From 0b8646c5c4d8f1191268812f98096b33c72bf803 Mon Sep 17 00:00:00 2001 From: Gaalbu Date: Sun, 13 Sep 2026 01:00:49 -0300 Subject: [PATCH] Document custom header forwarding to registries Signed-off-by: Gaalbu --- data/cli/engine/docker.yaml | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/data/cli/engine/docker.yaml b/data/cli/engine/docker.yaml index 81db02ea6eb1..ddd270c2ccab 100644 --- a/data/cli/engine/docker.yaml +++ b/data/cli/engine/docker.yaml @@ -194,6 +194,11 @@ long: |- understand these headers; it simply puts them into the messages. Docker does not allow these headers to change any headers it sets for itself. + When pulling or pushing images, the daemon forwards only custom headers whose + names start with `X-Meta-` to the registry. For example, use + `"X-Meta-MyHeader": "MyValue"` when the header should be included in a + registry request. + Alternatively, use the `DOCKER_CUSTOM_HEADERS` [environment variable](#environment-variables), which is available in v27.1 and higher. This environment-variable is experimental, and its exact behavior may change. @@ -277,7 +282,7 @@ long: |- ```json { "HttpHeaders": { - "MyHeader": "MyValue" + "X-Meta-MyHeader": "MyValue" }, "psFormat": "table {{.ID}}\\t{{.Image}}\\t{{.Command}}\\t{{.Labels}}", "imagesFormat": "table {{.ID}}\\t{{.Repository}}\\t{{.Tag}}\\t{{.CreatedAt}}", @@ -629,4 +634,3 @@ experimental: false experimentalcli: false kubernetes: false swarm: false -