Using Environment Variables¶

User-specified environment variables¶

You can specify environment variables to be made available to a task in two ways:

The envs field (dict) in a task YAML
The --env flag in the sky launch/exec CLI (takes precedence over the above)

The file_mounts, setup, and run sections of a task YAML can access the variables via the ${MYVAR} syntax.

Using in `file_mounts`¶

# Sets default values for some variables; can be overridden by --env.
envs:
  MY_BUCKET: skypilot-temp-gcs-test
  MY_LOCAL_PATH: tmp-workdir
  MODEL_SIZE: 13b

file_mounts:
    /mydir:
        name: ${MY_BUCKET}  # Name of the bucket.
        mode: MOUNT

    /another-dir2:
        name: ${MY_BUCKET}-2
        source: ["~/${MY_LOCAL_PATH}"]

    /checkpoint/${MODEL_SIZE}: ~/${MY_LOCAL_PATH}

The values of these variables are filled in by SkyPilot at task YAML parse time.

Using in `setup` and `run`¶

All user-specified environment variables are exported to a task’s setup and run commands (i.e., accessible when they are being run).

For example, this is useful for passing secrets (see below) or passing configurations:

# Sets default values for some variables; can be overridden by --env.
envs:
  MODEL_NAME: decapoda-research/llama-65b-hf

run: |
  python train.py --model_name ${MODEL_NAME} <other args>

$ sky launch --env MODEL_NAME=decapoda-research/llama-7b-hf task.yaml  # Override.

See complete examples at llm/vllm/serve.yaml and llm/vicuna/train.yaml.

Passing secrets¶

We recommend passing secrets to any node(s) executing your task by first making it available in your current shell, then using --env to pass it to SkyPilot:

$ sky launch -c mycluster --env WANDB_API_KEY task.yaml
$ sky exec mycluster --env WANDB_API_KEY task.yaml

Tip

In other words, you do not need to pass the value directly such as --env WANDB_API_KEY=1234.

SkyPilot environment variables¶

SkyPilot exports these environment variables for a task’s execution (while run commands are running):

Name	Definition	Example
`SKYPILOT_NODE_RANK`	Rank (an integer ID from 0 to `num_nodes-1`) of the node executing the task. Read more here.	0
`SKYPILOT_NODE_IPS`	A string of IP addresses of the nodes reserved to execute the task, where each line contains one IP address. Read more here.	1.2.3.4
`SKYPILOT_NUM_GPUS_PER_NODE`	Number of GPUs reserved on each node to execute the task; the same as the count in `accelerators: <name>:<count>` (rounded up if a fraction). Read more here.	0
`SKYPILOT_TASK_ID`	A unique ID assigned to each task. Useful for logging purposes: e.g., use a unique output path on the cluster; pass to Weights & Biases; etc. If a task is run as a managed spot job, then all recoveries of that job will have the same ID value. Read more here.	sky-2023-07-06-21-18-31-563597_myclus_id-1

The values of these variables are filled in by SkyPilot at task execution time.

You can access these variables in the following ways:

In the task YAML’s run commands (a Bash script), access them using the ${MYVAR} syntax;
In the program(s) launched in run, access them using the language’s standard method (e.g., os.environ for Python).

Using Environment Variables

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