1LORAX-COMPOSER(1) Lorax LORAX-COMPOSER(1)
2
6 lorax-composer - Lorax Composer Documentation
7 Authors
9 Brian C. Lane <bcl@redhat.com>
10 lorax-composer is an API server that allows you to build disk images
12 using Blueprints to describe the package versions to be installed into
13 the image. It is compatible with the Weldr project's bdcs-api REST
14 protocol. More information on Weldr can be found on the Weldr blog.
15 Behind the scenes it uses livemedia-creator and Anaconda to handle the
17 installation and configuration of the images.
18
20 · As of version 30.7 SELinux can be set to Enforcing. The current state
21 is logged for debugging purposes and if there are SELinux denials
22 they should be reported as a bug.
23 · All image types lock the root account, except for live-iso. You will
25 need to either use one of the Customizations methods for setting a
26 ssh key/password, install a package that creates a user, or use some‐
27 thing like cloud-init to setup access at boot time.
28
30 The best way to install lorax-composer is to use sudo dnf install
31 lorax-composer composer-cli, this will setup the weldr user and install
32 the systemd socket activation service. You will then need to enable it
33 with sudo systemctl enable lorax-composer.socket && sudo systemctl
34 start lorax-composer.socket. This will leave the server off until the
35 first request is made. Systemd will then launch the server and it will
36 remain running until the system is rebooted. This will cause some delay
37 in responding to the first request from the UI or composer-cli.
38 NOTE:
40 If you want lorax-composer to respond immediately to the first
41 request you can start and enable lorax-composer.service instead of
42 lorax-composer.socket
43
45 1. Create a weldr user and group by running useradd weldr
46 2. Remove any pre-existing socket directory with rm -rf /run/weldr/ A
48 new directory with correct permissions will be created the first
49 time the server runs.
50 3. Enable the socket activation with systemctl enable lorax-com‐
52 poser.socket && sudo systemctl start lorax-composer.socket.
53 NOTE: You can also run it directly with lorax-composer /path/to/blue‐
55 prints. However, lorax-composer does not react well to being started
56 both on the command line and via socket activation at the same time.
57 It is therefore recommended that you run it directly on the command
58 line only for testing or development purposes. For real use or devel‐
59 opment of other projects that simply use the API, you should stick to
60 socket activation only.
61 The /path/to/blueprints/ directory is where the blueprints' git repo
63 will be created, and all the blueprints created with the /api/v0/blue‐
64 prints/new route will be stored. If there are blueprint .toml files in
65 the top level of the directory they will be imported into the blueprint
66 git storage when lorax-composer starts.
67
69 Logs are stored under /var/log/lorax-composer/ and include all console
70 messages as well as extra debugging info and API requests.
71
73 Some security related issues that you should be aware of before running
74 lorax-composer:
75 · One of the API server threads needs to retain root privileges in
77 order to run Anaconda.
78 · Only allow authorized users access to the weldr group and socket.
80 Since Anaconda kickstarts are used there is the possibility that a user
82 could inject commands into a blueprint that would result in the kick‐
83 start executing arbitrary code on the host. Only authorized users
84 should be allowed to build images using lorax-composer.
85
87 Lorax Composer API Server
88 usage: lorax-composer [-h] [--socket SOCKET] [--user USER] [--group GROUP]
91 [--log LOG] [--mockfiles MOCKFILES]
92 [--sharedir SHAREDIR] [-V] [-c CONFIG]
93 [--releasever STRING] [--tmp TMP] [--proxy PROXY]
94 [--no-system-repos]
95 BLUEPRINTS
96 Positional Arguments
98 Path to the blueprints
99 Named Arguments
101 -socket
102 Path to the socket file to listen on
103 Default: "/run/weldr/api.socket"
105 -user User to use for reduced permissions
107 Default: "root"
109 -group Group to set ownership of the socket to
111 Default: "weldr"
113 -log Path to logfile (/var/log/lorax-composer/composer.log)
115 Default: "/var/log/lorax-composer/composer.log"
117 -mockfiles
119 Path to JSON files used for /api/mock/ paths
120 (/var/tmp/bdcs-mockfiles/)
121 Default: "/var/tmp/bdcs-mockfiles/"
123 -sharedir
125 Directory containing all the templates. Overrides config file
126 sharedir
127 V show program's version number and exit
129 Default: False
131 c, --config
133 Path to lorax-composer configuration file.
134 Default: "/etc/lorax/composer.conf"
136 -releasever
138 Release version to use for $releasever in dnf repository urls
139 -tmp Top level temporary directory
141 Default: "/var/tmp"
143 -proxy Set proxy for DNF, overrides configuration file setting.
145 -no-system-repos
147 Do not copy over system repos from /etc/yum.repos.d/ at startup
148 Default: False
150
152 The server runs as root, and as weldr. Communication with it is via a
153 unix domain socket (/run/weldr/api.socket by default). The directory
154 and socket are owned by root:weldr so that any user in the weldr group
155 can use the API to control lorax-composer.
156 At startup the server will check for the correct permissions and owner‐
158 ship of a pre-existing directory, or it will create a new one if it
159 doesn't exist. The socket path and group owner's name can be changed
160 from the cmdline by passing it the --socket and --group arguments.
161 It will then drop root privileges for the API thread and run as the
163 weldr user. The queue and compose thread still runs as root because it
164 needs to be able to mount/umount files and run Anaconda.
165
167 The welder-web GUI project can be used to construct blueprints and cre‐
168 ate composes using a web browser.
169 Or use the command line with composer-cli.
171
173 Blueprints are simple text files in TOML format that describe which
174 packages, and what versions, to install into the image. They can also
175 define a limited set of customizations to make to the final image.
176 Example blueprints can be found in the lorax-composer test suite, with
178 a simple one looking like this:
179 name = "base"
181 description = "A base system with bash"
182 version = "0.0.1"
183 [[packages]]
185 name = "bash"
186 version = "4.4.*"
187 The name field is the name of the blueprint. It can contain spaces, but
189 they will be converted to - when it is written to disk. It should be
190 short and descriptive.
191 description can be a longer description of the blueprint, it is only
193 used for display purposes.
194 version is a semver compatible version number. If a new blueprint is
196 uploaded with the same version the server will automatically bump the
197 PATCH level of the version. If the version doesn't match it will be
198 used as is. eg. Uploading a blueprint with version set to 0.1.0 when
199 the existing blueprint version is 0.0.1 will result in the new blue‐
200 print being stored as version 0.1.0.
201 [[packages]] and [[modules]]
203 These entries describe the package names and matching version glob to
204 be installed into the image.
205 The names must match the names exactly, and the versions can be an
207 exact match or a filesystem-like glob of the version using * wildcards
208 and ? character matching.
209 NOTE: As of lorax-composer-29.2-1 the versions are not used for dep‐
211 solving, that is planned for a future release. And currently there are
212 no differences between packages and modules in lorax-composer.
213 [[groups]]
215 These entries describe a group of packages to be installed into the
216 image. Package groups are defined in the repository metadata. Each
217 group has a descriptive name used primarily for display in user inter‐
218 faces and an ID more commonly used in kickstart files. Here, the ID is
219 the expected way of listing a group.
220 Groups have three different ways of categorizing their packages:
222 mandatory, default, and optional. For purposes of blueprints, manda‐
223 tory and default packages will be installed. There is no mechanism for
224 selecting optional packages.
225 Customizations
227 The [customizations] section can be used to configure the hostname of
228 the final image. eg.:
229 [customizations]
231 hostname = "baseimage"
232 This is optional and may be left out to use the defaults.
234 [customizations.kernel]
236 This allows you to append arguments to the bootloader's kernel command‐
237 line. This will not have any effect on tar or ext4-filesystem images
238 since they do not include a bootloader.
239 For example:
241 [customizations.kernel]
243 append = "nosmt=force"
244 [[customizations.sshkey]]
246 Set an existing user's ssh key in the final image:
247 [[customizations.sshkey]]
249 user = "root"
250 key = "PUBLIC SSH KEY"
251 The key will be added to the user's authorized_keys file.
253 WARNING:
255 key expects the entire content of ~/.ssh/id_rsa.pub
256 [[customizations.user]]
258 Add a user to the image, and/or set their ssh key. All fields for this
259 section are optional except for the name, here is a complete example:
260 [[customizations.user]]
262 name = "admin"
263 description = "Administrator account"
264 password = "$6$CHO2$3rN8eviE2t50lmVyBYihTgVRHcaecmeCk31L..."
265 key = "PUBLIC SSH KEY"
266 home = "/srv/widget/"
267 shell = "/usr/bin/bash"
268 groups = ["widget", "users", "wheel"]
269 uid = 1200
270 gid = 1200
271 If the password starts with $6$, $5$, or $2b$ it will be stored as an
273 encrypted password. Otherwise it will be treated as a plain text pass‐
274 word.
275 WARNING:
277 key expects the entire content of ~/.ssh/id_rsa.pub
278 [[customizations.group]]
280 Add a group to the image. name is required and gid is optional:
281 [[customizations.group]]
283 name = "widget"
284 gid = 1130
285 [customizations.timezone]
287 Customizing the timezone and the NTP servers to use for the system:
288 [customizations.timezone]
290 timezone = "US/Eastern"
291 ntpservers = ["0.north-america.pool.ntp.org", "1.north-america.pool.ntp.org"]
292 The values supported by timezone can be listed by running timedatectl
294 list-timezones.
295 If no timezone is setup the system will default to using UTC. The ntp
297 servers are also optional and will default to using the distribution
298 defaults which are fine for most uses.
299 In some image types there are already NTP servers setup, eg. Google
301 cloud image, and they cannot be overridden because they are required to
302 boot in the selected environment. But the timezone will be updated to
303 the one selected in the blueprint.
304 [customizations.locale]
306 Customize the locale settings for the system:
307 [customizations.locale]
309 languages = ["en_US.UTF-8"]
310 keyboard = "us"
311 The values supported by languages can be listed by running localectl
313 list-locales from the command line.
314 The values supported by keyboard can be listed by running localectl
316 list-keymaps from the command line.
317 Multiple languages can be added. The first one becomes the primary, and
319 the others are added as secondary. One or the other of languages or
320 keyboard must be included (or both) in the section.
321 [customizations.firewall]
323 By default the firewall blocks all access except for services that
324 enable their ports explicitly, like sshd. This command can be used to
325 open other ports or services. Ports are configured using the port:pro‐
326 tocol format:
327 [customizations.firewall]
329 ports = ["22:tcp", "80:tcp", "imap:tcp", "53:tcp", "53:udp"]
330 Numeric ports, or their names from /etc/services can be used in the
332 ports enabled/disabled lists.
333 The blueprint settings extend any existing settings in the image tem‐
335 plates, so if sshd is already enabled it will extend the list of ports
336 with the ones listed by the blueprint.
337 If the distribution uses firewalld you can specify services listed by
339 firewall-cmd --get-services in a customizations.firewall.services sec‐
340 tion:
341 [customizations.firewall.services]
343 enabled = ["ftp", "ntp", "dhcp"]
344 disabled = ["telnet"]
345 Remember that the firewall.services are different from the names in
347 /etc/services.
348 Both are optional, if they are not used leave them out or set them to
350 an empty list []. If you only want the default firewall setup this sec‐
351 tion can be omitted from the blueprint.
352 NOTE: The Google and OpenStack templates explicitly disable the fire‐
354 wall for their environment. This cannot be overridden by the blue‐
355 print.
356 [customizations.services]
358 This section can be used to control which services are enabled at boot
359 time. Some image types already have services enabled or disabled in
360 order for the image to work correctly, and cannot be overridden. eg.
361 ami requires sshd, chronyd, and cloud-init. Without them the image will
362 not boot. Blueprint services are added to, not replacing, the list
363 already in the templates, if any.
364 The service names are systemd service units. You may specify any sys‐
366 temd unit file accepted by systemctl enable eg. cockpit.socket:
367 [customizations.services]
369 enabled = ["sshd", "cockpit.socket", "httpd"]
370 disabled = ["postfix", "telnetd"]
371 [[repos.git]]
373 The [[repos.git]] entries are used to add files from a git reposi‐
374 tory<https://git-scm.com/> repository to the created image. The reposi‐
375 tory is cloned, the specified ref is checked out and an rpm is created
376 to install the files to a destination path. The rpm includes a summary
377 with the details of the repository and reference used to create it. The
378 rpm is also included in the image build metadata.
379 To create an rpm named server-config-1.0-1.noarch.rpm you would add
381 this to your blueprint:
382 [[repos.git]]
384 rpmname="server-config"
385 rpmversion="1.0"
386 rpmrelease="1"
387 summary="Setup files for server deployment"
388 repo="PATH OF GIT REPO TO CLONE"
389 ref="v1.0"
390 destination="/opt/server/"
391 · rpmname: Name of the rpm to create, also used as the prefix name in
393 the tar archive
394 · rpmversion: Version of the rpm, eg. "1.0.0"
396 · rpmrelease: Release of the rpm, eg. "1"
398 · summary: Summary string for the rpm
400 · repo: URL of the get repo to clone and create the archive from
402 · ref: Git reference to check out. eg. origin/branch-name, git tag, or
404 git commit hash
405 · destination: Path to install the / of the git repo at when installing
407 the rpm
408 An rpm will be created with the contents of the git repository refer‐
410 enced, with the files being installed under /opt/server/ in this case.
411 ref can be any valid git reference for use with git archive. eg. to use
413 the head of a branch set it to origin/branch-name, a tag name, or a
414 commit hash.
415 Note that the repository is cloned in full each time a build is
417 started, so pointing to a repository with a large amount of history may
418 take a while to clone and use a significant amount of disk space. The
419 clone is temporary and is removed once the rpm is created.
420
422 livemedia-creator supports a large number of output types, and only
423 some of these are currently available via lorax-composer. To add a new
424 output type to lorax-composer a kickstart file needs to be added to
425 ./share/composer/. The name of the kickstart is what will be used by
426 the /compose/types route, and the compose_type field of the POST to
427 start a compose. It also needs to have code added to the pylo‐
428 rax.api.compose.compose_args() function. The _MAP entry in this func‐
429 tion defines what lorax-composer will pass to pylorax.install‐
430 er.novirt_install() when it runs the compose. When the compose is fin‐
431 ished the output files need to be copied out of the build directory
432 (/var/lib/lorax/composer/results/<UUID>/compose/), pylorax.api.com‐
433 pose.move_compose_results() handles this for each type. You should
434 move them instead of copying to save space.
435 If the new output type does not have support in livemedia-creator it
437 should be added there first. This will make the output available to the
438 widest number of users.
439 Example: Add partitioned disk support
441 Partitioned disk support is something that livemedia-creator already
442 supports via the --make-disk cmdline argument. To add this to
443 lorax-composer it needs 3 things:
444 · A partitioned-disk.ks file in ./share/composer/
446 · A new entry in the _MAP in pylorax.api.compose.compose_args()
448 · Add a bit of code to pylorax.api.compose.move_compose_results() to
450 move the disk image from the compose directory to the results direc‐
451 tory.
452 The partitioned-disk.ks is pretty similar to the example minimal kick‐
454 start in ./docs/fedora-minimal.ks. You should remove the url and repo
455 commands, they will be added by the compose process. Make sure the
456 bootloader packages are included in the %packages section at the end of
457 the kickstart, and you will want to leave off the %end so that the com‐
458 pose can append the list of packages from the blueprint.
459 The new _MAP entry should be a copy of one of the existing entries, but
461 with make_disk set to True. Make sure that none of the other make_*
462 options are True. The image_name is what the name of the final image
463 will be.
464 move_compose_results() can be as simple as moving the output file into
466 the results directory, or it could do some post-processing on it. The
467 end of the function should always clean up the ./compose/ directory,
468 removing any unneeded extra files. This is especially true for the
469 live-iso since it produces the contents of the iso as well as the
470 boot.iso itself.
471
473 By default lorax-composer uses the host's configured repositories. It
474 copies the *.repo files from /etc/yum.repos.d/ into /var/lib/lorax/com‐
475 poser/repos.d/ at startup, these are immutable system repositories and
476 cannot be deleted or changed. If you want to add additional repos you
477 can put them into /var/lib/lorax/composer/repos.d/ or use the
478 /api/v0/projects/source/* API routes to create them.
479 The new source can be added by doing a POST to the
481 /api/v0/projects/source/new route using JSON (with Content-Type header
482 set to application/json) or TOML (with it set to text/x-toml). The
483 format of the source looks like this (in TOML):
484 name = "custom-source-1"
486 url = "https://url/path/to/repository/"
487 type = "yum-baseurl"
488 proxy = "https://proxy-url/"
489 check_ssl = true
490 check_gpg = true
491 gpgkey_urls = ["https://url/path/to/gpg-key"]
492 The proxy and gpgkey_urls entries are optional. All of the others are
494 required. The supported types for the urls are:
495 · yum-baseurl is a URL to a yum repository.
497 · yum-mirrorlist is a URL for a mirrorlist.
499 · yum-metalink is a URL for a metalink.
501 If check_ssl is true the https certificates must be valid. If they are
503 self-signed you can either set this to false, or add your Certificate
504 Authority to the host system.
505 If check_gpg is true the GPG key must either be installed on the host
507 system, or gpgkey_urls should point to it.
508 You can edit an existing source (other than system sources), by doing a
510 POST to the new route with the new version of the source. It will over‐
511 write the previous one.
512 A list of existing sources is available from
514 /api/v0/projects/source/list, and detailed info on a source can be
515 retrieved with the /api/v0/projects/source/info/<source-name> route. By
516 default it returns JSON but it can also return TOML if ?format=toml is
517 added to the request.
518 Non-system sources can be deleted by doing a DELETE request to the
520 /api/v0/projects/source/delete/<source-name> route.
521 The documentation for the source API routes can be found here
523 The configured sources are used for all blueprint depsolve operations,
525 and for composing images. When adding additional sources you must make
526 sure that the packages in the source do not conflict with any other
527 package sources, otherwise depsolving will fail.
528 DVD ISO Package Source
530 In some situations the system may want to only use a DVD iso as the
531 package source, not the repos from the network. lorax-composer and ana‐
532 conda understand file:// URLs so you can mount an iso on the host, and
533 replace the system repo files with a configuration file pointing to the
534 DVD.
535 · Stop the lorax-composer.service if it is running
537 · Move the repo files in /etc/yum.repos.d/ someplace safe
539 · Create a new iso.repo file in /etc/yum.repos.d/:
541 [iso]
543 name=iso
544 baseurl=file:///mnt/iso/
545 enabled=1
546 gpgcheck=1
547 gpgkey=file:///mnt/iso/RPM-GPG-KEY-redhat-release
548 · Remove all the cached repo files from /var/lib/lorax/composer/repos/
550 · Restart the lorax-composer.service
552 · Check the output of composer-cli status show for any output specific
554 depsolve errors. For example, the DVD usually does not include
555 grub2-efi-*-cdboot-* so the live-iso image type will not be avail‐
556 able.
557 If you want to add the DVD source to the existing sources you can do
559 that by mounting the iso and creating a source file to point to it as
560 described in the Package Sources documentation. In that case there is
561 no need to remove the other sources from /etc/yum.repos.d/ or clear the
562 cached repos.
563
565 Weldr Team
566
568 2018, Red Hat, Inc.
56930.19 May 06, 2019 LORAX-COMPOSER(1)