clawbot
bff65f4e2f
check / check (push) Waiting to run
Every setting X may instead be given as a file that X_FILE names, read once at start: its contents, less one trailing newline, are the value, checked as X would be. X and X_FILE both set, or a file that cannot be read, stops the start with a message naming the variable. The logged settings name the file, and mask a token read from one. SWWAF_LOG_REMOTE_TLS_CA_FILE, whose value is a file already, has no _FILE form. The health check reads only SWWAF_LISTEN_ADDR and SWWAF_UPSTREAM_URL, so no other setting or file can fail it. Judgement call: an invalid value read from a file is named as X, not X_FILE. Rule suppressed: gosec G304 on reading the named file, as for the CA file. Model: opus-5-5
103 lines
2.6 KiB
Go
103 lines
2.6 KiB
Go
package smallwebwaf
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import (
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"context"
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"errors"
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"fmt"
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"io"
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"net"
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"net/http"
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"net/url"
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"time"
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"sneak.berlin/go/smallwebwaf/internal/config"
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"sneak.berlin/go/smallwebwaf/internal/proxy"
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)
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// healthCheckTimeout bounds the whole health check.
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const healthCheckTimeout = 5 * time.Second
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var errHealthEndpoint = errors.New("smallwebwaf's health endpoint answered")
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// HealthCheck is the container's health check. It returns 0 while
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// smallwebwaf answers its health endpoint on 127.0.0.1, at the port in
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// SWWAF_LISTEN_ADDR, and the app accepts connections at the address in
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// SWWAF_UPSTREAM_URL. Otherwise it writes why to stderr and returns 1.
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// It reads no other setting, nor a file that another names, so neither
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// can fail it.
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// args are the arguments after `healthcheck`; it takes none, and given
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// one it names it on stderr and returns 1 without checking anything.
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func HealthCheck(
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ctx context.Context, args []string, lookupEnv func(string) (string, bool),
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stderr io.Writer,
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) int {
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if len(args) > 0 {
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_, _ = fmt.Fprintf(stderr,
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"smallwebwaf healthcheck: unexpected argument %q\n", args[0])
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return 1
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}
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err := healthCheck(ctx, lookupEnv)
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if err != nil {
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_, _ = fmt.Fprintln(stderr, "unhealthy:", err)
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return 1
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}
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return 0
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}
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func healthCheck(ctx context.Context, lookupEnv func(string) (string, bool)) error {
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ctx, cancel := context.WithTimeout(ctx, healthCheckTimeout)
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defer cancel()
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listenAddr, upstreamURL, err := config.ListenAddrAndUpstreamURL(lookupEnv)
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if err != nil {
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return fmt.Errorf("invalid setting: %w", err)
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}
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// The settings have checked that the address has a port.
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_, port, _ := net.SplitHostPort(listenAddr)
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health := "http://" + net.JoinHostPort("127.0.0.1", port) + proxy.HealthPath
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req, err := http.NewRequestWithContext(ctx, http.MethodGet, health, http.NoBody)
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if err != nil {
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return fmt.Errorf("make the request: %w", err)
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}
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res, err := http.DefaultClient.Do(req)
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if err != nil {
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return fmt.Errorf("ask smallwebwaf: %w", err)
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}
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_ = res.Body.Close()
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if res.StatusCode != http.StatusOK {
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return fmt.Errorf("%w %s", errHealthEndpoint, res.Status)
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}
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conn, err := (&net.Dialer{}).DialContext(ctx, "tcp", appAddress(upstreamURL))
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if err != nil {
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return fmt.Errorf("connect to the app: %w", err)
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}
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_ = conn.Close()
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return nil
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}
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// appAddress is the host and port of the app's URL, the port being the
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// scheme's own when the URL names none.
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func appAddress(app *url.URL) string {
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port := app.Port()
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if port == "" {
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port = "80"
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if app.Scheme == "https" {
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port = "443"
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}
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}
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return net.JoinHostPort(app.Hostname(), port)
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}
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