Add RESTful API endpoints for managing Groups members

Read-write access for group owners, read-only access for all other
members of a group, and no access for non-members.

Expands the server's AWS IAM policy to allow access to a few required
Cognito user pool API actions.  The policy files are .tftpl.json instead
of .json.tftpl to indicate that although templated they still remain
valid JSON (at least for the time being).

aws/iam/main.tf

@@ -42,7 +42,11 @@ resource "aws_iam_policy" "server" {
   name        = local.server_policy_name
   description = local.server_policy_description
 
-  policy = file("${path.module}/policy/${local.server_policy_file_name}.json")
+  policy = templatefile(
+    "${path.module}/policy/${local.server_policy_file_name}.tftpl.json", {
+      COGNITO_USER_POOL_ID = var.COGNITO_USER_POOL_ID
+    }
+  )
 }
 
 moved {

aws/iam/policy/NextstrainDotOrgServerInstance.json → aws/iam/policy/NextstrainDotOrgServerInstance.tftpl.json

@@ -32,6 +32,18 @@
       "Resource": [
         "arn:aws:s3:::nextstrain-groups/*"
       ]
+    },
+    {
+      "Sid": "CognitoUserPoolActions",
+      "Effect": "Allow",
+      "Action": [
+        "cognito-idp:AdminAddUserToGroup",
+        "cognito-idp:AdminRemoveUserFromGroup",
+        "cognito-idp:ListUsersInGroup"
+      ],
+      "Resource": [
+        "arn:aws:cognito-idp:us-east-1:827581582529:userpool/${COGNITO_USER_POOL_ID}"
+      ]
     }
   ]
 }

aws/iam/policy/NextstrainDotOrgServerInstanceDev.json → aws/iam/policy/NextstrainDotOrgServerInstanceDev.tftpl.json

@@ -43,6 +43,18 @@
         "arn:aws:s3:::nextstrain-groups/test/*",
         "arn:aws:s3:::nextstrain-groups/test-private/*"
       ]
+    },
+    {
+      "Sid": "CognitoUserPoolActions",
+      "Effect": "Allow",
+      "Action": [
+        "cognito-idp:AdminAddUserToGroup",
+        "cognito-idp:AdminRemoveUserFromGroup",
+        "cognito-idp:ListUsersInGroup"
+      ],
+      "Resource": [
+        "arn:aws:cognito-idp:us-east-1:827581582529:userpool/${COGNITO_USER_POOL_ID}"
+      ]
     }
   ]
 }

aws/iam/variable-COGNITO_USER_POOL_ID.tf

@@ -0,0 +1 @@
+../variable-COGNITO_USER_POOL_ID.tf

aws/variable-COGNITO_USER_POOL_ID.tf

@@ -0,0 +1,4 @@
+variable "COGNITO_USER_POOL_ID" {
+  type        = string
+  description = "Id of the Cognito user pool for this environment"
+}

docs/api-restful.rst

@@ -293,6 +293,16 @@ The following group settings endpoints exist::
 
     {GET, HEAD, PUT, DELETE, OPTIONS} /groups/{name}/settings/overview
 
+The following group membership endpoints exist::
+
+    {GET, HEAD, OPTIONS} /groups/{name}/settings/members
+
+    {GET, HEAD, OPTIONS} /groups/{name}/settings/roles
+
+    {GET, HEAD, OPTIONS} /groups/{name}/settings/roles/{role}/members
+
+    {GET, HEAD, PUT, DELETE, OPTIONS} /groups/{name}/settings/roles/{role}/members/{username}
+
 .. _motivation:
 
 Motivation

env/production/terraform.tf

@@ -52,6 +52,8 @@ module "iam" {
   }
 
   env = "production"
+
+  COGNITO_USER_POOL_ID = module.cognito.COGNITO_USER_POOL_ID
 }
 
 moved {

env/testing/terraform.tf

@@ -46,4 +46,6 @@ module "iam" {
   }
 
   env = "testing"
+
+  COGNITO_USER_POOL_ID = module.cognito.COGNITO_USER_POOL_ID
 }

src/app.js

@@ -347,6 +347,21 @@ app.routeAsync("/groups/:groupName/settings/overview")
   .optionsAsync(optionsGroup)
 ;
 
+app.routeAsync("/groups/:groupName/settings/members")
+  .getAsync(endpoints.groups.listMembers);
+
+app.routeAsync("/groups/:groupName/settings/roles")
+  .getAsync(endpoints.groups.listRoles);
+
+app.routeAsync("/groups/:groupName/settings/roles/:roleName/members")
+  .getAsync(endpoints.groups.listRoleMembers);
+
+app.routeAsync("/groups/:groupName/settings/roles/:roleName/members/:username")
+  .getAsync(endpoints.groups.getRoleMember)
+  .putAsync(endpoints.groups.putRoleMember)
+  .deleteAsync(endpoints.groups.deleteRoleMember)
+;
+
 app.route("/groups/:groupName/settings/*")
   .all(() => { throw new NotFound(); });
 

src/cognito.js

@@ -0,0 +1,85 @@
+/**
+ * Cognito user pool (IdP) management.
+ *
+ * @module cognito
+ */
+/* eslint-disable no-await-in-loop */
+import {
+  CognitoIdentityProviderClient,
+  AdminAddUserToGroupCommand,
+  AdminRemoveUserFromGroupCommand,
+  paginateListUsersInGroup,
+  UserNotFoundException,
+} from "@aws-sdk/client-cognito-identity-provider";
+
+import { COGNITO_USER_POOL_ID } from "./config.js";
+import { NotFound } from "./httpErrors.js";
+
+
+const REGION = COGNITO_USER_POOL_ID.split("_")[0];
+
+const cognito = new CognitoIdentityProviderClient({ region: REGION });
+
+
+/**
+ * Retrieve AWS Cognito users in a Cognito group.
+ *
+ * @param {string} name - Name of the AWS Cognito group
+ * @yields {object} user, see <https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/clients/client-cognito-identity-provider/interfaces/usertype.html>
+ */
+export async function* listUsersInGroup(name) {
+  const paginator = paginateListUsersInGroup({client: cognito}, {
+    UserPoolId: COGNITO_USER_POOL_ID,
+    GroupName: name,
+  });
+
+  for await (const page of paginator) {
+    yield* page.Users;
+  }
+}
+
+
+/**
+ * Add an AWS Cognito user to a Cognito group.
+ *
+ * @param {string} username
+ * @param {string} group - Name of the AWS Cognito group
+ * @throws {NotFound} if username is unknown
+ */
+export async function addUserToGroup(username, group) {
+  try {
+    await cognito.send(new AdminAddUserToGroupCommand({
+      UserPoolId: COGNITO_USER_POOL_ID,
+      Username: username,
+      GroupName: group,
+    }));
+  } catch (err) {
+    if (err instanceof UserNotFoundException) {
+      throw new NotFound(`unknown user: ${username}`);
+    }
+    throw err;
+  }
+}
+
+
+/**
+ * Remove an AWS Cognito user from a Cognito group.
+ *
+ * @param {string} username
+ * @param {string} group - Name of the AWS Cognito group
+ * @throws {NotFound} if username is unknown
+ */
+export async function removeUserFromGroup(username, group) {
+  try {
+    await cognito.send(new AdminRemoveUserFromGroupCommand({
+      UserPoolId: COGNITO_USER_POOL_ID,
+      Username: username,
+      GroupName: group,
+    }));
+  } catch (err) {
+    if (err instanceof UserNotFoundException) {
+      throw new NotFound(`unknown user: ${username}`);
+    }
+    throw err;
+  }
+}

src/endpoints/groups.js

@@ -1,7 +1,9 @@
 import * as authz from "../authz/index.js";
+import { NotFound } from "../httpErrors.js";
 import { Group } from "../groups.js";
 import {contentTypesProvided, contentTypesConsumed} from "../negotiate.js";
 import {deleteByUrls, proxyFromUpstream, proxyToUpstream} from "../upstream.js";
+import { slurp } from "../utils/iterators.js";
 import * as options from "./options.js";
 
 
@@ -152,13 +154,94 @@ async function receiveGroupLogo(req, res) {
 }
 
 
+/* Members and roles
+ */
+const listMembers = async (req, res) => {
+  const group = req.context.group;
+
+  authz.assertAuthorized(req.user, authz.actions.Read, group);
+
+  return res.json(await group.members());
+};
+
+
+const listRoles = (req, res) => {
+  const group = req.context.group;
+
+  authz.assertAuthorized(req.user, authz.actions.Read, group);
+
+  const roles = [...group.membershipRoles.keys()];
+  return res.json(roles.map(name => ({name})));
+};
+
+
+const listRoleMembers = async (req, res) => {
+  const group = req.context.group;
+  const {roleName} = req.params;
+
+  authz.assertAuthorized(req.user, authz.actions.Read, group);
+
+  return res.json(await slurp(group.membersWithRole(roleName)));
+};
+
+
+const getRoleMember = async (req, res) => {
+  const group = req.context.group;
+  const {roleName, username} = req.params;
+
+  authz.assertAuthorized(req.user, authz.actions.Read, group);
+
+  for await (const member of group.membersWithRole(roleName)) {
+    if (member.username === username) {
+      return res.status(204).end();
+    }
+  }
+
+  throw new NotFound(`user ${username} does not have role ${roleName} in group ${group.name}`);
+};
+
+
+const putRoleMember = async (req, res) => {
+  const group = req.context.group;
+  const {roleName, username} = req.params;
+
+  authz.assertAuthorized(req.user, authz.actions.Write, group);
+
+  await group.grantRole(roleName, username);
+
+  return res.status(204).end();
+};
+
+
+const deleteRoleMember = async (req, res) => {
+  const group = req.context.group;
+  const {roleName, username} = req.params;
+
+  authz.assertAuthorized(req.user, authz.actions.Write, group);
+
+  await group.revokeRole(roleName, username);
+
+  return res.status(204).end();
+};
+
+
 export {
   setGroup,
   optionsGroup,
+
   getGroupLogo,
   putGroupLogo,
   deleteGroupLogo,
+
   getGroupOverview,
   putGroupOverview,
   deleteGroupOverview,
+
+  listMembers,
+  listRoles,
+  listRoleMembers,
+
+  getRoleMember,
+  putRoleMember,
+  deleteRoleMember,
 };