@ -62,17 +62,23 @@ Any of the options described below can be passed to the watchtower process by se
docker run --rm centurylink/watchtower --help
```
* `--host, -h` - Docker daemon socket to connect to. Defaults to "unix:///var/run/docker.sock" but can be pointed at a remote Docker host by specifying a TCP endpoint as "tcp://hostname:port". The host value can also be provided by setting the `DOCKER_HOST` environment variable.
* `--interval, -i` - Poll interval (in seconds). This value controls how frequently watchtower will poll for new images. Defaults to 300 seconds (5 minutes).
* `--no-pull` - Do not pull new images. When this flag is specified, watchtower will not attempt to pull new images from the registry. Instead it will only monitor the local image cache for changes. Use this option if you are building new images directly on the Docker host without pushing them to a registry.
* `--cleanup` - Remove old images after updating. When this flag is specified, watchtower will remove the old image after restarting a container with a new image. Use this option to prevent the accumulation of orphaned images on your system as containers are updated.
* `--tls` - Use TLS when connecting to the Docker socket but do NOT verify the server's certificate. If you are connecting a TCP Docker socket protected by TLS you'll need to use either this flag or the `--tlsverify` flag (described below). The `--tlsverify` flag is preferred as it will cause the server's certificate to be verified before a connection is made.
* `--tlsverify` - Use TLS when connecting to the Docker socket and verify the server's certificate. If you are connecting a TCP Docker socket protected by TLS you'll need to use either this flag or the `--tls` flag (describe above).
* `--tlscacert` - Trust only certificates signed by this CA. Used in conjunction with the `--tlsverify` flag to identify the CA certificate which should be used to verify the identity of the server. The value for this flag can be either the fully-qualified path to the *.pem* file containing the CA certificate or a string containing the CA certificate itself. Defaults to "/etc/ssl/docker/ca.pem".
* `--tlscert` - Client certificate for TLS authentication. Used in conjunction with the `--tls` or `--tlsverify` flags to identify the certificate to use for client authentication. The value for this flag can be either the fully-qualified path to the *.pem* file containing the client certificate or a string containing the certificate itself. Defaults to "/etc/ssl/docker/cert.pem".
* `--tlskey` - Client key for TLS authentication. Used in conjunction with the `--tls` or `--tlsverify` flags to identify the key to use for client authentication. The value for this flag can be either the fully-qualified path to the *.pem* file containing the client key or a string containing the key itself. Defaults to "/etc/ssl/docker/key.pem".
* `--debug` - Enable debug mode. When this option is specified you'll see more verbose logging in the watchtower log file.
* `--help` - Show documentation about the supported flags.
* `--host, -h` Docker daemon socket to connect to. Defaults to "unix:///var/run/docker.sock" but can be pointed at a remote Docker host by specifying a TCP endpoint as "tcp://hostname:port". The host value can also be provided by setting the `DOCKER_HOST` environment variable.
* `--interval, -i` Poll interval (in seconds). This value controls how frequently watchtower will poll for new images. Defaults to 300 seconds (5 minutes).
* `--no-pull` Do not pull new images. When this flag is specified, watchtower will not attempt to pull new images from the registry. Instead it will only monitor the local image cache for changes. Use this option if you are building new images directly on the Docker host without pushing them to a registry.
* `--cleanup` Remove old images after updating. When this flag is specified, watchtower will remove the old image after restarting a container with a new image. Use this option to prevent the accumulation of orphaned images on your system as containers are updated.
* `--tls` Use TLS when connecting to the Docker socket but do NOT verify the server's certificate. If you are connecting a TCP Docker socket protected by TLS you'll need to use either this flag or the `--tlsverify` flag (described below). The `--tlsverify` flag is preferred as it will cause the server's certificate to be verified before a connection is made.
* `--tlsverify` Use TLS when connecting to the Docker socket and verify the server's certificate. If you are connecting a TCP Docker socket protected by TLS you'll need to use either this flag or the `--tls` flag (describe above).
* `--tlscacert` Trust only certificates signed by this CA. Used in conjunction with the `--tlsverify` flag to identify the CA certificate which should be used to verify the identity of the server. The value for this flag can be either the fully-qualified path to the *.pem* file containing the CA certificate or a string containing the CA certificate itself. Defaults to "/etc/ssl/docker/ca.pem".
* `--tlscert` Client certificate for TLS authentication. Used in conjunction with the `--tls` or `--tlsverify` flags to identify the certificate to use for client authentication. The value for this flag can be either the fully-qualified path to the *.pem* file containing the client certificate or a string containing the certificate itself. Defaults to "/etc/ssl/docker/cert.pem".
* `--tlskey` Client key for TLS authentication. Used in conjunction with the `--tls` or `--tlsverify` flags to identify the key to use for client authentication. The value for this flag can be either the fully-qualified path to the *.pem* file containing the client key or a string containing the key itself. Defaults to "/etc/ssl/docker/key.pem".
* `--debug` Enable debug mode. When this option is specified you'll see more verbose logging in the watchtower log file.
* `--help` Show documentation about the supported flags.
## Linked Containers
Watchtower will detect if there are links between any of the running containers and ensure that things are stopped/started in a way that won't break any of the links. If an update is detected for one of the dependencies in a group of linked containers, watchtower will stop and start all of the containers in the correct order so that the application comes back up correctly.
For example, imagine you were running a *mysql* container and a *wordpress* container which had been linked to the *mysql* container. If watchtower were to detect that the *mysql* container required an update, it would first shut down the linked *wordpress* container followed by the *mysql* container. When restarting the containers it would handle *mysql* first and then *wordpress* to ensure that the link continued to work.
Brian DeHamer
9 years ago