add env var to specify config location

cmd/headscale/cli/root.go

@@ -25,6 +25,9 @@ func init() {
 }
 
 func initConfig() {
+	if cfgFile == "" {
+		cfgFile = os.Getenv("HEADSCALE_CONFIG")
+	}
 	if cfgFile != "" {
 		err := headscale.LoadConfig(cfgFile, true)
 		if err != nil {

integration_cli_test.go

@@ -1739,6 +1739,8 @@ func (s *IntegrationCLITestSuite) TestLoadConfigFromCommand() {
 	assert.Nil(s.T(), err)
 	altConfig, err := os.ReadFile("integration_test/etc/alt-config.dump.gold.yaml")
 	assert.Nil(s.T(), err)
+	altEnvConfig, err := os.ReadFile("integration_test/etc/alt-env-config.dump.gold.yaml")
+	assert.Nil(s.T(), err)
 
 	_, err = ExecuteCommand(
 		&s.headscale,
@@ -1771,4 +1773,40 @@ func (s *IntegrationCLITestSuite) TestLoadConfigFromCommand() {
 	assert.Nil(s.T(), err)
 
 	assert.YAMLEq(s.T(), string(altConfig), string(altDumpConfig))
+
+	_, err = ExecuteCommand(
+		&s.headscale,
+		[]string{
+			"headscale",
+			"dumpConfig",
+		},
+		[]string{
+			"HEADSCALE_CONFIG=/etc/headscale/alt-env-config.yaml",
+		},
+	)
+	assert.Nil(s.T(), err)
+
+	altEnvDumpConfig, err := os.ReadFile("integration_test/etc/config.dump.yaml")
+	assert.Nil(s.T(), err)
+
+	assert.YAMLEq(s.T(), string(altEnvConfig), string(altEnvDumpConfig))
+
+	_, err = ExecuteCommand(
+		&s.headscale,
+		[]string{
+			"headscale",
+			"-c",
+			"/etc/headscale/alt-config.yaml",
+			"dumpConfig",
+		},
+		[]string{
+			"HEADSCALE_CONFIG=/etc/headscale/alt-env-config.yaml",
+		},
+	)
+	assert.Nil(s.T(), err)
+
+	altDumpConfig, err = os.ReadFile("integration_test/etc/config.dump.yaml")
+	assert.Nil(s.T(), err)
+
+	assert.YAMLEq(s.T(), string(altConfig), string(altDumpConfig))
 }

integration_test/etc/alt-env-config.dump.gold.yaml

@@ -0,0 +1,47 @@
+acl_policy_path: ""
+cli:
+  insecure: false
+  timeout: 5s
+db_path: /tmp/integration_test_db.sqlite3
+db_type: sqlite3
+derp:
+  auto_update_enabled: false
+  server:
+    enabled: false
+    stun:
+      enabled: true
+  update_frequency: 1m
+  urls:
+    - https://controlplane.tailscale.com/derpmap/default
+dns_config:
+  base_domain: headscale.net
+  domains: []
+  magic_dns: true
+  nameservers:
+    - 1.1.1.1
+ephemeral_node_inactivity_timeout: 30m
+node_update_check_interval: 100s
+grpc_allow_insecure: false
+grpc_listen_addr: :50443
+ip_prefixes:
+  - fd7a:115c:a1e0::/48
+  - 100.64.0.0/10
+listen_addr: 0.0.0.0:18080
+log_level: disabled
+logtail:
+  enabled: false
+metrics_listen_addr: 127.0.0.1:19090
+oidc:
+  scope:
+    - openid
+    - profile
+    - email
+  strip_email_domain: true
+private_key_path: private.key
+server_url: http://headscale:18080
+tls_client_auth_mode: relaxed
+tls_letsencrypt_cache_dir: /var/www/.cache
+tls_letsencrypt_challenge_type: HTTP-01
+unix_socket: /var/run/headscale.sock
+unix_socket_permission: "0o770"
+randomize_client_port: false

integration_test/etc/alt-env-config.yaml

@@ -0,0 +1,25 @@
+log_level: trace
+acl_policy_path: ""
+db_type: sqlite3
+ephemeral_node_inactivity_timeout: 30m
+node_update_check_interval: 100s
+ip_prefixes:
+  - fd7a:115c:a1e0::/48
+  - 100.64.0.0/10
+dns_config:
+  base_domain: headscale.net
+  magic_dns: true
+  domains: []
+  nameservers:
+    - 1.1.1.1
+db_path: /tmp/integration_test_db.sqlite3
+private_key_path: private.key
+listen_addr: 0.0.0.0:18080
+metrics_listen_addr: 127.0.0.1:19090
+server_url: http://headscale:18080
+
+derp:
+  urls:
+    - https://controlplane.tailscale.com/derpmap/default
+  auto_update_enabled: false
+  update_frequency: 1m