Merge pull request #42134 from tazjin/feat/journaldriver

Add package & NixOS module for journaldriver

1 files changed, 112 insertions, 0 deletions

diff --git a/nixos/modules/services/logging/journaldriver.nix b/nixos/modules/services/logging/journaldriver.nix
new file mode 100644
index 000000000000..74ac3d4c2365
--- /dev/null
+++ b/nixos/modules/services/logging/journaldriver.nix
@@ -0,0 +1,112 @@
+# This module implements a systemd service for running journaldriver,
+# a log forwarding agent that sends logs from journald to Stackdriver
+# Logging.
+#
+# It can be enabled without extra configuration when running on GCP.
+# On machines hosted elsewhere, the other configuration options need
+# to be set.
+#
+# For further information please consult the documentation in the
+# upstream repository at: https://github.com/aprilabank/journaldriver/
+
+{ config, lib, pkgs, ...}:
+
+with lib; let cfg = config.services.journaldriver;
+in {
+  options.services.journaldriver = {
+    enable = mkOption {
+      type        = types.bool;
+      default     = false;
+      description = ''
+        Whether to enable journaldriver to forward journald logs to
+        Stackdriver Logging.
+      '';
+    };
+
+    logLevel = mkOption {
+      type        = types.str;
+      default     = "info";
+      description = ''
+        Log level at which journaldriver logs its own output.
+      '';
+    };
+
+    logName = mkOption {
+      type        = with types; nullOr str;
+      default     = null;
+      description = ''
+        Configures the name of the target log in Stackdriver Logging.
+        This option can be set to, for example, the hostname of a
+        machine to improve the user experience in the logging
+        overview.
+      '';
+    };
+
+    googleCloudProject = mkOption {
+      type        = with types; nullOr str;
+      default     = null;
+      description = ''
+        Configures the name of the Google Cloud project to which to
+        forward journald logs.
+
+        This option is required on non-GCP machines, but should not be
+        set on GCP instances.
+      '';
+    };
+
+    logStream = mkOption {
+      type        = with types; nullOr str;
+      default     = null;
+      description = ''
+        Configures the name of the Stackdriver Logging log stream into
+        which to write journald entries.
+
+        This option is required on non-GCP machines, but should not be
+        set on GCP instances.
+      '';
+    };
+
+    applicationCredentials = mkOption {
+      type        = with types; nullOr path;
+      default     = null;
+      description = ''
+        Path to the service account private key (in JSON-format) used
+        to forward log entries to Stackdriver Logging on non-GCP
+        instances.
+
+        This option is required on non-GCP machines, but should not be
+        set on GCP instances.
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+    systemd.services.journaldriver = {
+      description = "Stackdriver Logging journal forwarder";
+      script      = "${pkgs.journaldriver}/bin/journaldriver";
+      after       = [ "network-online.target" ];
+      wantedBy    = [ "multi-user.target" ];
+
+      serviceConfig = {
+        Restart        = "always";
+        DynamicUser    = true;
+
+        # This directive lets systemd automatically configure
+        # permissions on /var/lib/journaldriver, the directory in
+        # which journaldriver persists its cursor state.
+        StateDirectory = "journaldriver";
+
+        # This group is required for accessing journald.
+        SupplementaryGroups = "systemd-journal";
+      };
+
+      environment = {
+        RUST_LOG                       = cfg.logLevel;
+        LOG_NAME                       = cfg.logName;
+        LOG_STREAM                     = cfg.logStream;
+        GOOGLE_CLOUD_PROJECT           = cfg.googleCloudProject;
+        GOOGLE_APPLICATION_CREDENTIALS = cfg.applicationCredentials;
+      };
+    };
+  };
+}