feat: added journald collection package to bootstrapper internal packages

bootstrapper/internal/journald/BUILD.bazel

@@ -0,0 +1,16 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("//bazel/go:go_test.bzl", "go_test")
+
+go_library(
+    name = "journald",
+    srcs = ["journald.go"],
+    importpath = "github.com/edgelesssys/constellation/v2/bootstrapper/internal/journald",
+    visibility = ["//bootstrapper:__subpackages__"],
+)
+
+go_test(
+    name = "journald_test",
+    srcs = ["journald_test.go"],
+    embed = [":journald"],
+    deps = ["@com_github_stretchr_testify//assert"],
+)

bootstrapper/internal/journald/journald.go

@@ -0,0 +1,47 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+/*
+Package journald provides functions to read and collect journald logs.
+*/
+package journald
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os/exec"
+)
+
+type command interface {
+	Output() ([]byte, error)
+}
+
+// Collector collects logs from journald.
+type Collector struct {
+	cmd command
+}
+
+// NewCollector creates a new Collector for journald logs.
+func NewCollector(ctx context.Context) (*Collector, error) {
+	cmd := exec.CommandContext(ctx, "journalctl")
+	if cmd.Err != nil {
+		return nil, cmd.Err
+	}
+	return &Collector{cmd}, nil
+}
+
+// Collect gets all journald logs from a service and returns a byte slice with the plain text logs.
+func (c *Collector) Collect() ([]byte, error) {
+	out, err := c.cmd.Output()
+	var exitErr *exec.ExitError
+	if errors.As(err, &exitErr) {
+		return nil, fmt.Errorf("executing %q failed: %s", c.cmd, exitErr.Stderr)
+	} else if err != nil {
+		return nil, fmt.Errorf("executing command: %w", err)
+	}
+	return out, nil
+}

bootstrapper/internal/journald/journald_test.go

@@ -0,0 +1,64 @@
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+
+package journald
+
+import (
+	"errors"
+	"os/exec"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type stubJournaldCommand struct {
+	outputReturn []byte
+	outputError  error
+}
+
+func (j *stubJournaldCommand) Output() ([]byte, error) {
+	return j.outputReturn, j.outputError
+}
+
+func TestCollect(t *testing.T) {
+	someError := errors.New("failed")
+
+	testCases := map[string]struct {
+		command      *stubJournaldCommand
+		wantedOutput []byte
+		wantErr      bool
+	}{
+		"success": {
+			command: &stubJournaldCommand{},
+		},
+		"execution failed": {
+			command: &stubJournaldCommand{outputError: someError},
+			wantErr: true,
+		},
+		"exit error": {
+			command: &stubJournaldCommand{outputError: &exec.ExitError{}},
+			wantErr: true,
+		},
+		"output check": {
+			command:      &stubJournaldCommand{outputReturn: []byte("asdf")},
+			wantedOutput: []byte("asdf"),
+		},
+	}
+
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			assert := assert.New(t)
+
+			collector := Collector{cmd: tc.command}
+
+			out, err := collector.Collect()
+			if tc.wantErr {
+				assert.Error(err)
+			}
+			assert.Equal(out, tc.wantedOutput)
+		})
+	}
+}