Use loglevel to dynamically change logrus' log level during runtime (#752) (#1861)

Signed-off-by: Grant Linville <[email protected]>

Author: g-linville

Dockerfile

@@ -11,6 +11,12 @@ RUN apk -U add curl
 RUN curl -sfL https://github.com/loft-sh/devspace/archive/refs/tags/v6.3.2.tar.gz | tar xzf - --strip-components=1
 RUN --mount=type=cache,target=/go/pkg --mount=type=cache,target=/root/.cache/go-build CGO_ENABLED=0 go build -o /usr/local/bin/acorn-helper -ldflags "-s -w" ./helper
 
+FROM ghcr.io/acorn-io/images-mirror/golang:1.20-alpine AS loglevel
+WORKDIR /usr/src
+RUN apk -U add curl
+RUN curl -sfL https://github.com/acorn-io/loglevel/archive/refs/tags/v0.1.6.tar.gz | tar xzf - --strip-components=1
+RUN --mount=type=cache,target=/go/pkg --mount=type=cache,target=/root/.cache/go-build CGO_ENABLED=0 go build -o /usr/local/bin/loglevel -ldflags "-s -w"
+
 FROM ghcr.io/acorn-io/images-mirror/golang:1.20 AS build
 COPY / /src
 WORKDIR /src
@@ -31,6 +37,7 @@ COPY --from=klipper-lb /usr/bin/entry /usr/local/bin/klipper-lb
 COPY ./scripts/ds-containerd-config-path-entry /usr/local/bin
 COPY ./scripts/setup-binfmt /usr/local/bin
 COPY --from=helper /usr/local/bin/acorn-helper /usr/local/bin/
+COPY --from=loglevel /usr/local/bin/loglevel /usr/local/bin/
 VOLUME /var/lib/buildkit
 
 COPY /scripts/acorn-helper-init /usr/local/bin

go.mod

@@ -14,7 +14,7 @@ require (
 	cuelang.org/go v0.5.0
 	github.com/AlecAivazis/survey/v2 v2.3.6
 	github.com/acorn-io/aml v0.0.0-20230619192500-1f56a8955db2
-	github.com/acorn-io/baaah v0.0.0-20230617011755-3291c17915f5
+	github.com/acorn-io/baaah v0.0.0-20230628211933-3f682344a78d
 	github.com/acorn-io/mink v0.0.0-20230523184405-ceaaa366d500
 	github.com/acorn-io/namegenerator v0.0.0-20220915160418-9e3d5a0ffe78
 	github.com/adrg/xdg v0.4.0

go.sum

@@ -94,8 +94,8 @@ github.com/acarl005/stripansi v0.0.0-20180116102854-5a71ef0e047d h1:licZJFw2RwpH
 github.com/acarl005/stripansi v0.0.0-20180116102854-5a71ef0e047d/go.mod h1:asat636LX7Bqt5lYEZ27JNDcqxfjdBQuJ/MM4CN/Lzo=
 github.com/acorn-io/aml v0.0.0-20230619192500-1f56a8955db2 h1:tWz51cHGC6GURkKqA4PdG3ObHz2YBrVzCfxXacNUqVY=
 github.com/acorn-io/aml v0.0.0-20230619192500-1f56a8955db2/go.mod h1:UEx5RRLFjryCEHN2pM59+d8A0mPJ3VAxggJOTzPymwg=
-github.com/acorn-io/baaah v0.0.0-20230617011755-3291c17915f5 h1:NdDW2tFRDHElXpcFeqTDKg6wB0uRLzJ5Kq0YDgYl/Dg=
-github.com/acorn-io/baaah v0.0.0-20230617011755-3291c17915f5/go.mod h1:LtwaWrYK/VuGptWxeD5Sgl0sgJV1ksicpTzyLilow1U=
+github.com/acorn-io/baaah v0.0.0-20230628211933-3f682344a78d h1:a+geMqB3U52a4+iMmLZ9R/EXkgxrp0QCetoqLAUnTD8=
+github.com/acorn-io/baaah v0.0.0-20230628211933-3f682344a78d/go.mod h1:LtwaWrYK/VuGptWxeD5Sgl0sgJV1ksicpTzyLilow1U=
 github.com/acorn-io/mink v0.0.0-20230523184405-ceaaa366d500 h1:tiM36bM+iMWuW9HM+YlM1GfNDXC7f565z8Be5epO0qM=
 github.com/acorn-io/mink v0.0.0-20230523184405-ceaaa366d500/go.mod h1:y6aYj2dF/SlU205bDfA43Y5c9sa/aYr4X5GDqYJzJTU=
 github.com/acorn-io/namegenerator v0.0.0-20220915160418-9e3d5a0ffe78 h1:5zs9L/CXNkuTdJSbhFWczAorbmx67nqlqswx5CQi7XI=

pkg/cli/apiserver.go

@@ -3,6 +3,7 @@ package cli
 import (
 	minkserver "github.com/acorn-io/mink/pkg/server"
 	cli "github.com/acorn-io/runtime/pkg/cli/builder"
+	"github.com/acorn-io/runtime/pkg/logserver"
 	"github.com/acorn-io/runtime/pkg/server"
 	"github.com/spf13/cobra"
 )
@@ -40,6 +41,8 @@ func (a *APIServer) Run(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
+	logserver.StartServerWithDefaults()
+
 	<-cmd.Context().Done()
 	return cmd.Context().Err()
 }

pkg/controller/controller.go

@@ -17,6 +17,7 @@ import (
 	"github.com/acorn-io/runtime/pkg/event"
 	"github.com/acorn-io/runtime/pkg/imagesystem"
 	"github.com/acorn-io/runtime/pkg/k8sclient"
+	"github.com/acorn-io/runtime/pkg/logserver"
 	"github.com/acorn-io/runtime/pkg/scheme"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/util/wait"
@@ -103,6 +104,7 @@ func (c *Controller) Start(ctx context.Context) error {
 		go wait.UntilWithContext(ctx, dnsInit.RenewAndSync, dnsRenewPeriodHours)
 
 		autoupgrade.StartSync(ctx, c.Router.Backend())
+		logserver.StartServerWithDefaults()
 	}()
 
 	return c.Router.Start(ctx)

pkg/logserver/logserver.go

@@ -0,0 +1,79 @@
+// Adapted from https://github.com/rancher/log/blob/52031d45f5fdb71cecb9a314865624b42514dbed/server/server.go
+// The only real differences here are that we are using logrus directly instead of a wrapper around it,
+// and that we are using an abstract namespace (non-file) socket.
+// This is only compatible with our fork of the client: https://github.com/acorn-io/loglevel
+
+package logserver
+
+import (
+	"fmt"
+	"net"
+	"net/http"
+	"os"
+
+	"github.com/sirupsen/logrus"
+)
+
+var (
+	DefaultSocketLocation = "\x00logserver"
+)
+
+// Server structure is used to the store backend information
+type Server struct {
+	SocketLocation string
+	Debug          bool
+}
+
+// StartServerWithDefaults starts the server with default values
+func StartServerWithDefaults() {
+	logrus.SetLevel(logrus.InfoLevel)
+	s := Server{
+		SocketLocation: DefaultSocketLocation,
+	}
+	s.Start()
+}
+
+// Start the server
+func (s *Server) Start() {
+	_ = os.Remove(s.SocketLocation)
+	go func() {
+		_ = s.ListenAndServe()
+	}()
+}
+
+// ListenAndServe is used to setup handlers and
+// start listening on the specified location
+func (s *Server) ListenAndServe() error {
+	logrus.Infof("Listening on %s", s.SocketLocation)
+	server := http.Server{}
+	http.HandleFunc("/v1/loglevel", s.loglevel)
+	socketListener, err := net.Listen("unix", s.SocketLocation)
+	if err != nil {
+		return err
+	}
+	return server.Serve(socketListener)
+}
+
+func (s *Server) loglevel(rw http.ResponseWriter, req *http.Request) {
+	// curl -X POST -d "level=debug" localhost:12345/v1/loglevel
+	logrus.Debugf("Received loglevel request")
+	if req.Method == http.MethodGet {
+		level := logrus.GetLevel().String()
+		_, _ = rw.Write([]byte(fmt.Sprintf("%s\n", level)))
+	}
+
+	if req.Method == http.MethodPost {
+		if err := req.ParseForm(); err != nil {
+			rw.WriteHeader(http.StatusInternalServerError)
+			_, _ = rw.Write([]byte(fmt.Sprintf("Failed to parse form: %v\n", err)))
+		}
+		level, err := logrus.ParseLevel(req.Form.Get("level"))
+		if err != nil {
+			rw.WriteHeader(http.StatusInternalServerError)
+			_, _ = rw.Write([]byte(fmt.Sprintf("Failed to parse loglevel: %v\n", err)))
+		} else {
+			logrus.SetLevel(level)
+			_, _ = rw.Write([]byte("OK\n"))
+		}
+	}
+}