QA: make sure we can run on Linux without Docker (#836)

* QA: make sure we can run from Linux

Previous changes made it much more difficult to run on Linux. Yet, to
do QA of Web Connectivity it's more practical to perform it on Linux using
also OONI Probe v2.x and Measurement Kit.

For this reason, this diff implements changes that should allow us to run
both on Linux and when using Docker.

While it's possible to create a Docker container where we deploy compiled
versions of MK and OONI Probe v2.x, it's more practical to use a Linux system
where they are already installed, like my Linux desktop.

Part of #810

* QA: fix running on Linux

1. we cannot write on QA/HOME when running on Linux so just
use `/tmp` as the HOME directory (slower but works)

2. the `/tmp` directory may be on another device than `/home`, so
we cannot move, then just perform a copy

Part of #810

QA/.dockerignore

@@ -0,0 +1 @@
+*

cmd/jafar/Dockerfile → QA/Dockerfile

@@ -1,3 +1,2 @@
 FROM alpine:edge
 RUN apk add go git musl-dev iptables tmux bind-tools curl sudo python3
-RUN adduser -D ooniprobe

QA/README.md

@@ -26,14 +26,13 @@ where `$nettest` is the nettest name (e.g. `telegram`) and `$ooni_exe`
 is the OONI Probe v2.x compatible binary to test.
 
 The Python script needs to run as root. Note however that sudo will also
-be used to run `$ooni_exe` with the privileges of the `$SUDO_USER` that
-called `sudo ./QA/$nettest.py $ooni_exe`.
+be used to run `$ooni_exe` with the privileges of the `nobody` user.
 
 ## Run QA using a docker container
 
 Run test in a suitable Docker container using:
 
-```
+```bash
 ./QA/rundocker.sh $nettest
 ```
 

QA/common.py

@@ -18,21 +18,22 @@ def execute(args):
 
 def execute_jafar_and_miniooni(ooni_exe, outfile, experiment, tag, args):
     """ Executes jafar and miniooni. Returns the test keys. """
+    tmpoutfile = "/tmp/{}".format(outfile)
     with contextlib.suppress(FileNotFoundError):
-        os.remove(outfile)  # just in case
+        os.remove(tmpoutfile)  # just in case
     execute(
         [
             "./jafar",
             "-main-command",
-            "%s -no '/home/ooniprobe/%s' %s" % (ooni_exe, outfile, experiment),
+            "{} -no '{}' --home /tmp {}".format(ooni_exe, tmpoutfile, experiment),
             "-main-user",
-            "ooniprobe",  # created in cmd/jafar/Dockerfile
+            "nobody",  # should be present on Unix
             "-tag",
             tag,
         ]
         + args
     )
-    shutil.move("/home/ooniprobe/{}".format(outfile), outfile)
+    shutil.copy(tmpoutfile, outfile)
     result = read_result(outfile)
     assert isinstance(result, dict)
     assert isinstance(result["test_keys"], dict)

QA/rundocker.bash

@@ -1,5 +1,5 @@
 #!/bin/sh
 set -ex
 DOCKER=${DOCKER:-docker}
-$DOCKER build -t jafar-qa ./cmd/jafar/
+$DOCKER build -t jafar-qa ./QA/
 $DOCKER run --privileged -v`pwd`:/jafar -w/jafar jafar-qa ./QA/pyrun.sh "$@"

libminiooni/libminiooni.go

@@ -28,8 +28,9 @@ import (
 // Options contains the options you can set from the CLI.
 type Options struct {
 	Annotations      []string
-	Inputs           []string
 	ExtraOptions     []string
+	HomeDir          string
+	Inputs           []string
 	NoBouncer        bool
 	NoGeoIP          bool
 	NoJSON           bool
@@ -68,14 +69,18 @@ func init() {
 		&collectorURLUnused, "collector", 'c',
 		"Unsupported option that used to set the collector base URL", "URL",
 	)
-	getopt.FlagLong(
-		&globalOptions.Inputs, "input", 'i',
-		"Add test-dependent input to the test input", "INPUT",
-	)
 	getopt.FlagLong(
 		&globalOptions.ExtraOptions, "option", 'O',
 		"Pass an option to the experiment", "KEY=VALUE",
 	)
+	getopt.FlagLong(
+		&globalOptions.HomeDir, "home", 0,
+		"Force specific home directory", "PATH",
+	)
+	getopt.FlagLong(
+		&globalOptions.Inputs, "input", 'i',
+		"Add test-dependent input to the test input", "INPUT",
+	)
 	getopt.FlagLong(
 		&globalOptions.NoBouncer, "no-bouncer", 0, "Don't use the OONI bouncer",
 	)
@@ -196,7 +201,10 @@ func (h *logHandler) HandleLog(e *log.Entry) (err error) {
 }
 
 // See https://gist.github.com/miguelmota/f30a04a6d64bd52d7ab59ea8d95e54da
-func gethomedir() string {
+func gethomedir(optionsHome string) string {
+	if optionsHome != "" {
+		return optionsHome
+	}
 	if runtime.GOOS == "windows" {
 		home := os.Getenv("HOMEDRIVE") + os.Getenv("HOMEPATH")
 		if home == "" {
@@ -244,7 +252,7 @@ func MainWithConfiguration(experimentName string, currentOptions Options) {
 	}
 	log.Log = logger
 
-	homeDir := gethomedir()
+	homeDir := gethomedir(currentOptions.HomeDir)
 	fatalIfFalse(homeDir != "", "home directory is empty")
 	miniooniDir := path.Join(homeDir, ".miniooni")
 	assetsDir := path.Join(miniooniDir, "assets")