docs: Improving ECS manual installation page
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@ -23,7 +23,7 @@ You must define a Task Definition which includes the following containers:
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* Your application container
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* An Envoy sidecar-proxy container
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* A Consul Agent container
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* A Consul client container
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* The `consul-ecs-mesh-init` container for service mesh setup
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* Optionally, a `consul-ecs-health-sync` container to sync ECS health checks into Consul
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@ -48,16 +48,18 @@ In your task definition, you'll need to define these important top-level fields:
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```
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| Field name | Type | Description |
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| ------------- | ------ | --------------------------------------------------------------------------------------------------- |
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| ---------------------- | ------ | ------------------------------------------------------------------------------------------------------------------ |
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| `family` | string | The task family name. This is used as the Consul service name, by default. |
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| `networkMode` | string | Must be `awsvpc`, which is the only network mode supported by Consul on ECS. |
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| `volumes` | list | These are volumes used to share information between containers, which is important for setup steps. |
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| `volumes` | list | Must be defined as shown above. Volumes ares used to share configuration between containers for intial task setup. |
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| `containerDefinitions` | list | The list of containers to run in this task (see below). |
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## Application container
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First, include your application container in the `containerDefinitions` list
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in the task definition. Ensure that the `dependsOn` field is set as shown below so that your application container starts in the correct order (see [task startup](/docs/ecs/architecture#task-startup) for more information):
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in the task definition. Ensure that the `dependsOn` field is set as shown below
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so that your application container starts in the correct order (see [task
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startup](/docs/ecs/architecture#task-startup) for more information):
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```json
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{
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@ -75,18 +77,19 @@ in the task definition. Ensure that the `dependsOn` field is set as shown below
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"containerName": "sidecar-proxy",
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"condition": "HEALTHY"
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}
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]
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],
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...
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}
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]
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}
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```
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| Field name | Type | Description |
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| ----------- | ------- | ------------------------------------------------------------------------------------------------------------------------ |
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| ----------- | ------- | -------------------------------------------------------------------------------------------------------------------------------- |
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| `name` | string | The name of your application container. |
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| `image` | string | The container image used to run your application. |
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| `essential` | boolean | Set this to `true` ensures your application container ties into the health of the task. All tasks must have at least one essential container. |
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| `dependsOn` | list | Container dependendencies are used to ensure the service mesh is ready before your application starts. |
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| `essential` | boolean | Must be `true` to ensure your application container ties into the health of the task. |
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| `dependsOn` | list | Must be set as show above. Container dependencies ensure your application container starts after service mesh setup is complete. |
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See the [ECS Task Definition](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task_definition_parameters.html) documentation for a complete reference.
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@ -94,6 +97,8 @@ See the [ECS Task Definition](https://docs.aws.amazon.com/AmazonECS/latest/devel
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The sidecar proxy container runs [Envoy proxy](/docs/connect/proxies/envoy) for Consul Connect.
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<CodeBlockConfig highlight="8-40">
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```json
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{
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"containerDefinitions": [
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@ -139,24 +144,29 @@ The sidecar proxy container runs [Envoy proxy](/docs/connect/proxies/envoy) for
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}
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```
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</CodeBlockConfig>
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In most cases, the `sidecar-proxy` container can be configured exactly as shown above.
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| Field name | Type | Description |
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| ----------- | ------- | ------------------------------------------------------------------------------------------------------------------ |
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| `name` | string | The name of the container, which should always be `sidecar-proxy`. |
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| `image` | string | The container image for Envoy. We recommend using `envoyproxy/envoy-alpine`. |
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| `dependsOn` | list | Envoy must start after `consul-ecs-mesh-init`, which creates the bootstrap configuration file for Envoy. |
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| `healthCheck` | list | A health check should be definied for Envoy's primary listener port. |
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| `mountPoints` | list | The mounts the `/consul` data volume which contains the Envoy configuration file. |
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| `ulimits` | list | Set the file descriptor limit, `nofile`, to a sufficiently high value so that Envoy does not fail to open sockets. |
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| `entrypoint` | list | A custom entrypoint binary is used to help facilitate graceful shutdown. |
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| ------------- | ------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------- |
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| `name` | string | The container name, which must be `sidecar-proxy`. |
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| `image` | string | The Envoy image. This must be a [supported version of Envoy](/docs/connect/proxies/envoy#supported-versions). |
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| `dependsOn` | list | Must be set as shown above to ensure Envoy starts after the `consul-ecs-mesh-init` has written the `envoy-bootstrap.json` config file for Envoy. |
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| `healthCheck` | list | Must be set as shown above to monitor the health of Envoy's primary listener port, which ties into container dependencies and startup ordering. |
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| `mountPoints` | list | Must be set as shown above to access the files shared in the `consul` directory, like the Envoy bootstrap configuration file and the `consul-ecs` binary. |
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| `ulimits` | list | The `nofile` ulimit must be raised to a sufficiently high value so that Envoy does not fail to open sockets. |
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| `entrypoint` | list | Must be set to the custom Envoy entrypoint to facilitate graceful shutdown. |
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| `command` | list | The startup command. This passes the bootstrap configuration to Envoy. |
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-> **NOTE**: Envoy and Consul must be compatible versions. See the [supported versions of Envoy](https://www.consul.io/docs/connect/proxies/envoy#supported-versions) for each Consul release.
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-> **NOTE**: Envoy and Consul must be compatible versions. See the [supported versions of Envoy](/docs/connect/proxies/envoy#supported-versions) in the Consul documentation.
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## `consul-client` container
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Each task must include a Consul client container in order for the task to join your Consul cluster.
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<CodeBlockConfig highlight="13-31">
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```json
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{
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"containerDefinitions": [
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@ -193,14 +203,15 @@ Each task must include a Consul client container in order for the task to join y
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}
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```
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</CodeBlockConfig>
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| Field name | Type | Description |
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| ----------- | ------- | ------------------------------------------------------------------------------------------------------------------------ |
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| `name` | string | The name of the Consul agent container, which should always be `consul-client`. |
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| `image` | string | The container image for Consul. Use our public AWS registry, `public.ecr.aws/hashicorp/consul`, to avoid rate limits. |
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| `mountPoints` | list | Mount the `/consul` data volume which contains the Envoy configuration file. |
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| `ulimits` | list | Set the file descriptor limit, `nofile`, to a sufficiently high value so that Envoy does not fail to open sockets. |
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| `entrypoint` | list | A custom entrypoint binary is used to run Envoy, in order to facilitate graceful shutdown. |
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| `command` | list | The startup command. See below for details.
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| ------------- | ------- | ------------------------------------------------------------------------------------------------------------------- |
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| `name` | string | The container name, which should always be `consul-client`. |
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| `image` | string | The Consul image. Use our public AWS registry, `public.ecr.aws/hashicorp/consul`, to avoid rate limits. |
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| `mountPoints` | list | Must be set as shown above. Volumes are mounted to share information with other containers for task setup. |
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| `entrypoint` | list | Must be set to a plain shell so that the startup `command` works properly. |
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| `command` | list | The startup command. See below for details. |
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The following is the recommended `command` script for the Consul agent.
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This is the same as the above `command` field, but is unescaped and has comments added.
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@ -212,7 +223,7 @@ cp /bin/consul /bin/consul-inject/consul
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# At runtime, determine the IP address assigned to this ECS Task.
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ECS_IPV4=$(curl -s $ECS_CONTAINER_METADATA_URI_V4 | jq -r '.Networks[0].IPv4Addresses[0]')
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# Define the Consul agent configuration file.
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# Write the Consul agent configuration file.
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cat << EOF > /consul/agent-defaults.hcl
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addresses = {
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dns = "127.0.0.1"
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@ -241,24 +252,30 @@ exec consul agent \
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-config-file /consul/agent-defaults.hcl
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```
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You can tailor the configuration above for your use case, but it's important to set the following fields as show:
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Set the following fields as shown above:
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| Field name | Type | Description |
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| -------------------- | ------- | ------------------------------------------------------------------------------------------------------------ |
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| `addresses.*` | strings | Set the DNS, GRPC, and HTTP addresses to `127.0.0.1` to ensure these are not accessible outside of the task. |
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| `advertise_addr` | string | This must be set to the task IP address so that other Consul agents know how to reach this agent. |
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| `client_addr` | string | This must bind to an interface reacable by other Consul agents. |
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| `leave_on_terminate` | boolean | This ensures this Consul agent will leave the cluster gracefully before exiting. |
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| `retry_join` | string | This must be set to your Consul server location(s) so this agent can join the Consul cluster. |
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| `advertise_addr` | string | Must be set to the task IP address so that other Consul agents know how to reach this agent. |
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| `client_addr` | string | Must be set to an interface reacable by other Consul agents. |
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| `datacenter` | string | Must be set to the Consul datacenter this task will join. |
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| `leave_on_terminate` | boolean | Must be set to `true` so that the Consul agent leaves the cluster gracefully before exiting. |
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| `retry_join` | string | Must be set to your Consul server location(s) so this agent can join the Consul cluster. |
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-> **NOTE**: It is important to use `exec` to start the Consul agent, so that the Consul agent runs as PID 1. This ensures
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-> **NOTE**: Use `exec` to start the Consul agent, so that the Consul agent runs as PID 1. This ensures
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the Consul agent directly receives signals from ECS, which is important for graceful shutdown of the Consul agent.
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Refer to the [Consul Agent documentation](/docs/agent/options#configuration_files) for a complete reference of Consul agent
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configuration options.
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## `mesh-init` container
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The mesh-init container runs at task startup to setup this instance for Consul service mesh.
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It will register this service and proxy with Consul and write Envoy bootstrap configuration
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to a shared volume.
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The `mesh-init` container runs at task startup to setup this instance for Consul service mesh.
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It registers the service and proxy for this task with Consul and writes Envoy bootstrap
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configuration to a shared volume.
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<CodeBlockConfig highlight="18-41">
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```json
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{
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@ -306,15 +323,17 @@ to a shared volume.
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}
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```
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</CodeBlockConfig>
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| Field name | Type | Description |
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| ----------- | ------- | ---------------------------------------------------------------------------------------------------------------------------- |
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| ----------- | ------- | ------------------------------------------------------------------------------------------------------------------- |
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| `name` | string | The container name should be `consul-ecs-mesh-init`. |
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| `image` | string | The `consul-ecs` image. Use our public AWS registry, `public.ecr.aws/hashicorp/consul-ecs`, to avoid rate limits. |
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| `mountPoints` | list | The mounts two volumes so that mesh-init can invoke the `consul` binary to write bootstrap Envoy configuration. |
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| `mountPoints` | list | Must be set as show above, so the `consul` and `consul-ecs` binaries can be shared among containers for task setup. |
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| `command` | list | Set the `["mesh-init"]` so that the container runs the `consul-ecs mesh-init` command. |
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| `environment` | list | This must include the `CONSUL_ECS_CONFIG_JSON` variable. See below for details. |
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Additional configuration is passed to the `consul-ecs mesh-init` command in JSON format using the `CONSUL_ECS_CONFIG_JSON` environment variable.
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Configuration is passed to the `consul-ecs mesh-init` command in JSON format using the `CONSUL_ECS_CONFIG_JSON` environment variable.
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Here is the sample config from above, expanded to be readable:
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```json
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@ -355,8 +374,9 @@ Optionally, Consul ECS can sync health checks for this task into Consul checks.
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This allows you to configure a health check for your application in one place, and
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see a consistent health status in both ECS and Consul.
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First, you'll need to add an ECS health check command to the container definition for your application.
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This configures a health check command that runs `curl localhost:9090/health` to check the application health:
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For example, the following defines an ECS health check command that runs `curl localhost:9090/health`:
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<CodeBlockConfig highlight="6-11">
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```json
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{
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}
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```
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See the [ECS health check documentation](https://docs.aws.amazon.com/AmazonECS/latest/developerguide/task_definition_parameters.html#container_definition_healthcheck) for details on defining ECS health checks.
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</CodeBlockConfig>
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Next, you must tell Consul ECS which containers will have their health status synced into Consul. To do this,
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set the `healthSyncContainers` field of the `CONSUL_ECS_CONFIG_JSON` variable to include your application container name.
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First, tell Consul ECS which containers need their health status synced into Consul. To do this,
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add the container name(s) to the `healthSyncContainers` list of the `CONSUL_ECS_CONFIG_JSON` variable:
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Here is the expanded configuration:
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<CodeBlockConfig highlight="3-3">
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```json
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{
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"bootstrapDir": "/consul",
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"healthSyncContainers": ["example-client-app"],
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"proxy": {
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"upstreams": [
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{
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"destinationName": "example-server-app",
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"localBindPort": 1234
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}
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]
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},
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"service": {
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"checks": [],
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"meta": {},
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"name": "example-client-app",
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"port": 9090,
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"tags": []
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}
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...
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}
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```
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Then, update the task definition so that the `consul-ecs-mesh-init` container uses new configuration.
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You should compact and escape the JSON configuration above, and copy the result into the `CONSUL_ECS_CONFIG_JSON`
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environment variable:
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</CodeBlockConfig>
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Next, pass the new configuration to the `consul-ecs-mesh-init` container. You should compact and escape the JSON
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configuration above, and copy the result into the `CONSUL_ECS_CONFIG_JSON` environment variable:
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<CodeBlockConfig highlight="7-10">
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```json
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{
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@ -429,9 +438,13 @@ environment variable:
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}
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```
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</CodeBlockConfig>
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Finally, include the `consul-ecs-health-sync` container in the `containerDefinitions` list.
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Be sure to pass the same value as above for the `CONSUL_ECS_CONFIG_JSON` environment
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variable:
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The exact same configuration for the `CONSUL_ECS_CONFIG_JSON` environment variable is used
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for the health sync container.
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<CodeBlockConfig highlight="23-40">
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```json
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{
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@ -478,13 +491,15 @@ variable:
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}
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```
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</CodeBlockConfig>
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| Field name | Type | Description |
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| ------------- | ------ | ----------------------------------------------------------------------------------------------------------------- |
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| `name` | string | The container name which should be `consul-ecs-health-sync`. |
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| `name` | string | The container name, which must be `consul-ecs-health-sync`. |
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| `image` | string | The `consul-ecs` image. Use our public AWS registry, `public.ecr.aws/hashicorp/consul-ecs`, to avoid rate limits. |
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| `command` | list | Set to `["health-sync"]` to run the `consul-ecs health-sync` command. |
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| `dependsOn` | list | The `health-sync` container should not start until `mesh-init` has finished service and proxy registration. |
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| `environment` | list | Set the `CONSUL_ECS_CONFIG_JSON` variable to pass configuration to the `consul-ecs health-sync command. |
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| `command` | list | Must be set to `["health-sync"]` to run the `consul-ecs health-sync` command. |
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| `dependsOn` | list | Must be set as shown above to ensure the `health-sync` container starts after service registration has completed. |
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| `environment` | list | Must include the `CONSUL_ECS_CONFIG_JSON` variable to pass configuration to the `consul-ecs health-sync` command. |
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# Next Steps
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