ngcplogs

Dockerhub

A modified version of the standard gcplogs docker logging driver. The standard gcplogs driver does not process the output from the containers, which means JSON logs result in a log like this:

gcplogs sample log

{
  "insertId": "1x3kge4f3if919",
  "jsonPayload": {
    "instance": {
      "id": "5968118946548037465",
      "zone": "us-east1-b",
      "name": "gcp-vm"
    },
    "message": "{\"app\":\"sample-app\",\"level\":\"error\",\"msg\":\"Error authenticating user\",\"time\":\"2024-03-14T13:27:42Z\"}",
    "container": {
      "imageId": "sha256:360b4beb988621daaa87572c42af11142a14ecc7c3a5b4cdf221d5d97b19acdc",
      "id": "32c7e2402ec77cf94121a52c9d284939038d0dff9952696a17b2fa6da74f47bb0",
      "imageName": "nanoandrew4/some-image",
      "name": "/sample-app",
      "created": "2023-09-07T23:01:22.718629265Z"
    }
  },
  "resource": {
    "type": "gce_instance",
    "labels": {
      "instance_id": "12345",
      "zone": "us-east1-b",
      "project_id": "someproject"
    }
  },
  "timestamp": "2024-03-14T13:27:42.033851150Z",
  "logName": "projects/someproject/logs/gcplogs-docker-driver",
  "receiveTimestamp": "2024-03-14T13:27:42.670937226Z"
}

This driver behaves similarly to the gcplogs one, but if it detects a JSON log, it unmarshals it and sends the unmarshalled map as the payload, resulting in a log like this (with the default options):

ngcplogs sample log

{
  "insertId": "yero77f8j919i9",
  "jsonPayload": {
    "message": "Updating at 2024-03-15 11:21:38.56773049 +0000 UTC m=+901.837891394\n",
    "app": "sample-app",
    "container": {
      "created": "2024-03-15T11:06:28.730214829Z",
      "id": "af2c42f7720c8dec812abc5d7cee903aaadf1cd04d87488f3ab1657b92977bc6",
      "name": "/sample-app",
      "imageId": "sha256:360b4beb988121df8587572c42af15102a14ecc7c3a5d4cdf221d5d67b29acdc",
      "imageName": "nanoandrew4/sample-app"
    },
    "instance": {
      "zone": "us-east1-b",
      "name": "gcp-vm",
      "id": "8319386972505717539"
    },
    "time": "2024-03-15T11:21:40Z"
  },
  "resource": {
    "type": "gce_instance",
    "labels": {
      "zone": "us-east1-b",
      "instance_id": "8390836155502727539",
      "project_id": "someproject"
    }
  },
  "timestamp": "2024-03-15T11:21:40.080322442Z",
  "severity": "INFO",
  "logName": "projects/someproject/logs/ngcplogs-docker-driver",
  "receiveTimestamp": "2024-03-15T11:21:44.099223634Z"
}

Non JSON logs will not be processed, and will be sent to GCP as they were received, without being manipulated.

Installation

The examples assume you want to use the amd64 version of the plugin, but you can replace it for another of the available tags

docker plugin install nanoandrew4/ngcplogs:linux-amd64-v1.3.0 --grant-all-permissions

In your daemon.json file, change the log-driver to nanoandrew4/ngcplogs:linux-amd64-v1.3.0, or just use the logging driver on specific containers instead of applying it globally.

If you have modified your daemon.json file, restart the daemon and docker services:

If you are running the plugin outside GCP, make sure to set the gcp-project log option, as well as either the credentials-file or credentials-json log option.

sudo systemctl daemon-reload && sudo systemctl restart docker

Upgrading

The examples assume you want to use the amd64 version of the plugin, but you can replace it for another of the available tags

First stop all containers using the plugin. Once they are all stopped, run the following commands to upgrade from v1.2.0 to linux-amd64-v1.3.0

docker plugin disable nanoandrew4/ngcplogs:v1.2.0
docker plugin rm nanoandrew4/ngcplogs:v1.2.0
docker plugin install nanoandrew4/ngcplogs:linux-amd64-v1.3.0 --grant-all-permissions

If you initially configured ngcplogs to be used globally in your daemon.json file, change the log-driver to nanoandrew4/ngcplogs:linux-amd64-v1.3.0. Finally, restart the daemon and docker services:

sudo systemctl daemon-reload && sudo systemctl restart docker

Start all your containers again, and they should be using the new version of the plugin

Configuration

The following log-opts are available for configuration:

log-opt	default	description
extract-json-message	true	Enables unmarshalling JSON messages and sending the jsonPayload as the unmarshalled map. Kind of the whole point of this plugin, but you can disable it so it behaves just like the gcplogs plugin if you wish
local-logging	false	Enables logging to a local file, so logs can be viewed with the docker logs command. If false, the command will show no output
extract-severity	true	Extracts the severity from JSON logs to set them for the log that will be sent to GCP. It will be removed from the jsonPayload section, since it is set at the root level. Currently the supported severity field names to extract are the following: severity, level
extract-msg	true	Extracts the msg field from JSON logs to set the message field GCP expects. It will be removed from the jsonPayload section, since it is set at the root level. Fields named msg are produced for example by the golang log/slog package.
extract-gcp	false	Extract trace, labels and source location fields if present and formatted for Google cloud logging. This is produced for example by the golang log/slog package with the slogdriver handler
extract-caddy	false	Extract trace and HTTP Request from caddy if present and format for Google cloud logging.
exclude-timestamp	false	Excludes timestamp fields from the final jsonPayload, since docker sends its own nanosecond precision timestamp for each log. Currently it can remove fields with the following names: timestamp, time, ts
sleep-interval	500	Milliseconds to sleep when there are no logs to send before checking again. The higher the value, the lower the CPU usage will be
credentials-file		Absolute path to the GCP credentials JSON file to use when authenticating (only necessary when running the plugin outside of GCP)
credentials-json		JSON string with the GCP credentials to use when authenticating (only necessary when running the plugin outside of GCP)

Building locally

To build locally, you first must install docker buildx.

If you want to build the plugin yourself for all supported architectures, use the makefile with the following command

make all

If you only want to build a specific architecture, run the following command, specifying the architecture to build

make all PLUGIN_SUPPORTED_ARCHS=linux/amd64