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1 -Volume Mapping (On-premise)
1 +novice-file-based-connectivity-processing-a-file-per-line
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1 -en
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1 1  {{container}}{{container layoutStyle="columns"}}(((
2 +In this microlearning, we will learn how you can define a header line in which you specify the naming of the various columns. Some external systems require a header line when you supply them with data via a flat file that is placed somewhere.
2 2  
3 -When you need to read and write files from an on-premise disk, you need to know the path in which the data is stored and make sure that the docker container in your runtime(s) running has access to this path. There are several ways of dealing with this challenge. First, this microlearning will discuss the various alternatives and best approaches in these scenarios.
4 -
5 5  Should you have any questions, please contact [[academy@emagiz.com>>mailto:academy@emagiz.com]].
6 6  
6 +* Last update: May 28th, 2021
7 +* Required reading time: 5 minutes
8 +
7 7  == 1. Prerequisites ==
8 8  
9 9  * Basic knowledge of the eMagiz platform
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10 10  
11 11  == 2. Key concepts ==
12 12  
13 -This microlearning centers around learning how to set up your volume mapping correctly so you can exchange file-based data on-premise.
15 +This microlearning centers around learning how to place a header line on a flat-file output.
14 14  
15 -By volume mapping, we mean: Creating a configuration through which the docker container can read and write data on a specific path on an on-premise machine.
17 +By header line we mean: A line in the output that defines the naming of the various columns
16 16  
17 -There are several options for volume mapping for your on-premise machine.
18 -* Volume
19 -* Bind mount
20 -* Temporary file system
21 -* Named pipe
19 +Some external parties require that the first line in the flat file output (i.e. CSV) is filled with column names (i.e. headers). In eMagiz, we call this line a header line.
22 22  
23 -== 3. Volume Mapping (On-premise) ==
21 +== 3. Header line ==
24 24  
25 -When you need to read and write files from an on-premise disk, you need to know the path in which the data is stored and make sure that the docker container in your runtime(s) running has access to this path. There are several ways of dealing with this challenge. First, this microlearning will discuss the various alternatives and best approaches in these scenarios.
23 +In this microlearning, we will learn how you can define a header line in which you specify the naming of the various columns. Some external systems require a header line when you supply them with data via a flat file that is placed somewhere. The header line is the first line in the flat file output. Within this line, the various column names are specified for clarity.
26 26  
27 -There are several options for volume mapping for your on-premise machine.
28 -* Volume
29 -* Bind mount
30 -* Temporary file system
31 -* Named pipe
25 +To add such a header line in eMagiz you need to navigate to the Create phase of eMagiz and open the exit flow in which you want to drop the file to a certain location. Within the context of this flow, we need to add functionality that will ensure that a header line is written to the output before any functional lines are added. To do so first enter "Start Editing" mode on flow level. After you have done so please add a file outbound channel adapter to the flow including an input channel. We will use this component to write our header line to the flat file output.
32 32  
33 -Below we will explain the differences between the various options available for your volume mapping. But before we do, we first explain how to set up this configuration within eMagiz. Then, you must navigate to Deploy -> Architecture on the model level. In this overview, you can access the Volume mapping per runtime deployed on-premise. To do so, you can right-click on the runtime to access the context menu.
27 +Ensure that the directory to which you reference is the same as in your functional file outbound channel adapter.
34 34  
35 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-volume-mapping-on-premise--volume-option-context-menu.png]]
29 +[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-header-line--file-outbound-channel-header-line.png]]
36 36  
37 -When you click this option, you will see the following pop-up. In this pop-up, you can define the machine-level and runtime-level volumes. More on that later. This is the starting point for configuring your volume mapping. We will walk through each available option and explain how they work and should be configured.
31 +Now it is time to turn our attention to the Advanced tab. For the Mode select Ignore. Select this option to ensure that the header line is only written down once when there is no output created yet and not somewhere in the middle, in the end, or every time. Furthermore, select the option Append New Line to ensure that the remainder of the information is not appended to the same line.
38 38  
39 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-volume-mapping-on-premise--volume-mapping-pop-up.png]]
33 +[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-header-line--file-outbound-channel-header-line-advanced.png]]
40 40  
41 -{{info}}Note that you should be in "Start editing" mode to make any changes to the configuration of your volume mapping.{{/info}}
35 +After you have done so we need to add a standard transformer that defines the various column names to be written to the flat file output. To do so add the standard transformer component to the canvas including an input channel. After you have done so define the relevant SpEL expression. In this case, we advise using a property value that represents a string of column names. The value of the property should be something as follows:
42 42  
43 -=== 3.1 Volume ===
37 +'Header1;Header2;Header3;Header4'
44 44  
45 -The first type available to you is Volume. With this option you create one or more folders on docker that is relevant for that runtime to read and/or write **persistent** data. To configure this type you need to link the runtime volume to a machine volume that you can create within the same pop-up. This means that you can re-use a "Machine volume" over multiple runtimes (i.e. containers).
39 +Do note that the separator, in this case, needs to match the requirements of the external system. At the flow configuration level, the standard transformer should look as follows.
46 46  
47 -So, at first we open the tab called "Machine volume". By pressing the "New" button we can define a new "Machine volume". In the pop-up that follows we can define the name of a machine volume and tell whether the volume already exists on your docker installation or not.
41 +[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-header-line--define-columns-names.png]]
48 48  
49 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-volume-mapping-on-premise--machine-volumes-configuration.png]]
43 +Our last step is to ensure that this piece of logic is tied to the main flow and is executed before writing the functional line(s) to the output file. To make that happen we need to add a wiretap to the flow. With the help of this functionality, you can define which part of the logic takes precedence over another part of the logic. To do so double click on the channel on which you want to place a wiretap, select the option wiretap and select the correct wiretap channel. After you have done this the result should be something as follows:
50 50  
51 -Once you have done so we press "Save" and switch back to the "Runtime volumes" tab. In here we press the "New" button to create a new "Runtime volume". In the pop-up that follows we first need to select the Type we want to use. For this example we use the type called "Volume". Based on your selection the relevant input fields will change.
45 +[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-header-line--wiretap-result.png]]
52 52  
53 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-volume-mapping-on-premise--runtime-volumes-configuration-type-volume.png]]
47 +With these couple of steps, you have now successfully added logic to your flow that will ensure that a header line is added before any functional line(s) are written to the output file.
54 54  
55 -The first thing we need to select is the "Machine volume". Once we have selected our "Machine volume" we need to select the Target that is specific for this runtime. This target defines the second part of the path to which the runtime will gain access. For example, when you fill in "/target" we can combine this with the "Machine volume" name to arrive at the correct directory from which eMagiz needs to read data (or write data to). So in our case this would be "/file-directory/target."
56 -
57 -The last setting we need to configure is to define which rights we will grant our runtime on the volume we are creating. The default setting is read/write rights for the runtime which is sufficient in most cases. The result of following these steps will be the following.
58 -
59 -[[image:Main.Images.Microlearning.WebHome@novice-file-based-connectivity-volume-mapping-on-premise--runtime-volumes-configuration-type-volume-filled-in.png]]
60 -
61 -{{warning}}Note, that when you use the Volume option the external system with which you exchange data on-premise via a file based method need to be able to write or read the data from the volume (i.e. directory) you have configured in Docker. Should this be a problem the Bind mount alternative discussed below should be considered.{{/warning}}
62 -
63 -=== 3.2 Bind mount ===
64 -
65 -An alternative option to read and write **persistent** data is to use the "Bind mount" option avaiable. In general we advice to use the "Volume" option because they have better performance and bind mounts are dependent on the directory structure and OS of the host machine. Having said that not all external systems can adapt to this that easily. That is why the "Bind mount" option can be of interest in your use case.
66 -
67 -To configure a "Bind mount" you need to define a source and a target directory that are linked to each other. The source directory defines the directory on your local system (that might already be in use currently to exchange files). The target directory defines a directory on your docker installation that can be accessed by the runtime.
68 -
69 -=== 3.3 Temporary file system ===
70 -
71 -=== 3.4 Named pipe ===
72 -
73 -The named pipe option can be selected but we yet have to see a valid use case within the context of eMagiz for using this option. Therefore we won't discuss this option further in this microlearning.
74 -
75 75  == 4. Assignment ==
76 76  
77 -Configure an entry in which you build the archiving and the clean up of the archiving.
51 +Configure an exit in which you define and write a header line to a flat-file output before adding functional lines.
78 78  This assignment can be completed with the help of the (Academy) project that you have created/used in the previous assignment.
79 79  
80 80  == 5. Key takeaways ==
81 81  
82 -* Archiving is used for audit purposes
83 -* Archiving is used for retry scenarios
84 -* Ensure that data is cleaned after a retention period to keep in control of the data
85 -* Don't forget the max messages per poll
56 +* The header line contains the names of the columns of the flat file output
57 +* Use the Ignore mode to ensure the header line is created once
58 +* Use the wiretap to ensure the header line is created first
86 86  
87 87  == 6. Suggested Additional Readings ==
88 88  
89 -If you are interested in this topic and want more information on it please read the help text provided by eMagiz and check out the following store content:
62 +There are no suggested additional readings on this topic
90 90  
91 -* [[File Archiving>>doc:Main.eMagiz Store.Accelerators.File Archiving.WebHome||target="blank"]]
92 -* [[Delete Folder(s)>>doc:Main.eMagiz Store.Accelerators.Delete Folder(s).WebHome||target="blank"]]
93 -
94 94  == 7. Silent demonstration video ==
95 95  
96 96  This video demonstrates how you could have handled the assignment and gives you some context on what you have just learned.
97 97  
98 -{{video attachment="novice-file-based-connectivity-characterset.mp4" reference="Main.Videos.Microlearning.WebHome"/}}
68 +{{video attachment="novice-file-based-connectivity-header-line.mp4" reference="Main.Videos.Microlearning.WebHome"/}}
99 99  
100 100  )))((({{toc/}}))){{/container}}{{/container}}