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Documentation / configuration/http

HTTP and HTTPS

An HTTP target sends a request and validates the final response status. HTTPS targets use the same http target type; the URL scheme selects TLS.

Flags

Flag Type Default Description
--http.<ID>.name string <ID> Name shown in logs.
--http.<ID>.address string required Target URL. Supports a resolved value.
--http.<ID>.address-detail enum origin URL detail shown in logs: origin, path, query, or full.
--http.<ID>.interval duration 0 Delay between requests. Uses --default-interval when 0.
--http.<ID>.max-attempts int --max-attempts Per-target attempt limit. 0 means unlimited.
--http.<ID>.backoff enum linear Retry backoff: linear or exponential.
--http.<ID>.max-interval duration 0 Maximum delay when backoff grows. 0 leaves it uncapped.
--http.<ID>.method enum GET GET, HEAD, POST, PUT, PATCH, DELETE, CONNECT, OPTIONS, or TRACE.
--http.<ID>.header string list empty Header in KEY=VALUE format. Repeat for multiple headers. Values support resolution.
--http.<ID>.allow-duplicate-headers bool false Preserve repeated headers with the same name.
--http.<ID>.expected-status-codes int list/ranges 200 Accepted statuses, such as 200,204,301-302.
--http.<ID>.follow-redirects bool true Follow redirects before validating the response.
--http.<ID>.max-redirects int 10 Maximum redirects to follow. 0 disables following.
--http.<ID>.skip-tls-verify bool false Disable TLS certificate verification.
--http.<ID>.timeout duration 2s Timeout for the complete request, including redirects.

Example

never \
  --http.api.address=https://api.example.com/healthz \
  --http.api.method=GET \
  --http.api.expected-status-codes=200,204 \
  --http.api.follow-redirects=true \
  --http.api.max-redirects=5 \
  --http.api.header="Authorization=env:API_TOKEN"

Redirects

When redirects are enabled, the checker validates the response after following at most max-redirects hops. Set follow-redirects=false or max-redirects=0 to validate the first redirect response instead. For example, a target expecting 301 should disable redirect following.

Headers

Repeat --http.<ID>.header to send multiple headers. Commas inside a value are preserved:

never \
  --http.api.address=https://api.example.com/healthz \
  --http.api.header="Accept=text/html, application/json" \
  --http.api.header="Cache-Control=no-cache, no-store"

Multiple headers in one environment variable are separated by newlines:

NEVER__HTTP_API_HEADER=$'Accept=text/html, application/json\nCache-Control=no-cache, no-store'

Address visibility

The default origin detail logs only the URL scheme and host. path includes the path, query includes its query string, and full also includes user credentials and fragments. Use query and full carefully because they can expose secrets. HTTP request errors do not echo the request URL.

Proxies

The HTTP checker honors Go’s standard HTTP_PROXY, HTTPS_PROXY, and NO_PROXY environment variables.