diff --git a/package.json b/package.json
index 716ae670..1a1cc7eb 100644
--- a/package.json
+++ b/package.json
@@ -8,6 +8,7 @@
     "@bazel/jasmine": "^0.35.0",
     "@bazel/typescript": "latest",
     "@types/jasmine": "^2.5.53",
+    "@types/mkdirp": "^0.5.2",
     "@types/node": "^12.6.9",
     "clang-format": "^1.2.2",
     "husky": "^1.3.1",
@@ -28,5 +29,10 @@
     "hooks": {
       "pre-commit": "yarn tslint --fix 'src/**/*.ts' -e '**/bower_components/**' -e '**/node_modules/**' && yarn git-clang-format"
     }
+  },
+  "dependencies": {
+    "js-yaml": "^3.13.1",
+    "mkdirp": "^0.5.1",
+    "request-lite": "^2.40.1"
   }
 }
diff --git a/src/shadowbox/infrastructure/BUILD b/src/shadowbox/infrastructure/BUILD
index 812caefa..8a4f1125 100644
--- a/src/shadowbox/infrastructure/BUILD
+++ b/src/shadowbox/infrastructure/BUILD
@@ -2,13 +2,46 @@ package(default_visibility=["//visibility:public"])
 load("@npm_bazel_typescript//:index.bzl", "ts_library")
 load("@npm_bazel_jasmine//:index.bzl", "jasmine_node_test")
 
+ts_library(
+    name = "clock",
+    srcs = ["clock.ts"],
+    deps = [
+        "@npm//@types/node",
+    ],
+)
+
+ts_library(
+    name = "filesystem_text_file",
+    srcs = ["filesystem_text_file.ts"],
+    deps = [
+        ":text_file",
+        "@npm//@types/node",
+    ],
+)
+
+ts_library(
+    name = "file_read",
+    srcs = ["file_read.ts"],
+    deps = [
+        "@npm//@types/node",
+    ],
+)
+
+ts_library(
+    name = "follow_redirects",
+    srcs = ["follow_redirects.ts"],
+    deps = [
+        "@npm//request-lite",
+        "@npm//@types/node",
+    ],
+)
+
 ts_library(
     name = "get_port",
     srcs = ["get_port.ts"],
     deps = [
         "@npm//@types/node",
     ],
-    tsconfig = "//:tsconfig.nodejs.json",
 )
 
 ts_library(
@@ -19,7 +52,6 @@ ts_library(
         "@npm//@types/jasmine",
         "@npm//@types/node",
     ],
-    tsconfig = "//:tsconfig.nodejs.json",
 )
 
 jasmine_node_test(
@@ -29,3 +61,63 @@ jasmine_node_test(
     ],
     size = "small",
 )
+
+ts_library(
+    name = "json_config",
+    srcs = ["json_config.ts"],
+    deps = [
+        ":file_read",
+        ":logging",
+        "@npm//@types/node",
+    ],
+)
+
+ts_library(
+    name = "logging",
+    srcs = ["logging.ts"],
+    deps = [
+        "@npm//@types/node",
+    ],
+)
+
+ts_library(
+    name = "prometheus_scraper",
+    srcs = ["prometheus_scraper.ts"],
+    deps = [
+        ":logging",
+        "@npm//@types/mkdirp",
+        "@npm//@types/node",
+        "@npm//mkdirp",
+        "@npm//js-yaml",
+    ],
+)
+
+ts_library(
+    name = "rollout",
+    srcs = ["rollout.ts"],
+    deps = [
+        "@npm//@types/node",
+    ],
+)
+
+ts_library(
+    name = "rollout_test_lib",
+    srcs = ["rollout.spec.ts"],
+    deps = [
+        ":rollout",
+        "@npm//@types/jasmine",
+    ],
+)
+
+jasmine_node_test(
+    name = "rollout_test",
+    deps = [
+        ":rollout_test_lib",
+    ],
+    size = "small",
+)
+
+ts_library(
+    name = "text_file",
+    srcs = ["text_file.ts"],
+)
\ No newline at end of file
diff --git a/src/shadowbox/infrastructure/filesystem_text_file.ts b/src/shadowbox/infrastructure/filesystem_text_file.ts
index 9a368cd4..5bea7016 100644
--- a/src/shadowbox/infrastructure/filesystem_text_file.ts
+++ b/src/shadowbox/infrastructure/filesystem_text_file.ts
@@ -13,7 +13,7 @@
 // limitations under the License.
 
 import * as fs from 'fs';
-import {TextFile} from '../model/text_file';
+import {TextFile} from './text_file';
 
 // Reads a text file if it exists, or null if the file is not found.
 // Throws any other error except file not found.
diff --git a/src/shadowbox/model/text_file.ts b/src/shadowbox/infrastructure/text_file.ts
similarity index 100%
rename from src/shadowbox/model/text_file.ts
rename to src/shadowbox/infrastructure/text_file.ts
diff --git a/src/shadowbox/server/mocks/mocks.ts b/src/shadowbox/server/mocks/mocks.ts
index 85bb8fcd..823dcd84 100644
--- a/src/shadowbox/server/mocks/mocks.ts
+++ b/src/shadowbox/server/mocks/mocks.ts
@@ -13,9 +13,8 @@
 // limitations under the License.
 
 import {PrometheusClient, QueryResultData} from '../../infrastructure/prometheus_scraper';
-import {DataUsageByUser} from '../../model/metrics';
+import {TextFile} from '../../infrastructure/text_file';
 import {ShadowsocksAccessKey, ShadowsocksServer} from '../../model/shadowsocks_server';
-import {TextFile} from '../../model/text_file';
 
 export class InMemoryFile implements TextFile {
   private savedText: string;
diff --git a/yarn.lock b/yarn.lock
index 436f595b..1563dc32 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -143,16 +143,23 @@
   resolved "https://registry.yarnpkg.com/@types/long/-/long-4.0.0.tgz#719551d2352d301ac8b81db732acb6bdc28dbdef"
   integrity sha512-1w52Nyx4Gq47uuu0EVcsHBxZFJgurQ+rTKS3qMHxR1GY2T8c2AJYd6vZoZ9q1rupaDjU0yT+Jc2XTyXkjeMA+Q==
 
+"@types/mkdirp@^0.5.2":
+  version "0.5.2"
+  resolved "https://registry.yarnpkg.com/@types/mkdirp/-/mkdirp-0.5.2.tgz#503aacfe5cc2703d5484326b1b27efa67a339c1f"
+  integrity sha512-U5icWpv7YnZYGsN4/cmh3WD2onMY0aJIiTE6+51TwJCttdHvtCYmkBNOobHlXwrJRL0nkH9jH4kD+1FAdMN4Tg==
+  dependencies:
+    "@types/node" "*"
+
+"@types/node@*", "@types/node@^12.6.9":
+  version "12.6.9"
+  resolved "https://registry.yarnpkg.com/@types/node/-/node-12.6.9.tgz#ffeee23afdc19ab16e979338e7b536fdebbbaeaf"
+  integrity sha512-+YB9FtyxXGyD54p8rXwWaN1EWEyar5L58GlGWgtH2I9rGmLGBQcw63+0jw+ujqVavNuO47S1ByAjm9zdHMnskw==
+
 "@types/node@^10.1.0":
   version "10.14.14"
   resolved "https://registry.yarnpkg.com/@types/node/-/node-10.14.14.tgz#a47955df2acf76ba7f0ac3b205d325da193dc9ad"
   integrity sha512-xXD08vZsvpv4xptQXj1+ky22f7ZoKu5ZNI/4l+/BXG3X+XaeZsmaFbbTKuhSE3NjjvRuZFxFf9sQBMXIcZNFMQ==
 
-"@types/node@^12.6.9":
-  version "12.6.9"
-  resolved "https://registry.yarnpkg.com/@types/node/-/node-12.6.9.tgz#ffeee23afdc19ab16e979338e7b536fdebbbaeaf"
-  integrity sha512-+YB9FtyxXGyD54p8rXwWaN1EWEyar5L58GlGWgtH2I9rGmLGBQcw63+0jw+ujqVavNuO47S1ByAjm9zdHMnskw==
-
 ansi-regex@^2.0.0:
   version "2.1.1"
   resolved "https://registry.yarnpkg.com/ansi-regex/-/ansi-regex-2.1.1.tgz#c3b33ab5ee360d86e0e628f0468ae7ef27d654df"
@@ -231,6 +238,11 @@ camelcase@^4.1.0:
   version "4.1.0"
   resolved "https://registry.yarnpkg.com/camelcase/-/camelcase-4.1.0.tgz#d545635be1e33c542649c69173e5de6acfae34dd"
 
+caseless@~0.6.0:
+  version "0.6.0"
+  resolved "https://registry.yarnpkg.com/caseless/-/caseless-0.6.0.tgz#8167c1ab8397fb5bb95f96d28e5a81c50f247ac4"
+  integrity sha1-gWfBq4OX+1u5X5bSjlqBxQ8kesQ=
+
 chalk@^1.1.0:
   version "1.1.3"
   resolved "https://registry.yarnpkg.com/chalk/-/chalk-1.1.3.tgz#a8115c55e4a702fe4d150abd3872822a7e09fc98"
@@ -423,6 +435,11 @@ foreground-child@^1.5.6:
     cross-spawn "^4"
     signal-exit "^3.0.0"
 
+forever-agent@~0.5.0:
+  version "0.5.2"
+  resolved "https://registry.yarnpkg.com/forever-agent/-/forever-agent-0.5.2.tgz#6d0e09c4921f94a27f63d3b49c5feff1ea4c5130"
+  integrity sha1-bQ4JxJIflKJ/Y9O0nF/v8epMUTA=
+
 fs.realpath@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/fs.realpath/-/fs.realpath-1.0.0.tgz#1504ad2523158caa40db4a2787cb01411994ea4f"
@@ -634,6 +651,14 @@ js-tokens@^3.0.0:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/js-tokens/-/js-tokens-3.0.1.tgz#08e9f132484a2c45a30907e9dc4d5567b7f114d7"
 
+js-yaml@^3.13.1:
+  version "3.13.1"
+  resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.13.1.tgz#aff151b30bfdfa8e49e05da22e7415e9dfa37847"
+  integrity sha512-YfbcO7jXDdyj0DGxYVSlSeQNHbD7XPWvrVWeVUujrQEoZzWJIRrCPoyk6kL6IAjAG2IolMK4T0hNUe0HOUs5Jw==
+  dependencies:
+    argparse "^1.0.7"
+    esprima "^4.0.0"
+
 js-yaml@^3.7.0:
   version "3.10.0"
   resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.10.0.tgz#2e78441646bd4682e963f22b6e92823c309c62dc"
@@ -654,6 +679,11 @@ json-parse-better-errors@^1.0.1:
   resolved "https://registry.yarnpkg.com/json-parse-better-errors/-/json-parse-better-errors-1.0.2.tgz#bb867cfb3450e69107c131d1c514bab3dc8bcaa9"
   integrity sha512-mrqyZKfX5EhL7hvqcV6WG1yYjnjeuYDzDhhcAAUrq8Po85NBQBJP+ZDUT75qZQ98IkUoBqdkExkukOU7Ts2wrw==
 
+json-stringify-safe@~5.0.0:
+  version "5.0.1"
+  resolved "https://registry.yarnpkg.com/json-stringify-safe/-/json-stringify-safe-5.0.1.tgz#1296a2d58fd45f19a0f6ce01d65701e2c735b6eb"
+  integrity sha1-Epai1Y/UXxmg9s4B1lcB4sc1tus=
+
 lcid@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/lcid/-/lcid-1.0.0.tgz#308accafa0bc483a3867b4b6f2b9506251d1b835"
@@ -704,6 +734,11 @@ mem@^1.1.0:
   dependencies:
     mimic-fn "^1.0.0"
 
+mime-types@~1.0.1:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/mime-types/-/mime-types-1.0.2.tgz#995ae1392ab8affcbfcb2641dd054e943c0d5dce"
+  integrity sha1-mVrhOSq4r/y/yyZB3QVOlDwNXc4=
+
 mimic-fn@^1.0.0:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/mimic-fn/-/mimic-fn-1.2.0.tgz#820c86a39334640e99516928bd03fca88057d022"
@@ -743,6 +778,11 @@ nice-try@^1.0.4:
   resolved "https://registry.yarnpkg.com/nice-try/-/nice-try-1.0.5.tgz#a3378a7696ce7d223e88fc9b764bd7ef1089e366"
   integrity sha512-1nh45deeb5olNY7eX82BkPO7SSxR5SSYJiPTrTdFUVYwAl8CKMA5N9PjTYkHiRjisVcxcQ1HXdLhx2qxxJzLNQ==
 
+node-uuid@~1.4.0:
+  version "1.4.8"
+  resolved "https://registry.yarnpkg.com/node-uuid/-/node-uuid-1.4.8.tgz#b040eb0923968afabf8d32fb1f17f1167fdab907"
+  integrity sha1-sEDrCSOWivq/jTL7HxfxFn/auQc=
+
 normalize-package-data@^2.3.2:
   version "2.4.0"
   resolved "https://registry.yarnpkg.com/normalize-package-data/-/normalize-package-data-2.4.0.tgz#12f95a307d58352075a04907b84ac8be98ac012f"
@@ -909,6 +949,11 @@ pump@^3.0.0:
     end-of-stream "^1.1.0"
     once "^1.3.1"
 
+qs@~1.2.0:
+  version "1.2.2"
+  resolved "https://registry.yarnpkg.com/qs/-/qs-1.2.2.tgz#19b57ff24dc2a99ce1f8bdf6afcda59f8ef61f88"
+  integrity sha1-GbV/8k3CqZzh+L32r82ln472H4g=
+
 read-pkg-up@^4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/read-pkg-up/-/read-pkg-up-4.0.0.tgz#1b221c6088ba7799601c808f91161c66e58f8978"
@@ -935,6 +980,18 @@ read-pkg@^4.0.1:
     parse-json "^4.0.0"
     pify "^3.0.0"
 
+request-lite@^2.40.1:
+  version "2.40.1"
+  resolved "https://registry.yarnpkg.com/request-lite/-/request-lite-2.40.1.tgz#08a8a151eaa84117e01d3e14fe765e8529b3f3df"
+  integrity sha1-CKihUeqoQRfgHT4U/nZehSmz898=
+  dependencies:
+    caseless "~0.6.0"
+    forever-agent "~0.5.0"
+    json-stringify-safe "~5.0.0"
+    mime-types "~1.0.1"
+    node-uuid "~1.4.0"
+    qs "~1.2.0"
+
 require-directory@^2.1.1:
   version "2.1.1"
   resolved "https://registry.yarnpkg.com/require-directory/-/require-directory-2.1.1.tgz#8c64ad5fd30dab1c976e2344ffe7f792a6a6df42"