diff options
| -rw-r--r-- | src/main.rs | 88 |
1 files changed, 57 insertions, 31 deletions
diff --git a/src/main.rs b/src/main.rs index b96467f643dd..9db3c94ecf39 100644 --- a/src/main.rs +++ b/src/main.rs @@ -21,16 +21,15 @@ //! to Stackdriver in batches. //! //! Stackdriver Logging has a concept of monitored resources. In the -//! simplest (and currently only supported) case this monitored -//! resource will be the GCE instance on which journaldriver is -//! running. +//! simplest case this monitored resource will be the GCE instance on +//! which journaldriver is running. //! //! Information about the instance, the project and required security //! credentials are retrieved from Google's metadata instance on GCP. //! -//! Things left to do: -//! * TODO 2018-06-15: Support non-GCP instances (see comment on -//! monitored resource descriptor) +//! To run journaldriver on non-GCP machines, users must specify the +//! `GOOGLE_APPLICATION_CREDENTIALS`, `GOOGLE_CLOUD_PROJECT` and +//! `LOG_NAME` environment variables. #[macro_use] extern crate failure; #[macro_use] extern crate hyper; @@ -103,17 +102,13 @@ lazy_static! { .build().expect("Could not create metadata client") }; - /// ID of the GCP project in which this instance is running. - static ref PROJECT_ID: String = get_metadata(METADATA_PROJECT_URL) - .expect("Could not determine project ID"); + /// ID of the GCP project to which to send logs. + static ref PROJECT_ID: String = get_project_id(); - /// ID of the current GCP instance. - static ref INSTANCE_ID: String = get_metadata(METADATA_ID_URL) - .expect("Could not determine instance ID"); - - /// GCP zone in which this instance is running. - static ref ZONE: String = get_metadata(METADATA_ZONE_URL) - .expect("Could not determine instance zone"); + /// Name of the log to write to (this should only be manually + /// configured if not running on GCP): + static ref LOG_NAME: String = env::var("LOG_NAME") + .unwrap_or("journaldriver".into()); /// Service account credentials (if configured) static ref SERVICE_ACCOUNT_CREDENTIALS: Option<Credentials> = @@ -121,20 +116,10 @@ lazy_static! { .and_then(|path| File::open(path).ok()) .and_then(|file| serde_json::from_reader(file).ok()); - /// Descriptor of the currently monitored instance. - /// - /// For GCE instances, this will be the GCE instance ID. For - /// non-GCE machines a sensible solution may be using the machine - /// hostname as a Cloud Logging log name, but this is not yet - /// implemented. - static ref MONITORED_RESOURCE: Value = json!({ - "type": "gce_instance", - "labels": { - "project_id": PROJECT_ID.as_str(), - "instance_id": INSTANCE_ID.as_str(), - "zone": ZONE.as_str(), - } - }); + /// Descriptor of the currently monitored instance. Refer to the + /// documentation of `determine_monitored_resource` for more + /// information. + static ref MONITORED_RESOURCE: Value = determine_monitored_resource(); /// Path to the file in which journaldriver should persist its /// cursor state. @@ -153,6 +138,47 @@ fn get_metadata(url: &str) -> Result<String> { Ok(output.trim().into()) } +/// Convenience helper for determining the project ID. +fn get_project_id() -> String { + env::var("GOOGLE_CLOUD_PROJECT") + .map_err(Into::into) + .or_else(|_: failure::Error| get_metadata(METADATA_PROJECT_URL)) + .expect("Could not determine project ID") +} + +/// Determines the monitored resource descriptor used in Stackdriver +/// logs. On GCP this will be set to the instance ID as returned by +/// the metadata server. +/// +/// On non-GCP machines the value is determined by using the +/// `GOOGLE_CLOUD_PROJECT` and `LOG_NAME` environment variables. +fn determine_monitored_resource() -> Value { + if let Ok(log) = env::var("LOG_NAME") { + json!({ + "type": "logging_log", + "labels": { + "project_id": PROJECT_ID.as_str(), + "name": log, + } + }) + } else { + let instance_id = get_metadata(METADATA_ID_URL) + .expect("Could not determine instance ID"); + + let zone = get_metadata(METADATA_ZONE_URL) + .expect("Could not determine instance zone"); + + json!({ + "type": "gce_instance", + "labels": { + "project_id": PROJECT_ID.as_str(), + "instance_id": instance_id, + "zone": zone, + } + }) + } +} + /// Represents the response returned by the metadata server's token /// endpoint. The token is normally valid for an hour. #[derive(Deserialize)] @@ -456,7 +482,7 @@ fn flush(client: &Client, /// https://cloud.google.com/logging/docs/reference/v2/rest/v2/entries/write fn prepare_request(entries: &[LogEntry]) -> Value { json!({ - "logName": format!("projects/{}/logs/journaldriver", PROJECT_ID.as_str()), + "logName": format!("projects/{}/logs/{}", PROJECT_ID.as_str(), LOG_NAME.as_str()), "resource": &*MONITORED_RESOURCE, "entries": entries, "partialSuccess": true |