test(e2e): add initial CLI tests

.github/workflows/e2e-cli.yaml

@@ -0,0 +1,54 @@
+name: kraft CLI Tests
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+    branches: [staging]
+    paths:
+      - '**'
+      - '!.github/**'
+
+jobs:
+
+  e2e-cli:
+    name: Test kraft CLI commands
+    runs-on: ubuntu-latest
+
+    env:
+      KRAFTKIT_NO_CHECK_UPDATES: 'true'
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Set up Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: '1.20.2'
+          cache: false
+
+      - name: Go caches
+        uses: actions/cache@v3
+        with:
+          path: |
+            ~/.cache/go-build
+            ~/go/pkg/mod
+          key: ${{ github.job }}-${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ github.job }}-${{ runner.os }}-go-
+
+      - name: Install libgit2/git2go
+        run: make git2go
+
+      - name: Install Ginkgo
+        run: go install github.com/onsi/ginkgo/v2/ginkgo
+
+      - name: Install kraft
+        run: |
+          go install \
+            -tags static \
+            -gcflags=all='' \
+            -ldflags='-s -w -X "kraftkit.sh/internal/version.version=v0.0.0-ci-e2e" -X "kraftkit.sh/internal/version.commit=0000000" -X "kraftkit.sh/internal/version.buildTime=Thu Jan  1 00:00:00 UTC 1970"' \
+            ./cmd/kraft
+
+      - name: Run e2e tests
+        run: ginkgo -v -p -randomize-all ./test/e2e/cli/

go.mod

@@ -39,6 +39,8 @@ require (
 	github.com/moby/moby v23.0.3+incompatible
 	github.com/muesli/reflow v0.3.0
 	github.com/muesli/termenv v0.15.1
+	github.com/onsi/ginkgo/v2 v2.9.2
+	github.com/onsi/gomega v1.27.4
 	github.com/opencontainers/go-digest v1.0.0
 	github.com/opencontainers/image-spec v1.1.0-rc2.0.20221005185240-3a7f492d3f1b
 	github.com/pkg/errors v0.9.1
@@ -96,6 +98,7 @@ require (
 	github.com/go-logr/logr v1.2.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/go-ole/go-ole v1.2.6 // indirect
+	github.com/go-task/slim-sprig v0.0.0-20230315185526-52ccab3ef572 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/glog v1.0.0 // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
@@ -104,6 +107,7 @@ require (
 	github.com/google/flatbuffers v23.1.21+incompatible // indirect
 	github.com/google/go-cmp v0.5.9 // indirect
 	github.com/google/go-querystring v1.1.0 // indirect
+	github.com/google/pprof v0.0.0-20210407192527-94a9f03dee38 // indirect
 	github.com/google/uuid v1.3.0 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 // indirect

go.sum

@@ -59,6 +59,9 @@ github.com/charmbracelet/harmonica v0.2.0/go.mod h1:KSri/1RMQOZLbw7AHqgcBycp8pgJ
 github.com/charmbracelet/lipgloss v0.6.0 h1:1StyZB9vBSOyuZxQUcUwGr17JmojPNm87inij9N3wJY=
 github.com/charmbracelet/lipgloss v0.6.0/go.mod h1:tHh2wr34xcHjC2HCXIlGSG1jaDF0S0atAUvBMP6Ppuk=
 github.com/checkpoint-restore/go-criu/v5 v5.3.0/go.mod h1:E/eQpaFtUKGOOSEBZgmKAcn+zUUwWxqcaKZlF54wK8E=
+github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
+github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
+github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
 github.com/cilium/ebpf v0.7.0/go.mod h1:/oI2+1shJiTGAMgl6/RgJr36Eo1jzrRcAWbcXO2usCA=
 github.com/cli/cli/v2 v2.23.0 h1:WT5llLrvm16Kc8xiPILX6HAXSe3gi+zoDnxGf5yUZr0=
 github.com/cli/cli/v2 v2.23.0/go.mod h1:d0dht8Zlv6k2YYjYosOvs1NCB+pbor7kxmf07V5ODtQ=
@@ -176,6 +179,8 @@ github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
 github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
 github.com/go-ole/go-ole v1.2.6 h1:/Fpf6oFPoeFik9ty7siob0G6Ke8QvQEuVcuChpwXzpY=
 github.com/go-ole/go-ole v1.2.6/go.mod h1:pprOEPIfldk/42T2oK7lQ4v4JSDwmV0As9GaiUsvbm0=
+github.com/go-task/slim-sprig v0.0.0-20230315185526-52ccab3ef572 h1:tfuBGBXKqDEevZMzYi5KSi8KkcZtzBcTgAUUtapy0OI=
+github.com/go-task/slim-sprig v0.0.0-20230315185526-52ccab3ef572/go.mod h1:9Pwr4B2jHnOSGXyyzV8ROjYa2ojvAY6HCGYYfMoC3Ls=
 github.com/gobwas/glob v0.2.3 h1:A4xDbljILXROh+kObIiy5kIaPYD8e96x1tgBhUI5J+Y=
 github.com/gobwas/glob v0.2.3/go.mod h1:d3Ez4x06l9bZtSvzIay5+Yzi0fmZzPgnTbPcKjJAkT8=
 github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
@@ -230,6 +235,8 @@ github.com/google/go-github/v32 v32.1.0/go.mod h1:rIEpZD9CTDQwDK9GDrtMTycQNA4JU3
 github.com/google/go-querystring v1.0.0/go.mod h1:odCYkC5MyYFN7vkCjXpyrEuKhc/BUO6wN/zVPAxq5ck=
 github.com/google/go-querystring v1.1.0 h1:AnCroh3fv4ZBgVIf1Iwtovgjaw/GiKJo8M8yD/fhyJ8=
 github.com/google/go-querystring v1.1.0/go.mod h1:Kcdr2DB4koayq7X8pmAG4sNG59So17icRSOU623lUBU=
+github.com/google/pprof v0.0.0-20210407192527-94a9f03dee38 h1:yAJXTCF9TqKcTiHJAE8dj7HMvPfh66eeA2JYW7eFpSE=
+github.com/google/pprof v0.0.0-20210407192527-94a9f03dee38/go.mod h1:kpwsk12EmLew5upagYY7GY0pfYCcupk39gWOCRROcvE=
 github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 h1:El6M4kTTCOh6aBiKaUGG7oYTSPP8MxqL4YI3kZKwcP4=
 github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510/go.mod h1:pupxD2MaaD3pAXIBCelhxNneeOaAeabZDe5s4K6zSpQ=
 github.com/google/uuid v1.1.2/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
@@ -242,6 +249,7 @@ github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T
 github.com/henvic/httpretty v0.1.0 h1:Htk66UUEbXTD4JR0qJZaw8YAMKw+9I24ZZOnDe/ti+E=
 github.com/henvic/httpretty v0.1.0/go.mod h1:ViEsly7wgdugYtymX54pYp6Vv2wqZmNHayJ6q8tlKCc=
 github.com/hinshun/vt10x v0.0.0-20220119200601-820417d04eec/go.mod h1:Q48J4R4DvxnHolD5P8pOtXigYlRuPLGl6moFx3ulM68=
+github.com/ianlancetaylor/demangle v0.0.0-20200824232613-28f6c0f3b639/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
 github.com/imdario/mergo v0.3.13/go.mod h1:4lJ1jqUDcsbIECGy0RUJAXNIhg+6ocWgb1ALK2O4oXg=
 github.com/imdario/mergo v0.3.14 h1:fOqeC1+nCuuk6PKQdg9YmosXX7Y7mHX6R/0ZldI9iHo=
 github.com/imdario/mergo v0.3.14/go.mod h1:WBLT9ZmE3lPoWsEzCh9LPo3TiwVN+ZKEjmz+hD27ysY=
@@ -331,6 +339,10 @@ github.com/muesli/termenv v0.13.0/go.mod h1:sP1+uffeLaEYpyOTb8pLCUctGcGLnoFjSn4Y
 github.com/muesli/termenv v0.15.1 h1:UzuTb/+hhlBugQz28rpzey4ZuKcZ03MeKsoG7IJZIxs=
 github.com/muesli/termenv v0.15.1/go.mod h1:HeAQPTzpfs016yGtA4g00CsdYnVLJvxsS4ANqrZs2sQ=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
+github.com/onsi/ginkgo/v2 v2.9.2 h1:BA2GMJOtfGAfagzYtrAlufIP0lq6QERkFmHLMLPwFSU=
+github.com/onsi/ginkgo/v2 v2.9.2/go.mod h1:WHcJJG2dIlcCqVfBAwUCrJxSPFb6v4azBwgxeMeDuts=
+github.com/onsi/gomega v1.27.4 h1:Z2AnStgsdSayCMDiCU42qIz+HLqEPcgiOCXjAU/w+8E=
+github.com/onsi/gomega v1.27.4/go.mod h1:riYq/GJKh8hhoM01HN6Vmuy93AarCXCBGpvFDK3q3fQ=
 github.com/opencontainers/go-digest v1.0.0-rc1/go.mod h1:cMLVZDEM3+U2I4VmLI6N8jQYUd2OVphdqWwCJHrFt2s=
 github.com/opencontainers/go-digest v1.0.0 h1:apOUWs51W5PlhuyGyz9FCeeBIOUDA/6nW8Oi/yOhh5U=
 github.com/opencontainers/go-digest v1.0.0/go.mod h1:0JzlMkj0TRzQZfJkVvzbP0HBR3IKzErnv2BNG4W4MAM=
@@ -529,6 +541,7 @@ golang.org/x/sys v0.0.0-20190606203320-7fc4e5ec1444/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20190916202348-b4ddaad3f8a3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191115151921-52ab43148777/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191204072324-ce4227a45e2e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200302150141-5c8b2ff67527/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

go.work.sum

@@ -208,9 +208,6 @@ github.com/certifi/gocertifi v0.0.0-20200922220541-2c3bb06c6054/go.mod h1:sGbDF6
 github.com/cespare/xxhash/v2 v2.1.2/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/chai2010/gettext-go v0.0.0-20160711120539-c6fed771bfd5/go.mod h1:/iP1qXHoty45bqomnu2LM+VVyAEdWN+vtSHGlQgyxbw=
 github.com/charmbracelet/glamour v0.5.1-0.20220727184942-e70ff2d969da/go.mod h1:HXz79SMFnF9arKxqeoHWxmo1BhplAH7wehlRhKQIL94=
-github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
-github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
-github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
 github.com/cli/browser v1.1.0/go.mod h1:HKMQAt9t12kov91Mn7RfZxyJQQgWgyS/3SZswlZ5iTI=
 github.com/cli/safeexec v1.0.0/go.mod h1:Z/D4tTN8Vs5gXYHDCbaM1S/anmEDnJb1iW0+EJ5zx3Q=
 github.com/cli/shurcooL-graphql v0.0.2/go.mod h1:tlrLmw/n5Q/+4qSvosT+9/W5zc8ZMjnJeYBxSdb4nWA=
@@ -338,7 +335,6 @@ github.com/google/pprof v0.0.0-20201023163331-3e6fc7fc9c4c/go.mod h1:kpwsk12EmLe
 github.com/google/pprof v0.0.0-20201203190320-1bf35d6f28c2/go.mod h1:kpwsk12EmLew5upagYY7GY0pfYCcupk39gWOCRROcvE=
 github.com/google/pprof v0.0.0-20210122040257-d980be63207e/go.mod h1:kpwsk12EmLew5upagYY7GY0pfYCcupk39gWOCRROcvE=
 github.com/google/pprof v0.0.0-20210226084205-cbba55b83ad5/go.mod h1:kpwsk12EmLew5upagYY7GY0pfYCcupk39gWOCRROcvE=
-github.com/google/pprof v0.0.0-20210407192527-94a9f03dee38/go.mod h1:kpwsk12EmLew5upagYY7GY0pfYCcupk39gWOCRROcvE=
 github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
 github.com/google/uuid v1.1.2 h1:EVhdT+1Kseyi1/pUmXKaFxYsDNy9RQYkMWRH68J/W7Y=
 github.com/googleapis/enterprise-certificate-proxy v0.2.1/go.mod h1:AwSRAtLfXpU5Nm3pW+v7rGDHp09LsPtGY9MduiEsR9k=
@@ -382,7 +378,6 @@ github.com/hashicorp/serf v0.8.2/go.mod h1:6hOLApaqBFA1NXqRQAsxw9QxuDEvNxSQRwA/J
 github.com/henvic/httpretty v0.0.6/go.mod h1:X38wLjWXHkXT7r2+uK8LjCMne9rsuNaBLJ+5cU2/Pmo=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
-github.com/ianlancetaylor/demangle v0.0.0-20200824232613-28f6c0f3b639/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
 github.com/imdario/mergo v0.3.5/go.mod h1:2EnlNZ0deacrJVfApfmtdGgDfMuh/nq6Ok1EcJh5FfA=
 github.com/imdario/mergo v0.3.6/go.mod h1:2EnlNZ0deacrJVfApfmtdGgDfMuh/nq6Ok1EcJh5FfA=
 github.com/imdario/mergo v0.3.12/go.mod h1:jmQim1M+e3UYxmgPu/WyfjB3N3VflVyUjjjwH0dnCYA=
@@ -459,9 +454,11 @@ github.com/onsi/ginkgo v0.0.0-20170829012221-11459a886d9c/go.mod h1:lLunBs/Ym6LB
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/ginkgo v1.12.1/go.mod h1:zj2OWP4+oCPe1qIXoGWkgMRwljMUYCdkwsT2108oapk=
 github.com/onsi/ginkgo v1.14.0/go.mod h1:iSB4RoI2tjJc9BBv4NKIKWKya62Rps+oPG/Lv9klQyY=
+github.com/onsi/ginkgo v1.16.4 h1:29JGrr5oVBm5ulCWet69zQkzWipVXIol6ygQUe/EzNc=
 github.com/onsi/ginkgo v1.16.4/go.mod h1:dX+/inL/fNMqNlz0e9LfyB9TswhZpCVdJM/Z6Vvnwo0=
 github.com/onsi/ginkgo/v2 v2.1.4/go.mod h1:um6tUpWM/cxCK3/FK8BXqEiUMUwRgSM4JXG47RKZmLU=
 github.com/onsi/ginkgo/v2 v2.4.0/go.mod h1:iHkDK1fKGcBoEHT5W7YBq4RFWaQulw+caOMkAt4OrFo=
+github.com/onsi/ginkgo/v2 v2.9.1/go.mod h1:FEcmzVcCHl+4o9bQZVab+4dC9+j+91t2FHSzmGAPfuo=
 github.com/onsi/gomega v0.0.0-20170829124025-dcabb60a477c/go.mod h1:C1qb7wdrVGGVU+Z6iS04AVkA3Q65CEZX59MT0QO5uiA=
 github.com/onsi/gomega v1.7.1/go.mod h1:XdKZgCCFLUoM/7CFJVPcG8C1xQ1AJ0vpAezJrB7JYyY=
 github.com/onsi/gomega v1.10.1/go.mod h1:iN09h71vgCQne3DLsj+A5owkum+a2tYe+TOCB1ybHNo=
@@ -700,7 +697,6 @@ golang.org/x/sys v0.0.0-20191001151750-bb3f8db39f24/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20191002063906-3421d5a6bb1c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191005200804-aed5e4c7ecf9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191120155948-bd437916bb0e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20191204072324-ce4227a45e2e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191228213918-04cbcbbfeed8/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200106162015-b016eb3dc98e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200113162924-86b910548bc1/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

hack/tools.go

@@ -0,0 +1,13 @@
+//go:build tools
+
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright (c) 2023, Unikraft GmbH and The KraftKit Authors.
+// Licensed under the BSD-3-Clause License (the "License").
+// You may not use this file except in compliance with the License.
+
+package hack
+
+// These imports ensure that build tools are included in Go modules so that we
+// can `go install` them in module-aware mode.
+// See https://github.com/golang/go/wiki/Modules#how-can-i-track-tool-dependencies-for-a-module
+import _ "github.com/onsi/ginkgo/v2/ginkgo"

test/e2e/cli/cli_suite_test.go

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright (c) 2023, Unikraft GmbH and The KraftKit Authors.
+// Licensed under the BSD-3-Clause License (the "License").
+// You may not use this file except in compliance with the License.
+
+package cli_test
+
+import (
+	"testing"
+
+	. "github.com/onsi/ginkgo/v2" //nolint:stylecheck
+	. "github.com/onsi/gomega"    //nolint:stylecheck
+)
+
+func TestCli(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "CLI Suite")
+}

test/e2e/cli/version_test.go

@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright (c) 2023, Unikraft GmbH and The KraftKit Authors.
+// Licensed under the BSD-3-Clause License (the "License").
+// You may not use this file except in compliance with the License.
+
+package cli_test
+
+import (
+	"os/exec"
+
+	. "github.com/onsi/ginkgo/v2" //nolint:stylecheck
+	. "github.com/onsi/gomega"    //nolint:stylecheck
+
+	fcmd "kraftkit.sh/test/e2e/framework/cmd"
+)
+
+var _ = Describe("kraft version", func() {
+	var cmd *exec.Cmd
+
+	var stdout *fcmd.IOStream
+	var stderr *fcmd.IOStream
+
+	BeforeEach(func() {
+		stdout = fcmd.NewIOStream()
+		stderr = fcmd.NewIOStream()
+
+		cmd = fcmd.NewKraft(stdout, stderr)
+		cmd.Args = append(cmd.Args, "version")
+	})
+
+	When("invoked without flags or positional arguments", func() {
+		It("should print the version and exit gracefully", func() {
+			err := cmd.Run()
+			Expect(err).ToNot(HaveOccurred())
+
+			Expect(stderr.String()).To(BeEmpty())
+			Expect(stdout).To(MatchRegexp(`^kraft [\w\.-]+ \([\w]+\) [\w\.-]+ .+\n$`))
+		})
+	})
+
+	When("invoked with the --help flag", func() {
+		BeforeEach(func() {
+			// The help subsystem is managed by cobra and fails when top-level flags
+			// are passed, so we ensure to keep only the command name and subcommand
+			// from the original cmd.
+			cmd.Args = []string{cmd.Args[0], cmd.Args[len(cmd.Args)-1], "--help"}
+		})
+
+		It("should print the command's help", func() {
+			err := cmd.Run()
+			Expect(err).ToNot(HaveOccurred())
+
+			Expect(stderr.String()).To(BeEmpty())
+			Expect(stdout).To(MatchRegexp(`^Show kraft version information\n`))
+		})
+	})
+
+	When("invoked with positional arguments", func() {
+		BeforeEach(func() {
+			cmd.Args = append(cmd.Args, "some-arg")
+		})
+
+		It("should print an error and exit", func() {
+			err := cmd.Run()
+			Expect(err).To(HaveOccurred())
+			Expect(err).To(BeAssignableToTypeOf((*exec.ExitError)(nil)))
+
+			eErr := err.(*exec.ExitError)
+			Expect(eErr.ProcessState.ExitCode()).To(Equal(1))
+
+			Expect(stderr.String()).To(BeEmpty())
+			Expect(stdout).To(MatchRegexp(`^unknown command "some-arg" for "kraft version"\n$`))
+		})
+	})
+})

test/e2e/framework/cmd/cmd.go

@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: BSD-3-Clause
+// Copyright (c) 2023, Unikraft GmbH and The KraftKit Authors.
+// Licensed under the BSD-3-Clause License (the "License").
+// You may not use this file except in compliance with the License.
+
+package cmd
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os/exec"
+
+	gomegafmt "github.com/onsi/gomega/format"
+)
+
+// NewKraft returns a kraft OS command that uses the given IO streams and has
+// pre-set flags to use the given paths.
+func NewKraft(stdout, stderr *IOStream) *exec.Cmd {
+	cmd := exec.Command("kraft")
+	cmd.Stdout = stdout
+	cmd.Stderr = stderr
+
+	return cmd
+}
+
+// IOStream represents an IO stream to be used by OS commands and suitable
+// for assertions and reporting in tests.
+type IOStream struct {
+	b *bytes.Buffer
+}
+
+var (
+	_ io.ReadWriter            = (*IOStream)(nil)
+	_ fmt.Stringer             = (*IOStream)(nil)
+	_ gomegafmt.GomegaStringer = (*IOStream)(nil)
+)
+
+// NewIOStream returns an initialized IOStream.
+func NewIOStream() *IOStream {
+	return &IOStream{
+		b: &bytes.Buffer{},
+	}
+}
+
+func (s *IOStream) Read(p []byte) (n int, err error) {
+	return s.b.Read(p)
+}
+
+func (s *IOStream) Write(p []byte) (n int, err error) {
+	return s.b.Write(p)
+}
+
+func (s *IOStream) String() string {
+	return s.b.String()
+}
+
+func (s *IOStream) GomegaString() string {
+	return s.String()
+}