|
| 1 | +# Sources of Configuration |
| 2 | + |
| 3 | +In `bootc`-land it is preferred for the source of truth to be the container itself. For `image-builder` that means that certain instructions can be stored inside the container and will be used by `image-builder` when present. We get various bits and bobs from different places . This page describes what we get from where. |
| 4 | + |
| 5 | +## `bootc print-config` |
| 6 | + |
| 7 | +## Filesystem |
| 8 | + |
| 9 | +`image-builder` will use several files with different purposes from the container filesystem if they exist. These files are expected to exist in the `/usr/lib/image-builder/bootc` directory. |
| 10 | + |
| 11 | +For historical reasons `image-builder` will also see if these files exist in the `/usr/lib/bootc-image-builder` directory. The `/usr/lib/image-builder/bootc` directory has preference and any containers using the `/usr/lib/bootc-image-builder` path should be changed to use `/usr/lib/image-builder/bootc` instead. |
| 12 | + |
| 13 | +### `disk.yaml` |
| 14 | + |
| 15 | +A YAML file containing the partition layout to use when turning the container image into a disk image. The canonical location for this file is `/usr/lib/image-builder/bootc/disk.yaml`. |
| 16 | + |
| 17 | +If present this will replace the base partition tables that `image-builder` uses during build. Blueprint customizations can be applied on top by end-users that want to modify their deployments. |
| 18 | + |
| 19 | +A quick example that sets up a very default partition layout (BIOS boot, ESP, XBOOTLDR, and root partition) before explanation and more complex examples. |
| 20 | + |
| 21 | +> [!WARNING] |
| 22 | +> *The BIOS boot partition is currently required by `bootupd`, hence we've included it here in every example. This might change in the future and be dependent on the container itself; see [this issue](https://github.com/coreos/bootupd/issues/1067).* |
| 23 | +
|
| 24 | +```yaml |
| 25 | +mount_configuration: "units" |
| 26 | +partition_table: |
| 27 | + type: "gpt" |
| 28 | + partitions: |
| 29 | + - size: "1 MiB" |
| 30 | + type: "21686148-6449-6e6F-744e-656564454649" |
| 31 | + bootable: true |
| 32 | + - size: "200 MiB" |
| 33 | + type: "c12a7328-f81f-11d2-ba4b-00a0c93ec93b" |
| 34 | + payload_type: "filesystem" |
| 35 | + payload: |
| 36 | + type: "vfat" |
| 37 | + mountpoint: "/boot/efi" |
| 38 | + label: "ESP" |
| 39 | + fstab_options: "defaults,uid=0,gid=0,umask=077,shortname=winnt" |
| 40 | + fstab_freq: 0 |
| 41 | + fstab_passno: 2 |
| 42 | + - size: "2 GiB" |
| 43 | + type: "bc13c2ff-59e6-4262-a352-b275fd6f7172" |
| 44 | + payload_type: "filesystem" |
| 45 | + payload: |
| 46 | + type: "ext4" |
| 47 | + label: "boot" |
| 48 | + mountpoint: "/boot" |
| 49 | + fstab_options: "defaults" |
| 50 | + fstab_freq: 0 |
| 51 | + fstab_passno: 0 |
| 52 | + - size: "4 GiB" |
| 53 | + type: "44479540-f297-41b2-9af7-d131d5f0458a" |
| 54 | + payload_type: "filesystem" |
| 55 | + payload: |
| 56 | + type: "ext4" |
| 57 | + label: "root" |
| 58 | + mountpoint: "/" |
| 59 | + fstab_options: "defaults" |
| 60 | + fstab_freq: 0 |
| 61 | + fstab_passno: 0 |
| 62 | +``` |
| 63 | +
|
| 64 | +*The type UUIDs used in this example come from the [Discoverable Partitions Specification](https://uapi-group.org/specifications/specs/discoverable_partitions_specification/).* |
| 65 | +
|
| 66 | +`mount_configuration` is an enum and can hold the values `fstab`, `units`, or `none`. It dictates how the mountpoints are configured in the disk image. `fstab` will write an `/etc/fstab`, `units` will write systemd mount unit files, and `none` will do neither; leaving it up to tooling such as `systemd-gpt-auto-generator` to figure out what to mount where. |
| 67 | + |
| 68 | +`partition_table` is an object with the following properties: |
| 69 | + |
| 70 | +- `type`, an `enum` that can be `gpt` or `dos` and sets the partition table format to use. |
| 71 | +- `partitions`, a list of objects each of which represents a partition. |
| 72 | + |
| 73 | +#### Partitions |
| 74 | + |
| 75 | +Each partition can have the following properties: |
| 76 | + |
| 77 | +- `size`, a string with units to set the size of the partition. |
| 78 | +- `type`, the partition type GPT UUID *or* DOS ID. |
| 79 | + |
| 80 | +- `bootable`, an *optional* boolean indicating that this partition is legacy BIOS bootable (GPT) or active (DOS). |
| 81 | +- `uuid`, an *optional* string containing the partition UUID itself. Should be omitted and will be based on a PRNG, fixing this value can lead to issues trying to mount the same disk multiple times. |
| 82 | +- `label`, an *optional* `string` containing the partition name (**not** the filesystem label) for GPT. |
| 83 | +- `attrs`, an *optional* array of unsigned integers that set partition attribute flags for GPT. |
| 84 | + |
| 85 | +- `payload_type`, an `enum` that contains one `filesystem`, `luks`, `lvm`, `btrfs`, `raw`. This field dictates what goes into the `payload` object that comes next. |
| 86 | +- `payload`, an object based on the value of `payload_type`. `payload_type`s and their `payload` contents are explained below. |
| 87 | + |
| 88 | +##### Payloads |
| 89 | + |
| 90 | +###### Filesystem |
| 91 | + |
| 92 | +For a `payload_type: filesystem` the `payload` has the following properties: |
| 93 | + |
| 94 | +- `type` |
| 95 | +- `mountpoint`, a `string` that tells where this partition should be mounted. |
| 96 | + |
| 97 | + |
| 98 | +- `label`, an *optional* `string` that contains the filesystem label. |
| 99 | +- `fstab_options` |
| 100 | +- `fstab_freq` |
| 101 | +- `fstab_passno` |
| 102 | + |
| 103 | +Here's an example defining a few partition with XFS filesystem(s): |
| 104 | + |
| 105 | +``` |
| 106 | +mount_configuration: "units" |
| 107 | +partition_table: |
| 108 | + type: "gpt" |
| 109 | + partitions: |
| 110 | + - size: "1 MiB" |
| 111 | + type: "21686148-6449-6e6F-744e-656564454649" |
| 112 | + bootable: true |
| 113 | + - size: "200 MiB" |
| 114 | + type: "c12a7328-f81f-11d2-ba4b-00a0c93ec93b" |
| 115 | + payload_type: "filesystem" |
| 116 | + payload: |
| 117 | + type: "vfat" |
| 118 | + mountpoint: "/boot/efi" |
| 119 | + label: "ESP" |
| 120 | + fstab_options: "defaults,uid=0,gid=0,umask=077,shortname=winnt" |
| 121 | + fstab_freq: 0 |
| 122 | + fstab_passno: 2 |
| 123 | + - size: "2 GiB" |
| 124 | + type: "bc13c2ff-59e6-4262-a352-b275fd6f7172" |
| 125 | + payload_type: "filesystem" |
| 126 | + payload: |
| 127 | + type: "xfs" |
| 128 | + label: "boot" |
| 129 | + mountpoint: "/boot" |
| 130 | + - payload_type: "filesystem" |
| 131 | + payload: |
| 132 | + type: "xfs" |
| 133 | + label: "root" |
| 134 | + mountpoint: "/" |
| 135 | +``` |
| 136 | + |
| 137 | +###### LVM |
| 138 | + |
| 139 | +> [!WARNING] |
| 140 | +> LVM configurations currently do not work with bootable containers in `image-builder`. |
| 141 | + |
| 142 | +For a `payload_type: lvm` the `payload` has the following properties: |
| 143 | + |
| 144 | +- `name` |
| 145 | +- `description` |
| 146 | +- `logical_volumes` a list of objects. |
| 147 | + |
| 148 | +The `logical_volumes` objects have the following properties: |
| 149 | + |
| 150 | +- `size`, a string with units to set the size of the partition. |
| 151 | +- `name`, a `string` with the name of the volume group. |
| 152 | + |
| 153 | +- `payload_type` |
| 154 | +- `payload` |
| 155 | + |
| 156 | +An example of using the `lvm` payload: |
| 157 | + |
| 158 | +``` |
| 159 | +mount_configuration: "fstab" |
| 160 | +partition_table: |
| 161 | + type: "gpt" |
| 162 | + partitions: |
| 163 | + - size: "1 MiB" |
| 164 | + bootable: true |
| 165 | + type: "21686148-6449-6e6F-744e-656564454649" |
| 166 | + - size: "200 MiB" |
| 167 | + type: "c12a7328-f81f-11d2-ba4b-00a0c93ec93b" |
| 168 | + payload_type: "filesystem" |
| 169 | + payload: |
| 170 | + type: "vfat" |
| 171 | + mountpoint: "/boot/efi" |
| 172 | + label: "ESP" |
| 173 | + fstab_options: "defaults,uid=0,gid=0,umask=077,shortname=winnt" |
| 174 | + fstab_freq: 0 |
| 175 | + fstab_passno: 2 |
| 176 | + - size: "2 GiB" |
| 177 | + type: "bc13c2ff-59e6-4262-a352-b275fd6f7172" |
| 178 | + payload_type: "filesystem" |
| 179 | + payload: |
| 180 | + type: "ext4" |
| 181 | + label: "boot" |
| 182 | + mountpoint: "/boot" |
| 183 | + fstab_options: "defaults" |
| 184 | + - size: "8 GiB" |
| 185 | + type: "44479540-f297-41b2-9af7-d131d5f0458a" |
| 186 | + payload_type: "lvm" |
| 187 | + payload: |
| 188 | + name: "systemVG" |
| 189 | + logical_volumes: |
| 190 | + - size: "4 GiB" |
| 191 | + name: "LVroot" |
| 192 | + payload_type: "filesystem" |
| 193 | + payload: |
| 194 | + type: "xfs" |
| 195 | + label: "root" |
| 196 | + mountpoint: "/" |
| 197 | + fstab_options: "defaults" |
| 198 | +``` |
| 199 | + |
| 200 | +*Note the nested payload to put a filesystem inside the `LVRoot` logical volume.* |
| 201 | + |
| 202 | +###### btrfs |
| 203 | + |
| 204 | +For a `payload_type: btrfs` the `payload` has the following properties: |
| 205 | + |
| 206 | +- `subvolumes`, a list of objects. |
| 207 | + |
| 208 | +The `subvolumes` objects have the following properties: |
| 209 | + |
| 210 | +- `name` |
| 211 | +- `mountpoint` |
| 212 | + |
| 213 | +An example of using the `btrfs` payload: |
| 214 | + |
| 215 | +```yaml |
| 216 | +mount_configuration: "units" |
| 217 | +partition_table: |
| 218 | + type: "gpt" |
| 219 | + partitions: |
| 220 | + - size: "1 MiB" |
| 221 | + bootable: true |
| 222 | + type: "21686148-6449-6e6F-744e-656564454649" |
| 223 | + - size: "200 MiB" |
| 224 | + type: "c12a7328-f81f-11d2-ba4b-00a0c93ec93b" |
| 225 | + payload_type: "filesystem" |
| 226 | + payload: |
| 227 | + type: "vfat" |
| 228 | + mountpoint: "/boot/efi" |
| 229 | + label: "ESP" |
| 230 | + fstab_options: "defaults,uid=0,gid=0,umask=077,shortname=winnt" |
| 231 | + fstab_freq: 0 |
| 232 | + fstab_passno: 2 |
| 233 | + - size: "2 GiB" |
| 234 | + type: "bc13c2ff-59e6-4262-a352-b275fd6f7172" |
| 235 | + payload_type: "filesystem" |
| 236 | + payload: |
| 237 | + type: "ext4" |
| 238 | + label: "boot" |
| 239 | + mountpoint: "/boot" |
| 240 | + fstab_options: "defaults" |
| 241 | + fstab_freq: 0 |
| 242 | + fstab_passno: 0 |
| 243 | + - size: "4 GiB" |
| 244 | + type: "44479540-f297-41b2-9af7-d131d5f0458a" |
| 245 | + payload_type: "btrfs" |
| 246 | + payload: |
| 247 | + subvolumes: |
| 248 | + - name: "root" |
| 249 | + mountpoint: "/" |
| 250 | + - name: "home" |
| 251 | + mountpoint: "/home" |
| 252 | + - name: "var" |
| 253 | + mountpoint: "/var" |
| 254 | +``` |
| 255 | + |
| 256 | +*To use `btrfs` your container must set its configured root filesystem to `btrfs`, or it must be passed when `image-builder` is called.* |
| 257 | + |
| 258 | +*To use `btrfs` your build host and container kernel must support `btrfs`.* |
| 259 | + |
| 260 | +###### LUKS |
| 261 | + |
| 262 | +Allows for setting up disk encryption with luks. Contains other payloads (filesystems). |
| 263 | + |
| 264 | +For a `payload_type: luks` the `payload` has the following properties: |
| 265 | + |
| 266 | +- `label` |
| 267 | +- `cipher` |
| 268 | +- `passphrase` |
| 269 | +- `pbkdf` |
| 270 | +- `clevis` |
| 271 | + |
| 272 | +- `payload_type` |
| 273 | +- `payload` |
| 274 | + |
| 275 | +An example of how you can use the `luks` payload. |
| 276 | + |
| 277 | +```yaml |
| 278 | +
|
| 279 | +``` |
| 280 | + |
| 281 | +###### raw |
| 282 | + |
| 283 | +For a `payload_type: raw` the `payload` has the following properties: |
| 284 | + |
| 285 | +- |
| 286 | + |
| 287 | +### `iso.yaml` |
| 288 | + |
| 289 | +A YAML file containing instructions for constructing an ISO. This YAML file is only used for the `generic-iso` image type which makes as few assumptions as possible and thus needs extra instructions to tell it what to do. Read [more about the `generic-iso`](./10-installers.md) to see what you can do with this file. |
| 290 | + |
| 291 | +```yaml |
| 292 | +label: "Fedora-bootc-Installer" |
| 293 | +grub2: |
| 294 | + entries: |
| 295 | + - name: "Install Fedora (bootc)" |
| 296 | + linux: "/images/pxeboot/vmlinuz inst.stage2=hd:LABEL=Fedora-bootc-Installer console=tty0 inst.text selinux=0" |
| 297 | + initrd: "/images/pxeboot/initrd.img" |
| 298 | +``` |
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