device: add a helper to generate uapi configs

This makes it easier to work with configs in tests.
It'll see heavier use over upcoming commits;
this commit only adds the infrastructure.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>

diff --git a/device/device_test.go b/device/device_test.go
index a91e6ca2aac8a6aaeda163bd96f5f42b6a652dde..a89dcc2073472b2c9f398e8fd8a1abe43c1eb7d4 100644 (file)
--- a/device/device_test.go
+++ b/device/device_test.go
@@ -6,11 +6,10 @@
 package device
 
 import (
-       "bufio"
        "bytes"
        "fmt"
+       "io"
        "net"
-       "strings"
        "testing"
        "time"
 
@@ -26,39 +25,57 @@ func getFreePort(t *testing.T) string {
        return fmt.Sprintf("%d", l.LocalAddr().(*net.UDPAddr).Port)
 }
 
+// uapiCfg returns a reader that contains cfg formatted use with IpcSetOperation.
+// cfg is a series of alternating key/value strings.
+// uapiCfg exists because editors and humans like to insert
+// whitespace into configs, which can cause failures, some of which are silent.
+// For example, a leading blank newline causes the remainder
+// of the config to be silently ignored.
+func uapiCfg(cfg ...string) io.ReadSeeker {
+       if len(cfg)%2 != 0 {
+               panic("odd number of args to uapiReader")
+       }
+       buf := new(bytes.Buffer)
+       for i, s := range cfg {
+               buf.WriteString(s)
+               sep := byte('\n')
+               if i%2 == 0 {
+                       sep = '='
+               }
+               buf.WriteByte(sep)
+       }
+       return bytes.NewReader(buf.Bytes())
+}
+
 // genConfigs generates a pair of configs that connect to each other.
 // The configs use distinct, probably-usable ports.
-func genConfigs(t *testing.T) (cfgs [2]*bufio.Reader) {
-       const (
-               cfg1 = `private_key=481eb0d8113a4a5da532d2c3e9c14b53c8454b34ab109676f6b58c2245e37b58
-listen_port={{PORT1}}
-replace_peers=true
-public_key=f70dbb6b1b92a1dde1c783b297016af3f572fef13b0abb16a2623d89a58e9725
-protocol_version=1
-replace_allowed_ips=true
-allowed_ip=1.0.0.2/32
-endpoint=127.0.0.1:{{PORT2}}`
-
-               cfg2 = `private_key=98c7989b1661a0d64fd6af3502000f87716b7c4bbcf00d04fc6073aa7b539768
-listen_port={{PORT2}}
-replace_peers=true
-public_key=49e80929259cebdda4f322d6d2b1a6fad819d603acd26fd5d845e7a123036427
-protocol_version=1
-replace_allowed_ips=true
-allowed_ip=1.0.0.1/32
-endpoint=127.0.0.1:{{PORT1}}`
-       )
-
+func genConfigs(t *testing.T) (cfgs [2]io.Reader) {
        var port1, port2 string
        for port1 == port2 {
                port1 = getFreePort(t)
                port2 = getFreePort(t)
        }
-       for i, cfg := range []string{cfg1, cfg2} {
-               cfg = strings.ReplaceAll(cfg, "{{PORT1}}", port1)
-               cfg = strings.ReplaceAll(cfg, "{{PORT2}}", port2)
-               cfgs[i] = bufio.NewReader(strings.NewReader(cfg))
-       }
+
+       cfgs[0] = uapiCfg(
+               "private_key", "481eb0d8113a4a5da532d2c3e9c14b53c8454b34ab109676f6b58c2245e37b58",
+               "listen_port", port1,
+               "replace_peers", "true",
+               "public_key", "f70dbb6b1b92a1dde1c783b297016af3f572fef13b0abb16a2623d89a58e9725",
+               "protocol_version", "1",
+               "replace_allowed_ips", "true",
+               "allowed_ip", "1.0.0.2/32",
+               "endpoint", "127.0.0.1:"+port2,
+       )
+       cfgs[1] = uapiCfg(
+               "private_key", "98c7989b1661a0d64fd6af3502000f87716b7c4bbcf00d04fc6073aa7b539768",
+               "listen_port", port2,
+               "replace_peers", "true",
+               "public_key", "49e80929259cebdda4f322d6d2b1a6fad819d603acd26fd5d845e7a123036427",
+               "protocol_version", "1",
+               "replace_allowed_ips", "true",
+               "allowed_ip", "1.0.0.1/32",
+               "endpoint", "127.0.0.1:"+port1,
+       )
        return
 }