NATS logging driver

Docker logging driver for sending container the logs as events published to NATS in JSON format.

Usage

You can configure the default logging driver by passing the --log-driver option to the Docker daemon:

$ dockerd --log-driver=nats

You can set the logging driver for a specific container by using the --log-driver option to docker run:

$ docker run --log-driver=nats ...

This log driver does not implement a reader so it is incompatible with docker logs.

nats options

You can use the --log-opt NAME=VALUE flag to customize the logging driver for NATS:

Option	Required	Description
labels	optional	Comma-separated list of keys of labels, which should be included in message, if these labels are specified for container.
env	optional	Comma-separated list of keys of environment variables, which should be included in message, if these variables are specified for container.
tag	optional	Specify tag for message. Refer to the log tag option documentation for customizing the log tag format.
nats-servers	optional	NATS cluster nodes separated by commas. e.g. nats://127.0.0.1:4222,nats://127.0.0.1:4223. Defaults to localhost:4222
nats-max-reconnect	optional	Maximum attempts that the driver will try to connect before giving up. Defaults to infinite (-1)
nats-subject	optional	Specific subject to which logs will be published. Defaults to using tag if not specified
nats-user	optional	Specify user in case of authentication required
nats-pass	optional	Specify password in case of authentication required
nats-token	optional	Specify token in case of authentication required
nats-tls-ca-cert	optional	Specified the absolute path to the trust certificates signed by the CA
nats-tls-cert	optional	Specifies the absolute path to the TLS certificate file
nats-tls-key	optional	Specifies the absolute path to the TLS key file
nats-tls-skip-verify	optional	Specifies whether to skip verification by setting it to true

Below is an example usage of the driver for sending logs to a node in a NATS cluster to the docker.logs subject:

$ docker run --log-driver=nats \
             --log-opt nats-subject=docker.logs \
             --log-opt nats-servers=nats://nats-node-1:4222,nats://nats-node-2:4222,nats://nats-node-3:4222 \
             your/application

By default, the tag is used as the subject for NATS, so it has to be a valid subject in case subject it is left unspecified:

$ docker run --log-driver nats \
             --log-opt tag="docker.{{.ID}}.{{.ImageName}}"
             your/application

Secure connection to NATS using TLS can be customized by setting tls:// scheme in the URI and absolute paths to the certs and key files:

docker run --log-driver nats \
           --log-opt nats-tls-key=/srv/configs/certs/client-key.pem \
           --log-opt nats-tls-cert=/srv/configs/certs/client-cert.pem \
           --log-opt nats-tls-ca-cert=/srv/configs/certs/ca.pem \
           --log-opt nats-servers="tls://127.0.0.1:4223,tls://127.0.0.1:4222" \
           your/application

Skip verify is enabled by default, in order to deactivate we can specify nats-tls-skip-verify:

  docker run --log-driver nats \
             --log-opt nats-tls-skip-verify \
             --log-opt nats-servers="tls://127.0.0.1:4223,tls://127.0.0.1:4222" \
             your/application