Add podman search command

podman search queries a registry for a matching image and prints
the output.
I added a new flag called "registry" giving the user the option
to search a specific registry if they don't want to search all
their default registries.

Signed-off-by: umohnani8 <umohnani@redhat.com>

Closes: #241
Approved by: rhatdan

6 files changed, 464 insertions, 1 deletions

diff --git a/cmd/podman/main.go b/cmd/podman/main.go
index bda8ff517..f18615760 100644
--- a/cmd/podman/main.go
+++ b/cmd/podman/main.go
@@ -64,6 +64,7 @@ func main() {
 		rmiCommand,
 		runCommand,
 		saveCommand,
+		searchCommand,
 		startCommand,
 		statsCommand,
 		stopCommand,
diff --git a/cmd/podman/search.go b/cmd/podman/search.go
new file mode 100644
index 000000000..01eaa6729
--- /dev/null
+++ b/cmd/podman/search.go
@@ -0,0 +1,290 @@
+package main
+
+import (
+	"context"
+	"reflect"
+	"strconv"
+	"strings"
+
+	"github.com/containers/image/docker"
+	"github.com/pkg/errors"
+	"github.com/projectatomic/libpod/cmd/podman/formats"
+	"github.com/projectatomic/libpod/libpod"
+	"github.com/projectatomic/libpod/libpod/common"
+	"github.com/sirupsen/logrus"
+	"github.com/urfave/cli"
+)
+
+const (
+	descriptionTruncLength = 44
+	maxQueries             = 25
+)
+
+var (
+	searchFlags = []cli.Flag{
+		cli.StringSliceFlag{
+			Name:  "filter, f",
+			Usage: "filter output based on conditions provided (default [])",
+		},
+		cli.StringFlag{
+			Name:  "format",
+			Usage: "change the output format to a Go template",
+		},
+		cli.IntFlag{
+			Name:  "limit",
+			Usage: "limit the number of results",
+		},
+		cli.BoolFlag{
+			Name:  "no-trunc",
+			Usage: "do not truncate the output",
+		},
+		cli.StringSliceFlag{
+			Name:  "registry",
+			Usage: "specific registry to search",
+		},
+	}
+	searchDescription = `
+	Search registries for a given image. Can search all the default registries or a specific registry.
+	Can limit the number of results, and filter the output based on certain conditions.`
+	searchCommand = cli.Command{
+		Name:        "search",
+		Usage:       "search registry for image",
+		Description: searchDescription,
+		Flags:       searchFlags,
+		Action:      searchCmd,
+		ArgsUsage:   "TERM",
+	}
+)
+
+type searchParams struct {
+	Index       string
+	Name        string
+	Description string
+	Stars       int
+	Official    string
+	Automated   string
+}
+
+type searchOpts struct {
+	filter  []string
+	limit   int
+	noTrunc bool
+	format  string
+}
+
+type searchFilterParams struct {
+	stars       int
+	isAutomated *bool
+	isOfficial  *bool
+}
+
+func searchCmd(c *cli.Context) error {
+	args := c.Args()
+	if len(args) > 1 {
+		return errors.Errorf("too many arguments. Requires exactly 1")
+	}
+	if len(args) == 0 {
+		return errors.Errorf("no argument given, requires exactly 1 argument")
+	}
+	term := args[0]
+
+	if err := validateFlags(c, searchFlags); err != nil {
+		return err
+	}
+
+	runtime, err := getRuntime(c)
+	if err != nil {
+		return errors.Wrapf(err, "could not get runtime")
+	}
+	defer runtime.Shutdown(false)
+
+	format := genSearchFormat(c.String("format"))
+	opts := searchOpts{
+		format:  format,
+		noTrunc: c.Bool("no-trunc"),
+		limit:   c.Int("limit"),
+		filter:  c.StringSlice("filter"),
+	}
+
+	var registries []string
+	if len(c.StringSlice("registry")) > 0 {
+		registries = c.StringSlice("registry")
+	} else {
+		registries, err = libpod.GetRegistries()
+		if err != nil {
+			return errors.Wrapf(err, "error getting registries to search")
+		}
+	}
+
+	filter, err := parseSearchFilter(&opts)
+	if err != nil {
+		return err
+	}
+
+	return generateSearchOutput(term, registries, opts, *filter)
+}
+
+func genSearchFormat(format string) string {
+	if format != "" {
+		// "\t" from the command line is not being recognized as a tab
+		// replacing the string "\t" to a tab character if the user passes in "\t"
+		return strings.Replace(format, `\t`, "\t", -1)
+	}
+	return "table {{.Index}}\t{{.Name}}\t{{.Description}}\t{{.Stars}}\t{{.Official}}\t{{.Automated}}\t"
+}
+
+func searchToGeneric(params []searchParams) (genericParams []interface{}) {
+	for _, v := range params {
+		genericParams = append(genericParams, interface{}(v))
+	}
+	return genericParams
+}
+
+func (s *searchParams) headerMap() map[string]string {
+	v := reflect.Indirect(reflect.ValueOf(s))
+	values := make(map[string]string, v.NumField())
+
+	for i := 0; i < v.NumField(); i++ {
+		key := v.Type().Field(i).Name
+		value := key
+		values[key] = strings.ToUpper(splitCamelCase(value))
+	}
+	return values
+}
+
+func getSearchOutput(term string, registries []string, opts searchOpts, filter searchFilterParams) ([]searchParams, error) {
+	sc := common.GetSystemContext("", "", false)
+	// Max number of queries by default is 25
+	limit := maxQueries
+	if opts.limit != 0 {
+		limit = opts.limit
+	}
+
+	var paramsArr []searchParams
+	for _, reg := range registries {
+		results, err := docker.SearchRegistry(context.TODO(), sc, reg, term, limit)
+		if err != nil {
+			logrus.Errorf("error searching registry %q: %v", reg, err)
+			continue
+		}
+		index := reg
+		arr := strings.Split(reg, ".")
+		if len(arr) > 2 {
+			index = strings.Join(arr[len(arr)-2:], ".")
+		}
+
+		// limit is the number of results to output
+		// if the total number of results is less than the limit, output all
+		// if the limit has been set by the user, output those number of queries
+		limit := maxQueries
+		if len(results) < limit {
+			limit = len(results)
+		}
+		if opts.limit != 0 && opts.limit < len(results) {
+			limit = opts.limit
+		}
+
+		for i := 0; i < limit; i++ {
+			if len(opts.filter) > 0 {
+				// Check whether query matches filters
+				if !(matchesAutomatedFilter(filter, results[i]) && matchesOfficialFilter(filter, results[i]) && matchesStarFilter(filter, results[i])) {
+					continue
+				}
+			}
+			official := ""
+			if results[i].IsOfficial {
+				official = "[OK]"
+			}
+			automated := ""
+			if results[i].IsAutomated {
+				automated = "[OK]"
+			}
+			description := strings.Replace(results[i].Description, "\n", " ", -1)
+			if len(description) > 44 && !opts.noTrunc {
+				description = description[:descriptionTruncLength] + "..."
+			}
+			name := index + "/" + results[i].Name
+			if index == "docker.io" && !strings.Contains(results[i].Name, "/") {
+				name = index + "/library/" + results[i].Name
+			}
+			params := searchParams{
+				Index:       index,
+				Name:        name,
+				Description: description,
+				Official:    official,
+				Automated:   automated,
+				Stars:       results[i].StarCount,
+			}
+			paramsArr = append(paramsArr, params)
+		}
+	}
+	return paramsArr, nil
+}
+
+func generateSearchOutput(term string, registries []string, opts searchOpts, filter searchFilterParams) error {
+	searchOutput, err := getSearchOutput(term, registries, opts, filter)
+	if err != nil {
+		return err
+	}
+	if len(searchOutput) == 0 {
+		return nil
+	}
+	out := formats.StdoutTemplateArray{Output: searchToGeneric(searchOutput), Template: opts.format, Fields: searchOutput[0].headerMap()}
+	return formats.Writer(out).Out()
+}
+
+func parseSearchFilter(opts *searchOpts) (*searchFilterParams, error) {
+	filterParams := &searchFilterParams{}
+	ptrTrue := true
+	ptrFalse := false
+	for _, filter := range opts.filter {
+		arr := strings.Split(filter, "=")
+		switch arr[0] {
+		case "stars":
+			if len(arr) < 2 {
+				return nil, errors.Errorf("invalid `stars` filter %q, should be stars=<value>", filter)
+			}
+			stars, err := strconv.Atoi(arr[1])
+			if err != nil {
+				return nil, errors.Wrapf(err, "incorrect value type for stars filter")
+			}
+			filterParams.stars = stars
+			break
+		case "is-automated":
+			if len(arr) == 2 && arr[1] == "false" {
+				filterParams.isAutomated = &ptrFalse
+			} else {
+				filterParams.isAutomated = &ptrTrue
+			}
+			break
+		case "is-official":
+			if len(arr) == 2 && arr[1] == "false" {
+				filterParams.isOfficial = &ptrFalse
+			} else {
+				filterParams.isOfficial = &ptrTrue
+			}
+			break
+		default:
+			return nil, errors.Errorf("invalid filter type %q", filter)
+		}
+	}
+	return filterParams, nil
+}
+
+func matchesStarFilter(filter searchFilterParams, result docker.SearchResult) bool {
+	return result.StarCount >= filter.stars
+}
+
+func matchesAutomatedFilter(filter searchFilterParams, result docker.SearchResult) bool {
+	if filter.isAutomated != nil {
+		return result.IsAutomated == *filter.isAutomated
+	}
+	return true
+}
+
+func matchesOfficialFilter(filter searchFilterParams, result docker.SearchResult) bool {
+	if filter.isOfficial != nil {
+		return result.IsOfficial == *filter.isOfficial
+	}
+	return true
+}
diff --git a/completions/bash/podman b/completions/bash/podman
index 0087c56b9..b1033df1c 100644
--- a/completions/bash/podman
+++ b/completions/bash/podman
@@ -954,6 +954,19 @@ _podman_pull() {
     _complete_ "$options_with_args" "$boolean_options"
 }
 
+_podman_search() {
+	local options_with_args="
+	--filter -f
+	--format
+	--limit
+	--registry
+	"
+	local boolean_options="
+	--no-trunc
+	"
+	_complete_ "$options_with_args" "$boolean_options"
+}
+
 _podman_unmount() {
     _podman_umount $@
 }
@@ -1589,6 +1602,7 @@ _podman_podman() {
     rmi
     run
     save
+    search
     start
     stats
     stop
diff --git a/docs/podman-search.1.md b/docs/podman-search.1.md
new file mode 100644
index 000000000..668748d3f
--- /dev/null
+++ b/docs/podman-search.1.md
@@ -0,0 +1,115 @@
+% podman(1) podman-search - Tool to search registries for an image
+% Urvashi Mohnani
+# podman-search "1" "January 2018" "podman"
+
+## NAME
+podman search - Search a registry for an image
+
+## SYNOPSIS
+**podman search**
+**TERM**
+[**--filter**|**-f**]
+[**--format**]
+[**--limit**]
+[**--no-trunc**]
+[**--registry**]
+[**--help**|**-h**]
+
+## DESCRIPTION
+**podman search** searches a registry or a list of registries for a matching image.
+The user can specify which registry to search by setting the **--registry** flag, default
+is the default registries set in the config file - **/etc/containers/registries.conf**.
+The number of results can be limited using the **--limit** flag. If more than one registry
+is being searched, the limit will be applied to each registry. The output can be filtered
+using the **--filter** flag.
+
+**podman [GLOBAL OPTIONS]**
+
+**podman search [GLOBAL OPTIONS]**
+
+**podman search [OPTIONS] TERM**
+
+## OPTIONS
+
+**--filter, -f**
+Filter output based on conditions provided (default [])
+
+Supported filters are:
+- stars (int - number of stars the image has)
+- is-automated (boolean - true | false) - is the image automated or not
+- is-official (boolean - true | false) - is the image official or not
+
+**--format**
+Change the output format to a Go template
+
+Valid placeholders for the Go template are listed below:
+
+| **Placeholder** | **Description**              |
+| --------------- | ---------------------------- |
+| .Index          | Registry                     |
+| .Name           | Image name                   |
+| .Descriptions   | Image description            |
+| .Stars          | Star count of image          |
+| .Official       | "[OK]" if image is official  |
+| .Automated      | "[OK]" if image is automated |
+
+**--limit**
+Limit the number of results
+Note: The results from each registry will be limited to this value.
+Example if limit is 10 and two registries are being searched, the total
+number of results will be 20, 10 from each (if there are at least 10 matches in each).
+The order of the search results is the order in which the API endpoint returns the results.
+
+**--no-trunc**
+Do not truncate the output
+
+**--registry**
+Specific registry to search (only the given registry will be searched, not the default registries)
+
+## EXAMPLES
+
+```
+# podman search --limit 3 rhel
+INDEX        NAME                                 DESCRIPTION                                       STARS   OFFICIAL   AUTOMATED
+docker.io    docker.io/richxsl/rhel7              RHEL 7 image with minimal installation            9
+docker.io    docker.io/bluedata/rhel7             RHEL-7.x base container images                    1
+docker.io    docker.io/gidikern/rhel-oracle-jre   RHEL7 with jre8u60                                5                  [OK]
+redhat.com   redhat.com/rhel                      This platform image provides a minimal runti...   0
+redhat.com   redhat.com/rhel6                     This platform image provides a minimal runti...   0
+redhat.com   redhat.com/rhel6.5                   This platform image provides a minimal runti...   0
+```
+
+```
+# podman search alpine
+INDEX       NAME                                             DESCRIPTION                                       STARS   OFFICIAL   AUTOMATED
+docker.io   docker.io/library/alpine                         A minimal Docker image based on Alpine Linux...   3009    [OK]
+docker.io   docker.io/mhart/alpine-node                      Minimal Node.js built on Alpine Linux             332
+docker.io   docker.io/anapsix/alpine-java                    Oracle Java 8 (and 7) with GLIBC 2.23 over A...   272                [OK]
+docker.io   docker.io/tenstartups/alpine                     Alpine linux base docker image with useful p...   5                  [OK]
+```
+
+```
+# podman search --registry registry.fedoraproject.org fedora
+INDEX               NAME                               DESCRIPTION   STARS   OFFICIAL   AUTOMATED
+fedoraproject.org   fedoraproject.org/fedora                         0
+fedoraproject.org   fedoraproject.org/fedora-minimal                 0
+```
+
+```
+# podman search --filter=is-official alpine
+INDEX       NAME                       DESCRIPTION                                       STARS   OFFICIAL   AUTOMATED
+docker.io   docker.io/library/alpine   A minimal Docker image based on Alpine Linux...   3009    [OK]
+```
+
+```
+# podman search --registry registry.fedoraproject.org --format "table {{.Index}} {{.Name}}" fedora
+INDEX               NAME
+fedoraproject.org   fedoraproject.org/fedora
+fedoraproject.org   fedoraproject.org/fedora-minimal
+```
+
+## SEE ALSO
+podman(1), crio(8), crio.conf(5)
+
+## HISTORY
+January 2018, Originally compiled by Urvashi Mohnani <umohnani@redhat.com>
diff --git a/test/podman_search.bats b/test/podman_search.bats
new file mode 100644
index 000000000..07621d722
--- /dev/null
+++ b/test/podman_search.bats
@@ -0,0 +1,43 @@
+#!/usr/bin/env bats
+
+load helpers
+
+function teardown() {
+    cleanup_test
+}
+
+@test "podman search" {
+    run ${PODMAN_BINARY} ${PODMAN_OPTIONS} search alpine
+    echo "$output"
+    [ "$status" -eq 0 ]
+}
+
+@test "podman search registry flag" {
+    run ${PODMAN_BINARY} ${PODMAN_OPTIONS} search --registry registry.fedoraproject.org fedora
+    echo "$output"
+    [ "$status" -eq 0 ]
+}
+
+@test "podman search filter flag" {
+    run ${PODMAN_BINARY} ${PODMAN_OPTIONS} search --filter=is-official alpine
+    echo "$output"
+    [ "$status" -eq 0 ]
+}
+
+@test "podman search format flag" {
+    run ${PODMAN_BINARY} ${PODMAN_OPTIONS} search --format "table {{.Index}} {{.Name}}" alpine
+    echo "$output"
+    [ "$status" -eq 0 ]
+}
+
+@test "podman search no-trunc flag" {
+    run ${PODMAN_BINARY} ${PODMAN_OPTIONS} search --no-trunc alpine
+    echo "$output"
+    [ "$status" -eq 0 ]
+}
+
+@test "podman search limit flag" {
+    run ${PODMAN_BINARY} ${PODMAN_OPTIONS} search --limit 3 alpine
+    echo "$output"
+    [ "$status" -eq 0 ]
+}
\ No newline at end of file
diff --git a/transfer.md b/transfer.md
index 30e277a86..53d6c472c 100644
--- a/transfer.md
+++ b/transfer.md
@@ -60,6 +60,7 @@ There are other equivalents for these tools
 | `docker rmi`    | [`podman rmi`](./docs/podman-rmi.1.md)        |
 | `docker run`    | [`podman run`](./docs/podman-run.1.md)        |
 | `docker save`   | [`podman save`](./docs/podman-save.1.md)      |
+| `docker search` | [`podman search`](./docs/podman-search.1.md)  |
 | `docker start`  | [`podman start`](./docs/podman-start.1.md)    |
 | `docker stop`   | [`podman stop`](./docs/podman-stop.1.md)      |
 | `docker tag`    | [`podman tag`](./docs/podman-tag.1.md)        |
@@ -85,7 +86,6 @@ Those Docker commands currently do not have equivalents in `podman`:
 | `docker port`     ||
 | `docker rename`   | podman does not support rename, you need to use `podman rm` and  `podman create` to rename a container.|
 | `docker restart`  | podman does not support restart.  We recommend that you put your podman containers into a systemd unit file and use it for restarting applications.|
-| `docker search`   ||
 | `docker secret`   ||
 | `docker service`  ||
 | `docker stack`    ||