feat: jh admin landing-page show , disable and update cmd

CLAUDE.md

@@ -17,6 +17,7 @@ The application follows a command-line interface pattern using the Cobra library
 - **projects.go**: Project management using GraphQL API with user filtering
 - **user.go**: User information retrieval using GraphQL API and REST API for listing users
 - **tokens.go**: Token management operations (list) with REST API integration
+- **landing.go**: Landing page management (show, update, disable) with REST API integration
 - **git.go**: Git integration (clone, push, fetch, pull) with JuliaHub authentication
 - **julia.go**: Julia installation and management
 - **run.go**: Julia execution with JuliaHub configuration
@@ -31,7 +32,7 @@ The application follows a command-line interface pattern using the Cobra library
    - Stores tokens securely in `~/.juliahub` with 0600 permissions
 
 2. **API Integration**:
-   - **REST API**: Used for dataset operations (`/api/v1/datasets`, `/datasets/{uuid}/url/{version}`), registry operations (`/api/v1/ui/registries/descriptions`), token management (`/app/token/activelist`) and user management (`/app/config/features/manage`)
+   - **REST API**: Used for dataset operations (`/api/v1/datasets`, `/datasets/{uuid}/url/{version}`), registry operations (`/api/v1/ui/registries/descriptions`), token management (`/app/token/activelist`), user management (`/app/config/features/manage`), and landing page management (`/app/homepage` GET, `/app/config/homepage` POST/DELETE)
    - **GraphQL API**: Used for projects and user info (`/v1/graphql`)
    - **Headers**: All GraphQL requests require `X-Hasura-Role: jhuser` header
    - **Authentication**: Uses ID tokens (`token.IDToken`) for API calls
@@ -42,9 +43,10 @@ The application follows a command-line interface pattern using the Cobra library
    - `jh registry`: Registry operations (list with REST API, supports verbose mode)
    - `jh project`: Project management (list with GraphQL, supports user filtering)
    - `jh user`: User information (info with GraphQL)
-   - `jh admin`: Administrative commands (user management, token management)
+   - `jh admin`: Administrative commands (user management, token management, landing page)
    - `jh admin user`: User management (list all users with REST API, supports verbose mode)
    - `jh admin token`: Token management (list all tokens with REST API, supports verbose mode)
+   - `jh admin landing-page`: Landing page management (show/update/disable custom markdown landing page with REST API)
    - `jh clone`: Git clone with JuliaHub authentication and project name resolution
    - `jh push/fetch/pull`: Git operations with JuliaHub authentication
    - `jh git-credential`: Git credential helper for seamless authentication
@@ -113,6 +115,15 @@ go run . admin token list --verbose
 TZ=America/New_York go run . admin token list --verbose  # With specific timezone
 ```
 
+### Test landing page operations
+```bash
+go run . admin landing-page show
+go run . admin landing-page update '# Welcome to JuliaHub'
+go run . admin landing-page update --file landing.md
+cat landing.md | go run . admin landing-page update
+go run . admin landing-page disable
+```
+
 ### Test Git operations
 ```bash
 go run . clone john/my-project  # Clone from another user
@@ -308,6 +319,9 @@ jh run setup
 - Token list output is concise by default (Subject, Created By, and Expired status only); use `--verbose` flag for detailed information (signature, creation date, expiration date with estimate indicator)
 - Token dates are formatted in human-readable format and converted to local timezone (respects system timezone or TZ environment variable)
 - Token expiration estimate indicator only shown when `expires_at_is_estimate` is true in API response
+- Landing page commands (`jh admin landing-page`) use REST API: GET `/app/homepage` (show), POST `/app/config/homepage` (update), DELETE `/app/config/homepage` (disable); require appropriate permissions
+- Landing page `update` command accepts content inline as an argument, from a file via `--file`, or piped via stdin (priority: `--file` > arg > stdin)
+- Landing page response uses custom JSON unmarshaling (`homepageResponse`) to handle `message` being either an object or a string
 
 ## Implementation Details
 

README.md

@@ -196,6 +196,13 @@ go build -o jh .
   - Default: Shows only Subject, Created By, and Expired status
   - `jh admin token list --verbose` - Show detailed token information including signature, creation date, expiration date (with estimate indicator)
 
+#### Landing Page Management
+- `jh admin landing-page show` - Show the current custom landing page content (markdown and last-modified date)
+- `jh admin landing-page update <markdown-content>` - Set a custom markdown landing page
+  - `jh admin landing-page update --file landing.md` - Read content from a file
+  - `cat landing.md | jh admin landing-page update` - Read content from stdin
+- `jh admin landing-page disable` - Remove the custom landing page and revert to the default
+
 ### Update (`jh update`)
 
 - `jh update` - Check for updates and automatically install the latest version
@@ -282,6 +289,25 @@ jh admin token list -s yourinstall
 TZ=America/New_York jh admin token list --verbose
 ```
 
+### Landing Page Operations
+
+```bash
+# Show current custom landing page
+jh admin landing-page show
+
+# Set landing page from inline markdown
+jh admin landing-page update '# Welcome to JuliaHub'
+
+# Set landing page from a file
+jh admin landing-page update --file landing.md
+
+# Set landing page from stdin
+cat landing.md | jh admin landing-page update
+
+# Disable custom landing page (revert to default)
+jh admin landing-page disable
+```
+
 ### Git Workflow
 
 ```bash

landing.go

@@ -0,0 +1,217 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"time"
+)
+
+type homepageConfig struct {
+	Md        string `json:"md"`
+	UpdatedAt string `json:"updated_at"`
+}
+
+// homepageResponse handles `message` being either an object or a string.
+type homepageResponse struct {
+	Success bool `json:"success"`
+	Message *homepageConfig
+	RawMsg  json.RawMessage `json:"message"`
+}
+
+func (r *homepageResponse) UnmarshalJSON(data []byte) error {
+	type alias struct {
+		Success bool            `json:"success"`
+		Message json.RawMessage `json:"message"`
+	}
+	var a alias
+	if err := json.Unmarshal(data, &a); err != nil {
+		return err
+	}
+	r.Success = a.Success
+	r.RawMsg = a.Message
+	if len(a.Message) > 0 && a.Message[0] == '{' {
+		var cfg homepageConfig
+		if err := json.Unmarshal(a.Message, &cfg); err != nil {
+			return err
+		}
+		r.Message = &cfg
+	}
+	return nil
+}
+
+func showLandingPage(server string) error {
+	token, err := ensureValidToken()
+	if err != nil {
+		return fmt.Errorf("authentication required — run 'jh auth login' first")
+	}
+
+	url := fmt.Sprintf("https://%s/app/homepage", server)
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return fmt.Errorf("failed to create request: %w", err)
+	}
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token.IDToken))
+	req.Header.Set("Accept", "application/json")
+
+	client := &http.Client{Timeout: 30 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return fmt.Errorf("could not reach the server")
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode == http.StatusUnauthorized || resp.StatusCode == http.StatusForbidden {
+		return fmt.Errorf("you do not have permission to view the landing page configuration")
+	}
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("could not retrieve landing page (server returned %d)", resp.StatusCode)
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Errorf("could not read response from server")
+	}
+
+	var result homepageResponse
+	if err := json.Unmarshal(body, &result); err != nil {
+		return fmt.Errorf("unexpected response from server")
+	}
+
+	if !result.Success {
+		var msg string
+		_ = json.Unmarshal(result.RawMsg, &msg)
+		return fmt.Errorf("%s", msg)
+	}
+
+	if result.Message == nil {
+		fmt.Println("Currently using default landing screen content.")
+		return nil
+	}
+
+	fmt.Printf("Last updated: %s\n\n", formatTokenDate(result.Message.UpdatedAt))
+	fmt.Println(result.Message.Md)
+	return nil
+}
+
+func setLandingPage(server, content string) error {
+	token, err := ensureValidToken()
+	if err != nil {
+		return fmt.Errorf("authentication required — run 'jh auth login' first")
+	}
+
+	payload, err := json.Marshal(map[string]string{"content": content})
+	if err != nil {
+		return fmt.Errorf("could not prepare request")
+	}
+
+	url := fmt.Sprintf("https://%s/app/config/homepage", server)
+	req, err := http.NewRequest("POST", url, bytes.NewReader(payload))
+	if err != nil {
+		return fmt.Errorf("could not prepare request")
+	}
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token.IDToken))
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Accept", "application/json")
+
+	client := &http.Client{Timeout: 30 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return fmt.Errorf("could not reach the server")
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode == http.StatusUnauthorized || resp.StatusCode == http.StatusForbidden {
+		return fmt.Errorf("you do not have permission to update the landing page")
+	}
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("could not update landing page (server returned %d)", resp.StatusCode)
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Errorf("could not read response from server")
+	}
+
+	var result struct {
+		Success bool            `json:"success"`
+		Message json.RawMessage `json:"message"`
+	}
+	if err := json.Unmarshal(body, &result); err != nil || !result.Success {
+		var msg string
+		_ = json.Unmarshal(result.Message, &msg)
+		return fmt.Errorf("%s", msg)
+	}
+
+	fmt.Println("Successfully updated the landing page.")
+	return nil
+}
+
+func disableLandingPage(server string) error {
+	token, err := ensureValidToken()
+	if err != nil {
+		return fmt.Errorf("authentication required — run 'jh auth login' first")
+	}
+
+	url := fmt.Sprintf("https://%s/app/config/homepage", server)
+	req, err := http.NewRequest("DELETE", url, nil)
+	if err != nil {
+		return fmt.Errorf("could not prepare request")
+	}
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token.IDToken))
+	req.Header.Set("Accept", "application/json")
+
+	client := &http.Client{Timeout: 30 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return fmt.Errorf("could not reach the server")
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode == http.StatusUnauthorized || resp.StatusCode == http.StatusForbidden {
+		return fmt.Errorf("you do not have permission to disable the landing page")
+	}
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("could not disable landing page (server returned %d)", resp.StatusCode)
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Errorf("could not read response from server")
+	}
+
+	var result struct {
+		Success bool            `json:"success"`
+		Message json.RawMessage `json:"message"`
+	}
+	if err := json.Unmarshal(body, &result); err != nil || !result.Success {
+		var msg string
+		_ = json.Unmarshal(result.Message, &msg)
+		return fmt.Errorf("%s", msg)
+	}
+
+	fmt.Println("Successfully disabled the custom landing page.")
+	return nil
+}
+
+func readContentFromFileOrArgOrStdin(filePath, contentArg string) (string, error) {
+	if filePath != "" {
+		data, err := os.ReadFile(filePath)
+		if err != nil {
+			return "", fmt.Errorf("failed to read file %q: %w", filePath, err)
+		}
+		return string(data), nil
+	}
+	if contentArg != "" {
+		return contentArg, nil
+	}
+	// Fall back to stdin
+	data, err := io.ReadAll(os.Stdin)
+	if err != nil {
+		return "", fmt.Errorf("failed to read from stdin: %w", err)
+	}
+	return string(data), nil
+}