issue#785 inspect command - introduce a way to skip querying available tags for an image

cmd/skopeo/inspect.go

@@ -24,12 +24,13 @@ import (
 )
 
 type inspectOptions struct {
-	global    *globalOptions
-	image     *imageOptions
-	retryOpts *retry.RetryOptions
-	format    string
-	raw       bool // Output the raw manifest instead of parsing information about the image
-	config    bool // Output the raw config blob instead of parsing information about the image
+	global        *globalOptions
+	image         *imageOptions
+	retryOpts     *retry.RetryOptions
+	format        string
+	raw           bool // Output the raw manifest instead of parsing information about the image
+	config        bool // Output the raw config blob instead of parsing information about the image
+	doNotListTags bool // Do not list all tags available in the same repository
 }
 
 func inspectCmd(global *globalOptions) *cobra.Command {
@@ -60,6 +61,7 @@ See skopeo(1) section "IMAGE NAMES" for the expected format
 	flags.BoolVar(&opts.raw, "raw", false, "output raw manifest or configuration")
 	flags.BoolVar(&opts.config, "config", false, "output configuration")
 	flags.StringVarP(&opts.format, "format", "f", "", "Format the output to a Go template")
+	flags.BoolVarP(&opts.doNotListTags, "no-tags", "n", false, "Do not list the available tags from the repository in the output")
 	flags.AddFlagSet(&sharedFlags)
 	flags.AddFlagSet(&imageFlags)
 	flags.AddFlagSet(&retryFlags)
@@ -192,7 +194,7 @@ func (opts *inspectOptions) run(args []string, stdout io.Writer) (retErr error)
 	if dockerRef := img.Reference().DockerReference(); dockerRef != nil {
 		outputData.Name = dockerRef.Name()
 	}
-	if img.Reference().Transport() == docker.Transport {
+	if !opts.doNotListTags && img.Reference().Transport() == docker.Transport {
 		sys, err := opts.image.newSystemContext()
 		if err != nil {
 			return err

completions/bash/skopeo

@@ -132,6 +132,7 @@ _skopeo_inspect() {
      --raw
      --tls-verify
      --no-creds
+     --no-tags -n
     "
 
     local transports

docs/skopeo-inspect.1.md

@@ -77,6 +77,10 @@ The username to access the registry.
 
 The password to access the registry.
 
+**--no-tags**, **-n**=_bool_
+
+Do not list the available tags from the repository in the output. When `true`, the `RepoTags` array will be empty.  Defaults to `false`, which includes all available tags.
+
 ## EXAMPLES
 
 To review information for the image fedora from the docker.io registry:
@@ -106,6 +110,42 @@ $ skopeo inspect docker://docker.io/fedora
 }
 ```
 
+To inspect python from the docker.io registry and not show the available tags:
+```sh
+$ skopeo inspect --no-tags docker://docker.io/library/python
+{
+    "Name": "docker.io/library/python",
+    "Digest": "sha256:5ca194a80ddff913ea49c8154f38da66a41d2b73028c5cf7e46bc3c1d6fda572",
+    "RepoTags": [],
+    "Created": "2021-10-05T23:40:54.936108045Z",
+    "DockerVersion": "20.10.7",
+    "Labels": null,
+    "Architecture": "amd64",
+    "Os": "linux",
+    "Layers": [
+        "sha256:df5590a8898bedd76f02205dc8caa5cc9863267dbcd8aac038bcd212688c1cc7",
+        "sha256:705bb4cb554eb7751fd21a994f6f32aee582fbe5ea43037db6c43d321763992b",
+        "sha256:519df5fceacdeaadeec563397b1d9f4d7c29c9f6eff879739cab6f0c144f49e1",
+        "sha256:ccc287cbeddc96a0772397ca00ec85482a7b7f9a9fac643bfddd87b932f743db",
+        "sha256:e3f8e6af58ed3a502f0c3c15dce636d9d362a742eb5b67770d0cfcb72f3a9884",
+        "sha256:aebed27b2d86a5a3a2cbe186247911047a7e432b9d17daad8f226597c0ea4276",
+        "sha256:54c32182bdcc3041bf64077428467109a70115888d03f7757dcf614ff6d95ebe",
+        "sha256:cc8b7caedab13af07adf4836e13af2d4e9e54d794129b0fd4c83ece6b1112e86",
+        "sha256:462c3718af1d5cdc050cfba102d06c26f78fe3b738ce2ca2eb248034b1738945"
+    ],
+    "Env": [
+        "PATH=/usr/local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
+        "LANG=C.UTF-8",
+        "GPG_KEY=A035C8C19219BA821ECEA86B64E628F8D684696D",
+        "PYTHON_VERSION=3.10.0",
+        "PYTHON_PIP_VERSION=21.2.4",
+        "PYTHON_SETUPTOOLS_VERSION=57.5.0",
+        "PYTHON_GET_PIP_URL=https://github.com/pypa/get-pip/raw/d781367b97acf0ece7e9e304bf281e99b618bf10/public/get-pip.py",
+        "PYTHON_GET_PIP_SHA256=01249aa3e58ffb3e1686b7141b4e9aac4d398ef4ac3012ed9dff8dd9f685ffe0"
+    ]
+}
+```
+
 ```
 $ /bin/skopeo inspect --config docker://registry.fedoraproject.org/fedora --format "{{ .Architecture }}"
 amd64

systemtest/010-inspect.bats

@@ -108,4 +108,15 @@ END_EXPECT
                   "os - variant - architecture of $img"
 }
 
+@test "inspect: don't list tags" {
+    remote_image=docker://quay.io/fedora/fedora
+    # use --no-tags to not list any tags
+    run_skopeo inspect --no-tags $remote_image
+    inspect_output=$output
+    # extract the content of "RepoTags" property from the JSON output
+    repo_tags=$(jq '.RepoTags[]' <<<"$inspect_output")
+    # verify that the RepoTags was empty
+    expect_output --from="$repo_tags" "" "inspect --no-tags was expected to return empty RepoTags[]"
+}
+
 # vim: filetype=sh