How to run AWS ECS Task overriding environment variables

You have to provide a JSON document as documented under the --overrides option.

{  "containerOverrides": [    {      "name": "string",      "command": ["string", ...],      "environment": [        {          "name": "string",          "value": "string"        }        ...      ]    }    ...  ],  "taskRoleArn": "string"}

You have to specify the name of the container to get the environment override, and specify a list of environment key-value pairs.

You can specify the JSON document in-line with your argument or pass a file path argument to the task. I will show both ways.

Passing JSON in-line

Your command would look like this (fill in the value CONTAINER_NAME_FROM_TASK).

aws ecs run-task --overrides '{ "containerOverrides": [ { "name": "CONTAINER_NAME_FROM_TASK", "environment": [ { "name": "NAME", "value": "123" }, { "name": "DATE", "value": "1234-12-12" }, { "name": "SCRIPT", "value": "123456" } ] } ] }' --task-definition (...)

That does look rather ugly though, and would be annoying to edit. It also only works on Unix-y systems and would require quote escaping in Windows.

So alternatively, you can pass a file path to the AWS CLI and have it load your override JSON from a file.

Passing a file path argument

Create a file, let's call it overrides.json, and put the same JSON into it:

{    "containerOverrides": [{        "name": "CONTAINER_NAME_FROM_TASK",        "environment": [{            "name": "NAME",            "value": "123"        }, {            "name": "DATE",            "value": "1234-12-12"        }, {            "name": "SCRIPT",            "value": "123456"        }]    }]}

Then, assuming your file is in the current directory:

aws ecs run-task --overrides file://overrides.json --task-definition (..)

If your file is elsewhere in the filesystem and you're on a Linux/Unix-y system:

aws ecs run-task --overrides file:///path/to/overrides.json --task-definition (..)

If your file is elsewhere in the filesystem and you're doing this in Windows:

aws ecs run-task --overrides file://DRIVE_LETTER:\path\to\overrides.json --task-definition (..)