Configure layer 7 routing service¶

To further customize the layer 7 routing solution, you must update the ucp-interlock service with a new Docker configuration.

1. Find out what configuration is currently being used for the ucp-interlock service and save it to a file:

   CURRENT_CONFIG_NAME=$(docker service inspect --format '{{ (index .Spec.TaskTemplate.ContainerSpec.Configs 0).ConfigName }}' ucp-interlock)
   docker config inspect --format '{{ printf "%s" .Spec.Data }}' $CURRENT_CONFIG_NAME > config.toml
   

2. Make the necessary changes to the config.toml file.

3. Create a new Docker configuration object from the config.toml file:

   NEW_CONFIG_NAME="com.docker.ucp.interlock.conf-$(( $(cut -d '-' -f 2 <<< "$CURRENT_CONFIG_NAME") + 1 ))"
   docker config create $NEW_CONFIG_NAME config.toml
   

4. Update the ucp-interlock service to start using the new configuration:

   docker service update \
     --config-rm $CURRENT_CONFIG_NAME \
     --config-add source=$NEW_CONFIG_NAME,target=/config.toml \
     ucp-interlock
   

By default, the ucp-interlock service is configured to roll back to a previous stable configuration if you provide an invalid configuration.

If you want the service to pause instead of rolling back, you can update it with the following command:

docker service update \
  --update-failure-action pause \
  ucp-interlock

If you’ve customized the configuration used by the ucp-interlock service, you must update it again to use the Docker configuration object you’ve created.

TOML file configuration options¶

The following sections describe how to configure the primary Interlock services:

• Core
• Extension
• Proxy

Core configuration¶

The core configuration handles the Interlock service itself. The following configuration options are available for the ucp-interlock service.

Option	Type	Description
ListenAddr	string	Address to serve the Interlock GRPC API. Defaults to 8080.
DockerURL	string	Path to the socket or TCP address to the Docker API. Defaults to unix:// /var/run/docker.sock
TLSCACert	string	Path to the CA certificate for connecting securely to the Docker API.
TLSCert	string	Path to the certificate for connecting securely to the Docker API.
TLSKey	string	Path to the key for connecting securely to the Docker API.
AllowInsecure	bool	Skip TLS verification when connecting to the Docker API via TLS.
PollInterval	string	Interval to poll the Docker API for changes. Defaults to 3s.
EndpointOverride	string	Override the default GRPC API endpoint for extensions. The default is detected via Swarm.
Extensions	[]Extension	Array of extensions as listed below

Extension configuration¶

Interlock must contain at least one extension to service traffic. The following options are available to configure the extensions.

Option	Type	Description
Image	string	Name of the Docker image to use for the extenstion.
Args	[]string	Arguments to be passed to the extension service.
Labels	map[string]string	Labels to add to the extension service.
ContainerLabels	map[string]string	labels for the extension service tasks.
Constraints	[]string	One or more constraints to use when scheduling the extenstion service.
PlacementPreferences	[]string	One of more placement prefs.
ServiceName	string	Name of the extension service.
ProxyImage	string	Name of the Docker image to use for the proxy service.
ProxyArgs	[]string	Arguments to pass to the proxy service.
ProxyLabels	map[string]string	Labels to add to the proxy service.
ProxyContainerLabels	map[string]string	Labels to be added to the proxy service tasks.
ProxyServiceName	string	Name of the proxy service.
ProxyConfigPath	string	Path in the service for the generated proxy config.
ProxyReplicas	unit	Number or proxy service replicas.
ProxyStopSignal	string	Stop signal for the proxy service, for example SIGQUIT.
ProxyStopGracePeriod	string	Stop grace period for the proxy service in seconds, for example 5s.
ProxyConstraints	[]string	One or more constraints to use when scheduling the proxy service. Set the variable to false, as it is currenlty set to true by default.
ProxyPlacementPreferences	[]string	One or more placement prefs to use when scheduling the proxy service.
ProxyUpdateDelay	string	Delay between rolling proxy container updates.
ServiceCluster	string	Name of the cluster this extension services.
PublishMode	string (ingress or host)	Publish mode that the proxy service uses.
PublishedPort	int	Port on which the proxy service serves non-SSL traffic.
PublishedSSLPort	int	Port on which the proxy service serves SSL traffic.
Template	int	Docker configuration object that is used as the extension template.
Config	Config	Proxy configuration used by the extensions as described in this section.

Proxy¶

Options are made available to the extensions, and the extensions utilize the options needed for proxy service configuration. This provides overrides to the extension configuration.

Because Interlock passes the extension configuration directly to the extension, each extension has different configuration options available. Refer to the documentation for each extension for supported options:

• NGINX

Customize the default proxy service¶

The default proxy service used by UCP to provide layer 7 routing is NGINX. If users try to access a route that hasn’t been configured, they will see the default NGINX 404 page:

You can customize this by labeling a service with com.docker.lb.default_backend=true. In this case, if users try to access a route that’s not configured, they are redirected to this service.

As an example, create a docker-compose.yml file with:

version: "3.2"

services:
  demo:
    image: ehazlett/interlock-default-app
    deploy:
      replicas: 1
      labels:
        com.docker.lb.default_backend: "true"
        com.docker.lb.port: 80
    networks:
      - demo-network

networks:
  demo-network:
    driver: overlay

Set up your CLI client with a UCP client bundle, and deploy the service:

docker stack deploy --compose-file docker-compose.yml demo

If users try to access a route that’s not configured, they are directed to this demo service.

Example Configuration¶

The following is an example configuration to use with the NGINX extension.

ListenAddr = ":8080"
DockerURL = "unix:///var/run/docker.sock"
PollInterval = "3s"

[Extensions.default]
  Image = "docker/interlock-extension-nginx:3.2.5"
  Args = ["-D"]
  ServiceName = "interlock-ext"
  ProxyImage = "docker/ucp-interlock-proxy:3.2.5"
  ProxyArgs = []
  ProxyServiceName = "interlock-proxy"
  ProxyConfigPath = "/etc/nginx/nginx.conf"
  ProxyStopGracePeriod = "3s"
  PublishMode = "ingress"
  PublishedPort = 80
  ProxyReplicas = 1
  TargetPort = 80
  PublishedSSLPort = 443
  TargetSSLPort = 443
  [Extensions.default.Config]
    User = "nginx"
    PidPath = "/var/run/proxy.pid"
    WorkerProcesses = 1
    RlimitNoFile = 65535
    MaxConnections = 2048