Correctly read in input from a non-interactive stream for the CLI

If you pipe in a file to the `influx` CLI, it will not try to open the
interactive line reader, but instead just send the contents of the
entire file to the server.

CHANGELOG.md

@@ -26,6 +26,7 @@
 - [#5955](https://github.com/influxdata/influxdb/issues/5955): Make regex work on field and dimension keys in SELECT clause.
 - [#7470](https://github.com/influxdata/influxdb/pull/7470): Reduce map allocations when computing the TagSet of a measurement.
 - [#6894](https://github.com/influxdata/influxdb/issues/6894): Support `INFLUX_USERNAME` and `INFLUX_PASSWORD` for setting username/password in the CLI.
+- [#6896](https://github.com/influxdata/influxdb/issues/6896): Correctly read in input from a non-interactive stream for the CLI.
 
 ### Bugfixes
 

cmd/influx/cli/cli.go

@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"net"
 	"net/url"
 	"os"
@@ -18,6 +19,8 @@ import (
 	"syscall"
 	"text/tabwriter"
 
+	"golang.org/x/crypto/ssh/terminal"
+
 	"github.com/influxdata/influxdb/client"
 	"github.com/influxdata/influxdb/importer/v8"
 	"github.com/influxdata/influxdb/models"
@@ -58,6 +61,7 @@ type CommandLine struct {
 	Chunked          bool
 	Quit             chan struct{}
 	IgnoreSignals    bool // Ignore signals normally caught by this process (used primarily for testing)
+	ForceTTY         bool // Force the CLI to act as if it were connected to a TTY
 	osSignals        chan os.Signal
 	historyFilePath  string
 }
@@ -73,6 +77,22 @@ func New(version string) *CommandLine {
 
 // Run executes the CLI
 func (c *CommandLine) Run() error {
+	// If we are not running in an interactive terminal, read stdin completely
+	// and execute a query. Do not allow meta commands.
+	if !c.ForceTTY && !terminal.IsTerminal(int(os.Stdin.Fd())) {
+		if err := c.Connect(""); err != nil {
+			return fmt.Errorf(
+				"Failed to connect to %s\nPlease check your connection settings and ensure 'influxd' is running.",
+				c.Client.Addr())
+		}
+
+		cmd, err := ioutil.ReadAll(os.Stdin)
+		if err != nil {
+			return err
+		}
+		return c.ExecuteQuery(string(cmd))
+	}
+
 	if !c.IgnoreSignals {
 		// register OS signals for graceful termination
 		signal.Notify(c.osSignals, syscall.SIGINT, syscall.SIGTERM)

cmd/influx/cli/cli_test.go

@@ -48,6 +48,7 @@ func TestRunCLI(t *testing.T) {
 	c.Host = h
 	c.Port, _ = strconv.Atoi(p)
 	c.IgnoreSignals = true
+	c.ForceTTY = true
 	go func() {
 		close(c.Quit)
 	}()
@@ -69,6 +70,7 @@ func TestRunCLI_ExecuteInsert(t *testing.T) {
 	c.Precision = "ms"
 	c.Execute = "INSERT sensor,floor=1 value=2"
 	c.IgnoreSignals = true
+	c.ForceTTY = true
 	if err := c.Run(); err != nil {
 		t.Fatalf("Run failed with error: %s", err)
 	}