Advanced Build Operations - Builds | Developer Guide

Setting Build Resources
Setting Maximum Duration
Assigning Builds to Specific Nodes
Chaining Builds
Build Pruning

Setting Build Resources

By default, builds are completed by pods using unbound resources, such as memory and CPU. These resources can be limited by specifying resource limits in a project’s default container limits.

You can also limit resource use by specifying resource limits as part of the build configuration. In the following example, each of the resources, cpu, and memory parameters are optional:

apiVersion: "v1"
kind: "BuildConfig"
metadata:
  name: "sample-build"
spec:
  resources:
    limits:
      cpu: "100m" (1)
      memory: "256Mi" (2)

1	`cpu` is in CPU units: `100m` represents 0.1 CPU units (100 * 1e-3).
2	`memory` is in bytes: `256Mi` represents 268435456 bytes (256 * 2 ^ 20).

However, if a quota has been defined for your project, one of the following two items is required:

A resources section set with an explicit requests:
```
resources:
  requests: (1)
    cpu: "100m"
    memory: "256Mi"
```
1 The requests object contains the list of resources that correspond to the list of resources in the quota.
A limit range defined in your project, where the defaults from the LimitRange object apply to pods created during the build process.

Otherwise, build pod creation will fail, citing a failure to satisfy quota.

Setting Maximum Duration

When defining a BuildConfig, you can define its maximum duration by setting the completionDeadlineSeconds field. It is specified in seconds and is not set by default. When not set, there is no maximum duration enforced.

The maximum duration is counted from the time when a build pod gets scheduled in the system, and defines how long it can be active, including the time needed to pull the builder image. After reaching the specified timeout, the build is terminated by OpenShift Online.

The following example shows the part of a BuildConfig specifying completionDeadlineSeconds field for 30 minutes:

spec:
  completionDeadlineSeconds: 1800

This setting is not supported with the Pipeline Strategy option.

Assigning Builds to Specific Nodes

Builds can be targeted to run on specific nodes by specifying labels in the nodeSelector field of a build configuration. The nodeSelector value is a set of key/value pairs that are matched to node labels when scheduling the build pod.

apiVersion: "v1"
kind: "BuildConfig"
metadata:
  name: "sample-build"
spec:
  nodeSelector:(1)
    key1: value1
    key2: value2

1	Builds associated with this build configuration will run only on nodes with the `key1=value2` and `key2=value2` labels.

The nodeSelector value can also be controlled by cluster-wide default and override values. Defaults will only be applied if the build configuration does not define any key/value pairs for the nodeSelector and also does not define an explicitly empty map value of nodeSelector:{}. Override values will replace values in the build configuration on a key by key basis.

If the specified NodeSelector cannot be matched to a node with those labels, the build still stay in the Pending state indefinitely.

Chaining Builds

For compiled languages (Go, C, C++, Java, etc.), including the dependencies necessary for compilation in the application image might increase the size of the image or introduce vulnerabilities that can be exploited.

To avoid these problems, two builds can be chained together: one that produces the compiled artifact, and a second build that places that artifact in a separate image that runs the artifact.

Build Pruning

By default, builds that have completed their lifecycle are persisted indefinitely. You can limit the number of previous builds that are retained by supplying a positive integer value for successfulBuildsHistoryLimit or failedBuildsHistoryLimit as shown in the following sample build configuration.

apiVersion: "v1"
kind: "BuildConfig"
metadata:
  name: "sample-build"
spec:
  successfulBuildsHistoryLimit: 2 (1)
  failedBuildsHistoryLimit: 2 (2)

1	`successfulBuildsHistoryLimit` will retain up to two builds with a status of `completed`.
2	`failedBuildsHistoryLimit` will retain up to two builds with a status of `failed`, `cancelled`, or `error`.

Build pruning is triggered by the following actions:

Updating a build configuration.
A build completes its lifecycle.

Builds are sorted by their creation timestamp with the oldest builds being pruned first.