systemd.services.coder.environment in hosts/<host>/local.nix; no EnvironmentFile.
+    # Base env vars live here. Server secrets (e.g. OAuth) are merged in via
+    # systemd.services.coder.environment in hosts/<host>/local.nix; no
+    # EnvironmentFile. Admin bootstrap creds (CODER_ADMIN_*) are NOT set here —
+    # they live on coder-init-admin.service so they stay off the long-running
+    # server's environment.
     systemd.services.coder = {
       description = "Coder Server";
       wantedBy = [ "multi-user.target" ];
@@ -454,7 +457,9 @@ in
     };
 
     # ── Admin user bootstrap ──────────────────────────────────────────────────
-    # Reads CODER_ADMIN_* from coder.service environment (set via local.nix).
+    # Reads CODER_ADMIN_* from this service's own environment (set via
+    # local.nix as systemd.services.coder-init-admin.environment), keeping the
+    # admin credentials off the long-running coder.service.
     # Creates a local admin account once; sentinel prevents re-running.
     # If CODER_ADMIN_EMAIL is unset, skips and directs user to the browser wizard.
     systemd.services.coder-init-admin = {
@@ -463,8 +468,10 @@ in
       after = [ "coder.service" ];
       requires = [ "coder.service" ];
 
-      # Inherit the full coder.service environment so CODER_ADMIN_* and
-      # CODER_PG_CONNECTION_URL are available without duplication.
+      # Inherit the coder.service environment so CODER_PG_CONNECTION_URL (and the
+      # other server vars) are available without duplication. The CODER_ADMIN_*
+      # credentials are merged in on top via the coder-init-admin.environment
+      # definition in hosts/<host>/local.nix (NixOS merges attrset options).
       inherit (config.systemd.services.coder) environment;
 
       serviceConfig = {
@@ -603,7 +610,10 @@ in
       ];
       requires = [ "postgresql.service" ];
 
-      inherit (config.systemd.services.coder) environment;
+      # Step 8 mints a session token using CODER_ADMIN_EMAIL/PASSWORD, so pull in
+      # the coder-init-admin environment (which itself includes the coder.service
+      # vars plus the CODER_ADMIN_* credentials from local.nix).
+      inherit (config.systemd.services.coder-init-admin) environment;
 
       serviceConfig = {
         Type = "oneshot";

hosts/incus-vm/README.md

@@ -148,7 +148,7 @@ Edit `hosts/$HOSTNAME/local.nix` and at minimum set:
 ```nix
 services.coder-nixos.lanIp = "192.168.x.x";  # VM's primary IP
 
-systemd.services.coder.environment = {
+systemd.services.coder-init-admin.environment = {
   CODER_ADMIN_EMAIL    = "you@example.com";
   CODER_ADMIN_USERNAME = "admin";
   CODER_ADMIN_PASSWORD = "changeme";

local.nix.example

@@ -31,21 +31,27 @@ in
   # Use the email address linked to your GitHub account so that OAuth login
   # merges into this admin account automatically.
   # Skipped if CODER_ADMIN_EMAIL is empty (complete the wizard in the browser instead).
-  systemd.services.coder.environment = {
+  #
+  # These credentials live on coder-init-admin.service (the bootstrap service),
+  # NOT coder.service, so they stay out of the long-running server's environment.
+  systemd.services.coder-init-admin.environment = {
     CODER_ADMIN_EMAIL    = "you@example.com";  # change this
     CODER_ADMIN_USERNAME = "admin";
     CODER_ADMIN_PASSWORD = "changeme";         # change this
-
-    # ── GitHub OAuth (optional) ──────────────────────────────────────────────
-    # Leave this block commented out to use the built-in Coder GitHub App.
-    # CODER_OAUTH2_GITHUB_CLIENT_ID              = "";
-    # CODER_OAUTH2_GITHUB_CLIENT_SECRET          = "";
-    # CODER_OAUTH2_GITHUB_ALLOW_SIGNUPS          = "true";
-    # CODER_OAUTH2_GITHUB_DEFAULT_PROVIDER_ENABLE = "false";
-    # CODER_OAUTH2_GITHUB_ALLOW_EVERYONE         = "true";
-    # CODER_OAUTH2_GITHUB_ALLOWED_ORGS           = "my-org";
   };
 
+  # ── GitHub OAuth (optional) ────────────────────────────────────────────────
+  # Read by the long-running coder.service. Leave this block commented out to
+  # use the built-in Coder GitHub App.
+  # systemd.services.coder.environment = {
+  #   CODER_OAUTH2_GITHUB_CLIENT_ID              = "";
+  #   CODER_OAUTH2_GITHUB_CLIENT_SECRET          = "";
+  #   CODER_OAUTH2_GITHUB_ALLOW_SIGNUPS          = "true";
+  #   CODER_OAUTH2_GITHUB_DEFAULT_PROVIDER_ENABLE = "false";
+  #   CODER_OAUTH2_GITHUB_ALLOW_EVERYONE         = "true";
+  #   CODER_OAUTH2_GITHUB_ALLOWED_ORGS           = "my-org";
+  # };
+
   # ── Desktop / OS login account ─────────────────────────────────────────────
   # SDDM / SSH login. Change with `passwd ${nixosUsername}` after first boot;
   # initialPassword only fires on user creation.

nixos/_images/box-turnkey.nix

@@ -105,11 +105,13 @@
       initialPassword = "PleaseChangeMe1234";
     };
 
-    # coder-init-admin.service reads CODER_ADMIN_* from coder.service's
+    # coder-init-admin.service reads CODER_ADMIN_* from its own service
     # environment and creates a local admin on first boot, then mints a session
     # token and deploys the templates from /etc/nixos-repo/coderd. With these set
-    # the Coder instance is ready to use immediately.
-    systemd.services.coder.environment = {
+    # the Coder instance is ready to use immediately. These admin credentials are
+    # only needed by the bootstrap service, so they are kept off the long-running
+    # coder.service environment.
+    systemd.services.coder-init-admin.environment = {
       CODER_ADMIN_EMAIL = "admin@coder.com";
       CODER_ADMIN_USERNAME = "admin";
       CODER_ADMIN_PASSWORD = "PleaseChangeMe1234";