This commit is contained in:
Chris Bednarski 2015-11-18 16:45:39 -08:00
parent b9999dffbe
commit ea2756d6fb

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@ -32,8 +32,8 @@ task "webservice" {
The following options are available for use in the job specification. The following options are available for use in the job specification.
* `image` - The Docker image to run. The image may include a tag or * `image` - The Docker image to run. The image may include a tag or custom URL.
custom URL. By default it will be fetched from Docker Hub. By default it will be fetched from Docker Hub.
* `command` - (Optional) The command to run when starting the container. * `command` - (Optional) The command to run when starting the container.
@ -57,8 +57,9 @@ The following options are available for use in the job specification.
* `hostname` - (Optional) The hostname to assign to the container. When * `hostname` - (Optional) The hostname to assign to the container. When
launching more than one of a task (using `count`) with this option set, every launching more than one of a task (using `count`) with this option set, every
container the task starts will have the same hostname.* `dns_servers` - (Optional) A list of DNS servers for the container to use container the task starts will have the same hostname.* `dns_servers` -
(e.g. ["8.8.8.8", "8.8.4.4"]). *Docker API v1.10 and above only* (Optional) A list of DNS servers for the container to use (e.g. ["8.8.8.8",
"8.8.4.4"]). *Docker API v1.10 and above only*
* `search_domains` - (Optional) A list of DNS search domains for the container * `search_domains` - (Optional) A list of DNS search domains for the container
to use. to use.
@ -69,13 +70,17 @@ The following options are available for use in the job specification.
### Container Name ### Container Name
Nomad creates a container after pulling an image. Containers are named `{taskName}-{allocId}`. This is necessary in order to place more than one container from the same task on a host (e.g. with count > 1). This also means that each container's name is unique across the cluster. Nomad creates a container after pulling an image. Containers are named
`{taskName}-{allocId}`. This is necessary in order to place more than one
container from the same task on a host (e.g. with count > 1). This also means
that each container's name is unique across the cluster.
This is not configurable. This is not configurable.
### Authentication ### Authentication
If you want to pull from a private repo (for example on dockerhub or quay.io), you will need to specify credentials in your job via the `auth` option. If you want to pull from a private repo (for example on dockerhub or quay.io),
you will need to specify credentials in your job via the `auth` option.
The `auth` object supports the following keys: The `auth` object supports the following keys:
@ -103,11 +108,13 @@ task "secretservice" {
} }
``` ```
**Please note that these credentials are stored in Nomad in plain text.** Secrets management will be added in a later release. **Please note that these credentials are stored in Nomad in plain text.**
Secrets management will be added in a later release.
## Networking ## Networking
Docker supports a variety of networking configurations, including using host interfaces, SDNs, etc. Nomad uses `bridged` networking by default, like Docker. Docker supports a variety of networking configurations, including using host
interfaces, SDNs, etc. Nomad uses `bridged` networking by default, like Docker.
You can specify other networking options, including custom networking plugins You can specify other networking options, including custom networking plugins
in Docker 1.9. **You may need to perform additional configuration on the host in Docker 1.9. **You may need to perform additional configuration on the host
@ -116,7 +123,8 @@ scope of Nomad.
### Allocating Ports ### Allocating Ports
You can allocate ports to your task using the port syntax described on the [networking page](/docs/jobspec/networking.html). Here is a recap: You can allocate ports to your task using the port syntax described on the
[networking page](/docs/jobspec/networking.html). Here is a recap:
``` ```
task "webservice" { task "webservice" {
@ -129,9 +137,12 @@ task "webservice" {
### Forwarding and Exposing Ports ### Forwarding and Exposing Ports
A Docker container typically specifies which port a service will listen on by specifying the `EXPOSE` directive in the `Dockerfile`. A Docker container typically specifies which port a service will listen on by
specifying the `EXPOSE` directive in the `Dockerfile`.
Because dynamic ports will not match the ports exposed in your Dockerfile, Nomad will automatically expose all of the ports it allocates to your container. Because dynamic ports will not match the ports exposed in your Dockerfile,
Nomad will automatically expose all of the ports it allocates to your
container.
These ports will be identified via environment variables. For example: These ports will be identified via environment variables. For example:
@ -139,13 +150,18 @@ These ports will be identified via environment variables. For example:
port "http" {} port "http" {}
``` ```
If Nomad allocates port `23332` to your task for `http`, `23332` will be automatically exposed and forwarded to your container, and the driver will set an environment variable `NOMAD_PORT_http` with the value `23332` that you can read inside your container. If Nomad allocates port `23332` to your task for `http`, `23332` will be
automatically exposed and forwarded to your container, and the driver will set
an environment variable `NOMAD_PORT_http` with the value `23332` that you can
read inside your container.
This provides an easy way to use the `host` networking option for better performance. This provides an easy way to use the `host` networking option for better
performance.
### Using the Port Map ### Using the Port Map
If you prefer to use the traditional port-mapping method, you can specify the `port_map` option in your job specification. It looks like this: If you prefer to use the traditional port-mapping method, you can specify the
`port_map` option in your job specification. It looks like this:
``` ```
task "redis" { task "redis" {
@ -162,9 +178,13 @@ task "redis" {
} }
``` ```
If Nomad allocates port `23332` to your task, the Docker driver will automatically setup the port mapping from `23332` on the host to `6379` in your container, so it will just work! If Nomad allocates port `23332` to your task, the Docker driver will
automatically setup the port mapping from `23332` on the host to `6379` in your
container, so it will just work!
Note that by default this only works with `bridged` networking mode. It may also work with custom networking plugins which implement the same API for expose and port forwarding. Note that by default this only works with `bridged` networking mode. It may
also work with custom networking plugins which implement the same API for
expose and port forwarding.
### Networking Protocols ### Networking Protocols
@ -174,7 +194,9 @@ This is not configurable.
### Other Networking Modes ### Other Networking Modes
Some networking modes like `container` or `none` will require coordination outside of Nomad. First-class support for these options may be improved later through Nomad plugins or dynamic job configuration. Some networking modes like `container` or `none` will require coordination
outside of Nomad. First-class support for these options may be improved later
through Nomad plugins or dynamic job configuration.
## Host Requirements ## Host Requirements
@ -210,7 +232,8 @@ The `docker` driver has the following host-level configuration options:
* `docker.privileged.enabled` Defaults to `false`. Changing this to `true` will * `docker.privileged.enabled` Defaults to `false`. Changing this to `true` will
allow containers to use `privileged` mode, which gives the containers full allow containers to use `privileged` mode, which gives the containers full
access to the host's devices. Note that you must set a similar setting on the Docker daemon for this to work. access to the host's devices. Note that you must set a similar setting on the
Docker daemon for this to work.
Note: When testing or using the `-dev` flag you can use `DOCKER_HOST`, Note: When testing or using the `-dev` flag you can use `DOCKER_HOST`,
`DOCKER_TLS_VERIFY`, and `DOCKER_CERT_PATH` to customize Nomad's behavior. In `DOCKER_TLS_VERIFY`, and `DOCKER_CERT_PATH` to customize Nomad's behavior. In