fix: use IdleConnTimeout/ConnectTimeout

This is an attempt to set sensible timeouts on abra connections. This
might not be the last word on this but it seems that SSH connections now
bail out correctly and other kinds of commands don't explode (e.g.
logs).

Closes coop-cloud/organising#222.
Closes coop-cloud/organising#218.

go.mod

@@ -44,4 +44,5 @@ require (
 	github.com/sfreiberg/simplessh v0.0.0-20180301191542-495cbb862a9c
 	github.com/theupdateframework/notary v0.7.0 // indirect
 	github.com/xeipuuv/gojsonschema v1.2.0 // indirect
+	golang.org/x/sys v0.0.0-20210910150752-751e447fb3d0 // indirect
 )

pkg/client/client.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"time"
 
+	commandconnPkg "coopcloud.tech/abra/pkg/upstream/commandconn"
 	"github.com/docker/docker/client"
 	"github.com/sirupsen/logrus"
 )
@@ -14,8 +15,6 @@ import (
 func New(contextName string) (*client.Client, error) {
 	var clientOpts []client.Opt
 
-	clientOpts = append(clientOpts, client.WithTimeout(3*time.Second))
-
 	if contextName != "default" {
 		context, err := GetContext(contextName)
 		if err != nil {
@@ -27,11 +26,12 @@ func New(contextName string) (*client.Client, error) {
 			return nil, err
 		}
 
-		helper := newConnectionHelper(ctxEndpoint)
+		helper := commandconnPkg.NewConnectionHelper(ctxEndpoint)
 		httpClient := &http.Client{
 			// No tls, no proxy
 			Transport: &http.Transport{
-				DialContext: helper.Dialer,
+				DialContext:     helper.Dialer,
+				IdleConnTimeout: 30 * time.Second,
 			},
 		}
 

pkg/client/context.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 
+	commandconnPkg "coopcloud.tech/abra/pkg/upstream/commandconn"
 	command "github.com/docker/cli/cli/command"
 	dConfig "github.com/docker/cli/cli/config"
 	context "github.com/docker/cli/cli/context"
@@ -44,7 +45,7 @@ func createContext(name string, host string) error {
 		Endpoints: make(map[string]contextStore.EndpointTLSData),
 	}
 
-	dockerEP, dockerTLS, err := getDockerEndpointMetadataAndTLS(host)
+	dockerEP, dockerTLS, err := commandconnPkg.GetDockerEndpointMetadataAndTLS(host)
 	if err != nil {
 		return err
 	}

pkg/upstream/commandconn/connection.go

@@ -1,11 +1,10 @@
-package client
+package commandconn
 
 import (
 	"context"
 	"net"
 	"net/url"
 
-	commandconnPkg "coopcloud.tech/abra/pkg/client/commandconn"
 	"github.com/docker/cli/cli/connhelper"
 	"github.com/docker/cli/cli/connhelper/ssh"
 	"github.com/docker/cli/cli/context/docker"
@@ -20,7 +19,7 @@ import (
 //
 // ssh://<user>@<host> URL requires Docker 18.09 or later on the remote host.
 func GetConnectionHelper(daemonURL string) (*connhelper.ConnectionHelper, error) {
-	return getConnectionHelper(daemonURL, nil)
+	return getConnectionHelper(daemonURL, []string{"-o ConnectTimeout=5"})
 }
 
 func getConnectionHelper(daemonURL string, sshFlags []string) (*connhelper.ConnectionHelper, error) {
@@ -36,7 +35,7 @@ func getConnectionHelper(daemonURL string, sshFlags []string) (*connhelper.Conne
 		}
 		return &connhelper.ConnectionHelper{
 			Dialer: func(ctx context.Context, network, addr string) (net.Conn, error) {
-				return commandconnPkg.New(ctx, "ssh", append(sshFlags, sp.Args("docker", "system", "dial-stdio")...)...)
+				return New(ctx, "ssh", append(sshFlags, sp.Args("docker", "system", "dial-stdio")...)...)
 			},
 			Host: "http://docker.example.com",
 		}, nil
@@ -46,7 +45,7 @@ func getConnectionHelper(daemonURL string, sshFlags []string) (*connhelper.Conne
 	return nil, err
 }
 
-func newConnectionHelper(daemonURL string) *connhelper.ConnectionHelper {
+func NewConnectionHelper(daemonURL string) *connhelper.ConnectionHelper {
 	helper, err := GetConnectionHelper(daemonURL)
 	if err != nil {
 		logrus.Fatal(err)
@@ -74,7 +73,7 @@ func getDockerEndpoint(host string) (docker.Endpoint, error) {
 	return ep, nil
 }
 
-func getDockerEndpointMetadataAndTLS(host string) (docker.EndpointMeta, *dCliContextStore.EndpointTLSData, error) {
+func GetDockerEndpointMetadataAndTLS(host string) (docker.EndpointMeta, *dCliContextStore.EndpointTLSData, error) {
 	ep, err := getDockerEndpoint(host)
 	if err != nil {
 		return docker.EndpointMeta{}, nil, err