1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
|
---
type: concepts, howto
---
# Using Docker images
GitLab CI in conjunction with [GitLab Runner](../runners/README.md) can use
[Docker Engine](https://www.docker.com/) to test and build any application.
Docker is an open-source project that allows you to use predefined images to
run applications in independent "containers" that are run within a single Linux
instance. [Docker Hub][hub] has a rich database of pre-built images that can be
used to test and build your applications.
Docker, when used with GitLab CI, runs each job in a separate and isolated
container using the predefined image that is set up in
[`.gitlab-ci.yml`](../yaml/README.md).
This makes it easier to have a simple and reproducible build environment that
can also run on your workstation. The added benefit is that you can test all
the commands that we will explore later from your shell, rather than having to
test them on a dedicated CI server.
## Register Docker Runner
To use GitLab Runner with Docker you need to [register a new Runner][register]
to use the `docker` executor.
A one-line example can be seen below:
```bash
sudo gitlab-runner register \
--url "https://gitlab.example.com/" \
--registration-token "PROJECT_REGISTRATION_TOKEN" \
--description "docker-ruby-2.1" \
--executor "docker" \
--docker-image ruby:2.1 \
--docker-services postgres:latest \
--docker-services mysql:latest
```
The registered runner will use the `ruby:2.1` Docker image and will run two
services, `postgres:latest` and `mysql:latest`, both of which will be
accessible during the build process.
## What is an image
The `image` keyword is the name of the Docker image the Docker executor
will run to perform the CI tasks.
By default, the executor will only pull images from [Docker Hub][hub],
however this can be configured in the `gitlab-runner/config.toml` by setting
the [Docker pull policy][] to allow using local images.
For more information about images and Docker Hub, please read
the [Docker Fundamentals][] documentation.
## What is a service
The `services` keyword defines just another Docker image that is run during
your job and is linked to the Docker image that the `image` keyword defines.
This allows you to access the service image during build time.
The service image can run any application, but the most common use case is to
run a database container, e.g., `mysql`. It's easier and faster to use an
existing image and run it as an additional container than install `mysql` every
time the project is built.
You are not limited to have only database services. You can add as many
services you need to `.gitlab-ci.yml` or manually modify `config.toml`.
Any image found at [Docker Hub][hub] or your private Container Registry can be
used as a service.
Services inherit the same DNS servers, search domains, and additional hosts as
the CI container itself.
You can see some widely used services examples in the relevant documentation of
[CI services examples](../services/README.md).
### How services are linked to the job
To better understand how the container linking works, read
[Linking containers together][linking-containers].
To summarize, if you add `mysql` as service to your application, the image will
then be used to create a container that is linked to the job container.
The service container for MySQL will be accessible under the hostname `mysql`.
So, in order to access your database service you have to connect to the host
named `mysql` instead of a socket or `localhost`. Read more in [accessing the
services](#accessing-the-services).
### How the health check of services works
Services are designed to provide additional functionality which is **network accessible**.
It may be a database like MySQL, or Redis, and even `docker:stable-dind` which
allows you to use Docker in Docker. It can be practically anything that is
required for the CI/CD job to proceed and is accessed by network.
To make sure this works, the Runner:
1. Checks which ports are exposed from the container by default.
1. Starts a special container that waits for these ports to be accessible.
When the second stage of the check fails, either because there is no opened port in the
service, or the service was not started properly before the timeout and the port is not
responding, it prints the warning: `*** WARNING: Service XYZ probably didn't start properly`.
In most cases it will affect the job, but there may be situations when the job
will still succeed even if that warning was printed. For example:
- The service was started a little after the warning was raised, and the job is
not using the linked service from the beginning. In that case, when the
job needed to access the service, it may have been already there waiting for
connections.
- The service container is not providing any networking service, but it's doing
something with the job's directory (all services have the job directory mounted
as a volume under `/builds`). In that case, the service will do its job, and
since the job is not trying to connect to it, it won't fail.
### What services are not for
As it was mentioned before, this feature is designed to provide **network accessible**
services. A database is the simplest example of such a service.
NOTE: **Note:**
The services feature is not designed to, and will not add any software from the
defined `services` image(s) to the job's container.
For example, if you have the following `services` defined in your job, the `php`,
`node` or `go` commands will **not** be available for your script, and thus
the job will fail:
```yaml
job:
services:
- php:7
- node:latest
- golang:1.10
image: alpine:3.7
script:
- php -v
- node -v
- go version
```
If you need to have `php`, `node` and `go` available for your script, you should
either:
- Choose an existing Docker image that contains all required tools.
- Create your own Docker image, which will have all the required tools included
and use that in your job.
### Accessing the services
Let's say that you need a Wordpress instance to test some API integration with
your application.
You can then use for example the [tutum/wordpress][] image in your
`.gitlab-ci.yml`:
```yaml
services:
- tutum/wordpress:latest
```
If you don't [specify a service alias](#available-settings-for-services),
when the job is run, `tutum/wordpress` will be started and you will have
access to it from your build container under two hostnames to choose from:
- `tutum-wordpress`
- `tutum__wordpress`
NOTE: **Note:**
Hostnames with underscores are not RFC valid and may cause problems in 3rd party
applications.
The default aliases for the service's hostname are created from its image name
following these rules:
- Everything after the colon (`:`) is stripped.
- Slash (`/`) is replaced with double underscores (`__`) and the primary alias
is created.
- Slash (`/`) is replaced with a single dash (`-`) and the secondary alias is
created (requires GitLab Runner v1.1.0 or higher).
To override the default behavior, you can
[specify a service alias](#available-settings-for-services).
## Define `image` and `services` from `.gitlab-ci.yml`
You can simply define an image that will be used for all jobs and a list of
services that you want to use during build time:
```yaml
default:
image: ruby:2.2
services:
- postgres:9.3
before_script:
- bundle install
test:
script:
- bundle exec rake spec
```
It is also possible to define different images and services per job:
```yaml
default:
before_script:
- bundle install
test:2.1:
image: ruby:2.1
services:
- postgres:9.3
script:
- bundle exec rake spec
test:2.2:
image: ruby:2.2
services:
- postgres:9.4
script:
- bundle exec rake spec
```
Or you can pass some [extended configuration options](#extended-docker-configuration-options)
for `image` and `services`:
```yaml
default:
image:
name: ruby:2.2
entrypoint: ["/bin/bash"]
services:
- name: my-postgres:9.4
alias: db-postgres
entrypoint: ["/usr/local/bin/db-postgres"]
command: ["start"]
before_script:
- bundle install
test:
script:
- bundle exec rake spec
```
## Passing environment variables to services
You can also pass custom environment [variables](../variables/README.md)
to fine tune your Docker `images` and `services` directly in the `.gitlab-ci.yml` file.
For more information, see [custom environment variables](../variables/README.md#gitlab-ciyml-defined-variables)
```yaml
# The following variables will automatically be passed down to the Postgres container
# as well as the Ruby container and available within each.
variables:
HTTPS_PROXY: "https://10.1.1.1:8090"
HTTP_PROXY: "https://10.1.1.1:8090"
POSTGRES_DB: "my_custom_db"
POSTGRES_USER: "postgres"
POSTGRES_PASSWORD: "example"
PGDATA: "/var/lib/postgresql/data"
POSTGRES_INITDB_ARGS: "--encoding=UTF8 --data-checksums"
services:
- name: postgres:9.4
alias: db
entrypoint: ["docker-entrypoint.sh"]
command: ["postgres"]
image:
name: ruby:2.2
entrypoint: ["/bin/bash"]
before_script:
- bundle install
test:
script:
- bundle exec rake spec
```
## Extended Docker configuration options
> Introduced in GitLab and GitLab Runner 9.4.
When configuring the `image` or `services` entries, you can use a string or a map as
options:
- when using a string as an option, it must be the full name of the image to use
(including the Registry part if you want to download the image from a Registry
other than Docker Hub)
- when using a map as an option, then it must contain at least the `name`
option, which is the same name of the image as used for the string setting
For example, the following two definitions are equal:
1. Using a string as an option to `image` and `services`:
```yaml
image: "registry.example.com/my/image:latest"
services:
- postgresql:9.4
- redis:latest
```
1. Using a map as an option to `image` and `services`. The use of `image:name` is
required:
```yaml
image:
name: "registry.example.com/my/image:latest"
services:
- name: postgresql:9.4
- name: redis:latest
```
### Available settings for `image`
> Introduced in GitLab and GitLab Runner 9.4.
| Setting | Required | GitLab version | Description |
|------------|----------|----------------| ----------- |
| `name` | yes, when used with any other option | 9.4 |Full name of the image that should be used. It should contain the Registry part if needed. |
| `entrypoint` | no | 9.4 |Command or script that should be executed as the container's entrypoint. It will be translated to Docker's `--entrypoint` option while creating the container. The syntax is similar to [`Dockerfile`'s `ENTRYPOINT`][entrypoint] directive, where each shell token is a separate string in the array. |
### Available settings for `services`
> Introduced in GitLab and GitLab Runner 9.4.
| Setting | Required | GitLab version | Description |
|------------|----------|----------------| ----------- |
| `name` | yes, when used with any other option | 9.4 | Full name of the image that should be used. It should contain the Registry part if needed. |
| `entrypoint` | no | 9.4 |Command or script that should be executed as the container's entrypoint. It will be translated to Docker's `--entrypoint` option while creating the container. The syntax is similar to [`Dockerfile`'s `ENTRYPOINT`][entrypoint] directive, where each shell token is a separate string in the array. |
| `command` | no | 9.4 |Command or script that should be used as the container's command. It will be translated to arguments passed to Docker after the image's name. The syntax is similar to [`Dockerfile`'s `CMD`][cmd] directive, where each shell token is a separate string in the array. |
| `alias` | no | 9.4 |Additional alias that can be used to access the service from the job's container. Read [Accessing the services](#accessing-the-services) for more information. |
### Starting multiple services from the same image
> Introduced in GitLab and GitLab Runner 9.4. Read more about the [extended
configuration options](#extended-docker-configuration-options).
Before the new extended Docker configuration options, the following configuration
would not work properly:
```yaml
services:
- mysql:latest
- mysql:latest
```
The Runner would start two containers using the `mysql:latest` image, but both
of them would be added to the job's container with the `mysql` alias based on
the [default hostname naming](#accessing-the-services). This would end with one
of the services not being accessible.
After the new extended Docker configuration options, the above example would
look like:
```yaml
services:
- name: mysql:latest
alias: mysql-1
- name: mysql:latest
alias: mysql-2
```
The Runner will still start two containers using the `mysql:latest` image,
however now each of them will also be accessible with the alias configured
in `.gitlab-ci.yml` file.
### Setting a command for the service
> Introduced in GitLab and GitLab Runner 9.4. Read more about the [extended
configuration options](#extended-docker-configuration-options).
Let's assume you have a `super/sql:latest` image with some SQL database
inside it and you would like to use it as a service for your job. Let's also
assume that this image doesn't start the database process while starting
the container and the user needs to manually use `/usr/bin/super-sql run` as
a command to start the database.
Before the new extended Docker configuration options, you would need to create
your own image based on the `super/sql:latest` image, add the default command,
and then use it in job's configuration, like:
```Dockerfile
# my-super-sql:latest image's Dockerfile
FROM super/sql:latest
CMD ["/usr/bin/super-sql", "run"]
```
```yaml
# .gitlab-ci.yml
services:
- my-super-sql:latest
```
After the new extended Docker configuration options, you can now simply
set a `command` in `.gitlab-ci.yml`, like:
```yaml
# .gitlab-ci.yml
services:
- name: super/sql:latest
command: ["/usr/bin/super-sql", "run"]
```
As you can see, the syntax of `command` is similar to [Dockerfile's `CMD`][cmd].
### Overriding the entrypoint of an image
> Introduced in GitLab and GitLab Runner 9.4. Read more about the [extended
configuration options](#extended-docker-configuration-options).
Before showing the available entrypoint override methods, let's describe shortly
how the Runner starts and uses a Docker image for the containers used in the
CI jobs:
1. The Runner starts a Docker container using the defined entrypoint (default
from `Dockerfile` that may be overridden in `.gitlab-ci.yml`)
1. The Runner attaches itself to a running container.
1. The Runner prepares a script (the combination of
[`before_script`](../yaml/README.md#before_script-and-after_script),
[`script`](../yaml/README.md#script),
and [`after_script`](../yaml/README.md#before_script-and-after_script)).
1. The Runner sends the script to the container's shell STDIN and receives the
output.
To override the entrypoint of a Docker image, the recommended solution is to
define an empty `entrypoint` in `.gitlab-ci.yml`, so the Runner doesn't start
a useless shell layer. However, that will not work for all Docker versions, and
you should check which one your Runner is using. Specifically:
- If Docker 17.06 or later is used, the `entrypoint` can be set to an empty value.
- If Docker 17.03 or previous versions are used, the `entrypoint` can be set to
`/bin/sh -c`, `/bin/bash -c` or an equivalent shell available in the image.
The syntax of `image:entrypoint` is similar to [Dockerfile's `ENTRYPOINT`][entrypoint].
Let's assume you have a `super/sql:experimental` image with some SQL database
inside it and you would like to use it as a base image for your job because you
want to execute some tests with this database binary. Let's also assume that
this image is configured with `/usr/bin/super-sql run` as an entrypoint. That
means that when starting the container without additional options, it will run
the database's process, while Runner expects that the image will have no
entrypoint or that the entrypoint is prepared to start a shell command.
With the extended Docker configuration options, instead of creating your
own image based on `super/sql:experimental`, setting the `ENTRYPOINT`
to a shell, and then using the new image in your CI job, you can now simply
define an `entrypoint` in `.gitlab-ci.yml`.
**For Docker 17.06+:**
```yaml
image:
name: super/sql:experimental
entrypoint: [""]
```
**For Docker =< 17.03:**
```yaml
image:
name: super/sql:experimental
entrypoint: ["/bin/sh", "-c"]
```
## Define image and services in `config.toml`
Look for the `[runners.docker]` section:
```toml
[runners.docker]
image = "ruby:2.1"
services = ["mysql:latest", "postgres:latest"]
```
The image and services defined this way will be added to all job run by
that runner.
## Define an image from a private Container Registry
To access private container registries, the GitLab Runner process can use:
- [Statically defined credentials](#using-statically-defined-credentials). That is, a username and password for a specific registry.
- [Credentials Store](#using-credentials-store). For more information, see [the relevant Docker documentation](https://docs.docker.com/engine/reference/commandline/login/#credentials-store).
- [Credential Helpers](#using-credential-helpers). For more information, see [the relevant Docker documentation](https://docs.docker.com/engine/reference/commandline/login/#credential-helpers).
To define which should be used, the GitLab Runner process reads the configuration in the following order:
- `DOCKER_AUTH_CONFIG` variable provided as either:
- A [variable](../variables/README.md#gitlab-cicd-environment-variables) in `.gitlab-ci.yml`.
- A project's variables stored on the projects **Settings > CI/CD** page.
- `DOCKER_AUTH_CONFIG` variable provided as environment variable in `config.toml` of the Runner.
- `config.json` file placed in `$HOME/.docker` directory of the user running GitLab Runner process.
If the `--user` flag is provided to run the GitLab Runner child processes as unprivileged user,
the home directory of the main GitLab Runner process user will be used.
NOTE: **Note:**
GitLab Runner reads this configuration **only** from `config.toml` and ignores it if
it's provided as an environment variable. This is because GitLab Runnner uses **only**
`config.toml` configuration and doesn't interpolate **ANY** environment variables at
runtime.
### Requirements and limitations
- This feature requires GitLab Runner **1.8** or higher.
- For GitLab Runner versions **>= 0.6, <1.8** there was a partial
support for using private registries, which required manual configuration
of credentials on runner's host. We recommend to upgrade your Runner to
at least version **1.8** if you want to use private registries.
- Not available for [Kubernetes executor](https://docs.gitlab.com/runner/executors/kubernetes.html),
follow <https://gitlab.com/gitlab-org/gitlab-runner/issues/2673> for
details.
### Using statically-defined credentials
There are two approaches that you can take in order to access a
private registry. Both require setting the environment variable
`DOCKER_AUTH_CONFIG` with appropriate authentication info.
1. Per-job: To configure one job to access a private registry, add
`DOCKER_AUTH_CONFIG` as a job variable.
1. Per-runner: To configure a Runner so all its jobs can access a
private registry, add `DOCKER_AUTH_CONFIG` to the environment in the
Runner's configuration.
See below for examples of each.
#### Determining your `DOCKER_AUTH_CONFIG` data
As an example, let's assume that you want to use the `registry.example.com:5000/private/image:latest`
image which is private and requires you to login into a private container registry.
Let's also assume that these are the login credentials:
| Key | Value |
|:---------|:----------------------------|
| registry | `registry.example.com:5000` |
| username | `my_username` |
| password | `my_password` |
There are two ways to determine the value of `DOCKER_AUTH_CONFIG`:
- **First way -** Do a `docker login` on your local machine:
```bash
docker login registry.example.com:5000 --username my_username --password my_password
```
Then copy the content of `~/.docker/config.json`.
If you don't need access to the registry from your computer, you
can do a `docker logout`:
```bash
docker logout registry.example.com:5000
```
- **Second way -** In some setups, it's possible that Docker client
will use the available system keystore to store the result of `docker
login`. In that case, it's impossible to read `~/.docker/config.json`,
so you will need to prepare the required base64-encoded version of
`${username}:${password}` and create the Docker configuration JSON manually.
Open a terminal and execute the following command:
```bash
echo -n "my_username:my_password" | base64
# Example output to copy
bXlfdXNlcm5hbWU6bXlfcGFzc3dvcmQ=
```
Create the Docker JSON configuration content as follows:
```json
{
"auths": {
"registry.example.com:5000": {
"auth": "(Base64 content from above)"
}
}
}
```
#### Configuring a job
To configure a single job with access for `registry.example.com:5000`,
follow these steps:
1. Create a [variable](../variables/README.md#gitlab-cicd-environment-variables) `DOCKER_AUTH_CONFIG` with the content of the
Docker configuration file as the value:
```json
{
"auths": {
"registry.example.com:5000": {
"auth": "bXlfdXNlcm5hbWU6bXlfcGFzc3dvcmQ="
}
}
}
```
1. You can now use any private image from `registry.example.com:5000` defined in
`image` and/or `services` in your `.gitlab-ci.yml` file:
```yaml
image: registry.example.com:5000/namespace/image:tag
```
In the example above, GitLab Runner will look at `registry.example.com:5000` for the
image `namespace/image:tag`.
You can add configuration for as many registries as you want, adding more
registries to the `"auths"` hash as described above.
NOTE: **Note:**
The full `hostname:port` combination is required everywhere
for the Runner to match the `DOCKER_AUTH_CONFIG`. For example, if
`registry.example.com:5000/namespace/image:tag` is specified in `.gitlab-ci.yml`,
then the `DOCKER_AUTH_CONFIG` must also specify `registry.example.com:5000`.
Specifying only `registry.example.com` will not work.
### Configuring a Runner
If you have many pipelines that access the same registry, it'll
probably be better to setup registry access at the runner level. This
allows pipeline authors to have access to a private registry just by
running a job on the appropriate runner. It also makes registry
changes and credential rotations much simpler.
Of course this means that any job on that runner can access the
registry with the same privilege, even across projects. If you need to
control access to the registry, you'll need to be sure to control
access to the runner.
To add `DOCKER_AUTH_CONFIG` to a Runner:
1. Modify the Runner's `config.toml` file as follows:
```toml
[[runners]]
environment = ["DOCKER_AUTH_CONFIG={\"auths\":{\"registry.example.com:5000\":{\"auth\":\"bXlfdXNlcm5hbWU6bXlfcGFzc3dvcmQ=\"}}}"]
```
1. Restart the Runner service.
NOTE: **Note:** The double quotes included in the `DOCKER_AUTH_CONFIG`
data must be escaped with backslashes. This prevents them from being
interpreted as TOML.
NOTE: **Note:** The `environment` option is a list. So your Runner may
have existing entries and you should add this to the list, not replace
it.
### Using Credentials Store
> Support for using Credentials Store was added in GitLab Runner 9.5.
To configure credentials store, follow these steps:
1. To use a credentials store, you need an external helper program to interact with a specific keychain or external store.
Make sure helper program is available in GitLab Runner `$PATH`.
1. Make GitLab Runner use it. There are two ways to accomplish this. Either:
- Create a
[variable](../variables/README.md#gitlab-cicd-environment-variables)
`DOCKER_AUTH_CONFIG` with the content of the
Docker configuration file as the value:
```json
{
"credsStore": "osxkeychain"
}
```
- Or, if you are running self-hosted Runners, add the above JSON to
`${GITLAB_RUNNER_HOME}/.docker/config.json`. GitLab Runner will read this config file
and will use the needed helper for this specific repository.
NOTE: **Note:** `credsStore` is used to access ALL the registries.
If you will want to use both images from private registry and public images from DockerHub,
pulling from DockerHub will fail, because Docker daemon will try to use the same credentials for **ALL** the registries.
### Using Credential Helpers
> Support for using Credential Helpers was added in GitLab Runner 12.0
As an example, let's assume that you want to use the `aws_account_id.dkr.ecr.region.amazonaws.com/private/image:latest`
image which is private and requires you to log in into a private container registry.
To configure access for `aws_account_id.dkr.ecr.region.amazonaws.com`, follow these steps:
1. Make sure `docker-credential-ecr-login` is available in GitLab Runner's `$PATH`.
1. Make GitLab Runner use it. There are two ways to accomplish this. Either:
- Create a [variable](../variables/README.md#gitlab-cicd-environment-variables)
`DOCKER_AUTH_CONFIG` with the content of the
Docker configuration file as the value:
```json
{
"credHelpers": {
"aws_account_id.dkr.ecr.region.amazonaws.com": "ecr-login"
}
}
```
- Or, if you are running self-hosted Runners,
add the above JSON to `${GITLAB_RUNNER_HOME}/.docker/config.json`.
GitLab Runner will read this config file and will use the needed helper for this
specific repository.
1. You can now use any private image from `aws_account_id.dkr.ecr.region.amazonaws.com` defined in
`image` and/or `services` in your `.gitlab-ci.yml` file:
```yaml
image: aws_account_id.dkr.ecr.region.amazonaws.com/private/image:latest
```
In the example above, GitLab Runner will look at `aws_account_id.dkr.ecr.region.amazonaws.com` for the
image `private/image:latest`.
You can add configuration for as many registries as you want, adding more
registries to the `"credHelpers"` hash as described above.
## Configuring services
Many services accept environment variables which allow you to easily change
database names or set account names depending on the environment.
GitLab Runner 0.5.0 and up passes all YAML-defined variables to the created
service containers.
For all possible configuration variables check the documentation of each image
provided in their corresponding Docker hub page.
NOTE: **Note:**
All variables will be passed to all services containers. It's not
designed to distinguish which variable should go where.
### PostgreSQL service example
See the specific documentation for
[using PostgreSQL as a service](../services/postgres.md).
### MySQL service example
See the specific documentation for
[using MySQL as a service](../services/mysql.md).
## How Docker integration works
Below is a high level overview of the steps performed by Docker during job
time.
1. Create any service container: `mysql`, `postgresql`, `mongodb`, `redis`.
1. Create cache container to store all volumes as defined in `config.toml` and
`Dockerfile` of build image (`ruby:2.1` as in above example).
1. Create build container and link any service container to build container.
1. Start build container and send job script to the container.
1. Run job script.
1. Checkout code in: `/builds/group-name/project-name/`.
1. Run any step defined in `.gitlab-ci.yml`.
1. Check exit status of build script.
1. Remove build container and all created service containers.
## How to debug a job locally
NOTE: **Note:**
The following commands are run without root privileges. You should be
able to run Docker with your regular user account.
First start with creating a file named `build_script`:
```bash
cat <<EOF > build_script
git clone https://gitlab.com/gitlab-org/gitlab-runner.git /builds/gitlab-org/gitlab-runner
cd /builds/gitlab-org/gitlab-runner
make
EOF
```
Here we use as an example the GitLab Runner repository which contains a
Makefile, so running `make` will execute the commands defined in the Makefile.
Your mileage may vary, so instead of `make` you could run the command which
is specific to your project.
Then create some service containers:
```sh
docker run -d --name service-mysql mysql:latest
docker run -d --name service-postgres postgres:latest
```
This will create two service containers, named `service-mysql` and
`service-postgres` which use the latest MySQL and PostgreSQL images
respectively. They will both run in the background (`-d`).
Finally, create a build container by executing the `build_script` file we
created earlier:
```sh
docker run --name build -i --link=service-mysql:mysql --link=service-postgres:postgres ruby:2.1 /bin/bash < build_script
```
The above command will create a container named `build` that is spawned from
the `ruby:2.1` image and has two services linked to it. The `build_script` is
piped using STDIN to the bash interpreter which in turn executes the
`build_script` in the `build` container.
When you finish testing and no longer need the containers, you can remove them
with:
```sh
docker rm -f -v build service-mysql service-postgres
```
This will forcefully (`-f`) remove the `build` container, the two service
containers as well as all volumes (`-v`) that were created with the container
creation.
[Docker Fundamentals]: https://docs.docker.com/engine/understanding-docker/
[docker pull policy]: https://docs.gitlab.com/runner/executors/docker.html#how-pull-policies-work
[hub]: https://hub.docker.com/
[linking-containers]: https://docs.docker.com/engine/userguide/networking/default_network/dockerlinks/
[tutum/wordpress]: https://hub.docker.com/r/tutum/wordpress/
[postgres-hub]: https://hub.docker.com/r/_/postgres/
[mysql-hub]: https://hub.docker.com/r/_/mysql/
[entrypoint]: https://docs.docker.com/engine/reference/builder/#entrypoint
[cmd]: https://docs.docker.com/engine/reference/builder/#cmd
[register]: https://docs.gitlab.com/runner/register/
|