Sidecar Container

Sidecar

Sidecar defines a structure for creating Docker containers


resource "sidecar" "name" {
  ...
}

Attributes

Attribute
Description

Target target required type: Reference to Container

```hcl target = resource.container.ubuntu ```

Image image required type: block Image

Image defines a Docker image to use when creating the container.

image {
  name = "envoy:latest"
}

Entrypoint entrypoint type: []string

Entrypoint for the container, if not set, Jumppad starts the container using the entrypoint defined in the Docker image.

entrypoint = "/bin/bash"

Command command type: []string

Command allows you to specify a command to execute when starting a container. Command is specified as an array of strings, each part of the command is a separate string.

For example, to start a container and follow logs at /dev/null the following command could be used.

command = [
"tail",
"-f",
"/dev/null"
]

Environment environment type: map[string]string

Allows you to set environment variables in the container.

environment = {
PATH = "/user/local/bin"
}

Labels labels type: map[string]string

Labels to apply to the container

labels = {
  key = "value"
}

Volumes volume type: []block Volume

A volume allows you to specify a local volume which is mounted to the container when it is created. This stanza can be specified multiple times.

volume {
source      = "./"
destination = "/files"
}

Privileged privileged type: bool

Should the container run in Docker privileged mode?

privileged = true

Resources resources type: block Resources

Define resource constraints for the container

resources {
  cpu = 100
  memory = 1024
}

HealthCheck health_check type: block HealthCheckContainer

Define a health check for the container, the resource will only be marked as successfully created when the health check passes.

health_check {
  timeout = "30s"
  http {
    address = "http://localhost:8500/v1/status/leader"
    success_codes = [200]
  }

  tcp {
    address = "localhost:8500"
  }

  exec {
    script = <<-EOF
      #!/bin/bash
      curl "http://localhost:9090"
    EOF
  }
}

MaxRestartCount max_restart_count type: int

The maximum number of times a container will be restarted when it exits with a status code other than 0

max_restart_count = 3

Computed Attributes

These attributes are computed when the config is parsed and applied, and are therefore only known at parsetime or runtime.

Attribute
Description

Meta ID meta.id string

The full ID of the resource e.g. `resource.type.name`. This is computed from the full resource path:

// given the following resource
resource "container" "ubuntu" {
  ...
}

// the resulting id will be
resource.container.ubuntu

Meta Type meta.type string

The type of the resource. This taken from the type label of the resource definition.

// given the following resource
resource "container" "ubuntu" {
  ...
}

// the resulting type will be
container

Meta Name meta.name string

The name of the resource. This taken from the name label of the resource definition.

// given the following resource
resource "container" "ubuntu" {
  ...
}

// the resulting name will be
ubuntu

ContainerName container_name type: string

Fully qualified resource name for the container the sidecar is linked to, this can be used to access the sidecar from other sources.

name.container.local.jmpd.in

Image

Image defines a Docker image used when creating this container. An Image can be stored in a public or a private repository.


container {
  image {
    ...
  }
}

Attributes

Attribute
Description

Name name required type: string

Name of the image to use when creating the container, can either be the full canonical name or short name for Docker official images. e.g. `consul:v1.6.1` or `docker.io/consul:v1.6.1`.

name = "redis:latest"

Username username type: string

Username to use when connecting to a private image repository

username = "my_username"

Password password type: string

Password to use when connecting to a private image repository, for both username and password interpolated environment variables can be used in place of static values.

password = "my_password"

Computed Attributes

These attributes are computed when the config is parsed and applied, and are therefore only known at parsetime or runtime.

Attribute
Description

ID id type: string

ID is the unique identifier for the image, this is independent of tag and changes each time the image is built. An image that has been tagged multiple times also shares the same ID. ID string `hcl:"id,optional" json:"id,omitempty"`

Volume

A volume type allows the specification of an attached volume.


container {
  volume {
    ...
  }
}

Attributes

Attribute
Description

Source source required type: string

The source volume to mount in the container, can be specified as a relative `./` or absolute path `/usr/local/bin`. Relative paths are relative to the file declaring the container.

source = "./files/nginx"

Destination destination required type: string

The destination in the container to mount the volume to, must be an absolute path.

destination = "/etc/nginx"

Type type type: string

The type of the mount, can be one of the following values:

  • bind: bind the source path to the destination path in the container

  • volume: source is a Docker volume

  • tmpfs: create a temporary filesystem

type = "bind"

ReadOnly read_only type: bool

Whether or not the volume is read only.

read_only = true

BindPropagation bind_propagation type: string

Configures bind propagation for Docker volume mounts, only applies to bind mounts, can be one of the following values:

  • shared

  • slave

  • private

  • rslave

  • rprivate

For more information please see the Docker documentation https://docs.docker.com/storage/bind-mounts/#configure-bind-propagation

bind_propagation = "shared"

BindPropagationNonRecursive bind_propagation_non_recursive type: bool

Configures recursiveness of the bind mount.

By default Docker mounts with the equivalent of mount --rbind meaning that mounts below the the source directory are visible in the container. or instance running docker run --rm --mount type=bind,src=/,target=/host,readonly busybox will make /run of the host available as/host/run in the container. To make matters even worse it will be writable (since only the toplevel bind is set readonly, not the children).

If bind_propagation_non_recursive is set to true then the container will only see an empty /host/run, meaning thetmpfs which is typically mounted to /run on the host is not propagated into the container.

bind_propagation_non_recursive = true

SelinuxRelabel selinux_relabel type: string

Configures Selinux relabeling for the container (usually specified as :z or :Z) and can be one of the following values:

  • shared (Equivalent to :z)

  • private (Equivalent to :Z)

selinux_relabel = "shared"

Computed Attributes

These attributes are computed when the config is parsed and applied, and are therefore only known at parsetime or runtime.

Resources

A resources type allows you to configure the maximum resources which can be consumed.


container {
  resources {
    ...
  }
}

Attributes

Attribute
Description

CPU cpu type: int

Set the maximum CPU which can be consumed by the container in MHz, 1 CPU == 1000MHz.

cpu = 100

CPUPin cpu_pin type: []int

Pin the container CPU consumption to one or more logical CPUs. For example to pin the container to the core 1 and 4.

cpi_pin = [1,4]

Memory memory type: int

Maximum memory which a container can consume, specified in Megabytes.

memory = 2048

GPU gpu type: block GPU

GPU settings to pass through to container

gpu {
  driver = "nvidia"
  device_ids = ["0", "1"]
}

Computed Attributes

These attributes are computed when the config is parsed and applied, and are therefore only known at parsetime or runtime.

HealthCheckContainer

A health_check stanza allows the definition of a health check which must pass before the container is marked as successfully created. There are three different types of healthcheck http, tcp, and exec, these are not mutually exclusive, it is possible to define more than one health check.

Health checks are executed sequentially, if one health check fails, the following checks are not executed. The execution order is http, tcp, exec.


health_check {
  ...
}

Attributes

Attribute
Description

Timeout timeout required type: string

The maximum duration to wait before marking the health check as failed. Expressed as a Go duration, e.g. `1s` = 1 second, `100ms` = 100 milliseconds.

timeout = "60s"

HTTP http type: []block HealthCheckHTTP

HTTP Health Check block defining the address to check and expected status codes.

Can be specified more than once.

http {
  address = "localhost:8500"
}

TCP tcp type: []block HealthCheckTCP

TCP Health Check block defining the address to test.

Can be specified more than once.

tcp {
  address = "localhost:8500"
}

Exec exec type: []block HealthCheckExec

Exec Health Check block defining either a command to run in the current container, or a script to execute.

Can be specified more than once.

exec {
  command = ["pg_isready"]
}

Computed Attributes

These attributes are computed when the config is parsed and applied, and are therefore only known at parsetime or runtime.

HealthCheckHTTP

A HTTP health check executes an HTTP request for the given address and evaluates the response against the expected success_codes. If the reponse matches any of the given codes the check passes.


health_check {
  http {
    ...
  }
}

Attributes

Attribute
Description

Address address required type: string

The URL to check, health check expects a HTTP status code to be returned by the URL in order to pass the health check.

address = "http://localhost:8500/v1/status/leader"

Method method type: string

HTTP method to use when executing the check

method = "POST"

Body body type: string

HTTP body to send with the request

body = <<-EOF
{
  {"test": "123"}
}
EOF

Headers headers type: map[string]string

HTTP headers to send with the check

headers = {
  "X-Auth-Token": ["abc123"]
}

SuccessCodes success_codes type: []int

HTTP status codes returned from the endpoint when called. If the returned status code matches any in the array then the health check will pass.

success_codes = [200, 403]

Computed Attributes

These attributes are computed when the config is parsed and applied, and are therefore only known at parsetime or runtime.

HealthCheckTCP

A TCP health check attempts to open a connection to the given address. If a connection can be opened then the check passes.


health_check {
  tcp {
    ...
  }
}

Attributes

Attribute
Description

Address address required type: string

The adress to check.

address = "localhost:8500"

Computed Attributes

These attributes are computed when the config is parsed and applied, and are therefore only known at parsetime or runtime.

HealthCheckExec

Exec health checks allow you to execute a command or script in the current container. If the command or script receives an exit code 0 the check passes.


health_check {
  exec {
    ...
  }
}

Attributes

Attribute
Description

Command command type: []string

The command to execute, the command is run in the target container.

command = ["pg_isready"]

Script script type: string

A script to execute in the target container, the script is coppied to the container into the /tmp directory and is then executed.

script = <<-EOF
  #!/bin/bash
  FILE=/etc/resolv.conf
  if [ -f "$FILE" ]; then
    echo "$FILE exists."
  fi
EOF

ExitCode exit_code type: int

ExitCode to mark a successful check, default 0

exit_code = 0

Computed Attributes

These attributes are computed when the config is parsed and applied, and are therefore only known at parsetime or runtime.

PreviousContainerNextKubernetes

Last updated