Update RTD Placeholder

Dynamically pull the RTD version from the environment
variable delivered by RTD

Signed-off-by: Brett Logan <brett.t.logan@ibm.com>

docs/source/chaincode_lifecycle.md

@@ -148,7 +148,7 @@ consistent across organizations:
   endorse a transaction.
 - **Collection Configuration:** The path to a private data collection definition
   file associated with your chaincode. For more information about private data
-  collections, see the [Private Data architecture reference](https://hyperledger-fabric.readthedocs.io/en/{BRANCH}/private-data-arch.html).
+  collections, see the [Private Data architecture reference](https://hyperledger-fabric.readthedocs.io/en/{RTD_TAG}/private-data-arch.html).
 - **ESCC/VSCC Plugins:** The name of a custom endorsement or validation
   plugin to be used by this chaincode.
 - **Initialization:** If you use the low level APIs provided by the Fabric Chaincode

docs/source/conf.py

@@ -20,14 +20,19 @@
 #
 import os
 import sys
-sys.path.insert(0, os.path.abspath('.'))
+import sphinx_rtd_theme
+from os import environ
 
+sys.path.insert(0, os.path.abspath('.'))
 
-import sphinx_rtd_theme
+rtd_tag = 'latest'
+if environ.get('READTHEDOCS_VERSION') is not None:
+    rtd_tag = os.environ['READTHEDOCS_VERSION']
 
 placeholder_replacements = {
     "{BRANCH}" : "master",
-    "{BRANCH_DOC}" : "latest" # Used to target the correct ReadTheDocs distribution version
+    "{BRANCH_DOC}" : "latest", # Used to target the correct ReadTheDocs distribution version
+    "{RTD_TAG}": rtd_tag
 }
 
 # -- General configuration ------------------------------------------------

docs/source/docs_guide.md

@@ -100,15 +100,15 @@ folder](https://github.com/hyperledger/fabric/tree/master/docs) in the
 Hyperledger Fabric repository. Click on the following links to see how different
 source files map to their corresponding published topics.
 
-* [`/docs/source/index.rst`](https://raw.githubusercontent.com/hyperledger/fabric/master/docs/source/index.rst) maps to [Hyperledger Fabric title page](https://hyperledger-fabric.readthedocs.io/en/{BRANCH}/)
+* [`/docs/source/index.rst`](https://raw.githubusercontent.com/hyperledger/fabric/master/docs/source/index.rst) maps to [Hyperledger Fabric title page](https://hyperledger-fabric.readthedocs.io/en/{RTD_TAG}/)
 
 * [`/docs/source/developapps/developing-applications.rst`](https://raw.githubusercontent.com/hyperledger/fabric/master/docs/source/developapps/developing_applications.rst)
   maps to [Developing
-  applications](https://hyperledger-fabric.readthedocs.io/en/{BRANCH}/developapps/developing_applications.html)
+  applications](https://hyperledger-fabric.readthedocs.io/en/{RTD_TAG}/developapps/developing_applications.html)
 
 * [`/docs/source/peers/peers.md`](https://raw.githubusercontent.com/hyperledger/fabric/master/docs/source/peers/peers.md)
   maps to
-  [Peers](https://hyperledger-fabric.readthedocs.io/en/{BRANCH}/peers/peers.html)
+  [Peers](https://hyperledger-fabric.readthedocs.io/en/{RTD_TAG}/peers/peers.html)
 
 We'll see how to make changes to these files a little later.
 

docs/source/style_guide.md

@@ -6,9 +6,9 @@ While this style guide will also refer to best practices using ReStructured Text
 
 **When in doubt, use the docs themselves for guidance on how to format things.**
 
-* [For RST formatting](http://hyperledger-fabric.readthedocs.io/en/{BRANCH}/channel_update_tutorial.html).
+* [For RST formatting](http://hyperledger-fabric.readthedocs.io/en/{RTD_TAG}/channel_update_tutorial.html).
 
-* [For Markdown formatting](http://hyperledger-fabric.readthedocs.io/en/{BRANCH}/peers/peers.html).
+* [For Markdown formatting](http://hyperledger-fabric.readthedocs.io/en/{RTD_TAG}/peers/peers.html).
 
 If you just want to look at how things are formatted, you can navigate to the Fabric repo to look at the raw file by clicking on `Edit on Github` link in the upper right hand corner of the page. Then click the `Raw` tab. This will show you the formatting of the doc. **Do not attempt to edit the file on Github.** If you want to make a change, clone the repo and follow the instructions in [Contributing](./CONTRIBUTING.html) for creating pull requests.