kube-cloud-build
Specify container builds inside your Kubernetes manifests.
Kubernetes helps orchestrate container deployments. But before Kubernetes can orchestrate anything, the container images specified in your Kubernetes manifests must be built and available in an image registry. Making this happen can be much easier said than done!
kube-cloud-build integrates Kubernetes and Google Cloud Container Builder.
It lets you declare Cloud Container Builder build steps
for containers right inside the manifests where they are used. With the build
steps inside your manifests, any time you update the images specified by your
manifests, kube-cloud-build will automatically generate build requests based
on the missing images' build steps. Never write a build request by hand again!
kube-cloud-build examines your Kubernetes manifests, identifies images that
are missing from Google Container Registry (GCR), generates build requests for
the missing images, and submits the build requests for you.
To use this tool, just add Container Builder build steps to your manifests. Then, any time you update an image's tag in a manifest, run that manifest through this tool. It'll make sure the images you need are built and available on GCR. Deploy with confidence, knowing you wont receive an image pull error.
Install
$ npm install -g kube-cloud-build
Usage
Process a single manifest:
$ k8s-cloud-build -r repo -f examples/deployment.yaml
or an entire helm chart:
$ helm template /path/to/chart | k8s-cloud-build -r repo
Example
Suppose you have the following manifest:
$ cat examples/deployment.yaml
apiVersion: apps/v1beta2
kind: Deployment
metadata:
name: frontend
spec:
replicas: 3
template:
spec:
initContainers:
- name: init
image: gcr.io/some-project-123456/init:8f4dfd28dbc51960d0bd2d463c23593cb878fd14
containers:
- name: container1
image: gcr.io/some-project-123456/container1:v4
- name: container2
image: gcr.io/some-project-123456/container2:v4
You can deploy this manifest, but you will get a bunch of image pull errors if the images for the containers it specifies do not exist on GCR. You can build these images manually by submitting build requests to Container Builder, but with many manifests and containers this quickly becomes difficult to manage.
The solution: add your Container Builder build steps directly to your manifest:
$ cat examples/deployment.yaml
apiVersion: apps/v1beta2
kind: Deployment
metadata:
name: frontend
spec:
replicas: 3
template:
+ metadata:
+ annotations:
+ google.cloud.container.build: >
+ [{
+ "container": "init",
+ "steps": [{
+ "name": "gcr.io/cloud-builders/docker",
+ "dir": "init",
+ "args": [
+ "build",
+ "-t",
+ "gcr.io/some-project-123456/init:8f4dfd28dbc51960d0bd2d463c23593cb878fd14",
+ "."
+ ]
+ }]
+ },{
+ "container": "container1",
+ "steps": [{
+ "name": "gcr.io/cloud-builders/docker",
+ "dir": "container1",
+ "args": [
+ "build",
+ "-t",
+ "gcr.io/some-project-123456/container1:v4",
+ "."
+ ]
+ }]
+ },{
+ "container": "container2",
+ "steps": [{
+ "name": "gcr.io/cloud-builders/docker",
+ "dir": "container2",
+ "args": [
+ "build",
+ "-t",
+ "gcr.io/some-project-123456/container2:v4",
+ "."
+ ]
+ }]
+ }]
spec:
initContainers:
- name: init
image: gcr.io/some-project-123456/init:8f4dfd28dbc51960d0bd2d463c23593cb878fd14
containers:
- name: container1
image: gcr.io/some-project-123456/container1:v4
- name: container2
image: gcr.io/some-project-123456/container2:v4
Now feed this manifest to kube-cloud-build. It will communicate with GCR, identify images
that are missing, and ask which you want to build:
$ k8s-cloud-build -r repo -f deployment.yaml
? The following images are missing from Google Container Registry. Choose the ones you want to build: (Press <space> to select, <a> to toggle all, <i> to inverse selection)
❯◯ gcr.io/some-project-123456/init:8f4dfd28dbc51960d0bd2d463c23593cb878fd14
◯ gcr.io/some-project-123456/container1:v4
◯ gcr.io/some-project-123456/container2:v4
kube-cloud-build ignores images that are not part of your project
or lack build instructions. Given the images you select, kube-cloud-build
compiles the required containers' build steps into Container Builder build
requests. Steps are grouped into build requests by tag.
Review and optionally submit the requests:
{
"source": {
"repoSource": {
"projectId": "some-project-123456",
"repoName": "repo",
"commitSha": "8f4dfd28dbc51960d0bd2d463c23593cb878fd14"
}
},
"steps": [
{
"name": "gcr.io/cloud-builders/docker",
"dir": "init",
"args": [
"build",
"-t",
"gcr.io/some-project-123456/init:8f4dfd28dbc51960d0bd2d463c23593cb878fd14",
"."
]
}
],
"images": [
"gcr.io/some-project-123456/init:8f4dfd28dbc51960d0bd2d463c23593cb878fd14"
]
}
{
"source": {
"repoSource": {
"projectId": "some-project-123456",
"repoName": "repo",
"tagName": "v4"
}
},
"steps": [
{
"name": "gcr.io/cloud-builders/docker",
"dir": "container1",
"args": [
"build",
"-t",
"gcr.io/some-project-123456/container1:v4",
"."
]
},
{
"name": "gcr.io/cloud-builders/docker",
"dir": "container2",
"args": [
"build",
"-t",
"gcr.io/some-project-123456/container2:v4",
"."
]
}
],
"images": [
"gcr.io/some-project-123456/container1:v4",
"gcr.io/some-project-123456/container2:v4"
]
}
? Do you want to submit these build requests? (y/N)
If you choose "yes," kube-cloud-build will submit these build requests.
Usage
k8s-cloud-build -r <repository> [-f <file>]
-f Manifest file, if not reading from stdin
-r Google Source Repository to use in build requests
kube-cloud-build accepts input by way of the -f switch or on stdin.
stdin is useful for deploying Helm charts:
$ helm template /path/to/chart | k8s-cloud-build -r repo
The project ID and API access token used to communicate with the Google Cloud
API are determined using gcloud config config-helper.
If all required images are present on GCR, kube-cloud-build exits silently with status 0.
FAQ
What API calls does this tool make?
During the course of its operation, kube-cloud-build makes Google Cloud API
calls analogous to:
What resource types can this tool handle?
kube-cloud-build handles Kubernetes resources that are either a Pod or
contain a PodTemplateSpec:
PodCronJobDeploymentDaemonSetJobReplicaSetReplicationControllerStatefulSet
For each of these resources types, kube-cloud-build looks for a google.cloud.container.build
annotation inside of the metadata of the relevant Pod or
PodTemplateSpec.