91 lines
2.4 KiB
Go
91 lines
2.4 KiB
Go
package libimage
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import (
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"fmt"
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"github.com/pkg/errors"
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)
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// PullPolicy determines how and which images are being pulled from a container
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// registry (i.e., docker transport only).
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//
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// Supported string values are:
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// * "always" <-> PullPolicyAlways
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// * "missing" <-> PullPolicyMissing
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// * "newer" <-> PullPolicyNewer
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// * "never" <-> PullPolicyNever
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type PullPolicy int
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const (
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// This default value forces callers to setup a custom default policy.
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// Some tools use different policies (e.g., buildah-bud versus
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// podman-build).
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PullPolicyUnsupported PullPolicy = iota
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// Always pull the image.
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PullPolicyAlways
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// Pull the image only if it could not be found in the local containers
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// storage.
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PullPolicyMissing
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// Pull if the image on the registry is new than the one in the local
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// containers storage. An image is considered to be newer when the
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// digests are different. Comparing the time stamps is prone to
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// errors.
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PullPolicyNewer
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// Never pull the image but use the one from the local containers
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// storage.
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PullPolicyNever
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)
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// String converts a PullPolicy into a string.
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//
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// Supported string values are:
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// * "always" <-> PullPolicyAlways
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// * "missing" <-> PullPolicyMissing
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// * "newer" <-> PullPolicyNewer
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// * "never" <-> PullPolicyNever
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func (p PullPolicy) String() string {
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switch p {
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case PullPolicyAlways:
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return "always"
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case PullPolicyMissing:
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return "missing"
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case PullPolicyNewer:
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return "newer"
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case PullPolicyNever:
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return "never"
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}
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return fmt.Sprintf("unrecognized policy %d", p)
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}
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// Validate returns if the pull policy is not supported.
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func (p PullPolicy) Validate() error {
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switch p {
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case PullPolicyAlways, PullPolicyMissing, PullPolicyNewer, PullPolicyNever:
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return nil
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default:
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return errors.Errorf("unsupported pull policy %d", p)
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}
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}
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// ParsePullPolicy parses the string into a pull policy.
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//
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// Supported string values are:
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// * "always" <-> PullPolicyAlways
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// * "missing" <-> PullPolicyMissing
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// * "newer" <-> PullPolicyNewer
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// * "never" <-> PullPolicyNever
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func ParsePullPolicy(s string) (PullPolicy, error) {
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switch s {
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case "always":
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return PullPolicyAlways, nil
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case "missing":
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return PullPolicyMissing, nil
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case "newer":
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return PullPolicyNewer, nil
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case "never":
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return PullPolicyMissing, nil
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default:
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return PullPolicyUnsupported, errors.Errorf("unsupported pull policy %q", s)
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}
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}
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