Take the master key from KEEPORG_MASTER_KEY_FILE

Why: the usual way to hand a secret to a container is to mount it as a file
and name the path in the environment. Compose, swarm and Kubernetes all do
it that way, and it keeps the key out of the process environment and off any
disk the container can write.

What: the master key is now looked for in KEEPORG_MASTER_KEY, then
KEEPORG_MASTER_KEY_FILE, then the configured master_key_file. A secret file
may hold base64, with or without padding or a trailing newline, or exactly
32 raw bytes, because secret stores produce both.

Only the configured path is ever created, which is what keeps a plain
package install working with no setup. The two environment variables name a
key something else owns, so a missing one is reported and vault creation
refused. Minting a replacement there would be worse than failing: it opens
none of the existing vaults, and the mistake would otherwise surface one
failed merge at a time.

The compose example now provisions the key as a real secret rather than an
environment variable, and the Dockerfile and README show the same. Neither
names a version any more, so they stop drifting as the server is bumped.

Proved: unit tests for every source and precedence, all four accepted
encodings, and that a missing secret writes nothing anywhere. In real
containers: a podman secret carrying base64 survives a stop and start with
"1 vault keys available for merging" and merges a stale push afterwards; a
secret holding 32 raw bytes creates a vault; and a secret that failed to
mount is named in the startup log, with vault creation answering with the
three places a key may come from.

Dockerfile

@@ -7,8 +7,8 @@
 # to an OIDC provider, and nothing else. There is no shell in it: the binary
 # probes its own health.
 #
-#   podman build --format docker -t keeporgd:0.3.0 --build-arg VERSION=0.3.0 .
+#   podman build --format docker -t keeporgd:<version> --build-arg VERSION=<version> .
-#   docker build -t keeporgd:0.3.0 --build-arg VERSION=0.3.0 .
+#   docker build -t keeporgd:<version> --build-arg VERSION=<version> .
 #
 # podman needs --format docker, because the OCI image format has no
 # HEALTHCHECK field and drops it silently.
@@ -55,14 +55,21 @@ COPY --from=build /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certifica
 # KEEPORG_MASTER_KEY, the master key that unwraps the vault keys. They are
 # separate on purpose: whoever holds both can read every merge vault.
 #
-# Give the master key somewhere durable, one of these two ways:
+# Give the master key somewhere durable, one of these three ways:
 #
-#   -e KEEPORG_MASTER_KEY="$(head -c 32 /dev/urandom | base64)"   (preferred)
+#   --secret keeporg_master_key -e KEEPORG_MASTER_KEY_FILE=/run/secrets/keeporg_master_key
+#   -e KEEPORG_MASTER_KEY="$(head -c 32 /dev/urandom | base64)"
 #   -v keeporg-config:/etc/keeporg
 #
-# With neither, the server mints a key into the container's own layer on
+# The first is preferred: the key is never in the process environment and
-# first start and loses it on the next `run`. It says so loudly at startup,
+# never on a disk this container can write. The file may hold base64 or 32
-# and merging is all that stops working: clients still open their vaults.
+# raw bytes. Neither environment variable is ever created by the server, so
+# a secret that failed to mount is reported instead of being replaced.
+#
+# With none of the three, the server mints a key into the container's own
+# layer on first start and loses it on the next `run`. It says so loudly at
+# startup, and merging is all that stops working: clients still open their
+# vaults.
 COPY --from=build --chown=65532:65532 /out/var/lib/keeporg /var/lib/keeporg
 COPY --from=build --chown=65532:65532 /out/etc/keeporg /etc/keeporg
 VOLUME ["/var/lib/keeporg", "/etc/keeporg"]

README.md

@@ -64,15 +64,20 @@ make help       # every target
 Running the server in a container:
 
 ```bash
+head -c 32 /dev/urandom | base64 > master.key
+podman secret create keeporg_master_key master.key
 podman run -d -p 8765:8765 \
-  -e KEEPORG_MASTER_KEY="$(head -c 32 /dev/urandom | base64)" \
+  --secret keeporg_master_key \
+  -e KEEPORG_MASTER_KEY_FILE=/run/secrets/keeporg_master_key \
   -e KEEPORG_ADMIN_PASSWORD=change-me \
   -v keeporg-data:/var/lib/keeporg \
   keeporgd:latest -addr :8765 -data /var/lib/keeporg -url https://keeporg.example.com
 ```
 
 Keep that master key: it unwraps the vault keys, and without it the server
-can no longer merge. See [packaging/docker/compose.yaml](packaging/docker/compose.yaml).
+can no longer merge. `KEEPORG_MASTER_KEY` takes the base64 key directly if
+your secret store injects variables instead of files. See
+[packaging/docker/compose.yaml](packaging/docker/compose.yaml).
 
 ## Documentation
 

cmd/keeporgd/main.go

@@ -84,8 +84,9 @@ func main() {
 		dataDir    = flag.String("data", "", "data directory (overrides the config file)")
 		extURL     = flag.String("url", "", "externally reachable base URL (overrides the config file)")
 		masterKey  = flag.String("master-key-file", "",
-			"file holding the base64 master key that wraps the vault keys; "+
+			"file holding the master key that wraps the vault keys, created if "+
-				"$"+secret.MasterKeyEnv+" takes precedence over it")
+				"absent; $"+secret.MasterKeyEnv+" and $"+secret.MasterKeyFileEnv+
+				" take precedence over it and are never created")
 		showVer    = flag.Bool("version", false, "print the version and exit")
 		healthOnly = flag.Bool("healthcheck", false,
 			"probe a running server on this address and exit 0 if it is healthy")

docs/HANDOVER.md

@@ -234,11 +234,21 @@ Three different things are encrypted here, and they are worth keeping apart:
    returned by the API, never logged, and never leaves the process.
 3. **Account passwords.** Not stored at all; only PBKDF2-SHA256 verifiers.
 
-The master key comes from `KEEPORG_MASTER_KEY` (base64) or from
+The master key is looked for in three places, in order:
-`master_key_file`, which defaults to `/etc/keeporg/master.key` and is created
+
-with mode 0600 on first start. Without it the server still runs and still
+| Source | Shape | Created if absent |
-serves every key-less strategy; only vault creation and merging are refused,
+| --- | --- | --- |
-with a line in the log saying so.
+| `$KEEPORG_MASTER_KEY` | base64 | no |
+| `$KEEPORG_MASTER_KEY_FILE` | a path to a provisioned secret: base64, or 32 raw bytes | no |
+| `master_key_file` / `-master-key-file`, default `/etc/keeporg/master.key` | base64 | yes, mode 0600 |
+
+Only the configured path is ever created, which is what makes a plain
+package install work with no setup. The two environment variables name a key
+that something else owns, so a missing one is reported rather than replaced:
+minting a key in its place would open none of the existing vaults. Without
+any of the three the server still runs and still serves every key-less
+strategy; only vault creation and merging are refused, with a line in the
+log saying so.
 
 What this buys and what it does not:
 
@@ -425,9 +435,14 @@ Two directories matter, and the whole point is that they are separate:
 - `/var/lib/keeporg` — state and blobs. Mount a volume.
 - `/etc/keeporg` — `server.json` and, by default, the master key.
 
-**Give the master key somewhere durable**, either `KEEPORG_MASTER_KEY` from
+**Give the master key somewhere durable.** The best option is a provisioned
-your secret store, or `-master-key-file` pointing at a mounted secret, or a
+secret plus `KEEPORG_MASTER_KEY_FILE` naming where it landed, which is the
-volume on `/etc/keeporg`. A container started with none of those mints a key
+convention compose, swarm and Kubernetes all follow:
+`--secret keeporg_master_key -e KEEPORG_MASTER_KEY_FILE=/run/secrets/keeporg_master_key`.
+The key is then neither in the process environment nor on a disk the
+container can write, and the file may hold base64 or 32 raw bytes.
+`KEEPORG_MASTER_KEY` and a volume on `/etc/keeporg` also work. A container
+started with none of those mints a key
 into its own layer and loses it on the next `run`. That is survivable but
 annoying: the vaults still open for their users, and only merging stops. The
 server says so at startup —

internal/secret/keyring.go

@@ -15,37 +15,73 @@ import (
 // a vault: it can decrypt a vault, so it holds that vault's key.
 //
 // The wrapped secrets live in the server's state document; the key that
-// unwraps them does not. It comes from the environment or from a file
+// unwraps them does not. It comes from the environment, from a secret file
-// outside the data directory, so a copy of the data directory alone yields
+// an orchestrator provisioned, or from a file outside the data directory,
-// ciphertext. Whoever holds both holds the vaults.
+// so a copy of the data directory alone yields ciphertext. Whoever holds
+// both holds the vaults.
 type Keyring struct {
 	aead cipher.AEAD
 }
 
-// MasterKeyEnv names the environment variable holding a base64 master key,
+// Environment variables that supply the master key. Both are read before
-// which takes precedence over the key file.
+// any configured path.
-const MasterKeyEnv = "KEEPORG_MASTER_KEY"
+const (
+	// MasterKeyEnv holds the base64 key itself.
+	MasterKeyEnv = "KEEPORG_MASTER_KEY"
+	// MasterKeyFileEnv holds the path to a file containing it, which is how
+	// a container runtime or an orchestrator hands over a provisioned
+	// secret without putting it in the process environment.
+	MasterKeyFileEnv = "KEEPORG_MASTER_KEY_FILE"
+)
 
-// LoadKeyring reads the master key from the environment or from path,
+// keySize is the master key length in bytes.
-// creating one at path if neither exists.
+const keySize = 32
+
+// LoadKeyring finds the master key, in this order:
+//
+//  1. $KEEPORG_MASTER_KEY, the base64 key itself.
+//  2. $KEEPORG_MASTER_KEY_FILE, a path to a provisioned secret. It must
+//     already exist: something else owns that file, so a missing one is a
+//     misconfiguration to report, not a reason to mint a new key that would
+//     fail to open any existing vault.
+//  3. path, from -master-key-file or master_key_file in the configuration.
+//     This one is created on first run if it is absent, which is what makes
+//     a plain package install work with no setup.
+//
+// A file may hold the key as base64 text, with or without a trailing
+// newline, or as exactly 32 raw bytes, because secret stores produce both.
 func LoadKeyring(path string) (*Keyring, error) {
 	if v := strings.TrimSpace(os.Getenv(MasterKeyEnv)); v != "" {
-		key, err := base64.StdEncoding.DecodeString(v)
+		key, err := decodeKey([]byte(v))
 		if err != nil {
-			return nil, fmt.Errorf("secret: %s is not valid base64: %w", MasterKeyEnv, err)
+			return nil, fmt.Errorf("secret: $%s: %w", MasterKeyEnv, err)
 		}
 		return NewKeyring(key)
 	}
+
+	if p := strings.TrimSpace(os.Getenv(MasterKeyFileEnv)); p != "" {
+		b, err := os.ReadFile(p)
+		if err != nil {
+			return nil, fmt.Errorf("secret: $%s points at %s: %w",
+				MasterKeyFileEnv, p, err)
+		}
+		key, err := decodeKey(b)
+		if err != nil {
+			return nil, fmt.Errorf("secret: $%s file %s: %w", MasterKeyFileEnv, p, err)
+		}
+		return NewKeyring(key)
+	}
+
 	if path == "" {
-		return nil, errors.New("secret: no master key: set " + MasterKeyEnv +
+		return nil, errors.New("secret: no master key: set $" + MasterKeyEnv +
-			" or configure master_key_file")
+			", $" + MasterKeyFileEnv + ", or configure master_key_file")
 	}
 	b, err := os.ReadFile(path)
 	switch {
 	case err == nil:
-		key, derr := base64.StdEncoding.DecodeString(strings.TrimSpace(string(b)))
+		key, derr := decodeKey(b)
 		if derr != nil {
-			return nil, fmt.Errorf("secret: master key file %s is not valid base64: %w", path, derr)
+			return nil, fmt.Errorf("secret: master key file %s: %w", path, derr)
 		}
 		return NewKeyring(key)
 	case !os.IsNotExist(err):
@@ -53,7 +89,7 @@ func LoadKeyring(path string) (*Keyring, error) {
 	}
 	// First run: mint one. It is written with owner-only permissions and is
 	// the one file an operator must back up separately from the data.
-	key := randBytes(32)
+	key := randBytes(keySize)
 	if err := os.MkdirAll(filepath.Dir(path), 0o700); err != nil {
 		return nil, err
 	}
@@ -64,10 +100,28 @@ func LoadKeyring(path string) (*Keyring, error) {
 	return NewKeyring(key)
 }
 
+// decodeKey accepts the shapes a provisioned secret arrives in: exactly 32
+// raw bytes, or base64 text with or without padding and trailing newline.
+func decodeKey(b []byte) ([]byte, error) {
+	if len(b) == keySize {
+		return b, nil
+	}
+	text := strings.TrimSpace(string(b))
+	if key, err := base64.StdEncoding.DecodeString(text); err == nil {
+		return key, nil
+	}
+	if key, err := base64.RawStdEncoding.DecodeString(text); err == nil {
+		return key, nil
+	}
+	return nil, fmt.Errorf("expected %d raw bytes or a base64 key, got %d bytes "+
+		"that are neither", keySize, len(b))
+}
+
 // NewKeyring builds a keyring from a 32-byte key.
 func NewKeyring(key []byte) (*Keyring, error) {
-	if len(key) != 32 {
+	if len(key) != keySize {
-		return nil, fmt.Errorf("secret: master key must be 32 bytes, got %d", len(key))
+		return nil, fmt.Errorf("secret: master key must be %d bytes, got %d",
+			keySize, len(key))
 	}
 	block, err := aes.NewCipher(key)
 	if err != nil {

internal/secret/keyring_test.go

@@ -4,6 +4,7 @@ import (
 	"encoding/base64"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 )
 
@@ -90,3 +91,140 @@ func TestLoadKeyringRejectsAShortKey(t *testing.T) {
 		t.Fatal("a short master key was accepted")
 	}
 }
+
+// wrapWith is a helper: build a keyring from a known key and wrap a secret
+// with it, so another keyring can be checked for being the same key.
+func wrapWith(t *testing.T, key []byte) string {
+	t.Helper()
+	k, err := NewKeyring(key)
+	if err != nil {
+		t.Fatal(err)
+	}
+	wrapped, err := k.Wrap("v", "secret")
+	if err != nil {
+		t.Fatal(err)
+	}
+	return wrapped
+}
+
+// sameKey reports whether k is the keyring that produced wrapped.
+func sameKey(t *testing.T, k *Keyring, wrapped string) bool {
+	t.Helper()
+	got, err := k.Unwrap("v", wrapped)
+	return err == nil && got == "secret"
+}
+
+func TestMasterKeyFileEnvReadsAProvisionedSecret(t *testing.T) {
+	key := randBytes(32)
+	wrapped := wrapWith(t, key)
+
+	for _, tc := range []struct {
+		name    string
+		content []byte
+	}{
+		{"base64", []byte(base64.StdEncoding.EncodeToString(key))},
+		{"base64 with a trailing newline", []byte(base64.StdEncoding.EncodeToString(key) + "\n")},
+		{"base64 without padding", []byte(base64.RawStdEncoding.EncodeToString(key))},
+		{"32 raw bytes", key},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			path := filepath.Join(t.TempDir(), "secret")
+			if err := os.WriteFile(path, tc.content, 0o400); err != nil {
+				t.Fatal(err)
+			}
+			t.Setenv(MasterKeyEnv, "")
+			t.Setenv(MasterKeyFileEnv, path)
+			k, err := LoadKeyring("")
+			if err != nil {
+				t.Fatal(err)
+			}
+			if !sameKey(t, k, wrapped) {
+				t.Fatal("the key read from the secret file is not the one written")
+			}
+		})
+	}
+}
+
+// A secret that was supposed to be mounted and is not must be reported. A
+// new key minted in its place would open none of the existing vaults.
+func TestMissingSecretFileIsReportedAndMintsNothing(t *testing.T) {
+	dir := t.TempDir()
+	missing := filepath.Join(dir, "not-mounted")
+	configured := filepath.Join(dir, "master.key")
+	t.Setenv(MasterKeyEnv, "")
+	t.Setenv(MasterKeyFileEnv, missing)
+
+	_, err := LoadKeyring(configured)
+	if err == nil {
+		t.Fatal("a missing secret file was accepted")
+	}
+	if !strings.Contains(err.Error(), MasterKeyFileEnv) {
+		t.Fatalf("the error does not name the variable: %v", err)
+	}
+	if _, err := os.Stat(configured); !os.IsNotExist(err) {
+		t.Fatal("a replacement key was minted at the configured path")
+	}
+	if _, err := os.Stat(missing); !os.IsNotExist(err) {
+		t.Fatal("a key was written where the secret should have been mounted")
+	}
+}
+
+func TestMasterKeyEnvWinsOverTheSecretFile(t *testing.T) {
+	envKey, fileKey := randBytes(32), randBytes(32)
+	wrappedByEnv := wrapWith(t, envKey)
+
+	path := filepath.Join(t.TempDir(), "secret")
+	if err := os.WriteFile(path, fileKey, 0o400); err != nil {
+		t.Fatal(err)
+	}
+	t.Setenv(MasterKeyEnv, base64.StdEncoding.EncodeToString(envKey))
+	t.Setenv(MasterKeyFileEnv, path)
+
+	k, err := LoadKeyring("")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !sameKey(t, k, wrappedByEnv) {
+		t.Fatal("the secret file took precedence over the environment key")
+	}
+}
+
+func TestSecretFileWinsOverTheConfiguredPath(t *testing.T) {
+	secretKey := randBytes(32)
+	wrapped := wrapWith(t, secretKey)
+	dir := t.TempDir()
+
+	secretPath := filepath.Join(dir, "provisioned")
+	if err := os.WriteFile(secretPath, secretKey, 0o400); err != nil {
+		t.Fatal(err)
+	}
+	configured := filepath.Join(dir, "master.key")
+	if err := os.WriteFile(configured,
+		[]byte(base64.StdEncoding.EncodeToString(randBytes(32))), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	t.Setenv(MasterKeyEnv, "")
+	t.Setenv(MasterKeyFileEnv, secretPath)
+
+	k, err := LoadKeyring(configured)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !sameKey(t, k, wrapped) {
+		t.Fatal("the configured path took precedence over the provisioned secret")
+	}
+}
+
+func TestSecretFileContentIsValidated(t *testing.T) {
+	for _, content := range []string{"", "not base64 at all !!", "c2hvcnQ="} {
+		path := filepath.Join(t.TempDir(), "secret")
+		if err := os.WriteFile(path, []byte(content), 0o400); err != nil {
+			t.Fatal(err)
+		}
+		t.Setenv(MasterKeyEnv, "")
+		t.Setenv(MasterKeyFileEnv, path)
+		if _, err := LoadKeyring(""); err == nil {
+			t.Fatalf("content %q was accepted as a master key", content)
+		}
+	}
+}

internal/server/server.go

@@ -132,9 +132,10 @@ func (s *Server) checkVaultKeys() {
 	case broken > 0:
 		s.log.Printf("WARNING: %d of %d stored vault keys do not open with this "+
 			"master key. Those vaults cannot be merged until the original key is "+
-			"restored (%s or %s). Nothing is lost: clients still open the vaults "+
+			"restored ($%s, $%s, or %s). Nothing is lost: clients still open the "+
-			"with their own passwords.",
+			"vaults with their own passwords.",
-			broken, total, secret.MasterKeyEnv, s.cfg.MasterKeyFile)
+			broken, total, secret.MasterKeyEnv, secret.MasterKeyFileEnv,
+			s.cfg.MasterKeyFile)
 	}
 }
 

internal/server/vault.go

@@ -18,8 +18,9 @@ import (
 const MinVaultPasswordLen = 12
 
 var errNoKeyring = errors.New(
-	"this server has no master key, so it cannot hold vault keys: set " +
+	"this server has no master key, so it cannot hold vault keys: set $" +
-		secret.MasterKeyEnv + " or master_key_file and restart")
+		secret.MasterKeyEnv + ", $" + secret.MasterKeyFileEnv +
+		", or master_key_file, and restart")
 
 // createVault makes a new, empty KDBX database, encrypts it with the given
 // vault password and stores it as version 1. When the strategy needs the

packaging/deb/server/changelog

@@ -1,3 +1,16 @@
+keeporgd (0.4.0) unstable; urgency=medium
+
+  * Read the master key from the file named by KEEPORG_MASTER_KEY_FILE, the
+    convention compose, swarm and Kubernetes use for a provisioned secret.
+    The file may hold base64 or exactly 32 raw bytes.
+  * Neither master-key environment variable is ever created by the server:
+    a secret that failed to mount is reported at startup and vault creation
+    is refused, rather than replaced with a new key that would open none of
+    the existing vaults. Only the configured master_key_file is created on
+    first run.
+
+ -- tiredsysadmin <rcmd@garage.rcmd.space>  Fri, 30 Oct 2026 09:42:50 +0100
+
 keeporgd (0.3.0) unstable; urgency=medium
 
   * Container image: a scratch-based image of about 9 MB holding the static

packaging/docker/compose.yaml

@@ -1,24 +1,27 @@
-# A deployment of the KeepOrg server, showing the two things that are easy
+# A deployment of the KeepOrg server, showing the thing that is easiest to
-# to get wrong: where the master key comes from, and that it does not live
+# get wrong: where the master key comes from, and that it does not live in
-# in the data volume.
+# the data volume.
 #
-#   podman-compose up -d      (or docker compose up -d)
+#   head -c 32 /dev/urandom | base64 > master.key   # once; keep a copy safe
+#   chmod 600 master.key
+#   podman-compose up -d                            # or docker compose up -d
 #
-# Generate the master key once, and keep a copy somewhere safe:
+# The key is provisioned as a secret and named to the server with
-#   head -c 32 /dev/urandom | base64 > master.key
+# KEEPORG_MASTER_KEY_FILE, so it is never in the process environment and
-#
+# never on a disk the container can write. Without a key the server still
-# Without it the server still runs and still synchronizes; it only refuses
+# runs and still synchronizes; it only refuses to create or merge vaults.
-# to create or merge vaults.
 
 services:
   keeporgd:
-    # Override with KEEPORG_VERSION; `make docker` tags the version from
+    # `make docker` tags both the version from versions.mk and :latest.
-    # versions.mk and :latest.
+    # Pin with KEEPORG_VERSION in production.
-    image: keeporgd:${KEEPORG_VERSION:-0.3.0}
+    image: keeporgd:${KEEPORG_VERSION:-latest}
     build:
       context: ../..
       args:
-        VERSION: "${KEEPORG_VERSION:-0.3.0}"
+        # Only used when compose builds the image itself; `make docker`
+        # stamps the real version.
+        VERSION: "${KEEPORG_VERSION:-dev}"
     restart: unless-stopped
     # Terminate TLS in front of this, and set external_url to the address a
     # browser sees: invite links, device approval and the OIDC redirect are
@@ -29,23 +32,27 @@ services:
       - "-url=https://keeporg.example.com"
     ports:
       - "127.0.0.1:8765:8765"
+    secrets:
+      - keeporg_master_key
     environment:
-      # Preferred: the key never touches a disk the container can write.
+      KEEPORG_MASTER_KEY_FILE: /run/secrets/keeporg_master_key
-      # Read it from your secret store and pass it in.
+      # The alternative, when the key comes from a store that injects
-      KEEPORG_MASTER_KEY: "${KEEPORG_MASTER_KEY:?set KEEPORG_MASTER_KEY, see the comment above}"
+      # variables rather than files. One or the other, not both.
+      # KEEPORG_MASTER_KEY: "${KEEPORG_MASTER_KEY:-}"
+      #
       # Only read on the very first start, when no accounts exist yet.
       KEEPORG_ADMIN_PASSWORD: "${KEEPORG_ADMIN_PASSWORD:-}"
     volumes:
       - keeporg-data:/var/lib/keeporg
-      # Only needed instead of KEEPORG_MASTER_KEY above, or to mount a
-      # server.json. Keep it on different storage from keeporg-data.
-      # - keeporg-config:/etc/keeporg
     # The server writes one directory and needs no privileges at all.
     read_only: true
     cap_drop: ["ALL"]
     security_opt: ["no-new-privileges:true"]
     user: "65532:65532"
 
+secrets:
+  keeporg_master_key:
+    file: ./master.key
+
 volumes:
   keeporg-data:
-  # keeporg-config:

versions.mk

@@ -1,6 +1,6 @@
 # Single source of truth for all platform versions (semver).
 # Bump with: make bump PLATFORM=<server|linux|macos|windows|bsd|android> PART=<major|minor|patch>
-VERSION_SERVER   := 0.3.0
+VERSION_SERVER   := 0.4.0
 VERSION_LINUX    := 0.2.0
 VERSION_MACOS    := 0.2.0
 VERSION_WINDOWS  := 0.2.0