Service

A Service is a horizontally-scalable collection of durable Processes.

Processes that belong to a Service are automatically restarted upon termination.

Services can be scaled to a static count or autoscaled in a range based on metrics.

Definition

services:
  web:
    build: .
    health: /check
    port: 5000
    scale: 3
services:
  grpc:
    build: .
    port: grpc:5551
    grpcHealthEnabled: true
services:
  web:
    agent: false
    annotations:
      - test.annotation.org/value=foobar
    build:
      manifest: Dockerfile
      path: .
    certificate:
      duration: 2160h 
    command: bin/web
    deployment:
      minimum: 25
      maximum: 100
    domain: ${WEB_HOST}
    drain: 10
    dnsConfig:
      ndots: 5
    environment:
      - FOO
      - BAR=qux
    health:
      grace: 10
      interval: 5
      path: /check
      timeout: 3
    liveness:
      path: /liveness/check
      grace: 15
      interval: 5
      timeout: 3
      successThreshold: 1
      failureThreshold: 3
    internal: false
    ingressAnnotations:
      - nginx.ingress.kubernetes.io/limit-rpm=10
    labels:
      convox.com/test: true
    lifecycle:
      preStop: "sleep 10"
      postStart: "sleep 10"
    port: 5000
    ports:
      - 5001
      - 5002
    privileged: false
    scale:
      count: 1-3
      limit:
        cpu: 256
        memory: 1024
      cpu: 128
      memory: 512
      targets:
        cpu: 50
        memory: 80
        external:
          - name: "datadogmetric@default:web-requests"
            averageValue: 200
    singleton: false
    sticky: true
    termination:
      grace: 45
    test: make test
    timeout: 180
    tls:
      redirect: true
    whitelist: 10.0.0.128/16,192.168.0.1/32
Attribute Type Default Description
agent boolean false Set to true to declare this Service as an Agent
annotations list A list of annotation keys and values to populate the metadata for the deployed pods and their serviceaccounts
build string/map . Build definition (see below)
certificate map Define certificate parameters
command string CMD of Dockerfile The command to run to start a Process for this Service
deployment map Manual control over deployment parameters
domain string A custom domain(s) (comma separated) to route to this Service
dnsConfig map Dns config for the service
drain number The number of seconds to wait for connections to drain when terminating a Process of this Service. Only applies for version 2 rack services. For version 3 rack services use termination grace period termination.grace
environment list A list of environment variables (with optional defaults) to populate from the Release environment
grpcHealthEnabled boolean false Enables liveliness health check for grpc. It should follow the grpc health protocol (ref: k8s)
health string/map / Health check definition (see below)
liveness map Liveness check definition (see below). By default it is disabled. If it fails then service will restart
image string An external Docker image to use for this Service (supercedes build)
ingressAnnotations list A list of annotation keys and values to add in ingress resource. Check below for reserved annotation keys
internal boolean false Set to true to make this Service only accessible inside the Rack
internalRouter boolean false Set it to true to make this Service only accessible using internal loadbalancer. You also have to set the rack parameter internal_router to true
labels map Custom labels for k8s resources. See here for (syntax and character set)[https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#syntax-and-character-set]. Also following keys are reserved: system, rack, app, name, service, release, type
lifecycle map The prestop and poststart hooks enable running commands before terminating and after starting the container, respectively
port string The port that the default Rack balancer will use to route incoming traffic. For grpc service specify the scheme: grpc:5051
ports list A list of ports available for internal service discovery or custom Balancers
privileged boolean true Set to false to prevent Processes of this Service from running as root inside their container
scale map 1 Define scaling parameters (see below)
singleton boolean false Set to true to prevent extra Processes of this Service from being started during deployments
sticky boolean false Set to true to enable sticky sessions
termination map Termination related configuration
test string A command to run to test this Service when running convox test
timeout number 60 Timeout period (in seconds) for reading/writing requests to/from your service
tls map TLS-related configuration
volumeOptions list List of volumes to attach with service
whitelist string Comma delimited list of CIDRs, e.g. 10.0.0.0/24,172.10.0.1, to allow access to the service

Environment variables declared on convox.yml will be populated for a Service.

*annotations

You can use annotations to attach arbitrary non-identifying metadata to objects. Clients such as tools and libraries can retrieve this metadata. On Convox, annotations will reflect in pods and service accounts.

Here are some examples of information that can be recorded in annotations:

  • Build, release, or image information like timestamps, release IDs, git branch, PR numbers, image hashes, and registry address.
  • Fields managed by a declarative configuration layer. Attaching these fields as annotations distinguishes them from default values set by clients or servers, and from auto-generated fields and fields set by auto-sizing or auto-scaling systems.
  • User or tool/system provenance information, such as URLs of related objects from other ecosystem components.
  • Configure a service to assume an IAM Role(AWS and GCP only). For example:
environment:
  - PORT=3000
services:
  web:
    annotations:
      - eks.amazonaws.com/role-arn=arn:aws:iam::accountID:role/yourOwnIAMRole
    domain: ${HOST}
    build: .
    port: 3000

build

Attribute Type Default Description
manifest string Dockerfile The filename of the Dockerfile
path string . The path (relative to convox.yml) to build for this Service

Specifying build as a string will set the path and leave the other values as defaults.

certificate

Attribute Type Default Description
duration string 2160h Certificate renew frequency period

deployment

Attribute Type Default Description
maximum number 200 The maximum percentage of Processes to allow during rolling deploys
minimum number 50 The minimum percentage of healthy Processes to keep alive during rolling deploys

 

dnsConfig

Attribute Type Default Description
ndots int The ndots option for the dns config

 

ingressAnnotations

This accepts list of strings where in each string annotation key and value is separated by = sign:

services:
  web:
    ...
    ingressAnnotations:
      - nginx.ingress.kubernetes.io/limit-rpm=10
      - nginx.ingress.kubernetes.io/enable-access-log=false
  ...

Reserved annotation keys:

  • alb.ingress.kubernetes.io/scheme
  • cert-manager.io/cluster-issuer
  • cert-manager.io/duration
  • nginx.ingress.kubernetes.io/backend-protocol
  • nginx.ingress.kubernetes.io/proxy-connect-timeout
  • nginx.ingress.kubernetes.io/proxy-read-timeout
  • nginx.ingress.kubernetes.io/proxy-send-timeout
  • nginx.ingress.kubernetes.io/server-snippet
  • nginx.ingress.kubernetes.io/affinity
  • nginx.ingress.kubernetes.io/session-cookie-name
  • nginx.ingress.kubernetes.io/ssl-redirect
  • nginx.ingress.kubernetes.io/whitelist-source-range

lifecycle

Attribute Type Default Description
perStop string The pre stop command
postStart string The post stop command

 

health

Attribute Type Default Description
grace number 5 The number of seconds to wait for a Process to start before starting health checks
interval number 5 The number of seconds between health checks
path string / The path to request for health checks
timeout number 4 The number of seconds to wait for a successful response
disable bool false To disable the healthcheck

Specifying health as a string will set the path and leave the other values as defaults.

 

liveness

Attribute Type Default Description
grace number 10 The number of seconds to wait for a Process to start before starting liveness checks
interval number 5 The number of seconds between health checks
path string The path to request for health checks
timeout number 5 The number of seconds to wait for a successful response
successThreshold number 1 The number of seconds to wait for a successful response
failureThreshold number 3 The number of seconds to wait for a successful response

If you want to enable liveness check, you have to specify path and others are optional

scale

Attribute Type Default Description
count number 1 The number of Processes to run for this Service. For autoscaling use a range, e.g. 1-5
cpu number 256 The number of CPU units to reserve for Processes of this Service where 1000 units is a full CPU
gpu map The number/type of GPUs to reserve for Processes of this Service
memory number 512 The number of MB of RAM to reserve for Processes of this Service
targets map Target metrics to trigger autoscaling
limit map The maximum cpu or memory usage limit

Specifying scale as a number will set the count and leave the other values as defaults.

scale.gpu

Attribute Type Default Description
count number The number of GPUs to reserve for Processes of this Service
vendor string nvidia The GPU vendor to target for Processes of this Service

Specifying gpu as a number will set the count and leave the vendor as default. Specifying a gpu value and not specifying the cpu or memory to reserve will remove their defaults to purely reserve based on GPU. You should ensure that your Rack is running on GPU enabled instances (of the correct vendor) before specifying the gpu section in your convox.yml

scale.targets

Attribute Type Default Description
cpu number The percentage of CPU utilization to target for Processes of this Service
memory number The percentage of memory utilization to target for Processes of this Service
external map The array of the external metrics based on which it will scale the Service

scale.limit

Attribute Type Default Description
cpu number The number of CPU units to limit for Processes of this Service where 1000 units is a full CPU
memory number The number of MB of RAM to limit for Processes of this Service

scale.targets.[]external

Attribute Type Default Description
name string The name of the metric
matchLabels map Key value lablels for the metrics
averageValue number The target value of the average of the metric across all relevant pods
value number The target value of the metric
services:
  web:
    build: .
    port: 3000
    scale:
      count: 1-3
      targets:
        external:
          - name: "datadogmetric@default:web-requests"
            averageValue: 200

 

termination

Attribute Type Default Description
grace number 30 The number of seconds to wait for Processes to gracefully exit before killing them

 

tls

Attribute Type Default Description
redirect boolean true Whether or not HTTP requests should be redirected to HTTPS using a 308 response code

 

[]volumeOptions

Attribute Type Default Description
emptyDir map Configuration for emptyDir volume

 

[]volumeOptions.emptyDir

Attribute Type Default Description
id string Required. Id of the volume.
mountPath string Required. Path in the serive file system to mount the volume
medium string Optional. Specifies the emptyDir medium. Allowed values: "Memory" or ""
environment:
  - PORT=3000
services:
  web:
    build: .
    port: 3000
    volumeOptions:
      - emptyDir:
          id: "test-vol"
          mountPath: "/my/test/vol"

 

Command Line Interface

Listing Services

    $ convox services -a myapp
    SERVICE  DOMAIN                                PORTS
    web      web.convox.0a1b2c3d4e5f.convox.cloud  443:5000

Scaling a Service

    $ convox scale web --count 3 --cpu 256 --memory 1024 -a myapp`1
    Scaling web... OK

Restarting a Service

    $ convox services restart web -a myapp
    Restarting web... OK

Restarting a Service will begin a rolling restart with graceful termination of each Process of the Service.