From a3d4238b9ce653d2863fbc93057ed4162a83221e Mon Sep 17 00:00:00 2001 From: Sebastiaan van Stijn Date: Thu, 19 Jul 2018 13:45:32 +0200 Subject: [PATCH] Add "Warnings" to /info endpoint, and move detection to the daemon When requesting information about the daemon's configuration through the `/info` endpoint, missing features (or non-recommended settings) may have to be presented to the user. Detecting these situations, and printing warnings currently is handled by the cli, which results in some complications: - duplicated effort: each client has to re-implement detection and warnings. - it's not possible to generate warnings for reasons outside of the information returned in the `/info` response. - cli-side detection has to be updated for new conditions. This means that an older cli connecting to a new daemon may not print all warnings (due to it not detecting the new conditions) - some warnings (in particular, warnings about storage-drivers) depend on driver-status (`DriverStatus`) information. The format of the information returned in this field is not part of the API specification and can change over time, resulting in cli-side detection no longer being functional. This patch adds a new `Warnings` field to the `/info` response. This field is to return warnings to be presented by the user. Existing warnings that are currently handled by the CLI are copied to the daemon as part of this patch; This change is backward-compatible with existing clients; old client can continue to use the client-side warnings, whereas new clients can skip client-side detection, and print warnings that are returned by the daemon. Example response with this patch applied; ```bash curl --unix-socket /var/run/docker.sock http://localhost/info | jq .Warnings ``` ```json [ "WARNING: bridge-nf-call-iptables is disabled", "WARNING: bridge-nf-call-ip6tables is disabled" ] ``` Signed-off-by: Sebastiaan van Stijn --- api/swagger.yaml | 13 +++++++ api/types/types.go | 1 + daemon/info.go | 2 + daemon/info_unix.go | 75 +++++++++++++++++++++++++++++++++++++ daemon/info_windows.go | 3 ++ docs/api/version-history.md | 2 + 6 files changed, 96 insertions(+) diff --git a/api/swagger.yaml b/api/swagger.yaml index 672b598929..3906899050 100644 --- a/api/swagger.yaml +++ b/api/swagger.yaml @@ -3904,6 +3904,19 @@ definitions: such as number of nodes, and expiration are included. type: "string" example: "Community Engine" + Warnings: + description: | + List of warnings / informational messages about missing features, or + issues related to the daemon configuration. + + These messages can be printed by the client as information to the user. + type: "array" + items: + type: "string" + example: + - "WARNING: No memory limit support" + - "WARNING: bridge-nf-call-iptables is disabled" + - "WARNING: bridge-nf-call-ip6tables is disabled" # PluginsInfo is a temp struct holding Plugins name diff --git a/api/types/types.go b/api/types/types.go index ae9e27dca1..ed62fd41e5 100644 --- a/api/types/types.go +++ b/api/types/types.go @@ -206,6 +206,7 @@ type Info struct { InitCommit Commit SecurityOptions []string ProductLicense string `json:",omitempty"` + Warnings []string } // KeyValue holds a key/value pair diff --git a/daemon/info.go b/daemon/info.go index 3575fdda38..cc9ad8ac61 100644 --- a/daemon/info.go +++ b/daemon/info.go @@ -134,6 +134,8 @@ func (daemon *Daemon) fillDriverInfo(v *types.Info) { v.Driver = drivers v.DriverStatus = ds + + fillDriverWarnings(v) } func (daemon *Daemon) fillPluginsInfo(v *types.Info) { diff --git a/daemon/info_unix.go b/daemon/info_unix.go index 864e8816a9..98935cca70 100644 --- a/daemon/info_unix.go +++ b/daemon/info_unix.go @@ -4,6 +4,7 @@ package daemon // import "github.com/docker/docker/daemon" import ( "context" + "fmt" "os/exec" "strings" @@ -68,6 +69,80 @@ func (daemon *Daemon) fillPlatformInfo(v *types.Info, sysInfo *sysinfo.SysInfo) logrus.Warnf("failed to retrieve %s version: %s", defaultInitBinary, err) v.InitCommit.ID = "N/A" } + + if !v.MemoryLimit { + v.Warnings = append(v.Warnings, "WARNING: No memory limit support") + } + if !v.SwapLimit { + v.Warnings = append(v.Warnings, "WARNING: No swap limit support") + } + if !v.KernelMemory { + v.Warnings = append(v.Warnings, "WARNING: No kernel memory limit support") + } + if !v.OomKillDisable { + v.Warnings = append(v.Warnings, "WARNING: No oom kill disable support") + } + if !v.CPUCfsQuota { + v.Warnings = append(v.Warnings, "WARNING: No cpu cfs quota support") + } + if !v.CPUCfsPeriod { + v.Warnings = append(v.Warnings, "WARNING: No cpu cfs period support") + } + if !v.CPUShares { + v.Warnings = append(v.Warnings, "WARNING: No cpu shares support") + } + if !v.CPUSet { + v.Warnings = append(v.Warnings, "WARNING: No cpuset support") + } + if !v.IPv4Forwarding { + v.Warnings = append(v.Warnings, "WARNING: IPv4 forwarding is disabled") + } + if !v.BridgeNfIptables { + v.Warnings = append(v.Warnings, "WARNING: bridge-nf-call-iptables is disabled") + } + if !v.BridgeNfIP6tables { + v.Warnings = append(v.Warnings, "WARNING: bridge-nf-call-ip6tables is disabled") + } +} + +func fillDriverWarnings(v *types.Info) { + if v.DriverStatus == nil { + return + } + for _, pair := range v.DriverStatus { + if pair[0] == "Data loop file" { + msg := fmt.Sprintf("WARNING: %s: usage of loopback devices is "+ + "strongly discouraged for production use.\n "+ + "Use `--storage-opt dm.thinpooldev` to specify a custom block storage device.", v.Driver) + + v.Warnings = append(v.Warnings, msg) + continue + } + if pair[0] == "Supports d_type" && pair[1] == "false" { + backingFs := getBackingFs(v) + + msg := fmt.Sprintf("WARNING: %s: the backing %s filesystem is formatted without d_type support, which leads to incorrect behavior.\n", v.Driver, backingFs) + if backingFs == "xfs" { + msg += " Reformat the filesystem with ftype=1 to enable d_type support.\n" + } + msg += " Running without d_type support will not be supported in future releases." + + v.Warnings = append(v.Warnings, msg) + continue + } + } +} + +func getBackingFs(v *types.Info) string { + if v.DriverStatus == nil { + return "" + } + for _, pair := range v.DriverStatus { + if pair[0] == "Backing Filesystem" { + return pair[1] + } + } + return "" } // parseInitVersion parses a Tini version string, and extracts the version. diff --git a/daemon/info_windows.go b/daemon/info_windows.go index bf97971479..2c1ff460c3 100644 --- a/daemon/info_windows.go +++ b/daemon/info_windows.go @@ -8,3 +8,6 @@ import ( // fillPlatformInfo fills the platform related info. func (daemon *Daemon) fillPlatformInfo(v *types.Info, sysInfo *sysinfo.SysInfo) { } + +func fillDriverWarnings(v *types.Info) { +} diff --git a/docs/api/version-history.md b/docs/api/version-history.md index 7c18799fc5..6f0083e90e 100644 --- a/docs/api/version-history.md +++ b/docs/api/version-history.md @@ -21,6 +21,8 @@ keywords: "API, Docker, rcli, REST, documentation" and `OperatingSystem` if the daemon was unable to obtain this information. * `GET /info` now returns information about the product license, if a license has been applied to the daemon. +* `GET /info` now returns a `Warnings` field, containing warnings and informational + messages about missing features, or issues related to the daemon configuration. * `POST /swarm/init` now accepts a `DefaultAddrPool` property to set global scope default address pool * `POST /swarm/init` now accepts a `SubnetSize` property to set global scope networks by giving the length of the subnet masks for every such network