diff options
Diffstat (limited to 'modules/caddyhttp/reverseproxy/healthchecks.go')
| -rw-r--r-- | modules/caddyhttp/reverseproxy/healthchecks.go | 133 |
1 files changed, 109 insertions, 24 deletions
diff --git a/modules/caddyhttp/reverseproxy/healthchecks.go b/modules/caddyhttp/reverseproxy/healthchecks.go index c27b24f..ad21ccb 100644 --- a/modules/caddyhttp/reverseproxy/healthchecks.go +++ b/modules/caddyhttp/reverseproxy/healthchecks.go @@ -24,12 +24,12 @@ import ( "regexp" "runtime/debug" "strconv" - "strings" "time" + "go.uber.org/zap" + "github.com/caddyserver/caddy/v2" "github.com/caddyserver/caddy/v2/modules/caddyhttp" - "go.uber.org/zap" ) // HealthChecks configures active and passive health checks. @@ -106,6 +106,76 @@ type ActiveHealthChecks struct { logger *zap.Logger } +// Provision ensures that a is set up properly before use. +func (a *ActiveHealthChecks) Provision(ctx caddy.Context, h *Handler) error { + if !a.IsEnabled() { + return nil + } + + // Canonicalize the header keys ahead of time, since + // JSON unmarshaled headers may be incorrect + cleaned := http.Header{} + for key, hdrs := range a.Headers { + for _, val := range hdrs { + cleaned.Add(key, val) + } + } + a.Headers = cleaned + + h.HealthChecks.Active.logger = h.logger.Named("health_checker.active") + + timeout := time.Duration(a.Timeout) + if timeout == 0 { + timeout = 5 * time.Second + } + + if a.Path != "" { + a.logger.Warn("the 'path' option is deprecated, please use 'uri' instead!") + } + + // parse the URI string (supports path and query) + if a.URI != "" { + parsedURI, err := url.Parse(a.URI) + if err != nil { + return err + } + a.uri = parsedURI + } + + a.httpClient = &http.Client{ + Timeout: timeout, + Transport: h.Transport, + } + + for _, upstream := range h.Upstreams { + // if there's an alternative port for health-check provided in the config, + // then use it, otherwise use the port of upstream. + if a.Port != 0 { + upstream.activeHealthCheckPort = a.Port + } + } + + if a.Interval == 0 { + a.Interval = caddy.Duration(30 * time.Second) + } + + if a.ExpectBody != "" { + var err error + a.bodyRegexp, err = regexp.Compile(a.ExpectBody) + if err != nil { + return fmt.Errorf("expect_body: compiling regular expression: %v", err) + } + } + + return nil +} + +// IsEnabled checks if the active health checks have +// the minimum config necessary to be enabled. +func (a *ActiveHealthChecks) IsEnabled() bool { + return a.Path != "" || a.URI != "" || a.Port != 0 +} + // PassiveHealthChecks holds configuration related to passive // health checks (that is, health checks which occur during // the normal flow of request proxying). @@ -203,7 +273,7 @@ func (h *Handler) doActiveHealthCheckForAllHosts() { } addr.StartPort, addr.EndPort = hcp, hcp } - if upstream.LookupSRV == "" && addr.PortRangeSize() != 1 { + if addr.PortRangeSize() != 1 { h.HealthChecks.Active.logger.Error("multiple addresses (upstream must map to only one address)", zap.String("address", networkAddr), ) @@ -237,16 +307,35 @@ func (h *Handler) doActiveHealthCheckForAllHosts() { // the host's health status fails. func (h *Handler) doActiveHealthCheck(dialInfo DialInfo, hostAddr string, upstream *Upstream) error { // create the URL for the request that acts as a health check - scheme := "http" - if ht, ok := h.Transport.(TLSTransport); ok && ht.TLSEnabled() { - // this is kind of a hacky way to know if we should use HTTPS, but whatever - scheme = "https" - } u := &url.URL{ - Scheme: scheme, + Scheme: "http", Host: hostAddr, } + // split the host and port if possible, override the port if configured + host, port, err := net.SplitHostPort(hostAddr) + if err != nil { + host = hostAddr + } + if h.HealthChecks.Active.Port != 0 { + port := strconv.Itoa(h.HealthChecks.Active.Port) + u.Host = net.JoinHostPort(host, port) + } + + // this is kind of a hacky way to know if we should use HTTPS, but whatever + if tt, ok := h.Transport.(TLSTransport); ok && tt.TLSEnabled() { + u.Scheme = "https" + + // if the port is in the except list, flip back to HTTP + if ht, ok := h.Transport.(*HTTPTransport); ok { + for _, exceptPort := range ht.TLS.ExceptPorts { + if exceptPort == port { + u.Scheme = "http" + } + } + } + } + // if we have a provisioned uri, use that, otherwise use // the deprecated Path option if h.HealthChecks.Active.uri != nil { @@ -256,16 +345,6 @@ func (h *Handler) doActiveHealthCheck(dialInfo DialInfo, hostAddr string, upstre u.Path = h.HealthChecks.Active.Path } - // adjust the port, if configured to be different - if h.HealthChecks.Active.Port != 0 { - portStr := strconv.Itoa(h.HealthChecks.Active.Port) - host, _, err := net.SplitHostPort(hostAddr) - if err != nil { - host = hostAddr - } - u.Host = net.JoinHostPort(host, portStr) - } - // attach dialing information to this request, as well as context values that // may be expected by handlers of this request ctx := h.ctx.Context @@ -279,11 +358,17 @@ func (h *Handler) doActiveHealthCheck(dialInfo DialInfo, hostAddr string, upstre } ctx = context.WithValue(ctx, caddyhttp.OriginalRequestCtxKey, *req) req = req.WithContext(ctx) - for key, hdrs := range h.HealthChecks.Active.Headers { - if strings.ToLower(key) == "host" { - req.Host = h.HealthChecks.Active.Headers.Get(key) - } else { - req.Header[key] = hdrs + + // set headers, using a replacer with only globals (env vars, system info, etc.) + repl := caddy.NewReplacer() + for key, vals := range h.HealthChecks.Active.Headers { + key = repl.ReplaceAll(key, "") + if key == "Host" { + req.Host = repl.ReplaceAll(h.HealthChecks.Active.Headers.Get(key), "") + continue + } + for _, val := range vals { + req.Header.Add(key, repl.ReplaceKnown(val, "")) } } |