Documentation
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Overview ¶
Package probe implements readiness and liveness checks the controller runs against a container: an HTTP(S) request to its published port, or a command exec'd inside it. See ADR 002 for why the controller probes rather than trusting Docker's own HEALTHCHECK state.
WaitReady polls until a freshly started container is ready, gating a deploy's cutover. Check runs a single attempt, for the level-triggered liveness check, where the reconcile loop itself is the retry loop.
Index ¶
Constants ¶
const ( DefaultMaxRedirects = 10 DefaultExecOutputBytes = 512 DefaultTimeout = 2 * time.Second DefaultInterval = 2 * time.Second )
Defaults applied by Limits' zero fields. MaxRedirects matches net/http's own client default, which is what probes followed before it was configurable.
const ( EnvMaxRedirects = "APP_PROBE_MAX_REDIRECTS" EnvExecOutputBytes = "APP_PROBE_EXEC_OUTPUT_BYTES" EnvDefaultTimeout = "APP_PROBE_DEFAULT_TIMEOUT" EnvDefaultInterval = "APP_PROBE_DEFAULT_INTERVAL" )
Environment variables LimitsFromEnv reads.
const ( SchemeHTTP = "http" SchemeHTTPS = "https" )
Supported HTTP probe schemes.
const DefaultExpectedStatus = "200-299"
DefaultExpectedStatus is the status set a probe with no expected_status accepts.
Variables ¶
This section is empty.
Functions ¶
func DescribeCommand ¶
DescribeCommand renders cmd for a status message, unwrapping the ["/bin/sh", "-c", script] form back to the script the operator wrote.
func ShellCommand ¶
ShellCommand wraps script as the argv an exec probe runs it through.
Types ¶
type Config ¶
type Config struct {
Path string
Scheme string
Host string
TLSSkipVerify bool
// FollowRedirects nil keeps the historical behavior (follow, bounded by
// Limits.MaxRedirects); an explicit false judges the 3xx itself.
FollowRedirects *bool
ExpectedStatus string
Exec []string
Interval time.Duration
Timeout time.Duration
}
Config is one probe's settings. A non-empty Exec makes it an exec probe; otherwise it is an HTTP probe against Path. Zero Interval or Timeout means "not specified" and falls back to the Prober's Limits.
type Executor ¶
type Executor interface {
ExecProbe(ctx context.Context, containerID string, cmd []string) (exitCode int, output string, err error)
}
Executor runs cmd inside a container and reports its exit code and combined output. err is for failures to run the command at all.
type Failure ¶
type Failure struct {
Kind FailureKind
Reason string
Err error
}
Failure is one failed probe attempt. Its Error text is written for an operator: it names the request or command and exactly what went wrong.
type FailureKind ¶
type FailureKind string
FailureKind classifies why a probe attempt failed.
const ( FailureStatus FailureKind = "UnexpectedStatus" FailureRedirect FailureKind = "UnexpectedRedirect" FailureTooManyHops FailureKind = "TooManyRedirects" FailureConnect FailureKind = "ConnectionFailed" FailureTLS FailureKind = "TLSVerifyFailed" FailureTimeout FailureKind = "Timeout" FailureExitCode FailureKind = "ExecNonZeroExit" FailureExecError FailureKind = "ExecFailed" FailureExecNotReady FailureKind = "ExecUnavailable" )
Failure kinds.
type Limits ¶
type Limits struct {
MaxRedirects int
ExecOutputBytes int
DefaultTimeout time.Duration
DefaultInterval time.Duration
}
Limits bounds probe behavior. Zero fields take the package defaults.
type Prober ¶
type Prober struct {
// contains filtered or unexported fields
}
Prober runs probes with shared transport and limits.
func New ¶
New builds a Prober. A nil client means http.DefaultClient; a nil exec makes every exec probe fail with FailureExecNotReady.
type StatusSet ¶
type StatusSet struct {
// contains filtered or unexported fields
}
StatusSet is a parsed expected_status value: a union of status codes and ranges.
func ParseStatusSet ¶
ParseStatusSet parses "200-399", "200,204,301-302" or a single code. Commas and whitespace both separate entries; an empty string yields the 2xx default.
Source Files