org.avocado.Extensions

Manages Avocado Linux system extensions (sysext and confext images). This interface provides methods to list, merge, unmerge, refresh, enable, disable, and query the status of extensions.

Interface Definition

# Extension management for Avocado Linux system extensions
interface org.avocado.Extensions

type Extension (
    name: string,
    version: ?string,
    path: string,
    isSysext: bool,
    isConfext: bool,
    isDirectory: bool
)

type ExtensionStatus (
    name: string,
    version: ?string,
    isSysext: bool,
    isConfext: bool,
    isMerged: bool,
    origin: ?string,
    imageId: ?string
)

# List all available extensions in the extensions directory
method List() -> (extensions: []Extension)

# Merge extensions using systemd-sysext and systemd-confext
# Supports streaming: client may set more=true to receive per-message progress
method Merge() -> (message: string, done: bool)

# Unmerge extensions
# Supports streaming: client may set more=true to receive per-message progress
method Unmerge(unmount: ?bool) -> (message: string, done: bool)

# Refresh extensions (unmerge then merge)
# Supports streaming: client may set more=true to receive per-message progress
method Refresh() -> (message: string, done: bool)

# Enable extensions for a specific OS release version
method Enable(extensions: []string, osRelease: ?string) -> (enabled: int, failed: int)

# Disable extensions for a specific OS release version
method Disable(extensions: ?[]string, all: ?bool, osRelease: ?string) -> (disabled: int, failed: int)

# Show status of merged extensions
method Status() -> (extensions: []ExtensionStatus)

error ExtensionNotFound (name: string)
error MergeFailed (reason: string)
error UnmergeFailed (reason: string)
error ConfigurationError (message: string)
error CommandFailed (command: string, message: string)

Types

Extension

Represents an extension image or directory available on the filesystem.

Field	Type	Description
name	string	Extension name (derived from the image filename)
version	?string	Extension version, if embedded in the image metadata
path	string	Absolute path to the extension image or directory
isSysext	bool	true if this is a system extension (overlays /usr)
isConfext	bool	true if this is a configuration extension (overlays /etc)
isDirectory	bool	true if the extension is a plain directory rather than an image file

ExtensionStatus

Represents the current status of an extension, including whether it is merged into the running system.

Field	Type	Description
name	string	Extension name
version	?string	Extension version
isSysext	bool	true if this is a system extension
isConfext	bool	true if this is a configuration extension
isMerged	bool	true if the extension is currently merged into the root filesystem
origin	?string	Origin identifier (e.g., the TUF target name)
imageId	?string	Image digest or build identifier

Methods

List

List all available extensions in the extensions directory.

Signature: List() -> (extensions: []Extension)

Parameters: None.

Returns:

Field	Type	Description
extensions	[]Extension	Array of available extension objects

C Example:

VarlinkObject *parameters = NULL;
VarlinkObject *reply = NULL;
long r;

varlink_object_new(&parameters);
r = varlink_connection_call(connection, "org.avocado.Extensions.List", parameters, 0, &reply);
if (r < 0) {
    fprintf(stderr, "Call failed: %s\n", varlink_error_string(-r));
    varlink_object_unref(parameters);
    return;
}

VarlinkArray *extensions;
varlink_object_get_array(reply, "extensions", &extensions);

for (unsigned long i = 0; i < varlink_array_get_n_elements(extensions); i++) {
    VarlinkObject *ext;
    varlink_array_get_object(extensions, i, &ext);

    const char *name, *path;
    bool is_sysext, is_confext;

    varlink_object_get_string(ext, "name", &name);
    varlink_object_get_string(ext, "path", &path);
    varlink_object_get_bool(ext, "isSysext", &is_sysext);
    varlink_object_get_bool(ext, "isConfext", &is_confext);

    printf("%-30s  sysext=%d  confext=%d  %s\n", name, is_sysext, is_confext, path);
}

varlink_object_unref(reply);
varlink_object_unref(parameters);

Merge

Merge all enabled extensions into the running system using systemd-sysext and systemd-confext.

Signature: Merge() -> (message: string, done: bool)

Parameters: None.

Returns (streaming):

Field	Type	Description
message	string	Progress message describing the current step
done	bool	true on the final reply

Streaming: Yes. Call with VARLINK_CALL_MORE to receive progress updates.

C Example:

VarlinkObject *parameters = NULL;
long r;

varlink_object_new(&parameters);

r = varlink_connection_call(connection, "org.avocado.Extensions.Merge",
                            parameters, VARLINK_CALL_MORE, NULL);
if (r < 0) {
    fprintf(stderr, "Call failed: %s\n", varlink_error_string(-r));
    varlink_object_unref(parameters);
    return;
}

VarlinkObject *reply = NULL;
while ((r = varlink_connection_reply(connection, &reply)) >= 0) {
    const char *message;
    varlink_object_get_string(reply, "message", &message);
    printf("[merge] %s\n", message);

    bool done;
    varlink_object_get_bool(reply, "done", &done);

    varlink_object_unref(reply);
    reply = NULL;

    if (done)
        break;
}

varlink_object_unref(parameters);

Unmerge

Unmerge extensions from the running system.

Signature: Unmerge(unmount: ?bool) -> (message: string, done: bool)

Parameters:

Field	Type	Description
unmount	?bool	If true, also unmount the extension images. Defaults to false.

Returns (streaming):

Field	Type	Description
message	string	Progress message describing the current step
done	bool	true on the final reply

Streaming: Yes. Call with VARLINK_CALL_MORE to receive progress updates.

C Example:

VarlinkObject *parameters = NULL;
long r;

varlink_object_new(&parameters);
varlink_object_set_bool(parameters, "unmount", true);

r = varlink_connection_call(connection, "org.avocado.Extensions.Unmerge",
                            parameters, VARLINK_CALL_MORE, NULL);
if (r < 0) {
    fprintf(stderr, "Call failed: %s\n", varlink_error_string(-r));
    varlink_object_unref(parameters);
    return;
}

VarlinkObject *reply = NULL;
while ((r = varlink_connection_reply(connection, &reply)) >= 0) {
    const char *message;
    varlink_object_get_string(reply, "message", &message);
    printf("[unmerge] %s\n", message);

    bool done;
    varlink_object_get_bool(reply, "done", &done);

    varlink_object_unref(reply);
    reply = NULL;

    if (done)
        break;
}

varlink_object_unref(parameters);

Refresh

Unmerge and then re-merge all enabled extensions. This is equivalent to calling Unmerge followed by Merge.

Signature: Refresh() -> (message: string, done: bool)

Parameters: None.

Returns (streaming):

Field	Type	Description
message	string	Progress message describing the current step
done	bool	true on the final reply

Streaming: Yes. Call with VARLINK_CALL_MORE to receive progress updates.

C Example:

VarlinkObject *parameters = NULL;
long r;

varlink_object_new(&parameters);

r = varlink_connection_call(connection, "org.avocado.Extensions.Refresh",
                            parameters, VARLINK_CALL_MORE, NULL);
if (r < 0) {
    fprintf(stderr, "Call failed: %s\n", varlink_error_string(-r));
    varlink_object_unref(parameters);
    return;
}

VarlinkObject *reply = NULL;
while ((r = varlink_connection_reply(connection, &reply)) >= 0) {
    const char *message;
    varlink_object_get_string(reply, "message", &message);
    printf("[refresh] %s\n", message);

    bool done;
    varlink_object_get_bool(reply, "done", &done);

    varlink_object_unref(reply);
    reply = NULL;

    if (done)
        break;
}

varlink_object_unref(parameters);

Enable

Enable one or more extensions for a specific OS release version. Enabling an extension makes it available for merging.

Signature: Enable(extensions: []string, osRelease: ?string) -> (enabled: int, failed: int)

Parameters:

Field	Type	Description
extensions	[]string	List of extension names to enable
osRelease	?string	Target OS release version. If omitted, the current OS release is used.

Returns:

Field	Type	Description
enabled	int	Number of extensions successfully enabled
failed	int	Number of extensions that failed to enable

C Example:

VarlinkObject *parameters = NULL;
VarlinkObject *reply = NULL;
long r;

varlink_object_new(&parameters);

VarlinkArray *ext_list;
varlink_array_new(&ext_list);
varlink_array_append_string(ext_list, "my-app");
varlink_array_append_string(ext_list, "my-config");
varlink_object_set_array(parameters, "extensions", ext_list);

r = varlink_connection_call(connection, "org.avocado.Extensions.Enable", parameters, 0, &reply);
if (r < 0) {
    fprintf(stderr, "Call failed: %s\n", varlink_error_string(-r));
    varlink_object_unref(parameters);
    return;
}

const char *error_name = NULL;
if (varlink_reply_is_error(reply, &error_name)) {
    fprintf(stderr, "Error: %s\n", error_name);
} else {
    int64_t enabled, failed;
    varlink_object_get_int(reply, "enabled", &enabled);
    varlink_object_get_int(reply, "failed", &failed);
    printf("Enabled: %ld, Failed: %ld\n", enabled, failed);
}

varlink_object_unref(reply);
varlink_object_unref(parameters);

Disable

Disable extensions for a specific OS release version. Disabled extensions will not be included in subsequent merge operations.

Signature: Disable(extensions: ?[]string, all: ?bool, osRelease: ?string) -> (disabled: int, failed: int)

Parameters:

Field	Type	Description
extensions	?[]string	List of extension names to disable. Omit if using all.
all	?bool	If true, disable all extensions.
osRelease	?string	Target OS release version. If omitted, the current OS release is used.

Returns:

Field	Type	Description
disabled	int	Number of extensions successfully disabled
failed	int	Number of extensions that failed to disable

C Example:

VarlinkObject *parameters = NULL;
VarlinkObject *reply = NULL;
long r;

varlink_object_new(&parameters);
varlink_object_set_bool(parameters, "all", true);

r = varlink_connection_call(connection, "org.avocado.Extensions.Disable", parameters, 0, &reply);
if (r < 0) {
    fprintf(stderr, "Call failed: %s\n", varlink_error_string(-r));
    varlink_object_unref(parameters);
    return;
}

int64_t disabled, failed;
varlink_object_get_int(reply, "disabled", &disabled);
varlink_object_get_int(reply, "failed", &failed);
printf("Disabled: %ld, Failed: %ld\n", disabled, failed);

varlink_object_unref(reply);
varlink_object_unref(parameters);

Status

Show the current merge status of all extensions.

Signature: Status() -> (extensions: []ExtensionStatus)

Parameters: None.

Returns:

Field	Type	Description
extensions	[]ExtensionStatus	Array of extension status objects

C Example:

VarlinkObject *parameters = NULL;
VarlinkObject *reply = NULL;
long r;

varlink_object_new(&parameters);
r = varlink_connection_call(connection, "org.avocado.Extensions.Status", parameters, 0, &reply);
if (r < 0) {
    fprintf(stderr, "Call failed: %s\n", varlink_error_string(-r));
    varlink_object_unref(parameters);
    return;
}

VarlinkArray *extensions;
varlink_object_get_array(reply, "extensions", &extensions);

for (unsigned long i = 0; i < varlink_array_get_n_elements(extensions); i++) {
    VarlinkObject *ext;
    varlink_array_get_object(extensions, i, &ext);

    const char *name;
    bool is_merged;

    varlink_object_get_string(ext, "name", &name);
    varlink_object_get_bool(ext, "isMerged", &is_merged);

    printf("%-30s  %s\n", name, is_merged ? "merged" : "not merged");
}

varlink_object_unref(reply);
varlink_object_unref(parameters);

Errors

ExtensionNotFound

Returned when a referenced extension name does not exist in the extensions directory.

Parameter	Type	Description
name	string	The extension name that was not found

Trigger: Passing an unknown extension name to Enable or Disable.

MergeFailed

Returned when the merge operation fails.

Parameter	Type	Description
reason	string	Human-readable description of the failure

Trigger: systemd-sysext merge or systemd-confext merge exits with a non-zero status, or an internal error occurs during the merge process.

UnmergeFailed

Returned when the unmerge operation fails.

Parameter	Type	Description
reason	string	Human-readable description of the failure

Trigger: systemd-sysext unmerge or systemd-confext unmerge exits with a non-zero status.

ConfigurationError

Returned when the extension configuration is invalid.

Parameter	Type	Description
message	string	Description of the configuration problem

Trigger: Malformed extension metadata, missing required fields, or incompatible OS release versions.

CommandFailed

Returned when an external command executed during extension management fails.

Parameter	Type	Description
command	string	The command that failed
message	string	The command's error output or exit status

Trigger: Any subprocess invoked during merge, unmerge, enable, or disable operations exits with a non-zero status.