--- name: "systemd-imdsd@.service" section: "8" platform: "linux" package: "systemd" version: "262.1-1" release: "Arch Linux 2026-11-01" platforms: ["linux"] url: "https://new.carta.tech/systemd-imdsd@.service" --- # systemd-imdsd@.service(8) Cloud IMDS (Instance Metadata Service) client ## NAME systemd-imdsd@.service, systemd-imdsd, systemd-imdsd.socket, systemd-imdsd-early-network.service - Cloud IMDS (Instance Metadata Service) client ## SYNOPSIS systemd-imdsd@.service systemd-imdsd.socket systemd-imdsd-early-network.service /usr/lib/systemd/systemd-imdsd ## DESCRIPTION **systemd-imdsd@.service** is a system service that provides local access to IMDS (Instance Metadata Service; or equivalent) functionality, as provided by many public clouds. The service provides a Varlink IPC interface via /run/systemd/io.systemd.InstanceMetadata to query IMDS fields. systemd-imdsd-early-network.service is a system service that generates a [**systemd-networkd.service**(8)](/systemd-networkd.service/8.md) compatible [**systemd.network**(5)](/systemd.network/5.md) file for configuring the early-boot network in order to be able to contact the IMDS endpoint. The [**systemd-imds**(1)](/systemd-imds/1.md) tool may be used to query information from this service. ## KERNEL COMMAND LINE OPTIONS The IMDS endpoint is typically determined automatically via [**hwdb**(7)](/hwdb/7.md) records, but can also be configured explicitly via the kernel command line, via the following options: *systemd.imds.network=* Takes one of "off", "locked", "unlocked". Controls whether and how to set up networking for IMDS endpoint access. Unless set to "off" early boot networking is enabled, ensuring that the IMDS endpoint can be reached. If set to "locked" direct access to the IMDS endpoint by regular unprivileged processes is disabled via a "prohibit" route, so that any access must be done through systemd-imdsd@.service or its associated tools. If set to "unlocked" (the default) this "prohibit" route is not created, and regular unprivileged processes can directly contact IMDS. Added in version 261. *systemd.imds.vendor=* A short string identifying the cloud vendor. Example: ``` systemd.imds.vendor=foobarcloud ``` Added in version 261. *systemd.imds.token\_url=* If a bearer token must be acquired to talk to the IMDS service, this is the URL to acquire it from. Added in version 261. *systemd.imds.refresh\_header\_name=* Takes a HTTP header field name (excluding the ":") that declares the header field for passing the TTL value (in seconds) to the HTTP server when acquiring a token. Only applies if *systemd.imds.token\_url=* is set too. Added in version 261. *systemd.imds.data\_url=* Takes the base URL to acquire the IMDS data from (the IMDS "endpoint"). All data fields are acquired from below this URL. This URL should typically not end in "/". The data URLs are concatenated from this base URL, the IMDS "key" and the suffix configured via *systemd.imds.data\_url\_suffix=* below. Well-known IMDS "keys" can be configured via the *systemd.imds.key=\** options below. Example: ``` systemd.imds.data_url=http://169.254.169.254/metadata ``` Added in version 261. *systemd.imds.data\_url\_suffix=* If specified, this field is appended to the end of the data URL (after appending the IMDS "key" to the data base URL), see above. Example: ``` systemd.imds.data_url_suffix=?api-version=2025-04-07&format=text ``` Added in version 261. *systemd.imds.token\_header\_name=* Takes a HTTP header field name (excluding the ":") that declares the header field to pass the bearer token acquired from the token URL (see above) in. Only applies if *systemd.imds.token\_url=* is set too. Added in version 261. *systemd.imds.extra\_header=* Takes a full HTTP header expression (both field name and value, separated by a colon ":") to pass to the HTTP server when requesting data. May be used multiple times to set multiple headers. Example: ``` systemd.imds.extra_header=Metadata:true ``` Added in version 261. *systemd.imds.address\_ipv4=* Configures the IPv4 address the IMDS endpoint is contacted on. This should typically be the IP address also configured via *systemd.imds.data\_url=* (if IPv4 is used) and is used to set up IP routing. Example: ``` systemd.imds.address_ipv4=169.254.169.254 ``` Added in version 261. *systemd.imds.address\_ipv6=* Configures the IPv6 address the IMDS endpoint is contacted on. This should typically be the IP address also configured via *systemd.imds.data\_url=* (if IPv6 is used) and is used to set up IP routing. Added in version 261. *systemd.imds.key.hostname=*, *systemd.imds.key.region=*, *systemd.imds.key.zone=*, *systemd.imds.key.ipv4\_public=*, *systemd.imds.key.ipv6\_public=*, *systemd.imds.key.ssh\_key=*, *systemd.imds.key.userdata=*, *systemd.imds.key.userdata\_base=*, *systemd.imds.key.userdata\_base64=* Configures strings to concatenate to the data base URL (see above) to acquire data for various "well-known" fields. These strings must begin with a "/". They should return the relevant data in plain text. A special case are the three "userdata" keys: the option *systemd.imds.key.userdata\_base=* should be used if the IMDS service knows a concept of multiple userdata fields, and a field identifier thus still needs to be appended to the userdata base URL. The option *systemd.imds.key.userdata=* should be used if only a single userdata field is supported. The option *systemd.imds.key.userdata\_base64=* should be used in the same case, but only if the userdata field is encoded in Base64. Example: ``` systemd.imds.key.hostname=/instance/compute/osProfile/computerName ``` Added in version 261. ## CREDENTIALS systemd-imdsd@.service supports the service credentials logic as implemented by *ImportCredential=*/*LoadCredential=*/*SetCredential=* (see [**systemd.exec**(5)](/systemd.exec/5.md) for details). The following credentials are used when passed in: *imds.vendor*, *imds.vendor\_token*, *imds.refresh\_header\_name*, *imds.data\_url*, *imds.data\_url\_suffix*, *imds.token\_header\_name*, *imds.extra\_header*, *imds.extra\_header2*, *imds.extra\_header3*, *imds.extra\_header...*, *imds.address\_ipv4*, *imds.address\_ipv6*, *imds.key\_hostname*, *imds.key\_region*, *imds.key\_zone*, *imds.key\_ipv4\_public*, *imds.key\_ipv6\_public*, *imds.key\_ssh\_key*, *imds.key\_userdata*, *imds.key\_userdata\_base*, *imds.key\_userdata\_base64* The various IMDS endpoint parameters. The semantics are very close to those configurable via kernel command line, see above for the matching list. Added in version 261. ## SEE ALSO [**systemd**(1)](/systemd/1.md), [**systemd-imds**(1)](/systemd-imds/1.md), [**systemd-imds-generator**(8)](/systemd-imds-generator/8.md), [**systemd-networkd.service**(8)](/systemd-networkd.service/8.md)