Set environment variables¶

Set a container's environment in its [Container] section with Environment. [Service] Environment= would only reach the podman process that starts the container, not the container itself.

Use the map form¶

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sysdef: containers: app: spec: {
    unit: Container: {
        Image: "registry.example.com/app:1.4"
        Environment: {
            TZ:       "Europe/Vienna"
            GREETING: "hello world"
        }
    }
}

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"unit": {
  "Container": {
    "Image": "registry.example.com/app:1.4",
    "Environment": {
      "TZ": "Europe/Vienna",
      "GREETING": "hello world"
    }
  }
}

syslet writes one Environment= line per variable and quotes values that contain whitespace:

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Environment="GREETING=hello world"
Environment=TZ=Europe/Vienna

An empty string sets the variable to an empty value.

A list of NAME=value strings works as well, ["TZ=Europe/Vienna"], with the same quoting. In CUE, prefer the map: maps from several places merge, so a shared file can set defaults and a host file can add variables; two different values for the same variable are a conflict CUE reports.

Apply a change¶

Any change to Environment is a change to the unit, so syslet restarts the container. To change settings without a restart, put them in a config file the service reloads (see Mount config files and dirs).

Keep secrets out¶

Environment values are written to the unit file and shown in every plan. Pass passwords and tokens as secrets instead (see Pass a secret to a container).