feat: add info command

cmd/chisel/cmd_help.go

@@ -155,7 +155,7 @@ type helpCategory struct {
 var helpCategories = []helpCategory{{
 	Label:       "Basic",
 	Description: "general operations",
-	Commands:    []string{"find", "help", "version"},
+	Commands:    []string{"find", "info", "help", "version"},
 }, {
 	Label:       "Action",
 	Description: "make things happen",

cmd/chisel/cmd_info.go

@@ -0,0 +1,137 @@
+package main
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/jessevdk/go-flags"
+	"gopkg.in/yaml.v3"
+
+	"github.com/canonical/chisel/internal/setup"
+)
+
+var shortInfoHelp = "Show information about package slices"
+var longInfoHelp = `
+The info command shows detailed information about package slices.
+
+It accepts a whitespace-separated list of strings. The list can be
+composed of package names, slice names, or a combination of both. The
+default output format is YAML. When multiple arguments are provided,
+the output is a list of YAML documents separated by a "---" line.
+
+Slice definitions are shown verbatim according to their definition in
+the selected release. For example, globs are not expanded.
+`
+
+var infoDescs = map[string]string{
+	"release": "Chisel release name or directory (e.g. ubuntu-22.04)",
+}
+
+type infoCmd struct {
+	Release string `long:"release" value-name:"<branch|dir>"`
+
+	Positional struct {
+		Queries []string `positional-arg-name:"<pkg|slice>" required:"yes"`
+	} `positional-args:"yes"`
+}
+
+func init() {
+	addCommand("info", shortInfoHelp, longInfoHelp, func() flags.Commander { return &infoCmd{} }, infoDescs, nil)
+}
+
+func (cmd *infoCmd) Execute(args []string) error {
+	if len(args) > 0 {
+		return ErrExtraArgs
+	}
+
+	release, err := obtainRelease(cmd.Release)
+	if err != nil {
+		return err
+	}
+
+	packages, notFound := selectPackageSlices(release, cmd.Positional.Queries)
+
+	for i, pkg := range packages {
+		data, err := yaml.Marshal(pkg)
+		if err != nil {
+			return err
+		}
+		if i > 0 {
+			fmt.Fprintln(Stdout, "---")
+		}
+		fmt.Fprint(Stdout, string(data))
+	}
+
+	if len(notFound) > 0 {
+		for i := range notFound {
+			notFound[i] = strconv.Quote(notFound[i])
+		}
+		return fmt.Errorf("no slice definitions found for: " + strings.Join(notFound, ", "))
+	}
+
+	return nil
+}
+
+// selectPackageSlices takes in a release and a list of query strings
+// of package names and/or slice names, and returns a list of packages
+// containing the found slices. It also returns a list of query
+// strings that were not found.
+func selectPackageSlices(release *setup.Release, queries []string) (packages []*setup.Package, notFound []string) {
+	var pkgOrder []string
+	pkgSlices := make(map[string][]string)
+	allPkgSlices := make(map[string]bool)
+
+	sliceExists := func(key setup.SliceKey) bool {
+		pkg, ok := release.Packages[key.Package]
+		if !ok {
+			return false
+		}
+		_, ok = pkg.Slices[key.Slice]
+		return ok
+	}
+	for _, query := range queries {
+		var pkg, slice string
+		if strings.Contains(query, "_") {
+			key, err := setup.ParseSliceKey(query)
+			if err != nil || !sliceExists(key) {
+				notFound = append(notFound, query)
+				continue
+			}
+			pkg, slice = key.Package, key.Slice
+		} else {
+			if _, ok := release.Packages[query]; !ok {
+				notFound = append(notFound, query)
+				continue
+			}
+			pkg = query
+		}
+		if len(pkgSlices[pkg]) == 0 && !allPkgSlices[pkg] {
+			pkgOrder = append(pkgOrder, pkg)
+		}
+		if slice == "" {
+			allPkgSlices[pkg] = true
+		} else {
+			pkgSlices[pkg] = append(pkgSlices[pkg], slice)
+		}
+	}
+
+	for _, pkgName := range pkgOrder {
+		var pkg *setup.Package
+		if allPkgSlices[pkgName] {
+			pkg = release.Packages[pkgName]
+		} else {
+			releasePkg := release.Packages[pkgName]
+			pkg = &setup.Package{
+				Name:    releasePkg.Name,
+				Archive: releasePkg.Archive,
+				Slices:  make(map[string]*setup.Slice),
+			}
+			for _, sliceName := range pkgSlices[pkgName] {
+				pkg.Slices[sliceName] = releasePkg.Slices[sliceName]
+			}
+		}
+		packages = append(packages, pkg)
+	}
+	return packages, notFound
+}

cmd/chisel/cmd_info_test.go

@@ -0,0 +1,234 @@
+package main_test
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+
+	. "gopkg.in/check.v1"
+
+	chisel "github.com/canonical/chisel/cmd/chisel"
+	"github.com/canonical/chisel/internal/testutil"
+)
+
+type infoTest struct {
+	summary string
+	input   map[string]string
+	query   []string
+	err     string
+	stdout  string
+}
+
+var infoTests = []infoTest{{
+	summary: "A single slice inspection",
+	input:   infoRelease,
+	query:   []string{"mypkg1_myslice1"},
+	stdout: `
+		package: mypkg1
+		archive: ubuntu
+		slices:
+			myslice1:
+				contents:
+					/dir/file: {}
+	`,
+}, {
+	summary: "A single package inspection",
+	input:   infoRelease,
+	query:   []string{"mypkg2"},
+	stdout: `
+		package: mypkg2
+		archive: ubuntu
+		slices:
+			myslice:
+				contents:
+					/dir/another-file: {}
+	`,
+}, {
+	summary: "Multiple slices within the same package",
+	input:   infoRelease,
+	query:   []string{"mypkg1_myslice2", "mypkg1_myslice1"},
+	stdout: `
+		package: mypkg1
+		archive: ubuntu
+		slices:
+			myslice1:
+				contents:
+					/dir/file: {}
+			myslice2:
+				essential:
+					- mypkg1_myslice1
+					- mypkg2_myslice
+	`,
+}, {
+	summary: "Packages and slices",
+	input:   infoRelease,
+	query:   []string{"mypkg1_myslice1", "mypkg2", "mypkg1_myslice2"},
+	stdout: `
+		package: mypkg1
+		archive: ubuntu
+		slices:
+			myslice1:
+				contents:
+					/dir/file: {}
+			myslice2:
+				essential:
+					- mypkg1_myslice1
+					- mypkg2_myslice
+		---
+		package: mypkg2
+		archive: ubuntu
+		slices:
+			myslice:
+				contents:
+					/dir/another-file: {}
+	`,
+}, {
+	summary: "Package and its slices",
+	input:   infoRelease,
+	query:   []string{"mypkg1_myslice1", "mypkg1"},
+	stdout: `
+		package: mypkg1
+		archive: ubuntu
+		slices:
+			myslice1:
+				contents:
+					/dir/file: {}
+			myslice2:
+				essential:
+					- mypkg1_myslice1
+					- mypkg2_myslice
+	`,
+}, {
+	summary: "Same slice appearing multiple times",
+	input:   infoRelease,
+	query:   []string{"mypkg1_myslice1", "mypkg1_myslice1", "mypkg1_myslice1"},
+	stdout: `
+		package: mypkg1
+		archive: ubuntu
+		slices:
+			myslice1:
+				contents:
+					/dir/file: {}
+	`,
+}, {
+	summary: "No slices found",
+	input:   infoRelease,
+	query:   []string{"foo", "bar_foo"},
+	err:     `no slice definitions found for: "foo", "bar_foo"`,
+}, {
+	summary: "Some slices found, others not found",
+	input:   infoRelease,
+	query:   []string{"foo", "mypkg1_myslice1", "bar_foo"},
+	stdout: `
+		package: mypkg1
+		archive: ubuntu
+		slices:
+			myslice1:
+				contents:
+					/dir/file: {}
+					/dir/sub-dir/: {make: true, mode: 0644}
+	`,
+	err: `no slice definitions found for: "foo", "bar_foo"`,
+}, {
+	summary: "No args",
+	input:   infoRelease,
+	err:     "the required argument `<pkg|slice> (at least 1 argument)` was not provided",
+}, {
+	summary: "Empty, whitespace args",
+	input:   infoRelease,
+	query:   []string{"", "    "},
+	err:     `no slice definitions found for: "", "    "`,
+}, {
+	summary: "Ignore invalid slice names",
+	input:   infoRelease,
+	query:   []string{"foo_bar_foo", "a_b", "7_c", "a_b c", "a_b x_y"},
+	err:     `no slice definitions found for: "foo_bar_foo", "a_b", "7_c", "a_b c", "a_b x_y"`,
+}}
+
+var testKey = testutil.PGPKeys["key1"]
+
+var defaultChiselYaml = `
+	format: chisel-v1
+	archives:
+		ubuntu:
+			version: 22.04
+			components: [main, universe]
+			v1-public-keys: [test-key]
+	v1-public-keys:
+		test-key:
+			id: ` + testKey.ID + `
+			armor: |` + "\n" + testutil.PrefixEachLine(testKey.PubKeyArmor, "\t\t\t\t\t\t")
+
+var infoRelease = map[string]string{
+	"chisel.yaml": string(defaultChiselYaml),
+	"slices/mypkg1.yaml": `
+		package: mypkg1
+		essential:
+			- mypkg1_myslice1
+		slices:
+			myslice1:
+				contents:
+					/dir/file:
+			myslice2:
+				essential:
+					- mypkg2_myslice
+	`,
+	"slices/mypkg2.yaml": `
+		package: mypkg2
+		slices:
+			myslice:
+				contents:
+					/dir/another-file:
+	`,
+	"slices/mypkg3.yaml": `
+		package: mypkg3
+		essential:
+			- mypkg1_myslice1
+		slices:
+			myslice:
+				essential:
+					- mypkg2_myslice
+				contents:
+					/dir/other-file:
+					/dir/glob*:
+					/dir/sub-dir/:       {make: true, mode: 0644}
+					/dir/copy:           {copy: /dir/file}
+					/dir/symlink:        {symlink: /dir/file}
+					/dir/mutable:        {text: TODO, mutable: true, arch: riscv64}
+					/dir/arch-specific*: {arch: [amd64,arm64,i386]}
+					/dir/until:          {until: mutate}
+					/dir/unfolded:
+						copy: /dir/file
+						mode: 0644
+				mutate: |
+					# Test multi-line string.
+					content.write("/dir/mutable", foo)
+	`,
+}
+
+func (s *ChiselSuite) TestInfoCommand(c *C) {
+	for _, test := range infoTests {
+		c.Logf("Summary: %s", test.summary)
+
+		s.ResetStdStreams()
+
+		dir := c.MkDir()
+		for path, data := range test.input {
+			fpath := filepath.Join(dir, path)
+			err := os.MkdirAll(filepath.Dir(fpath), 0755)
+			c.Assert(err, IsNil)
+			err = os.WriteFile(fpath, testutil.Reindent(data), 0644)
+			c.Assert(err, IsNil)
+		}
+		test.query = append([]string{"info", "--release", dir}, test.query...)
+
+		_, err := chisel.Parser().ParseArgs(test.query)
+		if test.err != "" {
+			c.Assert(err, ErrorMatches, test.err)
+			continue
+		}
+		c.Assert(err, IsNil)
+		test.stdout = string(testutil.Reindent(test.stdout))
+		c.Assert(s.Stdout(), Equals, strings.TrimSpace(test.stdout)+"\n")
+	}
+}