diff --git a/caprover-oneclick/mattermost.json b/caprover-oneclick/mattermost.json
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+{
+  "captainVersion": "2",
+  "documentation": "https://hub.docker.com/r/mattermost/mattermost-team-edition",
+  "displayName": "Mattermost",
+  "description": "Mattermost Team Edition open source collaboration/chat software",
+  "dockerCompose": {
+    "version": "3.3",
+    "services": {
+      "$$cap_appname-postgres": {
+        "image": "postgres@$$cap_postgres_version",
+        "notExposeAsWebApp": "true",
+        "volumes": [
+          "$$cap_appname-postgres-data:/var/lib/postgresql/data"
+        ],
+        "restart": "always",
+        "environment": {
+          "POSTGRES_USER": "mattermost",
+          "POSTGRES_PASSWORD": "$$cap_pg_pass",
+          "POSTGRES_DB": "mattermost"
+        }
+      },
+      "$$cap_appname": {
+        "dockerfileLines": [
+          "FROM mattermost/mattermost-team-edition@$$cap_mattermost_version",
+          "RUN sed -i 's#api.segment.io#xx.example.com#gI' /mattermost/bin/mattermost",
+          "RUN sed -i 's#securityupdatecheck.mattermost.com#xxxxxxxxxxxxxxxxxxxxxx.example.com#gI' /mattermost/bin/mattermost"
+        ],
+        "containerHttpPort": "8065",
+        "depends_on": [
+          "$$cap_appname-postgres"
+        ],
+        "volumes": [
+          "$$cap_appname-data:/mattermost/data",
+          "$$cap_appname-logs:/mattermost/logs",
+          "$$cap_appname-config:/mattermost/config",
+          "$$cap_appname-plugins:/mattermost/plugins",
+          "$$cap_appname-clientplugins:/mattermost/client/plugins"
+        ],
+        "restart": "always",
+        "environment": {
+          "MM_SQLSETTINGS_DATASOURCE": "postgres://mattermost:$$cap_pg_pass@srv-captain--$$cap_appname-postgres:5432/mattermost?sslmode=disable&connect_timeout=10",
+          "MM_SERVICESETTINGS_SITEURL": "https://$$cap_appname.$$cap_root_domain",
+          "MM_LOGSETTINGS_ENABLEDIAGNOSTICS": "false",
+          "MM_SERVICESETTINGS_ENABLESECURITYFIXALERT": "false",
+          "MM_SQLSETTINGS_DRIVERNAME": "postgres"
+        }
+      }
+    }
+  },
+  "instructions": {
+    "start": "Open-source collaboration/chat server Mattermost Team Edition.",
+    "end": "Mattermost is deployed and available as srv-captain--$$cap_appname:80.  Note that the application may take a few minutes to become available.  Following deployment you must verify MM_SERVICESETTINGS_SITEURL in the application's environment refers to your app's official public URL."
+  },
+  "variables": [
+    {
+      "id": "$$cap_postgres_version",
+      "label": "Postgres Docker Image SHA Hash",
+      "defaultValue": "sha256:110d3325db02daa6e1541fdd37725fcbecb7d51411229d922562f208c51d35cc",
+      "description": "Check out their Docker page for the valid tags https://hub.docker.com/r/library/postgres/tags/ - default is 12.2 as of 2020-03-16"
+    },
+    {
+      "id": "$$cap_mattermost_version",
+      "label": "Mattermost Docker Image SHA Hash",
+      "defaultValue": "sha256:f8a4416d0a50a03ebacdbcd44790d5996230da3f48dbefd02307e4fd713567aa",
+      "description": "Check out their Docker page for the valid tags https://hub.docker.com/r/mattermost/mattermost-team-edition/tags - default is current as of 2020-03-16"
+    },
+    {
+      "id": "$$cap_pg_pass",
+      "label": "Postgres Password",
+      "description": "Password must be at least 30 characters.  Please use a random string.",
+      "validRegex": "/^[^\\@]{30,}$/"
+    }
+  ]
+}