b09b0ffcf9
Add a section to the config file called "health". Within this section, "filecheckers" and "httpcheckers" list checks to run. Each check specifies a file or URI, a time interval for the check, and a threshold specifying how many times the check must fail to reach an unhealthy state. Document the new options in docs/configuration.md. Add unit testing for both types of checkers. Add an UnregisterAll function in the health package to support the unit tests, and an Unregister function for consistency with Register. Fix a string conversion problem in the health package's HTTP checker. Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
37 lines
934 B
Go
37 lines
934 B
Go
package checks
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import (
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"errors"
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"net/http"
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"os"
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"strconv"
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"github.com/docker/distribution/health"
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)
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// FileChecker checks the existence of a file and returns and error
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// if the file exists, taking the application out of rotation
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func FileChecker(f string) health.Checker {
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return health.CheckFunc(func() error {
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if _, err := os.Stat(f); err == nil {
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return errors.New("file exists")
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}
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return nil
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})
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}
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// HTTPChecker does a HEAD request and verifies if the HTTP status
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// code return is a 200, taking the application out of rotation if
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// otherwise
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func HTTPChecker(r string) health.Checker {
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return health.CheckFunc(func() error {
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response, err := http.Head(r)
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if err != nil {
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return errors.New("error while checking: " + r)
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}
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if response.StatusCode != http.StatusOK {
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return errors.New("downstream service returned unexpected status: " + strconv.Itoa(response.StatusCode))
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}
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return nil
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})
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}
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